Special Report 1084 August Central Oregon Agricultural Research Center 2007 Annual Report

Transcription

1 Special Report 1084 August 2008 Central Oregon Agricultural Research Center 2007 Annual Report

2 For additional copies of this publication Central Oregon Agricultural Research Center 850 NW Dogwood Lane Madras, OR Visit our website

3 Agricultural Experiment Station Oregon State University Special Report 1084 August 2008 Central Oregon Agricultural Research Center 2007 Annual Report Trade-name products and services are mentioned as illustrations only. This does not mean that the Oregon State University Agricultural Experiment Station either endorses these products and services or intends to discriminate against products and services not mentioned.

4 Introduction The Central Oregon Agricultural Research Center (COARC) faculty and staff are pleased to present a summary of research activities conducted during The thirty reports in this publication focus on vegetable seed (6), grass seed (7), forages and cereals (4), potatoes and peppermint (3), potential new crops (7) and rangeland and non-crop areas (3). We welcome you to peruse through the report, read a few abstract and perhaps read the entire report on topics of particular interest. Over the last year we have met with a significant number of industry representatives and growers to get your input on how we can best meet the needs of the agricultural community. We would like to thank each of your for your interest in what we do, and for taking time to discuss issues that affect you. In addition, the COARC Advisory Council annually rates proposed research projects for relevance to the local agricultural industry. This provides information helpful to faculty in make appropriate adjustments in focus and time commitment. Some projects are conducted at the COARC Madras and Powell Butte locations, while others are more appropriately conducted with grower cooperators in commercial fields. A number of projects are joint efforts between local researchers and researchers on campus, other branch stations, or other agencies. An example is the bitterbrush plots with National Forest Service (NFS) researchers. In addition, COARC is establishing a landscape, fruit and vegetable demonstration garden and student learning center to broaden our impact with the local community. This will increase relevance, support from local citizens, and provide an interface where they will become familiar with agriculture-related issues. We are excited about the possibilities this opportunity will provide. We are continuing to expand and streamline our website. Feel free to check out our progress at You will find this publication on the website, along with previous reports and other helpful information. We are developing a searchable database of all research reports published by the COARC. We expect this database to expand in the near future to include research station reports from Klamath Falls, Hermiston, Burns and La Grande. It is our pleasure to work with you and generate relevant research-based information to meet local needs. Marvin Butler, Superintendent Central Oregon Agricultural Research Center Note: Any reference to a product or company is for specific information only and does not endorse or recommend that product or company to the exclusion of others that may be suitable. Nor should information and interpretation thereof be considered as recommendations for application of any pesticide. Pesticide labels should always be consulted before any pesticide use.

5 2007 Station Faculty and Staff Administrative: Marvin Butler, Superintendent, COARC, Professor, Crop and Soil Science, Chair, Jefferson County Extension Leta Morton, Office Specialist II, COARC Faculty: Dr. Fred Crowe, Associate Professor, Botany and Plant Pathology, COARC Farm Operations: Gerald Baker, Biotechnician, Powell Butte, COARC Robert Crocker, Biotechnician, Madras, COARC Seasonal Employees: Craig Fuller, Student Technician, Madras, COARC Dr. Brian Duggan, Assistant Professor, Crop and Soil Science, COARC Mylen Bohle, Associate Professor, Crop and Soil Science, COARC and Crook County Extension Steven James, Senior Faculty Research Assistant, Crop and Soil Science, COARC Rhonda Simmons, Senior Faculty Research Assistant, Crop and Soil Science, COARC Richard Affeldt, Instructor, Crop and Soil Science, COARC and Jefferson County Extension ii

6 List of Authors and Contributors Affeldt, Richard Instructor, Jefferson County Extension, Central Oregon Agricultural Research Center, Oregon State University Barber, Rex Local Grower, Terrebonne, Oregon Bohle, Mylen Associate Professor, Central Oregon Research Center, Oregon State University Brown, Charles Research Geneticist, USDA/ARS Vegetable and Forage Crops Research Laboratory, Prosser, Washington Butler, Marvin Professor, Central Oregon Agricultural Research Center, Oregon State University Carroll, Jim Crop Consultant, CHS, Madras, Oregon Cattani, Doug Research Biologist, The Scotts Company, Gervais, Oregon Comingore, Dan Crop Consultant, Wilbur-Ellis, Madras, Oregon Crocker, Robert Biotechnician, Central Oregon Agricultural Research Center, Oregon State University Crockett, Ron Research and Development, Monsanto, Vancouver, Washington Crowe, Fred Associate Professor, Central Oregon Agricultural Research Center, Oregon State University Dreves, Amy J. Research Associate, Crop and Soil Science, Oregon State University Duggan, Brian Assistant Professor, Central Oregon Agricultural Research Center, Oregon State University Fisher, Glenn Professor, Crop and Soil Science, Oregon State University James, Steven Senior Faculty Research Assistant, Central Oregon Agricultural Research Center, Oregon State University Larsen, Mark Senior Faculty Research Assistant, Crop and Soil Sciences, Oregon State University MacKenzie, John Crop Consultant, Wilbur-Ellis, Madras, Oregon Martens, Bruce Crop Consultant, Central Oregon Seeds Inc, Madras, Oregon Paye, Floyd Weed Specialist, Jefferson County Road Department, Madras, Oregon Peterson, Jim Professor, Crop and Soil Science, Oregon State University iii

7 Roff, Loren Local Grower, Roff Farms, Culver, Oregon Samsel, Linda Research Assistant, Central Oregon Agricultural Research Center, Oregon State University Simmons, Rhonda Senior Faculty Research Assistant, Central Oregon Agricultural Research Center, Oregon State University Simmons, Scott Crop Consultant, Round Butte Seed Growers, Prineville, Oregon Sullivan, Stan Local Grower, Madras, Oregon Verhoeven, Mary Instructor, Crop and Soil Sciences, Oregon State University Weber, Mike Managing Partner, Central Oregon Seeds, Inc., Madras, Oregon Zarnstorff, Mark PhD, Director of Agriculture Research/Technology, National Crop Insurance Services, Overland Park, Kansas iv

8 T A B L E of C O N T E NT S Weather Station 2007 Page I. Vegetable Seed Production Evaluation for Improved Control of Bacterial Blight of Carrot with Early Season Copper Bactericides, Repeated Irrigation of Low Amounts of Germination Stimulants for Reduction of Sclerotia of Sclerotimum cepivorum...5 Sampling and Damage Assessment of Pratylenchus Nematodes Associated with Wheat-Carrot Seed Crop Rotation in Central Oregon...13 Carrot Tolerance to Pendimethalin and Oxyfluorfen...15 Effect of Priming on Parsley Seed Germination...18 Garlic Tolerance to Bromoxynil...21 II. Grass Seed Production Non-thermal Residue Management in Kentucky Bluegrass...24 Kentucky Bluegrass Tolerance to Primisulfuron...27 Kentucky Bluegrass Tolerance to Mesotrione Applied in the Fall...31 Creeping Bentgrass Control with Mesotrione...34 HPPD Herbicide Screening on Seed Crops...39 Evaluation of Simulated Hail Damage to Kentucky Bluegrass Seed Production in Central Oregon, Jefferson County Smoke Management Pilot Balloon Observation, III. Forage and Cereals Production 2007 Winter and Spring Wheat Variety Trials...46 Control of Winter Grain Mite Infesting Timothy...51 Notes on and Control of the Clover Mite, Bryobia praetiosa Koch, Infesting Orchardgrass in Central Oregon...54 Weed Control in Grass/Alfalfa Mixed-Hay...57 IV. Potatoes and Peppermint Production Sensory Evaluation of Advanced Specialty Potato Selections...61 Sensitivity of Potato Selection AO to Metribuzin...66 Herbicide Efficacy and Residue Persistence in Peppermint...69 IV. Potential New Crops Winter Canola Variety Trial, Spring Canola and Mustard Variety Trial, Canola Growth Inhibitor Trial, Volunteer Canola Control with Linuron...84 Brassica Flowering Date Trial, Corn Variety Trial, Chickpea Variety Trial Yield and Composition, v

9 V. Rangeland and Non-Crop Areas Puncturevine Control in Right-of-Way Areas...96 Control of Medusahead and Cheatgrass on Central Oregon Rangelands with Landmark, Matrix, Plateau, and Journey, Control of Medusahead and Cheatgrass on Central Oregon Rangelands Using Outrider and Roundup Pro Alone and in Combination, vi

10 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP AIR TEMPERATURE ( o F) Avg. Maximum Avg. Minimum Mean AIR TEMP (no. of days) Max. 90 o F or Above Max. 32 o F or Below Min. 32 o F or Below Min. 0 o F or Below SOIL TEMP ( o F at 4 in.) Avg. Maximum Avg. Minimum SOIL TEMP ( o F at 8 in.) Avg. Maximum Avg. Minimum PRECIPITATION (in.) Monthly Total EVAPORATION (in.) Daily Avg WIND SPEED (mph) Daily Avg SOLAR RADIATION (langley) Daily Avg HUMIDITY (% relative humidity) Daily Avg Last Day Before First Day After Total Number of Days GROWING SEASON July 15 July 15 Between Temp. Mins. Air Temp Min. 32 o F or Below May 28 Sept o F or Below May 28 Sept o F or Below April 19 Oct WEATHER INFORMATION: 2007 WATER YEAR, POWELL BUTTE, OREGON (SOURCE: AGRIMET)

11 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP AIR TEMPERATURE ( o F) Avg. Maximum Avg. Minimum Mean Temp AIR TEMP (no. of days) Max. 90 o F or Above Max. 32 o F or Below Min. 32 o F or Below Min. 0 o F or Below SOIL TEMP ( o F at 4 in.) Avg. Maximum Avg. Minimum SOIL TEMP ( o F at 8 in.) Avg. Maximum Avg. Minimum PRECIPITATION (in.) Monthly Total EVAPORATION (in.) Daily Avg WIND SPEED (mph) Daily Avg SOLAR RADIATION (langley) Daily Avg HUMIDITY (% relative humidity) Daily Avg Last Day Before First Day After Total Number of Days GROWING SEASON July 15 July 15 Between Temp. Mins. Air Temp Min. 32 o F or Below May 28 Sept o F or Below May 5 Oct o F or Below April 3 Nov WEATHER INFORMATION: 2007 WATER YEAR, MADRAS, OREGON (SOURCE: AGRIMET)

12 Evaluation for Improved Control of Bacterial Blight of Carrot with Early Season Copper Bactericides, Rhonda Simmons, Fred Crowe, Robert Crocker, Bruce Martens, and Mike Weber Abstract A field trial was carried out to evaluate a number of antibacterial pesticides sprayed singly or in combination onto carrot foliage in a replicated field trial in the fall of 2006 (twice) and early spring of 2007 (once), following artificial point-source infestations of Xanthomonas campestris pv carotae (Xcc). The number of colony forming units (CFUs) per gram of dry foliage was used to calculate the mean number of bacteria present on plants. In late fall 2006, Xanthomonas was not recovered from infested-but-unsprayed plots, and initial post-winter recovery was very low. In infested-butunsprayed plots, frequency of recovery and net plot Xanthomonas populations on plants increased regularly through 2007, resulting in recovery from all replications of each variety. By mid-summer, all plots were highly infested with Xcc and many plots showed actual bacteria blight symptoms. Results did not show significant population control of bacteria by a specific single or combination chemical treatment and the trial was removed and seed was not harvested. All three varieties suffered widely different winter injury and frost heaving damage, which may have contributed to disease proliferation. Introduction Bacterial blight of carrots is incited by Xanthomonas campestris pv carotae. In carrot seed fields in central Oregon and central Washington, bacterial blight disease generally is mild and occasional, even frequently absent, although high disease incidence does flare up in some fields in some years. More problematic is that Xanthomonas is abundant on seed harvested from these regions, even in the absence of bacterial blight disease. Such infested seed, without treatment, may be a source of infection for more damaging disease in commercial plantings. The following summarizes the results of carrot seed field monitoring over several years in the Pacific Northwest (Du Toit et al. 2005): contamination levels of colony forming units (CFUs)/10,000 harvested seed are common for commercial seed lots from central Oregon and central Washington. In seed-to-seed production, Xanthomonas incidence on foliage becomes established on a very low proportion of plants soon after planting of seed in fall, increasing progressively in most fields until a high proportion of plants harbor a population before harvest the following year. On individual plants, the population increases very rapidly, frequently reaching levels of CFU/g dry weight. Seed lots used to plant seed fields almost never test positive for Xanthomonas, indicating that seed lots are either carefully chosen and/or that all or most are hot water treated. Sources for infestation of seed fields typically are local, probably originating in older seed fields. A few fields seem to escape all Xanthomonas infestation each year. Other crops and weeds appear not to harbor this strain of Xanthomonas. Investigations presented below probed the concept that antibacterial pesticide sprays may improve control of Xanthomonas infestation. Our working hypothesis has been that Xanthomonas management might be achieved if initial infestation could be eliminated soon after Xanthomonas arrives in newly seeded fields during the first month after emergence. It is this period when wind

13 blown inoculum is most prevalent (DuToit et al. 2005). Once Xanthomonas infestations become established, especially on larger plants where Xanthomonas populations may be very high and where spray coverage is difficult, chemical control would become much more difficult and probably unlikely. Even if fields become infested in spring or early summer, fall control might delay Xanthomonas population increases enough that lower seed infestation might result. Materials and Methods Three varieties of seed-to-seed carrots were established in a trial area and planted into strips with 2 replications of 11 treatments. Seeding was on 10 August 2006, on 30-inch rows in long strips through the field. Strips were separated by a 20-ft unplanted alley. Emergence was roughly September 1, after which carrots were removed by tillage from 30-ft cross-alleys between plots along the strips. Thus, plots were 20 ft wide (8 rows) by 20 ft long, separated by alleys either 20 or 30 ft wide. Plants were not thinned, and averaged 1 plant per 2 inches. Although frequent plant sampling did thin the plots slightly, plant stands remained at least as thick as commercial fields throughout the season. In central Oregon, seed-to-seed carrots initially are sprinkler irrigated prior to and after emergence through the fall. Irrigation from spring through fall may be by sprinkler, furrow, or drip. In this trial, sprinkler irrigation was continued through the growing season. All fertilization, herbicide application, and other practices were as per commercial production for the region. Only a female carrot line was planted to prevent this field from cross-pollinating with other fields in the area. No bees were installed at pollination, but bees, flies, and other insects were active on flowers. The field was removed before seed set. We attempted to initiate a mini-epidemic of Xanthomonas in each plot by establishing small, pointsource infestations simulating Xanthomonas-infested dust falling onto newly seeded carrot fields on September 27. Trial area was irrigated 30 minutes prior to infestation to wet foliage for adhesion of inoculum. The alley structure discussed above was intended to contain each mini-epidemic within each plot, and prevent plot-to-plot cross-contamination. Treatments were various antibacterial pesticide products sprayed onto foliage. Sprays were made on October 9 at the three- to four-leaf stage of growth. A repeat application was on October 23 when carrots had approximately five leaves. A third application was made on April 9 at which time only three to six small green leaves were present following winter die back of the fall foliage. Winter freeze and heaving damage occurred, which limited adequate sampling in several plots until later in the season. Previous trial data determined that coverage of carrot foliage was critical to product efficacy. A commercially designed tractor-mounted spray tank and boom were used in this trial, with nozzle orientation in a triangular fashion over each carrot row. Two nozzles sprayed towards the sides of seedling carrots, and one nozzle sprayed from above. This seemed to be the most optimal commercially used orientation available. All products were applied at 40 gal/acre broad acre, but only the carrot rows were sprayed so that in reality it was 20 gal/acre. For each plot, the tractorsprayer was started up in the middle of the alley so that it was at application speed by the time any spray was applied. Similarly, the spray was continued at pace until reaching well past each plot. Wide alleys allowed the spray rig to be easily maneuvered among plots. All applications included 9 oz/100 g water of Silken, a silicone-based spreader sticker, plus an antifoaming agent. Enough product was mixed in the spray tank to allow for spraying all six replications per treatment with a single tank. The tank and spray rig were purged between each treatment. Spray treatments included the following, with all rates as the amount of commercial product: - 2 -

14 1. Non infested (negative check, to assess plot-to-plot spread of Xcc) 2. Infested, no chemical treatment (positive check, to assess unmanaged infestation) 3. ManKocide 2.5 lb/acre 4. ManKocide 2.5 lb/acre + Tanos 8 oz/acre 5. ManKocide 2.5 lb/acre + Tanos 12 oz/acre 6. Kocide Tanos 8 oz/acre 7. Kocide Tanos 12 oz/acre 8. Serenade Max 3 lb/acre (Bacillus subtilis strain QST713) 9. Micro oz/acre (Streptomyces lydicus) 10. Chlorine (12.5 percent) 1 qt/acre Beginning a week after infestation, untreated check plots were sampled weekly until Xcc was detected, after which all plots were sampled on an approximately monthly basis except for midwinter. Sampling involved collecting foliage from 30 plants per plot, placing foliage into a new plastic bag, storing it in a refrigerator, chopping it finely within 24 hours of harvest, and soaking it in phosphate buffer for 1 hour on a gyratory shaker. A dilution series of the rinsate was prepared up to 10-7 onto XCS agar, a semi-selective medium for Xcc, using sterile technique. Dilution plates were incubated at 28ºC in the dark for one week, after which the numbers of CFUs were calculated. The chopped and rinsed leaves were dried at 55ºC and then weighed to calculate the mean number of CFUs per gram of dry weight. When small, all the foliage from each composited carrot was sampled. As plants became larger and bolted, plants were subsampled to include a representative amount of foliage, petioles, stems, and umbels. Results and Discussion Beginning in the spring of 2007, detection frequency increased regularly in the untreated check and most treated plots through the end of the season. Freezing temperatures and a wet spring caused many of the plots to heave and thus caused winter die back. In early May, only one variety produced enough new growth to adequately sample. Xanthomonas was detected in all five replications of the check plots by 7 May Plots sampled showed an equal level of bacteria. All the products used in this trial are nonresistant and none would be expected to sustain control for more than a short period of time or to protect new foliage. Presumably, their effects must have been from eliminating or reducing early infestations, thus greatly delaying epidemic buildup of Xcc. Two weeks later in May, all plots were sampled, and all plots contained levels of bacteria (Table 1). By June and July, symptoms were visible in the field in most plots, across all varieties. Levels of bacteria were extremely high and so monitoring this trial ended. A similar trial was initiated in the fall of 2007 that will be carried through The trial will be furrow irrigated beginning April It will include seven replications, with nine treatments of seed to seed plots as well as four treatments with steckling carrots. Treatments will focus on timing of copper bactericides in conjunction with multiple disease inoculations

15 Table 1. Log colony forming units (CFUs) recovered from seed carrots, Madras, Oregon. Log (CFUs/g dry foliage) Treatment 27-Oct 7-May* 22-May 5-Jul Non iinfested Infested, no chemical treatment ManKocide 2.5 lb/acre ManKocide 2.5 lb/acre + Tanos 8 oz/acre ManKocide 2.5 lb/acre + Tanos 12 oz/acre Kocide lb/acre Kocide Tanos 8 oz/acre Kocide Tanos 12 oz/acre Serenade Max 3 lb/acre Micro oz/acre Chlorine (12.5%) 1 qt/acre *Only one variety (2 replications) were sampled due to winter die back. References Du Toit, L.J., F.J. Crowe, M.L. Derie, R.B. Simmons, and G.Q. Pelter Bacterial blight in carrot seed crops in the Pacific Northwest. Plant Disease 89:

16 Repeated Irrigation of Low Amounts of Germination Stimulants for Reduction of Sclerotia of Sclerotium cepivorum Fred Crowe, Rhonda Simmons, and Bob Crocker Introduction Sclerotia of Sclerotium cepivorum, the Allium white rot fungus, specifically respond to Allium flavor and odor compounds that naturally volatilize away from Allium roots. Stimulants are specific to this fungus, and are all chemically related organic sulfur compounds (common structure 3C-S) (King and Coley-Smith 1968, Coley-Smith and King 1969) that dominate the unique flavor and odor of Allium species (Pruthi et al. 1959, King and Coley-Smith 1968, Coley-Smith and King 1969). With ideal soil temperature (range within 9-22 C [50-72 F]; optimum at C [59-65 F]) and moisture in the range of good soil tilth ( Mpa; optimum at Mpa), germination is high (Crowe and Hall 1980b) and continues as long as sufficient stimulants and nongerminated sclerotia remain in the soil (Crowe et al. 1980, Crowe, et al. 1994). When an onion or garlic crop is planted, roots ramify the entire soil profile and continuously leak such stimulants. As a result, during the growing season, the old sclerotial population disappears as sclerotia germinate (Crowe et al. 1980, Crowe et al. 1994). Once germinated, the fungus within each sclerotium is totally committed to infection of roots (or, if nearby, direct infection of bulbs), followed by formation of new sclerotia on rotting bulbs. Failing to grow into a bulb and reproduce results in death of the fungus, as it cannot grow or reproduce in any other way, such as on soil organic matter in soil or other types of plants (Scott 1956, Coley-Smith 1971, Crowe et al. 1980). Garlic and onion crops continuously leak stimulants at low rates, and elicit near-total germination of the population of sclerotia in a very natural process (Crowe et al. 1980). The true concentration of stimulants in the soil from root leakage has not been determined, but presumably is quite low on a part per million (ppm) basis of either total soil volume. In the laboratory, nearly 100 percent germination response of S. cepivorum occurred in infested field soil treated with single doses of diluted garlic or onion juice under controlled conditions (Coley-Smith 1960, Crowe et al. 1980), although such dilutions of 100 to 1,000 times were almost certainly many times higher than natural root leakage. Since the 1960 s, it has been speculated that germination stimulants artificially applied to soil when Allium crops were absent could trick sclerotia into germinating, greatly reducing and possibly even eradicating the fungus (T. Kosuge, University of California, Davis, personal communication, 1974; Coley-Smith and Parfitt 1986). However, all earlier attempts failed to elicit high germination response in the field, and a series of researchers gave up this approach using either natural stimulants or petroleum-derived Diallyl disulfide (DADS), which is a major stimulatory component of natural garlic juice (Elnaghy et al. 1971; Merriman et al. 1980, 1981; Entwistle and Munasinghe 1981; Entwistle et al. 1983, Coley-Smith and Parfitt 1986). In , we succeeded (Crowe et al. 1994) where others failed by understanding that the germination response is - 5 -

17 only highly efficient near the temperature and soil moisture optimum for the fungus. Timing of field applications depends on local soil temperature patterns, and on other farming constraints such as planting and harvesting of other crops. Where summer soil temperatures exceed 72 F, applications are restricted to fall or spring (or including winter in very mild regions), or to deeper soil layers still within the conducive temperature range. In our previous research field trials, when soil temperatures dropped below F, sclerotia of S. cepivorum become dormant, but DADS becomes non-volatile, thus any residual DADS reactivated in the spring when temperatures warmed above F. For single dosage applications in the field, a period of at least 2 months was required between soil temperatures of (with as much time in the mid-range as possible) to achieve percent germination response levels, discounting periods of time when soil temperature is colder. While not quantitative, we observed that the human nose could still detect Allium volatiles for 6-8 weeks after applications of high rates of stimulants, longer when soil temperature was very cool. In our earlier work, rates were chosen based on reported soil residence times for DADS (Coley-Smith and Parfitt 1986). These guidelines were very rough because small amounts of added stimulants are impossible to analytically discern from the background of non-organic and organic but nonstimulatory sulfur compounds in soil (R. Dick, Department of Crop and Soil Science, Oregon State University, personal communication; I. Tinsley, Department of Environmental and Molecular Toxicology, Oregon State University, personal communication). In our earlier work, we initially intended to mimic natural root leakage by applying DADS in irrigation water, but without knowing what rates to choose, it was determined that with high rates the odor of concentrated DADS was too intense to work with in the open air. On the other hand, we found that the rates initially chosen elicited very high germination responses. As a result, we refocused on fine-tuning single applications, either by spraying the soil surface followed by immediate tillage and/or flood irrigation, or by shank injection. The effect of repeated lower rates was never investigated. We empirically determined that single doses of DADS at 5 l/ha (roughly 1.9 gal/acre) or higher, applied in the absence of an Allium crop, resulted in percent germination of sclerotia (Crowe et al. 1994). When United Ag Products (UAP) took over commercialization of DADS beginning in about 1992, this was the base rate they used for their shank-injected applications. Work reported here revisited the concept of repeated dosages of very low rates of application, using garlic juice. Several lines of evidence suggest that garlic or onion juices could be highly diluted and remain at least partially stimulatory. These include some limited lab testing (Crowe 1978; Crowe, unpublished data from 2000 to 2001), together with the fact that sclerotia in untreated soil samples can germinate at high rates simply if onions or garlic are present in the same room (F. Crowe, unpublished data). After all, in the field, sclerotia respond to regular root leakage of stimulants from onions and garlic, and onion and garlic odors are very difficult to detect in undisturbed field soil if care is taken to avoid breaking roots (which causes added odors to accumulate). Our working hypothesis was that garlic may be effective at eliciting some germination down to levels detectable by the human nose. In a random test of six people in our - 6 -

18 laboratory, half could detect the flavor/odor of garlic extracts diluted to 1 ppm (weight: volume). The other half could detect just above this dilution. On a weight to volume basis, one pound (4-5 bulbs) of macerated garlic blended with one pound of water, coarsely filtered and diluted with 1 million pounds of water equals roughly 16,000 ft 3 of water. For irrigation of 2 to 3 inches of such extract-treated water per acre, that one pound of garlic could treat 1.5 to 2.2 acres with 1-ppm garlic extract. This might be highly cost-effective if repeated application reduced sclerotia populations substantially. Increasing the concentration might still be cost effective, especially for cull product source with little (or negative) value and/or if the number of repeat applications can be reduced. Materials and Methods Preliminary soil assays demonstrated that the trial area used in had a high, relatively uniform population of sclerotia formed on garlic in In the fall of 2006, winter wheat was planted into the trial area, at which time the population in the future trial area ranged from 250 to 1,000 intact, viable sclerotia/l of soil, and averaged approximately 500/l distributed to about 6 inches deep. Irrigated treatments were initiated soon after irrigation water was available in April The wheat was killed with Roundup in April so that plots could be sprayed more conveniently. Weeds were similarly treated several times during May through October. Freshly extracted commercial food-grade garlic juice was donated by The Garlic Company (Shafter, CA). The juice was received in 5-gal plastic buckets that were held refrigerated until use. The company indicated such storage results in minimal product degradation, and no apparent changes were noted as buckets were opened each 2 weeks of the summer. A fresh bucket was opened at each 2-week time of application, and a taste and odor dilution was sampled by the same 8 station staff. Detection of garlic odor and flavor occurred at 1 and 10 ppm by the same staff at each application period, half of the staff detecting at 1 ppm and the other half at 10 ppm. Treatments were 0, 0.1, 1.0, 10, 100, and 1,000 ppm diluted garlic juice. There were four replications of each treatment structured into a randomized block experimental design. Plots were 10 ft wide by 30 ft long. There were four replications in a randomized, experimental block design. In addition, two additional (nonreplicated) plots were located 20 ft from the trial area and included a no garlic treatment and a 10,000 (1 percent) garlic juice treatment. All treatments were made at 2-week intervals from mid- April to mid-october Applications were calculated as if the amount of garlic juice were distributed throughout 2 inches of irrigation water applied once every 2 weeks, but in practice the garlic juice was partially diluted and sprayed onto each plot just ahead of sprinkler application of 2 inches of water. In addition, Advantage soil surfactant was included in each application to assist in product infiltration through the soil profile. A non-replicated plot of a very high rate of application was located outside the trial area, along with a non-treated plot. At each application, the non-garlic control application was applied first, followed by the - 7 -

19 increasing rates. Treatments were all applied soon after dawn when there was no wind and when temperatures were coolest, to avoid both drift and evaporation of stimulants. Temperature was never above 60 F at time of application. Sprinklers were started immediately upon completion of the last spray application. The entire spray series was completed within 20 minutes on each date of application. Two 12-core (from 1-inch-diameter soil tubes) subsamples were collected to 6 inches deep, and were bulked and assayed separately immediately pretreatment and monthly thereafter the day before treatment periods. At each assay period, sclerotia were counted and determined to be alive or dead. In previous studies, living sclerotia were germinable by stimulants if older than 1 year from production on the previous garlic crop (Crowe et al. 1980), thus alive is equivalent to viable. Throughout the season, viabilities were not found to vary statistically between treatments (P < 5 percent), so an average percentage viability was calculated for each sampling date. As in the past, the coefficient of variation between such subsamples increased with lower inoculum densities, but the average number of sclerotia from the two subsamples still were considered sufficient to represent the recovery from each plot. The average number of sclerotia recovered from each plot was converted to a percentage of the average number found upon pretreatment sampling in April. The soil assay involves sieving soil to the size of sclerotia and counting sclerotia amongst soil residue under a microscope. We noted if sclerotia were found in an active state of germination. Soil temperatures were monitored under irrigated conditions at 4 and 8 inches deep from a USDA-managed weather station located at the same research center at Madras. Results Sclerotia recovered at each sampling date were observed to see if they were intact and viable. At the same time, sclerotia in the state of active germination were recorded; active germination is notable by a hyphal plug of mycelium emerging from a single point (sometimes two points) on the rind of a sclerotium. Prior to application of garlic treatments, no sclerotia were actively germinating in mid-april. From mid-may through mid-october, no germinating sclerotia were found in soil in any non-garlic plots. Beginning mid-may through mid-july, some sclerotia were found to be germinating in all garlic juice-treated plots, with increasing frequency of such recovery at higher rates of garlic juice application. This was clear evidence that garlic juice elicited some germination in all garlic juice treatments. However, no active germination was observed in any garlic juice treatment after mid-july. Soil temperature data at 4 and 8 inches (10 and 20 cm) were collected by the automated AgriMet weather station located at the Central Oregon Agricultural Research Center. Soil temperatures were within the F (10-22 C) range suitable for stimulated germination beginning in April and extending until early July For several weeks in early to mid-july, soil temperatures exceeded this range at both 4 and 8 inches, and - 8 -

20 sclerotia of S. cepivorum would not be expected to germinate for some undetermined period of time thereafter, which was reported above. We expected germination to resume later in the summer as soil temperatures dropped back into the conducive range, but this was not observed. As a result, soil recovery data are shown below only for the period of April through July 2007; no changes were seen in population levels after July. The number of viable, intact sclerotia was determined for each monthly soil sampling. Data for each plot were averaged for the two subsamples. Coefficients of variation were determined but are not reported here. As expected, coefficient of variation between duplicate samples was high, but determined to be acceptable. For each monthly sampling date, data were reported as: 1. Mean recovery of intact, viable sclerotia for each treatment for the four replications. These data are not shown because plot-to-plot recoveries are so variable, even in plots before any applications. 2. Mean percentages of the pretreatment recoveries converted to percentages of the mid-april recovery on a plot-by-plot basis (the primary transformation, see Table 1). 3. Mean percentages of the non-garlic treatment for each monthly sampling. This was a secondary transformation following the first transformation above, i.e., percentages of percentages (see Table 2). The validity of this transformation is discussed below. Both tables reflect a drop in recovery of intact, viable sclerotia. Such declines were attributed to stimulated germination as observed for soil assay residue under the microscope. In general, there was a relative decrease in percentage recovery with respect to garlic juice concentration as shown in Table 1. The apparent increase in recovery in water-only treated check plots was not attributed to any real increase in sclerotial numbers due to either reproduction or splitting of aggregated sclerotia. Instead, the increase was attributed to increasing soil compaction that elevated the actual concentration of sclerotia in each fixed-volume soil sample. Such compaction was observed to occur as wheat roots decayed and as plots were irrigated during the season. The second transformation of data (Table 2) was done to correct for such apparent increases. When transformed, the untreated check plots were corrected to 100 percent for each sampling date (Table 2); the relative decline in recovery was more pronounced at increasing rates of application of garlic juice. Data are not shown from the two remote plots. These were included only as additional checks in case plot-to-plot interactions were observed (e.g., if it appeared that drift might have resulted in some stimulated germination in main-trial non-garlic treated plots). In general, the same patterns of sclerotial germination were seen in these plots, although even more stimulated germination was observed at the very high rate of garlic juice application, and even lower recovery of intact, viable sclerotia was found from May to July

21 Table 1. Mean percentage recovery of intact, viable sclerotia of S. cepivorum from plots treated with either water (check) or garlic juice at various concentrations (ppm). Each individual check plot automatically equals 100 percent prior to first treatment in mid- April Mid-April Mid-May Mid-June Mid-July check a 118 a 131 a 0.1 ppm a 73 b 73 bc 1.0 ppm ab 85 ab 91 abc 10 ppm ab 77 b 109 ab 100 ppm a 65 b 77 bc 1,000 ppm b 47 b 55 c Table 2. Mean percentage recover of intact, viable sclerotia of S. cepivorum from plots treated with either water (check) or garlic juice at various concentrations (ppm). Each individual check plot adjusted to 100 percent prior to first treatment in mid-april 2007, then re-adjusted to 100 percent for each sample date at subsequent sampling times. Mean per Mid-April Mid-May Mid-June Mid-July check a 100 a 100 a 0.1 ppm a 62 b 56 bc 1.0 ppm ab 72 ab 69 abc 10 ppm ab 65 b 83 ab 100 ppm a 55 b 59 bc 1,000 ppm b 40 b 42 c Discussion We clearly were able to move diluted garlic juice to depths sufficient to stimulate sclerotia, as observed visually (actively germinating sclerotia) and by decline in relative recovery of intact, viable sclerotia. Thus, we are convinced that this trial proved that the concept of repeated application of inexpensive low levels of stimulants was sound. Over a few months, natural decline in sclerotial numbers or viability is minimal. Given the very high initial population levels present in plots, and only modest decline in actual numbers, none of these plots could be replanted to onions or garlic without much greater reduction in sclerotial numbers. Most likely, many improvements and modifications could be implemented to improve on our results. We did not stratify sampling routinely to demonstrate that stimulants reached all depths equally well, but very limited sampling suggests that this occurred. We likely applied too many applications of soil wetting agent; fewer applications should be investigated. It also is likely that results will vary greatly among soil types, most specifically regarding the infiltration characteristics that might promote or impede movement of stimulants applied in irrigation water. In addition, the type of irrigation would influence not only infiltration but also evaporative losses of stimulant components (especially if DADS was

22 used rather than diluted garlic juice). In this trial, garlic juice was not fully diluted in the irrigation water, but was applied somewhat concentrated to soil immediately before sprinklers were turned on. Whether this truly simulated fully diluted juice was assumed, but future work should address the uncertainty that our applications may have moved in a concentrated pulse ahead of most of the following irrigation water. Crop management in our trial was unlike any commercial management, and irrigation by crop variations would need to be addressed in future work and by each farmer attempting to treat in this manner. As a proof of concept, we did not concern ourselves with this issue at this time. We were surprised that stimulated germination was not observed to resume later in the summer as soil temperatures dropped well below 72 F (22 C) and well into the optimum range for stimulated germination. This delay in response could be an item for future investigation. In most summers, soil temperature in central Oregon would not exceed 72 F at any depth during the summer, so 2007 was considered rather hot. Soil temperature, of course, is one of the greater factors to consider in regions where soil temperatures routinely exceed 72 F during much of the growing season; any treatments such as those in this trial must be limited to fall, winter, and spring. Literature Cited Coley-Smith, J.R Studies of the biology of Sclerotium cepivorum. IV. Germination of sclerotia. Annals of Applied Biology 48:8-18. Coley-Smith, J.R., and J.E. King The production of species of Allium of alkyl sulphides and their effect on germination of sclerotia of Sclerotium cepivorum. Berk. Annals of Applied Biology 64: Coley-Smith, J.R., and D. Parfitt, Some effects of diallyl disulphide on sclerotia of Sclerotium cepivorum: Possible novel control method for white rot disease of onions. Pesticide Science 37: Crowe, F The epidemiology of onion and garlic white rot disease, caused by Sclerotium cepivorum. Ph.D. Thesis, 104 pages, University of California, Davis. Crowe, F.J., J. Debons, T. Darnell, M. Thornton, D. Mcgrath, P. Koepsell, J. Laborde, and E. Redondo Control of Allium white rot with DADS and related products. Pages 7-22, Chemical Control Section, in Proceedings of the Fifth International Workshop on Allium White Rot, Cordoba, Spain. Crowe, F.J., and D.H. Hall. 1980a. Vertical distribution of sclerotia of Sclerotium cepivorum and host root systems relative to white rot of onion and garlic. Phytopathology 70:

23 Crowe, F.J., and D.H. Hall. 1980b. Soil temperature and moisture effects on sclerotium germination and infection of onion seedlings by Sclerotium cepivorum. Phytopathology 70: Crowe, F.J., D.H. Hall, A.S. Greathead, and K.G. Baghott Inoculum density of Sclerotium cepivorum and the incidence of white rot of onion and garlic. Phytopathology 70: Elnaghy, M.A., A.H. Moubasher, and S.E. Megala Stimulation of sclerotial germination of Sclerotium cepivorum by host-plant extracts. Plant and Soil 34: Entwistle, A.R., P.R. Merriman, H.L. Munasinghe, and P. Mitchell Diallyl disulphide to reduce the numbers of sclerotia of Sclerotium cepivorum in soil. Soil Biology and Biochemistry 14: Entwistle, A.R., and Munasinghe, H.L., Formation of secondary sclerotia by Sclerotium cepivorum. Transactions of the British Mycological Society 77: King, J.E., and J.R. Coley-Smith The effects of volatile products of Allium species and their extracts on germination of sclerotia of Sclerotium cepivorum Berk. Annals of Applied Biology 61: Merriman, P.R., S. Issacs, R.R. MacGregor, and G.B. Towers Control of white rot in dry bulb onions with artificial onion oil. Annals of Applied Biology 96: Merriman, P.R., I.M. Samson, and B. Schippers Stimulation of germination of sclerotia of Sclerotium cepivorum at different depths in soil by artificial onion oil. Netherlands Journal of Plant Pathology 87: Scott, M.R Studies on the biology of Sclerotium cepivorum Berk. I. Growth of the mycelium in soil. Annals of Applied Biology 44:

24 Sampling and Damage Assessment of Pratylenchus Nematodes Associated with Wheat-Carrot Seed Crop Rotations in Central Oregon Fred Crowe and Rhonda Simmons Introduction Pratylenchus nematodes can injure many crops, including grasses, cereal grain crops, and vegetables. There is anecdotal observation and concern that such nematodes sometimes injure seedlings of highly valued seed carrot crops in central Oregon, but the importance of population sizes, species composition, and timing of nematode sampling are not clear. Based on population levels considered damaging to crops in other regions, Pratylenchus root and soil assays from irrigated wheat, grass seed, and seed carrots in central Oregon sometimes appear very high. Research at Oregon State University-Pendleton on dryland wheat and on carrots in Australia suggested P. thornei may be of particular concern, but other species of Pratylenchus could be injurious as well. Seed-to-seed carrots common follow irrigated wheat and grass seed crops in central Oregon. Pratylenchus spp. is known to increase on cereals and grasses. Thus, increase of Pratylenchus on cereals and grasses may contribute to suspected carrot injury. This trial allowed us to investigate the benefit of commercially registered nematicide applied to soil where carrots were seeded into fields identified as having high Pratylenchus populations both in the previous wheat crop and current carrot planting. Materials and Methods In the first week of July 2006, around the last irrigation period, soil samples were collected from 26 irrigated wheat fields that growers and fieldmen thought might later be seeded to carrots in August or September Species of Pratylenchus found included P. thornei, P. neglectus, P. crenatus, and P. penetrans in various proportions per field, some with only one or two species, others with three or all four. Pratylenchus species may be found both within and outside of roots, when roots are present. Net populations of all species associated with irrigated wheat roots in July ranged from 0 to 208 total Pratylenchus/100 cc soil and 1 to 528 total Pratylenchus/g fresh root weight. Preliminarily, populations in excess of 100/100 cc soil or 240/g roots were considered potentially injurious. The soil threshold was exceeded in six (23 percent) of the fields; the root threshold was exceeded in eight (31 percent) of the fields; and both root and soil thresholds were exceeded in five (19 percent) of the fields. No evaluations were made of nematode versus wheat performance, although this could be a topic for future investigation. At the time of August-September carrot planting, we intended to resample soils from many of the original 26 surveyed fields (especially those with high nematode counts) in order to correlate these data with those from early July wheat soil and root samples. We expected that cultivation of wheat stubble in preparation for carrot seeding, together with the absence of roots at the time of carrot seeding, would result in a decline of Pratylenchus populations prior to planting of carrot seed in August and September. Unfortunately, only four of the surveyed fields were actually planted to carrots in 2006, so abundant correlative data were unavailable, but three of these were fields that earlier tested high for Pratylenchus. August soil samples from these three fields suggested that total Pratylenchus in soil (no roots were present) had

25 declined perhaps percent since July, but that populations remained at a level considered very high. Data are shown in Table 1. Table 1. Number total Pratylenchus (all species) from selected carrot fields in central Oregon. early July mid-august. Soil Roots Soil Field (per 100 cc) (per g fresh root) (per 100 cc) A B C With the cooperation of carrot growers and Wilbur-Ellis Co., post-planting nematicide trials were established in the three fields discussed above. Using commercial application rigs, Vydate L (oxamyl) at 1 gal/acre in 20 gal/acre water plus 1 qt/acre Superspread 7000 was applied immediately prior to overhead irrigation and within 1 week following carrot seedling emergence. Sprayed and unsprayed treatments were replicated three times in randomized block trials in each field. Vydate does not immediately kill nematodes but it does quickly disrupt nematode feeding, thus populations eventually decline (months). We assessed the efficacy of Vydate by observing carrots in the fall, then measuring carrot fresh and dry weight in March of Soil samples also were collected in early March No visual differences were noted in fall carrot seedling growth or in early spring carrot growth in March Extensive winter frost heaving of carrots was observed in many fields, but was not much noted in our trial fields. Mean fresh weight of 100 carrot taproots and foliage sampled in early March (and mean dry weight of 50 of these plants) was not significantly different (P < 5 percent), nor were there trends in favor of Vydate treatment or nontreatment. March soil and carrot root samples suggested a substantial but nevertheless non-statistically significant decline in Pratylenchus populations in Vydate-treated plots in one of three fields (data not shown) but no trend in the other two fields. Most likely, data from the one field would have been statistically significant if more replications had been included in the trial. It is unknown why Vydate didn t appear to lower Pratylenchus populations in the other two fields. Results and Discussion At final wheat irrigation and/or just prior to carrot planting appear to be reasonable times for collecting information on Pratylenchus populations with respect to fall carrot seeding. Because of the time required to process soil/root assays, only July sampling allows sufficient time for making nematicide application decisions close to carrot planting time. Four Pratylenchus species were common in carrot fields, but insufficient information was collected to determine which of them are singly or together injurious to seed carrots in central Oregon. Vydate treatment appeared to lower Pratylenchus populations from high to low levels in soil around seedling carrots in treated plots in one but not all trials, and beneficial plant response was measured. While it is possible that our Vydate treatments were applied too late if injury was restricted to a period during and immediately post-emergence, it seems likely that a period of injury would extend throughout seedling development. We might reconsider whether our measures of plant injury were sufficient; the adverse winter of may have confounded our early spring measurements. The demonstrated frequency of presumed high Pratylenchus populations in wheat-carrot rotations begs further investigation

26 Carrot Tolerance to Pendimethalin and Oxyfluorfen Richard Affeldt, John MacKenzie, and Bruce Martens Abstract Two field trials were conducted in commercial hybrid carrot fields to determine carrot tolerance to pendimethalin and oxyfluorfen applied as an over-the-top broadcast treatment at layby. Broadcasting oxyfluorfen resulted in necrotic spots on carrot leaves that were visible at 6 and 28 days after application, but were no longer evident 42 days after application. Pendimethalin resulted in almost no visual injury to carrots at either location. Introduction Pendimethalin (Prowl ) and oxyfluorfen (Galigan ) herbicides are currently registered for use in carrot seed as a directed spray at layby. This application technique requires special spray equipment that can make the application complicated. These herbicides would be more useful as an over-the-top broadcast treatment at layby, but it is unknown if adequate carrot crop safety can be maintained with this type of application. A single trial was conducted last year to evaluate carrot tolerance to pendimethalin (Affeldt et al. 2007). An unusual growth form was observed in that trial, but it was unclear if the growth form was the result of herbicide injury. The objective of these trials was to determine carrot tolerance to pendimethalin and oxyfluorfen applied as an overthe-top broadcast treatment at layby. Materials and Methods Two field trials were conducted in commercial hybrid carrot fields. The carrots were Nance type and were steckling transplanted. One field was west and one field was north of Madras, Oregon. Herbicide application dates and carrot growth stages are shown in Table 1. Plots were 10 ft by 15 ft with four replications arranged as randomized complete blocks, with two blocks in female rows and two blocks in male rows. Treatments were applied with a CO 2 backpack sprayer delivering 20 or 40 gal/acre operating at 20 psi and 3 mph. Crop injury was quantified by making visual evaluations on a percentage scale. After the herbicide applications, carrot seed was collected prior to the fields being swathed to conduct germination testing. Carrot flowers were sampled at various heights from the two replications that were in the female rows and combined into one sample. The samples were then dried at 80 F for 5 days. The flowers were broken apart by hand and a representative sample of seed was sent to a commercial testing lab. The testing procedure was conducted on 400 seeds randomly sampled and tested over a 14-day period

27 Results and Discussion The field north of Madras had less vigorous carrots than the field west of Madras. The north field was transplanted later than the west field, and the north field had a volunteer winter wheat infestation that competed for resources early in the season. Broadcasting oxyfluorfen resulted in necrotic spots on carrot leaves that were visible at 6 and 28 days after application, but were no longer evident 42 days after application (Tables 1 and 2). Injury from oxyfluorfen was more severe on the north field than on the west. Carrot seed germination from oxyfluorfen plots was not tested. Pendimethalin resulted in almost no visual injury to carrots at either location (Tables 1 and 2). There were no unusual growth habits in the carrot similar to what were observed in the trial in Carrot seed germination was extremely low compared to germination rates that would be typical for commercial seed production. There are at least two factors that likely are contributing to the low seed germination rate. First, the seed was not cleaned, which would have removed inert matter and immature seeds that ended up in the test samplte; this would also have increased the variability of the results. Second, the seed was handled differently than in a commercial operation. Samples were collected prior to the fields being swathed and were oven dried as opposed to air drying in the field. This process likely prevented some of the immature seed from ripening properly. Low seed germination and variability notwithstanding, pendimethalin at 1.9 lb/acre did not reduce germination at either location compared to untreated check plots. Pendimethalin at 3.8 lb/acre appears to have reduced germination in the west field. However, these differences in germination rate are not established statistically. The current pendimethalin label for carrot grown for seed allows for use rates of to 1.9 lb/acre (1 to 4 pt of Prowl H2O 3.8 CS). The rates evaluated in these trials represent one and two times the highest labeled rate. Therefore an over-the-top broadcast application of pendimethalin at layby should have adequate crop safety on carrot grown for seed at current labeled rates. References Affeldt, R., J. MacKenzie, B. Martens, and K. Farris Carrot tolerance to pendimethalin and mesotrione broadcast at layby. Central Oregon Agricultural Research Center 2006 Annual Report. Special Report 1072:5-6. Acknowledgements We would like to thank Kurt Farris for his involvement in planning this research. We would also like to thank Tom Kirsch with Madras Farms and Stan Sullivan for accommodating the trials in their production fields

28 Check Pendimethalin May Pendimethalin May Oxyfluorfen May Oxyfluorfen May Pendimethalin Jun Pendimethalin Jun Applications included non-ionic surfactant at 0.25% v/v. 2 Carrots were 6 inches tall and still in a vegetative growth stage. 3 Carrots were 40 inches tall and in an early reproductive growth stage. 4 Data shown are not means across replications. Seed was not cleaned prior to testing. Check Pendimethalin May Pendimethalin May Oxyfluorfen May Oxyfluorfen May Pendimethalin Jun Pendimethalin Jun Applications included non-ionic surfactant at 0.25% v/v. 2 Carrots were 3 inches tall and still in a vegetative growth stage. 3 Carrots were 36 inches tall and in an early reproductive growth stage. 4 Data shown are not means across replications. Seed was not cleaned prior to testing. Table 1. Carrot response to pendimethalin and oxyfluorfen west of Madras, Oregon, Herbicide Application Application Carrot injury Carrot seed Treatment rate date rate 17 May 8 June 22 June 6 July germination 4 lb/acre gal/acre % Table 2. Carrot response to pendimethalin and oxyfluorfen north of Madras, Oregon, Herbicide Application Application Carrot injury Carrot seed Treatment rate date rate 17 May 8 June 22 June 6 July germination 4 lb/acre gal/acre %

29 Effect of Priming on Parsley Seed Germination Brian Duggan and Rhonda Simmons Abstract Rapid seed germination is essential for parsley plants to survive the winter in the fields in central Oregon. The objective of this study was to examine whether seed priming could increase germination rate or percentage of parsley seed. Seeds of two cultivars (cv. Forest Green and Evergreen ) were subjected to seven different treatments: scarification (S), polyethylene glycol (PEG), S + PEG, gibberellic acid (GA), S + GA, water (W), and S + W. They were then sown, together with control untreated seeds, in trays containing commercial potting mix or soil from a farmer s field. Seeds sown in the potting mix emerged faster than those sown in the soil. The cultivar Forest Green exhibited a greater germination percentage than Evergreen. Scarification plus priming (S + PEG, S + GA, or S + W) significantly reduced germination speed and percentage compared to the control in the soil. In contrast, there was no difference between treatments at 425 growing degree days after sowing in potting mix. There was no interaction between cultivar and treatment at any point throughout the experiment. As far as field conditions are concerned, it is unlikely that parsley production benefits from any seed treatments tested in this experiment. Scarification plus priming was rather detrimental in parsley growth in potting mix. Introduction Parsley is sown as a seed crop in central Oregon and is typically slow to emerge when sown in early July. Growers are interested in applying seed priming to enhance seed germination and ensure rapid stand establishment. Pill and Kilian (2000) found that priming seeds with gibberellic acid (GA) increased germination rate, percentage and uniformity, and also the length of the hypocotyl when they were sown in a peat-lite medium. Priming of parsley seed is now common where parsley seedlings are sold in trays (personal communication Gordon Jamieson, Germain s Technology Group). This study was undertaken to determine whether a simple way of priming parsley seed is effective when seeds are sown under field conditions. Materials and Methods Seeds of cultivars Forest Green and Evergreen were primed prior to sowing. Treatments included: control (unprimed); priming in water (W); 192 g/l polyethylene glycol (PEG) or g/l gibberellic acid (GA) at 18 C for 7 days; scarification (S, rubbing gently on fine sandpaper for 10 sec), S + W, S + PEG, and S + GA. Twenty-five seeds of each cultivar and treatment combination were then sown 5 mm deep in the potting mix or soil from a local farmer s field placed in planting trays. Trays were then placed in a growth chamber at 18/10 C with 16 hours light/8 hours dark photoperiod (light intensity: 295µmol/m 2 /sec mercury lamps). The date of emergence was defined as

30 shoot emergence through soil surface. The experiment was terminated 450 growing degree days (GDD) (base temp of 0 C) after sowing. Results and Discussion Forest green seeds germinated faster and exhibited a greater germination percentage than Evergreen seeds (Fig. 1), while seeds sown in the potting mix germinated faster than those grown in soil with 50 percent of the final germination percentage achieved at 200 and 245 GDD for the potting mix and soil medium, respectively. It is unclear why germination was slower in the soil. It might have taken longer for seedlings to push through the surface crust of soil compared to that of potting mix. When sown in soil, control seeds had a greater germination percentage than any other treatment except for PEG (Fig. 2a). Scarification and priming in either GA, PEG, or water had the lowest germination. When the seeds were sown in potting mix there was no treatment that was significantly different from the control (Fig. 2b), although there was a tendency for the scarified seeds to germinate slower and have a lower germination percentage as observed in soil. There was no interaction between cultivar and treatment throughout the experiment. Pill and Kilian (2000) found that soaking parsley seeds in water or GA for a week decreased the germination percentage, while priming with PEG increased the germination from 74 percent to between 82 and 86 percent, depending on temperature, duration, and GA application after priming. This was not the case in the present study: we found that the unprimed seed had 88 percent germination in the soil medium. It may be that priming is successful in germinating less vigorous parsley seeds in some situations, but if there are few of these seeds in the seed lot then priming has little effect Forest Green Soil Evergreen Soil Forest Green Potting mix Evergreen Potting mix Germination % Growing degree days Figure 1. Germination of two parsley cultivars sown in trays containing soil or potting mix

31 a) 100 b) Control Scarified P.E.G. Scarified + P.E.G. G.A. Scarified + G.A. Water Scarified + Water N.S Control Scarified P.E.G. Scarified + P.E.G. G.A. Scarified + G.A. Water Scarified + Water N.S. N.S. N.S. 20 N.S Growing degree days Germination % 20 N.S. N.S. N.S Growing degree days Figure 2. Germination percentage of parsley seed in a) soil and b) potting mix after exposure to different priming treatments. Error bars indicate LSD (0.05) References Pill, W.G., and E.A. Kilian Germination and emergence of parsley in response to osmotic or matric seed priming and treatment with gibberellin. HortScience 35(5): Acknowledgements We wish to thank H. Siegenhagen and S. Minor for instigating this experiment

32 Garlic Tolerance to Bromoxynil Richard Affeldt and Scott Simmons Abstract Bromoxynil is vital for postemergence broadleaf weed control in garlic. However the current registration for bromoxynil on garlic limits its utility. The objective of these trials was to determine if garlic could tolerate bromoxynil at more than 0.5 lb/acre per season and applied after garlic was 12 inches tall. Two trials were conducted in commercial fields of garlic grown for seed, one near Prineville, Oregon and one near Culver, Oregon. Bromoxynil was applied at timings adequate to control weeds germinating in early spring, late spring, and early summer. Across both locations, garlic injury was observed only following the early spring application of bromoxynil at 1.0 lb/acre. Blue mustard, a winter-annual weed, was controlled well with an early spring application of bromoxynil; however, common lambsquarter and black nightshade, two summer-annual weeds, were controlled only with late spring or early summer applications of bromoxynil. Introduction The current registration for bromoxynil (Buctril 2 EC, Bayer Crop Science) on garlic requires that bromoxynil be applied before garlic reaches 12 inches in height and use is restricted to 0.5 lb/acre (2 pt product/acre) per season. Bromoxynil is a contact herbicide with little or no soil residual weed control activity. Garlic grown for seed is not a very competitive crop and presents opportunity for weed germination throughout the spring and early summer because it is not a very competitive crop and it does not form a dense canopy. Hand weeding costs in garlic would be reduced if bromoxynil could be applied at a higher rate per season and later in the season than what is allowed on the current label. The objective of these trials was to determine if garlic could tolerate bromoxynil at more than 0.5 lb/acre per season and applied after garlic was 12 inches tall. Materials and Methods Two trials were conducted in commercial fields of garlic grown for seed, one near Prineville, Oregon and one near Culver, Oregon. Bromoxynil was applied at timings adequate to control weeds germinating in early spring, late spring, and early summer (Table 1). Bromoxynil rates are shown in Table 2. Plots were 8 ft by 30 ft with four replications arranged as randomized complete blocks. Treatments were applied with a CO 2 backpack sprayer delivering 20 gal/acre operating at 20 psi and 3 mph. Crop injury and weed control were determined by making visual evaluations on a percentage scale. Results and Discussion Across both locations, garlic injury was observed only following the early spring (A) application of the higher rate of bromoxynil at 1.0 lb/acre (Table 2). Minor injury from the lower rate of bromoxynil (0.5 lb/acre) was observed in one plot of one treatment in

33 Culver. Injury observed on the garlic was recorded 11 to 14 days after application and appeared as early senescence of the lower leaves. No garlic injury was observed at either location from late spring (B) or early summer (C) applications of bromoxynil. Blue mustard (Chorispora tenella), a winter-annual also known as Jim Hill mustard, was completely controlled with a single early spring application of bromoxynil at 0.5 lb/acre at Prineville (Table 3). An overactive hand-weeding crew prevented subsequent weed control evaluations at Prineville. At Culver, there were two summer-annual weeds present at low populations, common lambsquarter (Chenopodium album) and black nightshade (Solanum nigrum). These weeds were not controlled with the early spring application of bromoxynil, because they had not yet emerged. A subsequent application of bromoxynil in late spring (A + B) suppressed these two weeds, and another application of bromoxynil in early summer (A + B + C) controlled these weeds very well. Acknowledgements We would like to thank Jim Carroll and Kurt Farris for their involvement in planning this research. We would also like to thank Bonnie Craig and H&T Farms for accommodating the trials in their production fields. Table 1. Bromoxynil application timing and garlic height for field trials conducted near Prineville and Culver, Oregon, Application timing Prineville Culver Date Height Date Height (inches) (inches) A (early spring) April 5 6 April 16 6 B (late spring) April May 2 16 C (early summer) June 8 24 June 8 24 Table 2. Garlic injury from bromoxynil applications near Prineville and Culver, Oregon, Application Bromoxynil Prineville 1 Culver 1 timing rate April 16 2 April 30 3 (lb a.i./acre) % injury Check A A A + B A + B + C No garlic injury was observed at either location from evaluations made on May 14, June 8, and June Evaluation was made 11 days after application A. 3 Evaluation was made 14 days after application A

34 Table 3. Weed control from bromoxynil applications near Prineville and Culver, Oregon, Application Bromoxynil Blue mustard 1 Common lambsquarter 2 Black nightshade 3 timing rate Prineville April 16 Culver June 21 (lb a.i./acre) % control Check A A A + B A + B + C Blue mustard (also called Jim Hill mustard) was 3 inches in diameter at the time of application A. 2 Common lambsquarter was 0.5 inches tall at application B. There was no common lambsquarter observed prior to application B. 3 Black nightshade was 0.5 inches tall at application C. There was no black nightshade observed prior to application C

35 Non-thermal Residue Management in Kentucky Bluegrass Richard Affeldt and Mike Weber Abstract Despite a significant amount of research that has investigated alternatives to field burning, a suitable replacement has not yet been discovered. A field trial to evaluate nonthermal residue management practices in large nonreplicated plots was established in the fall of Three treatments were applied to a third year stand of Geronimo Kentucky bluegrass after harvest: 1) bale plus regular flail, 2) bale plus vacuum flail, and 3) bale plus vacuum flail plus propane flame. Chemical methods of residue degradation were investigated, but were not tested. This research seems to further indicate that no currently available technology adequately replaces field burning in Kentucky bluegrass seed production systems in Oregon. Introduction Open field burning is a residue management practice that benefits Kentucky bluegrass seed production but it has unfavorable impacts on communities and the environment where seed is produced. Despite a significant amount of research that has investigated alternatives to field burning, a suitable replacement has not yet been discovered (Crowe et al. 1996). The objective was to build on the research that has been done by evaluating previously investigated methods on a large scale, in order to more clearly document the economic impact of non-thermal residue management. Chemical methods of residue degradation were also under consideration for comparison in the planning stages of this project, but were not included in the list of treatments for reasons discussed below. Materials and Methods A field trial to evaluate non-thermal residue management practices in large nonreplicated plots was established in the fall of Three treatments were applied to a third year stand of Geronimo Kentucky bluegrass after harvest: 1) bale plus regular flail, 2) bale plus vacuum flail, and 3) bale plus vacuum flail plus propane flame. Each treatment was visually evaluated for pest pressure. The 8-ft vacuum flail used was developed by Rear s Manufacturing in Eugene, Oregon. Plots were harvested with commercial equipment and seed yield was compared to the rest of the field, which was baled and burned. A sample of each seed lot was cleaned in order to determine clean seed yield for each treatment. Results and Discussion An effort to apply a bale plus sulfuric acid treatment in this trial was unsuccessful. The major obstacle was the deficiency in the application technology involved with sulfuric

36 acid, which is highly corrosive to most materials. Furthermore, the existing data (which are minimal) indicate that sulfuric acid has very little utility for residue breakdown. Another treatment that was considered was urea-sulfuric acid sold as N-pHuric. There is already a substantial amount of data indicating that urea-sulfuric acid is also not useful for residue breakdown. The residue management treatments that were applied in 2006 strongly influenced seed yield in Clean seed yield was 1,422 lb/acre from the field, which was baled and burned (Fig. 1). Clean seed yield from the bale plus regular flail treatment was 1,178 lb/acre, representing a 17 percent reduction compared to the field. Clean seed yield from the bale plus vacuum flail treatment was 1,337 lb/acre, representing a 6 percent reduction compared to the field. Clean seed yield from the bale plus vacuum flail plus propane flame treatment was 1,413 lb/acre, representing a decrease of less than 1 percent compared to the field. There were no clear differences in pest pressure and no need to implement different pest management practices across treatments. The vacuum flail removed post-harvest residues right down to the soil surface. Vacuum flailing plus propane flaming compared to burning resulted in minimal amounts of smoke and similar seed yield. However, it is highly unlikely that vacuum flailing will be a reasonable option for residue management. Aspects of vacuum flailing that were particularly problematic were: 1) flailing could only be performed at about 2 mph; 2) the collected residue is bulky and loose, making it difficult to transport; and 3) the residue contains enough soil to render it useless for livestock feed. We estimate that vacuum flailing took approximately 1 hour/acre. The operation of the vacuum flail was approximately $40/acre to cover maintenance and replacement cost. An additional $60/acre would cover cost of a tractor and operator. The total cost estimated to vacuum flail was $100/acre. If there is no replacement for field burning that results in similar seed yield and crop vigor, then the price structure for Kentucky bluegrass seed production will need to change as field burning becomes more restricted. This research indicates that current technology does not adequately replace field burning in Kentucky bluegrass seed production systems in Oregon. References Crowe, F.J., D.D. Coats, N.A. Farris, C.L. Yang, M.K. Durette, M.D. Butler, G.W. Mueller-Warrant, D.S. Culver, and S.C. Rosato Effects of various types of post-harvest residue management on Kentucky bluegrass seed yield in central Oregon, on-farm results from Pages in W.C. Young III, ed. Seed Production Research, Oregon State University

37 Acknowledgements We would like to thank the Jefferson County Smoke Management Committee for their involvement in planning this research. We would also like to thank Richard Coleman for accommodating the trial in his production field. Bale + open burn Clean seed yield = 1,422 lb/acre Bale + vacuum flail + propane flaming Clean seed yield = 1,413 lb/acre, Bale + vacuum flail Clean seed yield = 1,337 lb/acre Bale Clean seed yield = 1,178 lb/acre Figure 1. Images of Geronimo Kentucky bluegrass residue and stubble remaining after post-harvest operations were carried out in August 2006, and clean seed yield from respective treatments in

38 Kentucky Bluegrass Tolerance to Primisulfuron R.P. Affeldt and J.L. Carroll Abstract Primisulfuron can severely injure Kentucky bluegrass, but the injury varies from year to year and the factors that lead to this injury are unclear. Kentucky bluegrass response to primisulfuron was evaluated in five trials conducted in commercial fields near Madras, Oregon. Primisulfuron was applied at lb/acre (0.38 oz product/acre) at three timings in the fall: 2-leaf, 4-leaf, and tillered. The three fall-applied treatments were also followed by additional primisulfuron in the spring at lb/acre, for a total of six treatments. Kentucky bluegrass growth stage at the time of application strongly influenced sensitivity to primisulfuron: 2-leaf timings generally caused more injury than 4-leaf timings, which generally caused more injury than tillered timings. Also, primisulfuron applied in the fall followed by another application in the spring resulted in more injury than primisulfuron in the fall only. Varietal response to primisulfuron in order of least to most sensitive based on visual evaluations made May 23, 2007 was as follows: Julia, Shamrock, Abbey, Merit, and Barimpala. The influence of varietal response is unclear because these trials were not side-by-side comparisons of varieties. Introduction Primisulfuron (Beacon ) is the only effective herbicide option registered for controlling rough bluegrass (Poa trivialis) and downy brome (Bromus tectorum) in seedling Kentucky bluegrass (P. pratensis). Primisulfuron can severely injure Kentucky bluegrass, but the injury varies from year to year and the factors that lead to this injury are unclear. It is conventionally believed that some varieties are much more sensitive to primisulfuron than others, and that primisulfuron use on sensitive varieties should be completely avoided. Furthermore, Mueller-Warrant et al. (1997) reported differences in varietal sensitivity to primisulfuron. Finding the optimal timing for this herbicide is critical because it has a low margin for selectivity on these two weeds. Materials and Methods Kentucky bluegrass response to primisulfuron was evaluated in five trials conducted in commercial fields near Madras, Oregon. Varieties selected were Julia, Barimpala, Abbey, Merit, and Shamrock. Primisulfuron was applied at lb/acre (0.38 oz product/acre) at three timings in the fall: 2-leaf, 4-leaf, and tillered. The three fallapplied treatments were also followed by additional primisulfuron in the spring at lb/acre, for a total of six treatments. All five trials consisted of 10- by 25-ft plots arranged in randomized complete blocks replicated four times. Primisulfuron was applied with a CO 2 -pressurized backpack sprayer delivering 20 gal/acre at 20 psi. Crop injury was evaluated visually at vegetative and reproductive stages with a 0 to 100 percent rating scale

39 Results and Discussion Primisulfuron applications were made based on crop growth stage rather than calendar date (Table 1). Therefore, growing conditions at the time of application varied for each treatment across trials because of varying planting dates and irrigation methods. Kentucky bluegrass growth stage at the time of application strongly influenced sensitivity to primisulfuron: 2-leaf timings generally caused more injury than 4-leaf timings, which generally caused more injury than tillered timings (Table 2). Also, primisulfuron applied in the fall followed by another application in the spring resulted in more injury than primisulfuron in the fall only. The field of Julia had a severe infestation of downy brome, which had germinated in the fall and again in the spring. A single application of primisulfuron in the fall did not adequately control downy brome in this situation (Table 3). Downy brome control was 80 percent when primisulfuron was applied at the 2-leaf stage in the fall followed by another application in the spring; no other treatment controlled downy brome as well. The 2-leaf application timing also controlled 94 to 96 percent of henbit (Lamium amplexicaule). Varietal response to primisulfuron in order of least to most sensitive based on visual evaluations made May 23, 2007 was as follows: Julia, Shamrock, Abbey, Merit, and Barimpala. This is not a statistically established ranking. Results from Mueller- Warrant et al. (1997) with three of these varieties ( Shamrock, Abbey, and Merit ) indicated different levels of tolerance than what was observed here. However, the influence of varietal response is unclear because these trials were not side-by-side comparisons of varieties. Based on these results, it seems possible that growing conditions at the time of application more strongly influence crop tolerance than varietal response. References Mueller-Warrant, G.W., D.S. Culver, S.C. Rosato, and F.J. Crowe Kentucky bluegrass variety tolerance to primisulfuron. Pages in W.C. Young III, ed. Seed Production Research, Oregon State University. Acknowledgements We would like to thank Ryan Boyle, Jim Kaiser, Stan Sullivan, and Shawn Vibbert for accommodating the trials in their production fields

40 Table 1. Primisulfuron (Beacon ) application dates on seedling Kentucky bluegrass varieties near Madras, Oregon, Growth Abbey Barimpala Julia Merit Shamrock stage Application date leaf Sep 15, 2006 Oct 6, 2006 Sep 28, 2006 Sep 14, 2006 Oct 6, leaf Oct 6, 2006 Oct 28, 2006 Oct 6, 2006 Sep 28, 2006 Oct 28, 2006 Tillered Oct 28, 2006 Dec 12, 2006 Oct 28, 2006 Oct 28, 2006 Dec 12, 2006 Spring Mar 19, 2007 Mar 19, 2007 Mar 19, 2007 Mar 19, 2007 Mar 19,

41 Table 2. Response of first-year stands of Kentucky bluegrass varieties to primisulfuron (Beacon ) herbicide near Madras, Oregon, Crop growth stage Abbey Barimpala Julia 4 Merit Shamrock at application 1 Apr 10 2 May 23 3 Apr 10 2 May 23 3 Apr 10 2 Apr 10 2 May 23 3 Apr 10 2 May % Injury Check leaf leaf Tillered leaf + spring leaf + spring Tillered + spring Primisulfuron was applied at lb/acre with a non-ionic surfactant at 0.25% v/v. 2 Kentucky bluegrass was in vegetative growth stage. 3 Kentucky bluegrass was in reproductive growth stage. 4 Julia had a severe infestation of downy brome that prohibited a visual evaluation on May 23. Table 3. Weed control with primisulfuron (Beacon ) herbicide in Julia Kentucky bluegrass near Madras, Oregon, Crop growth stage at application 1 Henbit Nov 21, 2006 Downy brome May 23, % control Check leaf leaf Tillered leaf + spring leaf + spring Tillered + spring Primisulfuron was applied at lb/acre with a non-ionic surfactant at 0.25% v/v

42 Kentucky Bluegrass Tolerance to Mesotrione Applied in the Fall Richard Affeldt, Marvin Butler, Doug Cattani, and Linda Samsel Abstract Four field studies were conducted in commercial fields of Kentucky bluegrass to determine the impact of the use of mesotrione herbicide in the fall on seed production. Mesotrione was applied at two rates, 0.25 and 0.5 lb/acre at two timings, early October and early November alone, and in a sequence of October followed by November. Mesotrione was applied to the following Kentucky bluegrass varieties and growth stages 1) seedling Merit, 2) seedling Shamrock, 3) established Merit, and 4) established Shamrock. Kentucky bluegrass was highly tolerant to fall applications of mesotrione. Merit and Shamrock did not differ in their response to mesotrione regardless of growth stage. None of the mesotrione treatments reduced seed yield. Introduction Butler et al. (2005) reported that fall applications of mesotrione (Callisto ) did not cause visible injury to Kentucky bluegrass (Poa pratensis). However, the impact of mesotrione use on Kentucky bluegrass seed yield has not been measured. Kentucky bluegrass grown for seed in central Oregon is managed as a perennial, with an anticipated 3 to 5 years of seed production. New stands are planted in late August in order to achieve enough vegetative growth prior to winter to produce seed the following spring. Application of herbicides to Kentucky bluegrass in the fall can have adverse effects on seed production, particularly in newly established stands. Furthermore, some varieties can be more sensitive to herbicides than others. The objective of this study was to determine the impact of the use of mesotrione herbicide in the fall on Kentucky bluegrass crop injury and seed yield. Materials and Methods Four field studies were conducted in commercial fields of Kentucky bluegrass, the fields selected were 1) seedling Merit, 2) seedling Shamrock, 3) established Merit, and 4) established Shamrock. Mesotrione was applied at two rates of 0.25 and 0.5 lb/acre at two timings, early October and early November alone, and in a sequence of October followed by November (Table 1). Plots were 10 ft by 25 ft with four replications arranged as randomized complete blocks. Treatments were applied with a CO 2 backpack sprayer delivering 20 gal/acre, operating at 20 psi and 3 mph. Crop injury was quantified by making visual evaluations on a percentage scale. Seed yield was measured by harvesting a sample of grass from each plot into burlap sacks prior to the rest of the field being swathed. These samples were air dried and threshed in a Hege plot combine; seed samples were de-bearded and cleaned. Crop injury and clean seed yield data were subjected to Bartlett s test for homogeneity and analyzed using the generalized linear model and analysis of variance (ANOVA) in SAS

43 Results and Discussion Data for Merit and Shamrock varieties were pooled across locations for seedling and established fields because the variance was homogenous and location-by-treatment interactions were not significant. This indicated that the two varieties did not differ in their response to mesotrione in this production year. Kentucky bluegrass was highly tolerant to fall applications of mesotrione. October applications resulted in minor injury to seedling and to a lesser extent established Kentucky bluegrass (Tables 1 and 2). This injury did not persist through the fall as the grass became dormant; by December 16 there was no visible injury in either seedling or established Kentucky bluegrass. Furthermore, there was no visible injury in any of the trials from evaluations on March 12, April 16, and June 8, 2007 (data not shown). None of the mesotrione treatments reduced grass seed yield. References Butler, M.B., J.L. Carroll, and C.K. Campbell Control of Roundup Ready creeping bentgrass and roughstalk bluegrass in Kentucky bluegrass seed production in central Oregon. Pages in W.C. Young III, ed. Seed Production Research, Oregon State University. Acknowledgements We would like to thank Ryan and Don Boyle, Mike and Jim Cloud, and Stan Sullivan for accommodating the trials in their production fields. Table 1. Response of newly seeded Kentucky bluegrass to mesotrione (Callisto ) applied in the fall near Madras and Culver, Oregon, Mesotrione timing 2 Mesotrione rate Oct 16 (10 DAA) 3 Nov 14 (39 DAA) 3 Dec 16 (71/32 DAA) 4 Clean seed yield lb/acre % injury lb/acre Check ,603 Oct ,567 Nov ,630 Oct + Nov ,449 Oct ,461 Nov ,594 Oct + Nov ,355 LSD (P = 0.05) NS NS 1 Location-by-treatment interactions were not significant, so data for seedling Merit and Shamrock varieties were pooled across locations and analyzed together

44 2 Mesotrione applied at both locations on October 6, 2006 to 4-leaf Kentucky bluegrass and on November 14, 2006 to 5-tiller Kentucky bluegrass. All applications included crop oil concentrate at 1.0% v/v. 3 DAA = days after application. 4 Evaluation was made 71 days after October 6, 2006 application and 32 days after November 14, 2006 application. 5 Injury was the result of only the October 6, 2006 application. Table 2. Response of established Kentucky bluegrass to mesotrione (Callisto ) applied in the fall near Madras and Culver, Oregon, Mesotrione timing 2 Mesotrione rate Oct 16 (10 DAA) 3 Nov 14 (39 DAA) 3 Dec 16 (71/32 DAA) 4 Clean seed yield lb/acre % injury lb/acre Check ,239 Oct ,207 Nov ,109 Oct + Nov ,280 Oct ,080 Nov ,133 Oct + Nov ,132 LSD (P = 0.05) NS NS 1 Location-by-treatment interactions were not significant, so data for established Merit and Shamrock varieties were pooled across locations and analyzed together. 2 Mesotrione applied at both locations on October 6, 2006 to 2-inch tall Kentucky bluegrass and on November 14, 2006 to 3-inch tall Kentucky bluegrass. All applications included crop oil concentrate at 1.0% v/v. 3 DAA = days after application. 4 Evaluation was made 71 days after October 6, 2006 application and 32 days after November 14, 2006 application. 5 Injury was the result of only the October 6, 2006 application

45 Creeping Bentgrass Control with Mesotrione Richard Affeldt and Marvin Butler Abstract Creeping bentgrass is difficult to control as a weed in Kentucky bluegrass seed production fields. A field trial was conducted to quantify the efficacy of mesotrione in a commercial field of established Julia Kentucky bluegrass that was infested with established clumps of creeping bentgrass. Mesotrione did not completely control the clumps of creeping bentgrass. A lack of thorough coverage on creeping bentgrass plants likely resulted in reduced control from later applications of mesotrione. The most effective treatment was a dormant application of mesotrione at lb/acre followed by an early postemergence application of lb/acre. However, this treatment only killed 67 percent of the creeping bentgrass plants, and 33 percent of the remaining plants still produced a seed head. Introduction Creeping bentgrass (Agrostis stolonifera) is a stoloniferous perennial grass that is difficult to control as a volunteer in Kentucky bluegrass (Poa pratensis) seed production fields. The Oregon Department of Agriculture established a control area for the production of glyphosate-resistant creeping bentgrass seed north of Madras, Oregon. Four hundred acres of commercial plantings of glyphosate-resistant creeping bentgrass were started within the control area in 2002, harvested in 2003, and removed in the spring of 2004 prior to heading. A strategy to control volunteer creeping bentgrass in subsequent Kentucky bluegrass crops is needed. Butler et al. (2005) reported that fall applications of mesotrione (Callisto, Syngenta) were effective for controlling creeping bentgrass. However, those evaluations were made in a commercial field of creeping bentgrass. It is not clear how well mesotrione will control creeping bentgrass in Kentucky bluegrass fields. Materials and Methods A field trial was conducted in a commercial field of established Julia Kentucky bluegrass grown for seed near Madras, Oregon. The field was infested with established clumps of creeping bentgrass. Mesotrione was applied at four timings in the spring: dormant, early postemergence (EPOST), postemergence (POST), and late postemergence (LPOST) (Table 1). Mesotrione rates are shown in Table 2. Plots were 10 ft by 25 ft with four replications arranged as randomized complete blocks. Treatments were applied with a CO 2 backpack sprayer delivering 20 gal/acre operating at 20 psi and 3 mph. Crop injury and weed control were determined by making visual evaluations on a percentage scale. Creeping bentgrass mortality and heading were determined by assigning a yes or no rank to three randomly selected plants per plot; the percentage listed in Table 2 was calculated by dividing the number of yes rankings by the

46 subsamples across replications. Kentucky bluegrass seed yield was measured by harvesting a sample of grass from each plot into burlap sacks prior to the rest of the field being swathed. These samples were air dried and threshed in a Hege plot combine; seed samples were de-bearded and cleaned. Clean seed yield data were analyzed using the generalized linear model and analysis of variance in SAS. Results and Discussion Creeping bentgrass that infested the trial area was not glyphosate resistant. Kentucky bluegrass was too tall to make visual evaluations of creeping bentgrass injury from POST and LPOST applications (Table 2). In order to evaluate creeping bentgrass response to POST and LPOST applications of mesotrione, three plants per plot were flagged and evaluated as described above. It is likely that much of the mesotrione in POST and LPOST applications was intercepted by the Kentucky bluegrass canopy, so poor control of creeping bentgrass could have resulted from lack of coverage. Mesotrione did not completely control the clumps of creeping bentgrass especially at timings later than the dormant stage. Treated creeping bentgrass plants that were injured turned white, then necrotic, but new growth later developed from the clumps (Fig. 1). The new growth was consistently on the back side of the plant, away from the direction of the spray application; the coverage from the sprayer was probably not as good on the back side of the plant. The most effective treatment was a dormant application of mesotrione at lb/acre followed by an EPOST application of lb/acre. However, this treatment only killed 67 percent of the creeping bentgrass plants, and 33 percent of the remaining plants still produced seed heads (Table 2). The EPOST mesotrione treatment that included s- metolachor (Dual Magnum, Syngenta) did not differ from EPOST mesotrione applied alone. No crop injury was observed from evaluations on March 12, March 30, April 12, April 26 May 4, or May 14 (data not shown). None of the treatments or timings resulted in Kentucky bluegrass injury or reduced seed yield (Table 3). References Butler, M.B., J.L. Carroll, and C.K. Campbell Control of Roundup Ready creeping bentgrass and roughstalk bluegrass in Kentucky bluegrass seed production in central Oregon. Pages in W.C. Young III, ed. Seed Production Research, Oregon State University. Acknowledgements We would like to thank Ryan and Don Boyle for accommodating this trial in their production field

47 Table 1. Mesotrione application dates and plant growth stages near Madras, Oregon, Mesotrione timing Application date Kentucky bluegrass Creeping bentgrass Dormant 6 Mar 1.5-inch leaves 0.5-inch leaves Early POST 1 5 Apr 4-inch ht 4-inch dia POST 26 Apr 6-inch ht 6-inch dia Late POST 14 Apr boot stage 8-inch dia, 4-inch ht 1 POST = postemergence. Table 2. Volunteer creeping bentgrass response to mesotrione near Madras, Oregon, Mesotrione Injury Mortality 2 Heading 2 timing 1 Rate 16 Apr 26 Apr 3 Jul 3 Jul lb/acre % Check Dormant Dormant Dormant Early POST Early POST Early POST Early POST POST POST Late POST Late POST All applications included crop oil concentrate at 1.0% v/v. 2 Creeping bentgrass mortality and heading were determined by assigning a yes or no rank to three plants per plot; the percentage listed was calculated by dividing the number of yes rankings by 12 subsamples across replications. 3 Combined with s-metolachlor (Dual Magnum) at 1.27 lb/acre

48 Table 3. Kentucky bluegrass response to mesotrione near Madras, Oregon, Mesotrione Injury Clean seed timing 1 Rate 23 May 8 Jun yield lb/acre % lb/acre Check Dormant ,002 Dormant Dormant Early POST ,028 Early POST Early POST Early POST ,022 POST POST Late POST Late POST LSD (P = 0.05) NS 1 All applications included crop oil concentrate at 1.0% v/v. 2 Combined with s-metolachlor (Dual Magnum) at 1.27 lb/acre

49 Check 'A. Mesotrione 0.19 lb/acre 6 March 2007 AGSST: Dormant Mesotrione 0.38 lb/acre 6 March 2007 AGSST: Dormant LL4: Mesotrione 0.09 lb/acre 5 April 2007 AGSST: 4-in ht Mesotrione 0.19 lb/acre 5 April 2007 AGSST: 4-in ht Mesotrione 0.09 lb/acre followed by 0.19 lb/acre 6 March and 5 April, respectively AGSST: Dormant and 4-in ht, respectively Figure 1. Images of volunteer creeping bentgrass (AGSST) plants in a commercial field of Kentucky bluegrass grown for seed taken 16 April 2007 near Madras, Oregon

50 HPPD Herbicide Screening on Seed Crops Richard Affeldt Abstract A field trial was conducted to screen three HPPD-inhibitor herbicides in order to investigate their potential for use on specialty crops grown in central Oregon. Preemergence treatments of mesotrione and isoxaflutole and postemergence treatments of topramezone were applied to Kentucky bluegrass, rough bluegrass, carrot, and onion. Carrot and onion had no tolerance to any of the herbicide treatments. Kentucky and rough bluegrasses showed varying degrees of injury. All three of these herbicides controlled a wide spectrum of common broadleaf weeds. Given further study and the high levels of weed control from this class of herbicides, it may be possible that lower rates of these herbicides could be used selectively in Kentucky and rough bluegrasses. Introduction Herbicides that inhibit pigment development at a new site of action in plants are becoming commercially available. These herbicides are described as HPPD inhibitors because of the enzyme that is blocked in susceptible species. The use of these herbicides has recently become common in corn and soybean production systems. Little information exists in the literature about the tolerance of specialty crops to the HPPDinhibitor herbicides. The objective of this trial was to screen three of the commercially available HPPD inhibitors to investigate their potential for use on specialty crops grown in central Oregon. Materials and Methods A field trial was conducted at the Central Oregon Agricultural Research Center near Madras, Oregon. Three rows each of four crop species were planted on September 9, 2006: Kentucky bluegrass (Poa pratensis), rough bluegrass (P. trivialis), carrot (Daucus carota), and onion (Allium cepa). Pre-emergence treatments of mesotrione (Callisto ) and isoxaflutole (Balance Pro ) at two rates were applied following the first sprinkler irrigation on September 14. Postemergence treatments of topramezone (Impact ) at two rates were applied on November 17, 2006; plant growth stages at the time of application are listed in Table 1. Plots were 7 ft by 28 ft with four replications arranged as randomized complete blocks. Treatments were applied with a CO 2 backpack sprayer delivering 20 gal/acre operating at 20 psi and 3 mph. Crop injury and weed control were determined by making visual evaluations on a percentage scale on December 11, 2006 (data not shown) and April 7, Results and Discussion Carrot and onion had no tolerance to any of the herbicide treatments (Table 1). Kentucky bluegrass was moderately to severely injured from all treatments except the low rate of

51 topramezone. Injury to rough bluegrass was similar to that on Kentucky bluegrass, except that the low rate of isoxaflutole caused little injury. All three of these herbicides controlled a wide spectrum of common broadleaf weeds. Pre-emergence applications of mesotrione or isoxaflutole controlled 100 percent of common groundsel (Senecio vulgaris), henbit (Lamium amplexicaule), and flixweed (Descurainia sophia), tumble mustard (Sisymbrium altissimum), and prickly lettuce (Lactuca serriola). Mesotrione also controlled 100 percent of annual polemonium (Polemonium micranthum), also called Jacob s ladder, and isoxaflutole controlled 100 percent of blue mustard (Chorispora tenella), also called Jim Hill mustard. Topramezone controlled 93 percent or more of common groundsel, henbit, and flixweed; it controlled about 50 percent of blue mustard, tumble mustard, and prickly lettuce; but it did not control annual polemonium. Given further study and the high levels of weed control from this class of herbicides, it may be possible that lower rates of these herbicides could be used selectively in Kentucky and rough bluegrasses

52 Check Applied with non-ionic surfactant at 0.25% v/v on November 17, 2006 to 3- to 5-leaf Kentucky bluegrass, 2- to 4-leaf rough bluegrass and carrot, 1- to 2-leaf onion, 4-inch-diameter common groundsel, 1.5-inch-diameter henbit, flixweed, blue mustard, Mesotrione Mesotrione Isoxaflutole Isoxaflutole Topramezone Topramezone Applied September 14, 2006 pre-emergence to crops and weeds. tumble mustard, and annual polemonium, and 1-inch-diameter prickly lettuce. Table 1. Crop and weed response to three HPPD-inhibitor herbicides on April 7, 2007 at the Central Oregon Agricultural Research Center near Madras, Oregon. Kntky. Rough Common Blue Tumble Prickly Annual Treatment Rate bluegrass bluegrass Carrot Onion groundsel Henbit Flixweed mustard mustard lettuce polemonium (lb/acre) % injury % control

53 Evaluation of Simulated Hail Damage to Kentucky Bluegrass Seed Production in Central Oregon, 2007 Marvin Butler, Mark Zarnstorff, Linda Samsel and Roff Farms Abstract This is the first year of a multi-year study to determine the effect of simulated hail damage on Kentucky bluegrass seed yields. Treatments were inflicted at four growth stages in the spring to simulate 33, 67, and 100% damage. Treatments of 33% and 67% damage applied at head emergence caused significantly greater yield reductions than those applied at the boot stage, seed fill or just prior to harvest. It appears the plant may be particularly sensitive to damage at head emergence. When 100% damage was applied at the boot stage seed yield was only reduced by 50%, indicating the plants may be able to recover from significant damage at that stage. Introduction Kentucky bluegrass (Poa pratensis) seed production has historically been an integral part of agriculture in central Oregon. In recent years there has been a decline in acreage due to reduction in price from an over supply, but more recently acreage has rebounded. The objective of this project is to determine the impact from timing and severity of hail damage on seed production of Kentucky bluegrass. This information will assist the National Crop Insurance Service in developing methodology to evaluate hail damage on Kentucky bluegrass. Methods and Materials This is the first year of a multiple year evaluation on the effect of simulated hail damage on Kentucky bluegrass seed production. The study was conducted in a commercial fifthyear field under a center pivot with Roff Farms near Culver, Oregon. Plots were 5 ft by 15 ft, with 3-ft alleyways, replicated four times in a randomized complete block design. Variables established for this study included four treatment timings and three levels of damage. Damage treatments were inflicted at the boot stage, at head emergence, during seed fill following pollination and just prior to harvest. Severity of damage inflicted was 33, 67, and 100 percent compared to undamaged plots. A Jari mower was used to cut three-ft alleyways across the front and back of each block of plots. Treatments were made on May 14, May 28, June 26 and July 4 using a weed eater with plastic blades held on edge at a 45 degree angle or perpendicular to the ground for the 100 percent treatment. The target amount of foliage or seed heads removed was one-third of the growth, two-thirds of the growth, or removal of all plant material above 1-2 inches. A research-sized swather was used to harvest a 40-inch by 22-ft portion of each Kentucky bluegrass plot on July 5, the date commercial harvest of the field was begun. Samples were placed in large burlap bags and hung in the three-sided equipment

54 shed at the Central Oregon Agricultural Research Center to dry. When samples were dry they were combined using a stationary Hege, with seed samples processed using a debearder follow by a Clipper cleaner. Results and Discussion The data (Table 1) are interesting and perhaps a bit unexpected. It seems clear that damage at head emergence resulted in the greatest reduction in yield. Treatments that applied 33% or 67% damage at head emergence had a significantly greater effect on seed yield than other treatment timings. It appears that Kentucky bluegrass is particularly susceptible to damage at head emergence. Mowing the plots down like a lawn with 100% damage at the boot stage only reduced yield by 50%, though 67% damage reduced yield by 61%. Nevertheless, it seems to indicate the plant s ability to recover from significant damage at the boot stage. A check on our ability to estimate 33% and 65% damage is provided in the seed fill and near harvest applications dates, with 33% reducing seed yield about 25% and 67% damage reducing yield about 48%. It appears we are be a little light on our estimate of damage, as the plant wouldn t be expected to compensate in such a short time frame. Table 1. Simulated hail damage on Kentucky bluegrass grown for seed with damage inflicted at the boot stage, head emergence, seed filling and a day prior to harvest on July 5, Hail damage Seed yield Damage (%) Growth stage lb/acre % check Untreated a Near harvest 977 b Seed fill 956 b Boot 753 c Near harvest 706 c Boot 654 cd Seed fill 634 cd Boot 511 d Heads emerged 293 e Heads emerged 96 f Heads emerged 43 f Seed fill 0 f Near harvest 0 f 0 1 Mean separation with Least Significant Difference (LSD) at P

55 Jefferson County Smoke Management Pilot Balloon Observations, 2007 Linda Samsel and Marvin Butler Abstract Pilot balloon (Piball) observations are a major component of the daily decision-making process used in managing open field burning of grass seed and wheat fields in Jefferson County. Piballs are used to track local wind direction and speed. Piballs are released daily from the Central Oregon Agricultural Research Center between the times of 10:30 am and 2:30 pm. Piball releases allow for more accurate decisions under marginal conditions. The Piball is essential in minimizing adverse smoke impacts on the local communities. Introduction The Piball program that began in 1998 incorporates the weather balloon information into the daily routine along with the information the Jefferson County Smoke Management Team receives from the Oregon Department of Agriculture Weather Center. The objective is to provide real time wind patterns, wind speed and wind direction information that could be provided to the Smoke Management Coordinator in making a decision whether to allow burning. Materials and Methods Two daily balloon releases occurred, one it the morning and one in the afternoon between the times 10:30 am and 2:30 pm. The release times were requested daily from the Smoke Management Coordinator. The Piball was used to verify the forecast for upper level wind direction, speed and mixing height. Wind directions and speeds were determined at one-minute intervals for a period of ten minutes during each release using an observation Theodolite System and a 26-inch-diameter helium filled balloon. Taking that data and putting it on to the software program, Piball Analyzer, we were able to analyze the piball information in three different components. The first is the Piball Sounding, a spreadsheet translating the azimuth and elevation readings from the Piball into wind direction and average wind speed. The second is the hodograph, which charts wind direction. The third is the Profile page which graphs wind speed. The results are then provided to the Jefferson County Smoke Management Coordinator who uses this information in determining the field burning status for the day

56 Results During the 2007 burning season there were a total of 11,164 acres burned, 7,079 acres of grass, and 4085 acres of wheat. Emphasis is put on burning more acres on the better burn days and not allowing burning on the marginal days, when smoke may impact local communities. The open field burning began on July 23, and ended on September 21 st. One of this season challenges was the bulk of the acreage to be burned was delayed until the last 5 weeks of the season, when poor weather set in. In the last 5 weeks (a possible 25 burn days) we lost 3 days to voluntary no burn days, 4 days to rain, and 1 day to poor ventilation. There was 7,600 acres burned in 17 days. Vine burning season was from September 21 through October 19. The Piball program is an important tool for the determination of real time conditions. However, it is particularly helpful on marginal burn days to assist the program coordinator in the making the decisions whether to allow burning when conditions are either changing or hard to discern

57 2007 Winter and Spring Wheat Variety Trials Rhonda Simmons, Mylen Bohle, Mark Larsen, Mary Verhoeven, and Jim Petersen Introduction Cereals are an important rotational crop for central Oregon. Until recently, soft white wheat has been the most important class for grain production. Since 1998, when soft white wheat accounted for 65 percent of the acreage grown, the hard red wheat class has accounted for percent of the total acreage grown in 4 years out of the last 6, and percent in the two other years, including Since 1998, wheat acreage grown has ranged from a high of 13,955 acres in 1998, to a low of 10,283 acres grown in 2002, in Crook, Deschutes, and Jefferson counties. Central Oregon is well situated to the markets in Portland, Oregon. Public and private Pacific Northwest plant breeders release new cereal varieties each year. To provide growers with accurate, up-to-date information on variety performance, a statewide variety-testing program was initiated in 1993 with funding provided by the Oregon State University (OSU) Extension Service, OSU Agricultural Experiment Station, Oregon Wheat Commission, and the Oregon Grains Commission. Central Oregon Agricultural Research Center (COARC) has participated in the program every year since The Oregon Grain Commission budget no longer allows them to contribute to the statewide Oregon Elite Yield Trials, and Oregon Wheat Commission contributions to the trial have diminished because of their budget constraints. Yield, height, lodging, and heading dates were recorded for Madras, one of 12 locations around Oregon that participate in the statewide trials. Results are summarized and reported through extension publications, county extension newsletters such as the Central Oregon Ag Newsletter, as well as in other popular press media. Data are also summarized for all trials and are available on the OSU Cereals Extension web page ( ). For future reference, use the web page for earliest access to data, as trial results are posted as soon as they are available. Previous cereal variety and other production trial data ( ) are available at the following web site Due to budget constraints, this web site is no longer updated, but the information is still available. Materials and Methods The entries were planted into plots, 4.5 ft by 20 ft, at the rate of 30 seeds/ft 2, in 6-inch rows, 8- inch row spacing, with an Oyjord plot drill in a randomized block design, with 3 replications. The winter wheat trial was planted on September 26, 2006 and the spring wheat trial was planted on April 16, Soil samples were taken to a depth of 14 inches, the extent of the soil depth. The samples were analyzed by Agri-Check Laboratory at Umatilla, Oregon. Soil test results for winter wheat and spring wheat are presented in Tables 1 and 2, respectively. The nitrogen supply goal for winter wheat was 200 lb N/acre and for spring wheat was 160 lb N/acre

58 Table 1. Soil test results from samples taken on March 13, 2007, for the statewide Oregon Winter Elite Wheat Variety Trials, at Central Oregon Agricultural Research Center, Madras, Oregon. Soil depth ph 1 NO 3 NH 4 P K S (in) (lb/acre) (lb/acre) (ppm) (ppm) (ppm) NO 3 = nitrate, NH 4 = ammonia, P = phosphorus, K = potassium, S = sulfur. Table 2. Soil test results from samples taken on March 13, 2007, for the state-wide Oregon Spring Elite Wheat Variety Trials, at Central Oregon Agricultural Research Center, Madras, Oregon. Soil depth ph 1 NO 3 NH 4 P K S (in) (lb/acre) (lb/acre) (ppm) (ppm) (ppm) NO 3 = nitrate, NH 4 = ammonia, P = phosphorus, K = potassium, S = sulfur. The winter wheat was not fertilized; estimated total nitrogen (soil plus fertilizer N) available to the plants was 185 lb/acre. The spring wheat variety trial was fertilized with 250 lb/acre of (40 lb N, 40 lb P 2 O 5, 40 lb K 2 O per acre) on April 16, Estimated total nitrogen (soil plus fertilizer N) in the top 14 inches of soil available to the plants was 150 lb/acre. Weeds were controlled in winter wheat with an application of 1.5 pt/acre 24-D and 1.5 oz/acre of Banvel product, and 2 pt/100 gal non-ionic surfactant on April 21, Weeds were controlled in spring wheat using 1.5 pt/acre Bronate, 3 oz/acre Banvel, and 2 pt/100 gal nonionic surfactant on May 31, The trials were irrigated as needed with a 30-ft by 40-ft spacing, solid-set sprinkler (9/64-inch heads) irrigation system. Date of first irrigation for the winter wheat variety trial occurred on April 17, 2007 and the last irrigation occurred on June 2, Date of first irrigation for the spring wheat variety trial occurred on April 20, 2007 and the last irrigation was applied on July 17, Heading dates were recorded when 50 percent heading occurred. Just prior to harvest, lodging scores (percent of plot) and plant height (inches) measurements were taken. Harvested area was approximately 15 ft by 4.5 ft for the winter and spring wheat trial. A Hege plot combine was used to harvest the entries. Harvest dates for the winter wheat trial was August 14, 2006 and August 13, 2006 for the spring wheat trial. The grain samples were shipped to and processed at the OSU Hyslop Farm at Corvallis, Oregon, and percent protein was predicted by NIRS whole grain analyzer. Statistical analyses were by analysis of variance (ANOVA) using general linear model, PROC GLM, of SAS version 9.1 (SAS Institute, Cary, NC, 2002). Treatment means were separated by Fisher s protected least significant difference (PLSD 0.05) test

59 Results and Discussion Winter Wheat Trial The winter wheat trial yield average was bu/acre, and yields ranged from to bu/acre (Table 3). For the top-yielding 10 entries, Tubbs to Stephens, there were no significant differences between varieties with a yield range of to bu/acre (PLSD 0.05, 16 bu/acre). Average test weight for the trial was 60.5 lb/bu. Test weight ranged from 58.3 ( Masami ) to 62.9 lb/bu (ARSC ). Heading dates ranged from days from January 1 (doy) to 157.7, or a range of 6.4 days. Oregon line ORH was the earliest to head at (doy); ARS was the last entry to head at (doy). Average plant height was 40.7 inches for the trial. Heights ranged from 34.0 inches ( Gene ) to 47.0 inches (ARSC ). Lodging average was a bit higher than in previous years with 11.1 percent for the trial. Lodging ranged from 0 percent (16 entries) to 66.7 percent (ARSC ); 26 entries had scores of 10 percent or less. Protein average was 10.2 percent and ranged from 9.4 to 11.0 percent. Spring Wheat Trial The spring wheat trial average yield was bu/acre and yields ranged from 76.9 bu/acre to122.6 bu/acre (Table 4.). For the top-yielding seven entries, ML107-11A, 99 to Alpowa (a range of to bu/acre), there were no significant differences (PLSD 0.05, 12.7 bu/acre) between varieties. Average plant height for the trial was 36.0 inches, with a range of 31.3 inches (OR ) to 45.9 inches ( Hollis ). Jerome and OR , one relatively new release and one experimental line, were the two highest yielding varieties in the trial and had plant heights of 35.3 and 34.5 inches. Average test weight for the trial was 58.2 lb/bu. Test weight ranged from 54.1 (ML BK4) to 63.1 lb/bu ( Blanca Grande ). Lodging was very minimal this year. Average lodging for the trial was 4.1 percent, and ranged from 0 to 40 percent (ML BK4). Protein average was 13.6 percent and ranged from 11.5 to 15.9 percent

60 Table 3. Statewide variety testing program for winter wheat, Central Oregon Agricultural Research Center, Madras, OR, Class 1 Yield Test weight Heading Height Lodging Protein Variety or line bu/acre (lbs/bu) (doy) (in) (%) (%) Tubbs SWW OR SWW ID A SWW OSUPOP-27-3 SWW x SWW Tubbs-06/Rod Blend SWW AP 700CL SWW Salute SWW Simon SWW Stephens SWW Weatherford SWW Tubbs-06 SWW ID A SWW Brundage 96 SWW Westbred 528 SWW ID SWW ORCF-102 SWW ORH SWW OR SWW Madsen SWW OR SWW Goetze (ORH010920) SWW OR SWW ORSS-1757 SWW Xerpha (WA7973) SWW BU6W SWW OR SWW IDAHO 587 SWW CARA CLUB ORH10085 SWW ARS CLUB Masami SWW ORCF-101 SWW ORI CLUB ARS97C CLUB ARS00235 CLUB Gene SWW Mean PLSD (0.05) CV% SWW = soft white winter wheat

61 Table 4. Statewide variety testing program for spring wheat, Central Oregon Agricultural Research Center, Madras, OR, Class 1 Yield Test weight Heading Height Lodging Protein Variety or line bu/acre (lbs/bu) (doy) (in) (%) (%) Alpowa SWS Nick SWS WA SWS Alturas SWS Blanca Grande HWS Lolo HWS ML107-11A, 99 HWS ML042-37, A SWS Pettit SWS UI Lochsa HWS UI Alta Blanca HWS ML OR81-2 HWS Louise SWS Hank HRS OR HWS UI Winchester HRS OR HRS Macon HWS IDO630 WXY Jefferson HRS OSU Check SWS ID0377S HWS Jerome HRS IDO629 WXY Otis HWS Tara 2002 HRS Buck Pronto HRS WA HRS BORL95/RABE HRS OR HRS Winsome HWS OR HWS Hollis HRS ML BK4 SWS Mean PLSD (0.05) CV% SWS = soft white spring, HWS = hard white spring, HRS = hard red spring, WXY = waxy

62 Control of Winter Grain Mite Infesting Timothy Mylen G. Bohle, Glenn C. Fisher, and Amy J. Dreves Introduction The winter grain mite (WGM) (Penthaleus major, Duges) is a pest of cool-season grass pasture and seed crops throughout the Pacific Northwest. Although predominantly a pest east of the Cascade Mountains, populations of this mite have sporadically damaged fescue and perennial ryegrass seed crops in the Willamette Valley from the Silverton Hills to the south valley floor over the last decade. Unlike Tetranychidae spider mites that produce multiple generations and copious amounts of webbing on host plants during the hot and dry months of summer and early fall, the WGM becomes active in October, completes two or three generations through the following April, and does not produce webbing on host plants. Cool weather and short day lengths cause the reddish, over-summering eggs located at and below the soil line on host grasses to hatch, and the WGM emerges. The resulting blue-colored mites with bright orange legs feed throughout the fall, winter, and spring months, stunting plants and producing chlorosis of the leaves. Heavy populations surviving through the winter months retard spring regrowth and may kill individual crowns of the more susceptible pasture and seed grasses as well as cereal crops. This mite has the unusual habit of hiding in cracks and crevices of the soil during days of bright sunshine and/or high temperatures and windy conditions. This habit can make initial detection of the mite and symptom diagnosis difficult at times. Cool days and low light conditions bring the mites up to the foliage where they feed with piercing mouthparts, disrupting epidermal cells and drying leaves. Grasses suspected of WGM infestations should be sampled beginning in October. If symptoms are seen but the mites are not, dig some crowns and shake them briskly over a white enamel pan or paper. Use a 10-power hand lens to confirm that the moving specks you see are WGM. This mite does not respond predictably to traditional miticides used to control spider mites. In fact, the organophosphate insecticides dimethoate (e.g., DiGon, Dimate ) and chlopyrifos (Lorsban ), which do not control spider mites, have generally provided effective control of WGM on those cereal and grass seed crops for which uses are registered. Methods In the interest of identifying products with a likelihood of being registered for use on grasses, including both seed and hay crops, should resistance or re-registration difficulties become concerns, we evaluated different materials for the control of this pest. Nine treatments were evaluated in consecutive field trials for control of WGM infesting two different fields of timothy (Phleum pratense) managed for hay and pasture near Culver, Jefferson County, Oregon. A randomized complete block design with plots measuring

63 by 21 ft and replicated 4 times was used in both trials as grass was breaking winter dormancy. Products were applied on 24 February (trial 1) and on 12 March (trial 2), Insecticides were delivered with a CO 2 -powered backpack sprayer using a 4- nozzle (8002 flat fan) hand-held boom that covered a 6.5-ft swath. Spray pressure was set at 40 psi and delivered an equivalent volume of 30 gal/acre to the plots. Potassium nitrate fertilizer (10 lb/100 gal) was added to the Vendex treatment. A silicon surfactant at an equivalent rate of 8 oz/100 gal of spray solution was combined with all treatments except Acaritouch. Post-treatment evaluation of plots consisted of coring 3, 2.5-inch-diameter plugs to a depth of 1 inch from randomly selected crowns within the interior of the plots. Samples were taken in the morning and placed in paper bags within plastic Zip-lock bags for transport to laboratory, where plugs were screened and mites were counted under magnification. Total numbers of live mites were recorded on five different dates from 9 days after treatment (DAT) through 58 DAT for each plot in trial 1; and on two different dates, 13 and 28 DAT in trial 2. Data were subjected to analysis of variance (ANOVA) and means were separated using the Tukey s Studentized Multiple Range (HSD) Test at P = All values were transformed using square root transformation to equalize variance. Original means are presented in Table 1. Results Mite populations in the untreated control of trial 1 increased initially and then leveled off through 30 DAT. Mite populations had decreased by half at 45 DAT, and by 58 DAT few active mites were observed (Table 1). This is a natural decline as the mites lay aestivating (over-summering) eggs in response to increasing day length and temperatures. In trial 2, mite populations in the check plots held steady through 28 DAT, at which time the experiment was terminated early because the grower worked the field. The low and high rates of the pyrethroid, Mustang MAX TM, and the organophosphate, Dimethoate 4E, were comparable in control, providing the best suppression of WGM through the duration of both trials. Mustang MAX TM is a synthetic pyrethroid insecticide scheduled to be labeled by FMC Corp. for use on grass hay and seed crops in 2007 or

64 Table 1. Mean number of live winter grain mites (WGM) per 2.5-inch core taken through timothy grass crowns at varying times several days after treatment (DAT). Trial 1 Trial 2 4 Mar 12 Mar 25 Mar 9 Apr 22 Apr 23 Mar 9 Apr Treatment 1 Rate 9 DAT 17 DAT 30 DAT 45 DAT 58 DAT 13 DAT 28 DAT (product/acre) (no. per 2.5-inch core) Untreated check ab a 22.8 a 11.0 abc 2.0 abc 25.0 abc 29.0 ab Mustang MAX TM 0.8 lbs/gal 2 oz 0.3 c 0.8 c 0.3 c 0.0 c 0.8 bc 2.0 de 1.0 c Mustang MAX TM 0.8 lbs/gal 4 oz 1.8 bc 1.5 bc 0.0 c 0.0 c 4.8 a 0.5 e 0.3 c Kumulus DF Sulfur 80% 20 lb 7.3 ab 19.3 abc 11.0 ab 20.3 ab 0.5 c 50.0 ab 39.5 a Kumulus DF Sulfur 80% 30 lb 3.8 bc 25.0 a 22.5 a 10.3 abc 0.8 c 31.8 abc 14.0 abc Acaritouch 3 12 oz 11.8 a 39.3 a 28.5 a 7.8 abc 3.8 abc 14.0 cde 11.8 abc Acaritouch 25 oz 6.8 ab 25.3 a 10.0 ab 5.0 abc 2.3 abc 26.0 bcd 18.3 ab Dimethoate 4E 2/3 pt 0.3 c 1.0 c 1.0 bc 0.3 bc 0.5 c 1.0 e 3.5 bc Vendex 50 WP 2 lb 5.5 ab 25.5 a 15.8 a 17.8 a 2.0 abc 30.8 abc 19.5 ab + KNO 3 (10 lb./100 gal, H 2 O) Acramite 4SC 24 oz 3.0 bc 20.8 ab 13.75a 13.3 ab 3.8 ab 69.0 a 41.5 a 1 Mustang Max, Acaritouch, Dimethoate, Vendex, and Acramite are not labeled for use in Oregon on grass pasture or hay crops as of this time. Mustang Max is anticipated to have a grass pasture hay and seed crop label in 2007 or Acramite is anticipated to have a grass pasture hay and seed crop label in 2008 or Means followed by the same letter within a column do not differ significantly at P 0.05 (Tukey s HSD multiple comparisons). Mean values were square-root transformed to equalize variance. Original means presented in table. 3 Similar to an insecticidal soap

65 Notes on and Control of the Clover Mite, Bryobia praetiosa Koch, Infesting Orchardgrass in Central Oregon Mylen G. Bohle, Glenn C. Fisher, and Amy J. Dreves Introduction Localized infestations of clover mite (CLM) (Bryobia praetiosa Koch), typically a concern as a transient pest of dwellings, have injured orchardgrass pastures in Deschutes, Jefferson, and Crook counties since the late These mites are brownish and only about half the size of the winter grain mite (WGM) (Penthaleus major, Duges), which is an established pest of coolseason grass pasture and seed crops throughout the Pacific Northwest. A key diagnostic feature of the CLM is the front pair of legs. They are two to three times the length of the second, third, and fourth pairs of legs, which are all short and similar in length. The CLM is similar to the WGM in seasonality, behavior, and damage they cause to grass. Populations of CLM increase on grass pasture during late winter and spring, and cause stunting and yellowing of spring regrowth. Occasionally entire crowns die out. Populations of CLM usually persist through May before declining naturally. Those of WGM usually decline sometime in April. Like WGM, CLM hides in cracks and crevices of the soil during days of bright sunshine and/or high temperatures and windy conditions. This makes detection of mites and symptom diagnosis difficult. Cool, calm days and low light conditions bring the mites up to the foliage where they feed with piercing mouthparts, disrupting epidermal cells and drying leaves. Grasses suspected of CLM infestations should be sampled beginning in March. (Contrast this with WGM when populations are monitored beginning in October). If symptoms are seen but the mites are not, dig some crowns and shake them briskly over a white enamel pan or paper. Use a 10-power hand lens to confirm that the moving specks you see are CLM. It is important to re-emphasize that this damage is nearly synchronous with and resembles that of WGM. The beginning of a severe CLM infestion can look like a fertilizer burn in the field. Populations of CLM seem to appear slightly later in the winter than those of WGM, and persist slightly longer into the spring than those of WGM. Unfortunately, our knowledge and understanding of the biology of CLM in central Oregon is incomplete at best. In other areas of the United States, CLM is thought to over-winter as eggs in grass or as mites on trees or shrubs adjacent the pastures. These over-wintering mites move into grasses throughout the winter and early spring. Although the CLM is not yet reported in grass seed crops in central Oregon, its damage potential and proximity to bluegrasses is cause for concern

66 Methods In the interest of identifying effective products for CLM control with a likelihood of being labeled or registered for use on grasses, including both seed and hay crops, we evaluated different products in the spring of Eight products were evaluated for control of CLM infesting a 4-year-old orchardgrass (Dactylis glomerata) pasture near Tumalo, Deschutes County, Oregon. The field trial was designed as a randomized complete block with plots measuring 21 by 21 ft and replicated 4 times. Grass was breaking dormancy, and regrowth on crowns from the previous fall was from 2 to 4 inches at the time treatments were applied on 27 April. Insecticides were delivered with a CO 2 -powered backpack sprayer using a 5-nozzle (8002 flat fan) hand-held boom that covered a 6.5-ft swath. Spray pressure was set at 30 psi, and delivered an equivalent of 30 gal/acre. Post-treatment evaluation of plots consisted of extracting 3, 2.5-inch-diameter plugs to a depth of 1 inch from randomly selected orchardgrass crowns. Samples were placed in paper bags for transport to our laboratory in Corvallis where Berlese funnels equipped with 25W bulbs extracted all arthropods from the plugs into 70 percent ethanol by treatment. All stages of CLM were counted and recorded for all plots on 2 May (5 days after treatment [DAT]), 8 May (11 DAT), 16 May (19 DAT), and 22 May (25 DAT). In addition, numerically defined visual assessments of CLM damage in all plots were made on the last three sample dates. These were averaged to provide a subjective evaluation of treatment effectiveness based on grass vigor. The assessment was based on relative grass height and color and employed a scale of 1 to 4 (1 representing least regrowth and most chlorosis; 4 representing greatest regrowth and least chlorosis). Data collected were subjected to analysis of variance (ANOVA) and means were separated using the Tukey s Studentized Multiple Range (HSD) Test at P = All values were transformed using square root transformation to equalize variance. Original means are presented in Tables 1 and 2. Results The Dimethoate treatment had significantly fewer mites than the untreated control (UTC) at all four sampling dates post-treatment (Table 1). Acramite had significantly fewer mites than the other treatments at 5 and 11 DAT. Populations of CLM declined dramatically in all plots beginning 19 DAT. Only one treatment, dimethoate, had a mean visual damage assessment score significantly greater than the UTC (Table 2). Dimethoate is currently registered for use only on grass seed crops and with no feeding of any part of the crop to livestock restrictions. Acramite and bifenthrin (Discipline, Capture ) are being processed through the federal IR-4 program for product registration on grass pasture and seed crops with provisions for feeding treated grass to livestock. Mustang MAX and Warrior are anticipated to have Federal labels for grass pastures and seed crops in 2007 or Baythroid is currently labeled for use on grasses. Methyl parathion is labeled for use on grass pastures, but its toxicity to mammals has generally precluded its use in Oregon. Oberon 2 SC does not carry a label for use on grasses

67 Table 1. Number of clover mites per 2.5-inch core taken through orchardgrass crowns at several days after treatment (DAT). No. of clover mites per 3, 2-inch grass crown cores Product May 2 May 8 May 16 May 22 Treatment rate 5 DAT 11 DAT 19 DAT 25 DAT (oz/a) (no. per 2.5-inch core) Untreated abc a ab 89.1 ab Mustang MAX ab a a a Warrior W/Z ab a ab 52.0 ab Baythroid ab ab a a Discipline a abc ab 8.3 b Methyl Parathion a 68.5 d 93.3 ab 33.8 ab Oberon 2 SC abc a ab 53.6 ab Acramite 4F bc bcd ab 48.7 ab Dimethoate 4E c 68.5 cd 20.8 b 5.0 b 1 Means followed by the same letter within a column do not differ significantly at P 0.05 (Tukey s HSD multiple comparisons). Mean values were square-root transformed to equalize variance. Table 2. A damage value was assessed by visually rating treated plots for mite damage on a scale of 1 (most damage) to 4 (least damage) and averaged over three different evaluations. Product Visual assessment of clover mite damage (oz/acre) (1 to 4) UTC b 1 Mustang MAX b Warrior W/Z a Baythroid ab Discipline ab Methyl Parathion b Oberon 2SC b Acramite 4F ab Dimethoate 4E a 1 Means followed by the same letter within a column do not differ significantly at P 0.05 (Tukey s HSD multiple comparisons). Mean values were square-root transformed to equalize variance

68 Weed Control in Grass/Alfalfa Mixed Hay Richard Affeldt and Scott Simmons Abstract Herbicide options in mixed stands of grass and alfalfa harvested for hay are limited, partially because selectivity is difficult to achieve in mixed stands. Currently metribuzin (Sencor ) is the only herbicide that is clearly registered for use in mixed stands of grass and alfalfa for hay. The objective of these trials was to determine crop safety with herbicides that could be registered for use in mixed hay. Two trials were conducted in commercial fields of orchardgrass/alfalfa mixed hay, one near Prineville, Oregon and one near Madras, Oregon. Nine herbicide treatments were applied near the end of winter dormancy on February 28, 2007 in Prineville and on March 2, 2007 in Madras. Orchardgrass was much more likely to be injured than alfalfa with all the dormant treatments. Three treatments were somewhat safe on the orchardgrass across locations: 1) metribuzin at 0.25 lb, 2) metribuzin at 0.25 lb plus paraquat, and 3) flumioxazin. None of the other dormant treatments demonstrated an appropriate margin of crop safety across locations. Introduction In 2006 in central Oregon (Crook, Deschutes, and Jefferson counties) there were roughly 7,500 acres of grass/alfalfa mixed hay. Mixed hay yields approximately 5.5 to 7 tons per acre per season and is currently being sold from $120 to $180 per ton, depending on the quality, for a gross value ranging from $660 to $1,260 per acre in central Oregon. Herbicide options in mixed stands of grass and alfalfa for hay are limited, partially because selectivity is difficult to achieve in mixed stands. Currently metribuzin is the only herbicide that is clearly registered for use in mixed stands of grass and alfalfa for hay. Labels for products like bromoxynil (Buctril ) and paraquat (Gramoxone Inteon ) are less clear on whether or not they can be used in mixed stands. According to the Sencor 75 DF label, metribuzin can severely injure grasses in mixed stands, especially at high labeled rates. Furthermore, metribuzin does not work well on problematic weeds like shepherd's-purse (Capsella bursa-pastoris), flixweed (Descurainia sophia), and downy brome (Bromus tectorum) in mixed hay, so in order to achieve acceptable weed control, metribuzin is often used at higher rates. Several herbicides have recently been or are soon to be registered for use in alfalfa: flumioxazin (Chateau ), pronamide (Kerb ), and pendimethalin (Prowl H20 ). There is some likelihood that these herbicides could also be registered for use in grass/alfalfa mixed hay, depending on the rates used and crop tolerance. If these herbicides are safe for use in grass/alfalfa mixtures, they would be useful tools to improve control of the problem weeds mentioned above and limit the yield loss resulting from metribuzin use

69 The objective of these trials was to determine crop safety with herbicides that could be registered for use in mixed hay. Materials and Methods Two trials were conducted in commercial fields of orchardgrass (Dactylis glomerata)/alfalfa mixed-hay, one near Prineville, Oregon and one near Madras, Oregon. Nine herbicide treatments were applied near the end of winter dormancy on February 28, 2007 in Prineville and on March 2, 2007 in Madras and one treatment was applied postdormancy on April 5, 2007 at both locations. The dormant treatments included: terbacil (Sinbar ), pronamide, flumioxazin, imazapic (Plateau ), metribuzin at 0.25 and 0.5 lb/acre, paraquat, metribuzin plus paraquat, and pendimethalin plus paraquat; the postdormancy treatment was bromoxynil plus 2,4-DB (Butyrac 200 ). Plots were 10 ft by 28 ft with four replications arranged as randomized complete blocks. Treatments were applied with a CO 2 backpack sprayer delivering 20 gal/acre operating at 20 psi and 3 mph. Crop injury was determined by making visual evaluations from March through May on a percentage scale. The final evaluation was made prior to first cutting and describes the orchardgrass stand density in each treatment as a percent of the check (noted as stand in Tables 1 and 2) and orchardgrass heading in each treatments as percent of the check (noted as heading in Tables 1 and 2). Treatments that resulted in no visible reduction in stand or heading were rated 100 percent. Treatments that thinned the stand but did not diminish the heads that the remaining plants produced were rated something like 60 and 60 percent. Treatments that reduced heading beyond what resulted only from stand thinning were rated something like 80 and 40 percent. Results and Discussion Orchardgrass was much more likely to be injured than alfalfa with all the dormant treatments (Tables 1 and 2). The second visual evaluation was made 63 and 61 days after treatment for Madras and Prineville, respectively, at which point none of the dormantapplied treatments resulted in severe injury to the alfalfa. Three treatments were somewhat safe on the orchardgrass across locations: 1) metribuzin at 0.25 lb, 2) metribuzin at 0.25 lb plus paraquat, and 3) flumioxazin. Orchardgrass injury from flumioxazin was slightly greater in Prineville than in Madras. None of the other dormant treatments demonstrated an appropriate margin of crop safety across locations. In Prineville, terbacil and pronamide resulted in minor reductions in orchardgrass stand density and heading; in Madras, both treatments greatly reduced heading. Paraquat resulted in severe orchardgrass injury in Madras, but in Prineville injury was much less, possibly because the orchardgrass in Madras was no longer dormant on the March 2 application date. This would also account for the orchardgrass injury from pendimethalin plus paraquat at Madras. In Prineville, however, orchardgrass injury from pendimethalin plus paraquat was noticeably greater than from paraquat alone

70 Weed populations at both locations were inadequate for visual evaluation. Acknowledgements We would like to thank Rod Fessler, CHS for his involvement in planning this research. We would also like to thank Jerry Breese and Hemenway Farms for accommodating the trials in their production fields. Table 1. Response of established orchardgrass/alfalfa mixed hay to herbicides near Madras, Oregon, March 31 May 4 May 22 Orchardgrass Orchard- Orchardgrass Treatment 1 Rate Alfalfa Alfalfa grass Stand Heading (lb/acre) % injury % of check Check Terbacil Pronamide Flumioxazin Imazapic Metribuzin Metribuzin Paraquat Metribuzin paraquat Pendimethalin paraquat Bromoxynil ,4-DB All treatments were applied with non-ionic surfactant at 0.25 % v/v. 2 Treatments were applied March 2, 2007 to dormant alfalfa and orchardgrass. 3 Treatments were applied April 5, 2007 to 3-inch-tall alfalfa and 5-inch-tall orchardgrass

71 Table 2. Response of established orchardgrass/alfalfa mixed hay to herbicides near Prineville, Oregon, April 5 April 30 June 8 Orchardgrass Orchard- Orchardgrass Treatment 1 Rate Alfalfa Alfalfa grass Stand Heading (lb/acre) % injury % of check Check Terbacil Pronamide Flumioxazin Imazapic Metribuzin Metribuzin Paraquat Metribuzin paraquat Pendimethalin paraquat Bromoxynil ,4-DB All treatments were applied with non-ionic surfactant at 0.25 % v/v. 2 Treatments were applied March 2, 2007 to dormant alfalfa and orchardgrass. 3 Treatments were applied April 5, 2007 to 3-inch tall alfalfa and 5-inch tall orchardgrass

72 Sensory Evaluations of Advanced Specialty Potato Selections Steven R. James and Charles R. Brown Abstract Sensory evaluations were performed on an array of specialty potato selections as part of a field day held on October 18, 2006 at the Powell Butte location of Central Oregon Agricultural Research Center. Specialty potatoes of various colors and shapes were baked, fried as wedges or included in salads, and evaluated for taste, texture, smell, and overall visual impression. Evaluators preferred the visual appeal of fried wedges made from POR01PG45-5, but found wedges prepared from POR01PG22-1 and OR less appealing. A clear separation in visual impression was observed among the three potato salad preparations. The salad made with selection POR02PG37-2 was rated highest in visual appeal followed by POR01PG20-12 and POR01PG16-1. No significant differences (P = 5 percent) were observed among the selections in taste, texture, or smell for any of the preparation methods. Introduction Specialty potatoes are increasing in popularity. In the United States, traditional potatoes include round white-fleshed potatoes that are chipped, boiled, or baked and white-fleshed russet types that are baked or processed into French fries. Red-skinned, white-fleshed varieties have also been popular. Specialty potatoes encompass a variety of skin colors, flesh colors, and tuber shapes. Skin colors include red, yellow, orange, blue, and combinations of those colors. Flesh colors include various hues of yellow, red, and purple that are sometimes arranged in eye-catching patterns. Tuber shapes of specialty potatoes can be long, oblong, or round but can also include peanut shapes, banana shapes, fingerlings, or other variations. Specialty potatoes are ideally suited for organic and nontraditional markets. Specialty potatoes may have enhanced human health benefits due to higher levels of antioxidants than traditional white-fleshed potatoes. Elevated levels of carotenoids have been observed in yellow- and orange-fleshed selections, while increased anthocyanin levels have been noted in red- and purple-fleshed selections (Brown 2006). Producing specialty potatoes with potential human health benefits under organic systems has generated significant interest. Therefore, the TriState (Oregon, Washington, Idaho) Potato Variety Development Program began making genetic crosses and evaluating the subsequent progeny in recent years. A number of the selections are now nearing commercial release. Many experiments have been conducted to evaluate the yield, storability, and pest resistance of specialty selections nearing release. Sensory evaluations have been lacking, so this study was designed to quantify culinary qualities for an array of specialty selections with varied skin and flesh colors

73 Materials and Methods On October 18, 2006, a field day was held at the Powell Butte location of Central Oregon Agricultural Research Center. An invitation was extended to the general public via a local newspaper that highlighted this event with photos and text as the featured event of the field day in central Oregon. Seventy people responded to the invitation. The program featured two presentations that discussed the development and testing of specialty potatoes and also the health benefits of specialty potatoes. A meal followed that included barbequed hamburgers and specialty potatoes presented in three ways: baked, fried wedges, or included in a salad. Samples were presented by selection and labeled by name (Fig. 1). They were grouped by preparation method. Shepody, a white-skinned, whitefleshed variety, was included with the fried wedge samples as a reference. Table 1 provides a description for each selection included in the evaluations. Figure 1. Presentation of specialty potato samples. 375 F in commercial soybean frying oil. The salads were identical in make-up except for the potato ingredient. Some of the purple color leached from the potatoes and caused the egg yolks to turn green in the salad prepared with purple-fleshed selection POR01PG16-1. Baked samples were washed and baked for 1 hour at 350 F and presented as whole potatoes sliced in half. Samples to be fried were cut into longitudinally cut wedges. The number of wedges per tuber varied with the size of the tubers. Wedges were fried for approximately 7 minutes at Evaluation forms were distributed and explained prior to presentation of the prepared samples. Participants were asked to rate the samples for taste, texture, smell, and visual impression on a one to five scale: 1 = horrible, 2 = poor, 3 = OK, 4 = good, and 5 = excellent. They were coached on possible considerations for each trait as follows: Taste: pleasant, bitter, off flavors, after-taste, etc. Texture: fluffy, moist, waxy, grainy, etc. Smell: pleasing, burnt, buttery, etc. Visual Impression: the eye appeal of the sample

74 Samples were presented as part of a buffet-style meal. Participants were allowed to select any or all of the potato samples they desired. Most participants rated from three to eight preparations. Overall averages were calculated from the responses after the evaluation forms were received. Responses were analyzed using an analysis of variance with uneven sample sizes. Table 1. Tuber characteristics for the potato selections featured in the sensory study, Powell Butte, Central Oregon Agricultural Research Center. Selection Skin color Flesh color Shape OR Dark purple Mottled purple with light vascular Round OR Dark purple Mottled purple Long POR01PG16-1 Dark purple Dark purple Fingerling POR01PG45-5 Lavender Light yellow Round POR01PG20-12 Dark red Mottled red Oblong POR01PG22-1 Dark red Mottled red Fingerling POR02PG2-4 Dark red Red with a white star Round POR02PG4-2 Yellow with red splashes Deep yellow Round POR02PG37-2 Yellow with red eyes Yellow Round Shepody White White Oblong Results and Discussion Sensory evaluation results are presented in Tables 2 4. Overall, ratings were very positive for all sensory categories and specialty potato selections. No significant differences (P = 5 percent) were observed among the selections in taste, texture, or smell for any of the preparation methods. No differences were observed among the sensory traits when the selections were prepared as baked products. Baking tends to reduce the impact of skin colors, resulting in more uniform brownish-colored products. Shepody is a variety that is known for excellent taste, regardless of preparation method. It received the highest rating for taste among fried wedges, the only test in which it was included. Evaluators noted differences in visual impressions among the specialty selections in the fried wedge and potato salad preparations. They preferred wedges had the look of traditional jo-jo potatoes. POR01PG45-5 has a lavender skin, but when fried loses the purple coloration in favor of a light brown skin. The least appealing fried wedge selection was OR , with purple skin and flesh. The red-skinned, redfleshed fingerling POR01PG22-1 Figure 2. Samples of fried potato wedges

75 had a more favorable visual impression than the purple selection, but was less appealing than the more traditional-looking selections POR01PG45-5 and Shepody. A clear separation in visual impression was observed among the three potato salad preparations. The potato salad made with the specialty selection POR02PG37-2 received the highest ratings for any trait or selection. This selection is similar to Yukon Gold in both external and internal appearance. Yukon Gold was not included in any of the evaluations, however. The red-skinned, red-fleshed selection POR01PG20-12 scored Figure 3. Potato salad featuring POR01PG second in visual impression while the purple-skinned, purple-fleshed selection POR01PG16-1 was rated last in visual impression. Table 2. Sensory evaluations for four specialty potato selections prepared as fry wedges. Visual Overall Selection Taste Texture Smell impression average POR01PG POR01PG OR Shepody LSD (5 %) NS NS NS 0.39 NS No. observations 7 to 26 6 to 25 5 to 22 7 to 26 Table 3. Sensory evaluations for three specialty selections prepared as baked potatoes. Visual Overall Selection Taste Texture Smell impression average OR POR02PG POR02PG LSD (5 %) NS NS NS NS NS No. observations 18 to to to to