Plant & Pest Advisory

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Vegetable Crops Edition August 10, 2011 Plant & Pest Advisory A Rutgers Cooperative Extension Publication Manganese Deficiency in Commercial Tomato Production Meredith Melendez, Senior Program

1 Vegetable Crops Edition August 10, 2011 Plant & Pest Advisory A Rutgers Cooperative Extension Publication Manganese Deficiency in Commercial Tomato Production Meredith Melendez, Senior Program Coordinator of Agriculture Mercer County and Michelle Infante-Casella, Agriculture Agent, Gloucester County Maganese deficiency in this tomato plant was confirmed with tissue testing. Photo by Michelle Infante-Casella, Rutgers NJAES. INSIDE Manganese Deficiency in Commercial Tomato Production...1 Field Notes: Extreme Heat on Fall Greens Plantings...2 IPM Update...2 Weekly Weather Summary...5 Introducing: What's in Season from the Garden State...6 Manganese (Mn) plays many important roles within plants, particularly for the splitting of water molecules necessary for photosynthesis. Manganese is also important for nitrogen synthesis, nitrate assimilation, and is an enzyme component. Manganese also plays a role in electron transport during photosynthesis, assimilation of CO2 in photosynthesis and the activation of enzyme systems. Deficiency is often seen as chlorosis due to its roles in the process of photosynthesis. Manganese is commonly found in New Jersey soils. Deficiencies are seen in soils with higher ph, where manganese begins to become insoluble. Toxicity of manganese can also occur, and is usually directly related to low ph levels. Common symptoms of manganese deficiency include a lightening of the green leaf color. These leaves will gradually turn yellow in the areas farthest from the major veins. The yellow will become more prominent and the veins will continue to stay green, giving the leaves a mottled appearance. This chlorosis indicates the leaves failure to function normally and a reduced ability to produce chlorophyll. The leaves can become completely yellow and necrosis of the tissue will begin. This necrosis will start as small brown pinpoints beginning in the yellow areas expanding in size as the deficiency progresses. Leaves can also exhibit drying in their tips and interveinal puckering. Tomato growth can become spindly, with little to no blossoming or fruit formation. Manganese deficiencies should be dealt with as quickly as possible for increased tomato production. Foliar fertilizer with inorganic or chelate manganese is the most effective way to get quick results. Manganese is not readily remobilized within the plant and a second or third foliar application may be needed to achieve desired results. Application rates for soil applied manganese vary depending on soil test levels of Mn, soil ph and soil organic matter levels. Banded application is usually recommended for soil applications. Page 1 Vol. 17 No. 20

2 Field Notes: Extreme Heat on Fall Greens Plantings Richard W. VanVranken, Atlantic County Agricultural Agent Lettuces, greens and herbs (cilantro, parsley, dill) planted for the Fall season in the greater Vineland area have gone through a week of 100 degree weather. If they managed to germinate and not get cooked by that heat (watering 3X per day didn t help, maybe hurt, as soil temps remained in the 90s even after watering), they ve now potentially had scattered heavy rains saturating fields every 2-4 days since then potentially washing away fertilizers and herbicides. At this point, the best recommendations to make sure surviving plants will make it to harvest include additional sidedressings of fertilizer (especially N) and application of Ridomil Gold or Quadris to try to stave off the spread of Pythium that is present in some plants. IPM Update Kristian Holmstrom, Research Project Coordinator II, Vegetable IPM Program Sweet Corn The second European corn borer (ECB) flight is now declining with highest catches occurring in parts of Burlington, Cumberland and Salem counties (See ECB map). Catches will most likely fluctuate between low and moderate numbers over the next several weeks. Larval feeding is present in most areas at this time, and will continue to increase over the next several weeks. Check 5 consecutive plants each in 10 random locations throughout the field. Look for the characteristic shot-hole injury on leaves and/or discolored areas on the emerging tassels that indicate an active infestation. Consider treating when 12% or more plants are infested. As always, be sure to treat plantings as they reach the full tassel stage to eliminate ECB larvae as they move out of the tassels and down the plant. This will prevent ear infestations to a large degree. The highest nightly ECB catches for the previous week are as follows: Indian Mills 3 Allamuchy 1 Denville 1 Shiloh 3 Burlington 1 Lawrenceville 1 Tabernacle 3 Cinnaminson 1 Little York 1 Georgetown 2 Croton 1 Sergeantsville 1 Corn earworm moth (CEW) catches are now increasing throughout the state. This is the beginning of the late summer influx of adults. At the present time, the highest numbers range from Cape May County northwest through Gloucester County, but moderate catches are occurring through much of the state (see CEW map). Catches should increase over the next several weeks, although cooler night temperatures may temporarily slow down activity. This population is a threat to silking stage sweet corn. Be sure to access local trap catch data to determine the frequency with which silking sweet corn must be treated to prevent infestation from CEW. The highest nightly CEW catches for the previous week are as follows: Pole Tavern 13 Eldora 5 RAREC 5 New Egypt 8 Folsom 5 Centerton 4 Downer 7 Green Creek 5 Hillsborough 4 Medford 6 Indian Mills 5 Springdale 4 Silking Spray Schedules*: South 3days Central 3 days North 4 days * Note: These are general recommendations. Local trap catches may indicate some variation in the frequency of insecticide applications to silking corn. Fall armyworm (FAW) feeding is present in many New Jersey whorl stage corn fields at this time, including northern county locations. Feeding is patchy within fields, but this can change if the adult population increases. Currently, adults are reasonably low for this time of year. FAW create numerous window-panes on corn leaves when larvae are small. These areas of injury lead down into the whorl. As the larvae grow, feeding becomes more dramatic, with large, ragged holes See IPM on page 2 Page 2 Vol. 17 No. 20

3 IPM from page 2 developing on leaves. Large amounts of droppings may also be seen in the whorl of an affected plant. Scout for this pest as for ECB. Consider treating when 12% or more plants are infested with FAW, ECB or a combination of the two. Be aware that some synthetic pyrethroid insecticides have not been as effective against FAW in recent years. It may be necessary to switch materials to get good control of FAW. See the 2011 Commercial Vegetable Production Recommendations for suggested materials. Corn leaf rust is present on a few whorl and later stage plantings at this time. While infections have been relatively light, it is important to limit the number of pustules on young corn. While scouting for insect damage, look at the older leaves for red-brown spots of powdery spores. These pustules have the appearance of paprika on the leaf surface. Recent hot weather does not favor the development of this disease. However, if the weather cools again, pustules may increase, and water loss from numerous rust pustules can result in poor ear size. Additionally, pustules on the husks make the ears unsightly to consumers. Many varieties are resistant to this fungal disease, so check the seed source for that information. Generally, if pustules do not appear until the plant is in the pre-tassel stage or later, no yield reduction will occur. Pumpkins and winter squash Most pumpkin and winter squash fields now have powdery mildew (PM) lesions present on older leaves. While scouting for insects, be sure to check the upper and lower surfaces of two older leaves per plant. At the first sign of PM, commence the regular protectant fungicide program. See the 2011 Commercial Vegetable Production Recommendations for labeled materials and suggested rotations. It is not uncommon to find spots on the older leaves at this time. These lesions often begin as dark, watersoaked spots. Ultimately, they dry and the centers fall out. These lesions are symptoms of bacterial leaf spot. This disease will damage foliage as it matures, and can result in the formation of pits on fruit. These pits become areas where rot starts, and will reduce the holding life of the fruit. Generally copper applications are required to minimize loss from this disease. See the 2011 Commercial Vegetable Production Recommendations for labeled materials. As yet, no sign of downy mildew (DM) has occurred on pumpkins or winter squash in the northern counties. This pathogen is currently present, and widespread on cucumbers in southern NJ, and has recently been discovered on cantaloupes in southern NJ and a susceptible cucumber variety in the DM sentinel plot at the Snyder Research and Extension Farm in Pittstown, Hunterdon County. This will be monitored frequently for signs of DM on cantaloupe, watermelon, pumpkin, acorn and butternut squash. Changes in the status of the infection will be published in this newsletter. At this time, squash bug eggs and nymph groups are a common sight in pumpkin fields. These bugs extract plant sap from leaves and stems, but do no real damage to the plants. Nymphs cluster together and begin as small green bugs with black legs. After molting, they become ash gray in color. Eggs are copper colored and are laid in neat rows. Brown Marmorated Stinkbug (BMSB) BMSB adult catches are rising and falling for reasons that are unclear. It is interesting to note that catches all seem to rise at the same time throughout the state, although there are great differences in the magnitude of the catches. Overall, numbers are fairly high, especially in the southern third of the state (See BMSB map). Mating pairs of adult BMSB have been sighted in pepper plantings in northern NJ. Feeding is now starting to show up in Hunterdon County, and is likely present elsewhere. Scouting of peppers is advisable, and particular care should be taken in identifying egg masses and nymphs. Nymphs cannot fly, and will feed exclusively on the crop. For photos useful in ID of this pest, see the website: If a shake cloth is available, it is best to place it between plants and then shake plants over the cloth. BMSB present in the canopy are likely to release from the plants in an effort to escape harm. Approach plants carefully, as adult BMSB may fly away if disturbed. Be sure to check all crops with a history of stink bug injury. This includes brambles, all beans, peppers and tomatoes on which fruit are present. Consider treating if BMSB eggs or nymphs are found in any sample. The highest nightly BMSB catches for the previous week are as follows: Shirley 104 RAREC 42 Downer 36 Indian Mills 50 Hammonton 40 Farmingdale 34 Pittstown 49 Tabernacle 40 New Egypt 28 Woodstown 44 Crosswicks 37 Hillsborough 25 Peppers ECB feeding on peppers is increasing. It is time to consider treating to limit fruit damage from this pest. Generally, where blacklight trap catches have recently averaged one or more ECB per night (shaded and crosshatched areas on the map, and blue and green areas on the web version at: edu/ipm/vegetable/pest%20maps/maparchive.htm#2011), and fruit are greater than ½ in diameter, insecticides are warranted. See the 2011 Commercial Vegetable Production Recommendations for materials useful in controlling ECB. Note that some materials that are effective for ECB may not control BMSB. Aphid populations have begun to increase in some pepper plantings in the northern counties. These insects are often controlled naturally if broad spectrum See Aphids on page 4 Page 3 Vol. 17 No. 20

Aphids from page 3 insecticides are not used. However, if treatments for ECB or stinkbugs have been applied, aphid numbers can increase rapidly.

Look at two leaves per plant. If the number of aphids exceeds approximately 120 per 100 leaves, consider treating to reduce the population.

See the BMSB section for recommendations on scouting for this pest in peppers. Beet armyworm (BAW) pheromone traps have recently been deployed in parts of southern New Jersey.

4 Aphids from page 3 insecticides are not used. However, if treatments for ECB or stinkbugs have been applied, aphid numbers can increase rapidly. While pepper plants can tolerate significant aphid feeding, their droppings can coat fruit, resulting in a dark, sticky residue on the surface. Check 5 consecutive plants each in 10 random locations. Look at two leaves per plant. If the number of aphids exceeds approximately 120 per 100 leaves, consider treating to reduce the population. If hot-spots exist in the field where droppings are beginning to accumulate on fruit, spot treatments may be useful. See the 2011 Commercial Vegetable Production Recommendations for labeled materials. See the BMSB section for recommendations on scouting for this pest in peppers. Beet armyworm (BAW) pheromone traps have recently been deployed in parts of southern New Jersey. These traps have captured BSW adults, although larval injury has not been reported to date. BAW larvae will initially feed on terminals, resulting in ragged holes in the young leaves. Small larvae may be found among the buds near terminal growth. As the larvae grow, they will begin to feed on fruit. The larvae are greenish in color with a prominent dark spot on each side just behind the head. Consider treating if this feeding has been found in the field. Currently, the highest catches are in the Woodstown area (29/night). Generally, growers in southern NJ should be looking for this pest in peppers now. At the present time, there is an infestation of BAW on cabbage in Hunterdon County, although it is confined to a small area. It is not typical for this pest to infest crops in northern NJ, but growers should be alert to the possibility. Tomatoes Brown stinkbugs (natives) are now increasing as well as BMSB, with individuals and egg masses present in tomatoes. Feeding has also been found recently in this crop. This is the time of year when adults are present and moving around in search of food and egg laying sites. Tomatoes are a favored host, especially if dry weather reduces the availability of native host plants. Now is the time to pay attention to fruit in the field for signs of feeding. Stinkbug feeding on tomatoes first appears as a diffuse whitish blotch on green fruit. The spot changes to bright yellow as the fruit matures. If this feeding is on the increase in the field or in harvested fruit, consider treating to suppress the population. Page 4 Vol. 17 No. 20

5 Weekly Weather Summary Keith Arnesen, Ph.D., Agricultural Meteorologist Temperatures averaged much above normal, averaging 75 degrees north, 78 degrees central, and 78 degrees south. Extremes were 98 degrees at Trenton on the 2nd, and 60 degrees at Charlotteburg on the 4th. Weekly rainfall averaged 1.21 inches north, 0.79 inches central, and 0.65 inches south. The heaviest 24 hour total reported was 1.40 inches at Belvidere on the 6th to 7th. Estimated soil moisture, in percent of field capacity, this past week averaged 85 percent north, 77 percent central and 64 percent south. Four inch soil temperatures averaged 75 degrees north, 78 degrees central and 72 degrees south. Weather Summary for the Week Ending 8 am Monday 8/ 8/11 R A I N F A L L TEMPERATURE GDD BASE50 MON WEATHER STATIONS WEEK TOTAL DEP MX MN AVG DEP TOT DEP %FC BELVIDERE BRIDGE* CANOE BROOK CHARLOTTEBURG FLEMINGTON NEWTON FREEHOLD LONG BRANCH NEW BRUNSWICK TOMS RIVER TRENTON DOWNSTOWN HAMMONTON POMONA SEABROOK MISSING SOUTH HARRISON** NA 2618 NA NA *Belvidere appears to be having extreme thermometer problems. TemperatureS are way too low. Problem fixed as of July 14th, but earlier bad numbers have affected cumlative values for temperature. ** SOUTH HARRISON RAIN GAUGE HAS BEEN DOWN FOR SEVERAL WEEKS. WES KLINE -- GDD BASE 40 PINEY HOLLOW LAST WEEK 269 (ENDING 7/11/11 ) THIS WEEK 257 (Ending 7/18/11) Page 5 Vol. 17 No. 20

during the growing season that highlights

other agricultural products coming from New

Kirby Cukes? Ewww...There s a Worm in my Corn!

Pickling Would our Parents Recognize Today

Why Grow and Test Organic Livestock Feeds

Apples: the Cold, Hard Facts I Yam NOT a

Department of Agriculture s Jersey Fresh

rutgers.edu for current and back issues.

6 What s in Season from the Garden State Introducing: What s in Season from the Garden State a free monthly e-newsletter during the growing season that highlights the little known facts about the food and other agricultural products coming from New Jersey s farms and local waters. Some highlights from previous issues: A Peach for All Seasons What s Wrong with Kirby Cukes? Ewww...There s a Worm in my Corn! Hot or Not, Jersey Packs a Peck, even for Pickling Would our Parents Recognize Today s New Sweet Corns? Why Grow and Test Organic Livestock Feeds and Forages? Apples: the Cold, Hard Facts I Yam NOT a Yam! Also includes current New Jersey Department of Agriculture s Jersey Fresh Availability Report Subscribe at njfarmfresh@njaes.rutgers.edu and visit for current and back issues. Direct Markets: Use What's in Season from the Garden State as a handout to keep your customers informed! Page 6 Vol. 17 No. 20

7 Plant & Pest Advisory Rutgers School of Environmental and Biological Sciences ASB II, 57 US Hwy. 1 New Brunswick, N.J PLANT & PEST ADVISORY VEGETABLE CROPS EDITION CONTRIBUTORS Rutgers NJAES Cooperative Extension Specialists Gerald M. Ghidiu, Ph.D., Vegetable Entomology George Hamilton, Ph.D., Pest Management Joseph R. Heckman, Ph.D., Soil Fertility Bradley A. Majek, Ph.D., Weed Science Andy Wyenandt, Ph.D., Vegetable Pathology Rutgers NJAES-CE County Agricultural Agents Atlantic, Richard W. VanVranken ( ) Burlington, Raymond J. Samulis ( ) Cape May, Jenny Carleo ( ) Cumberland, Wesley Kline, Ph.D. ( ) Gloucester, Michelle Infante-Casella ( ) Hunterdon, Winfred P. Cowgill, Jr. ( ) Middlesex, William T. Hlubik ( ) Monmouth, Bill Sciarappa, Ph.D. ( ) Morris, Peter J. Nitzsche ( ) Passaic, Elaine Fogerty, Agric. Assistant ( ) Salem ( ) Warren, William H. Tietjen ( ) Vegetable IPM Program ( ) Joseph Ingerson-Mahar, Vegetable IPM Coordinator Kristian E. Holmstrom, Research Project Coordinator II Newsletter Production Jack Rabin, Associate Director for Farm Services, NJAES Cindy Rovins, Agricultural Communications Editor Pesticide User Responsibility: Use pesticides safely and follow instructions on labels. The pesticide user is reponsible for proper use, storage and disposal, residues on crops, and damage caused by drift. For specific labels, special local-needs label 24(c) registration, or section 18 exemption, contact RCE in your County. Use of Trade Names: No discrimination or endorsement is intended in the use of trade names in this publication. In some instances a compound may be sold under different trade names and may vary as to label clearances. Reproduction of Articles: RCE invites reproduction of individual articles, source cited with complete article name, author name, followed by Rutgers Cooperative Extension, Plant & Pest Advisory Newsletter. The Vegetable Crops On-Line Resource Center website is a dedicated source for information on production, insect, weed and disease management, food safety, marketing and more: For back issues of the Plant & Pest Advisory:

Plant & Pest Advisory

Vegetable Crops Edition July 7, 2010 Plant & Pest Advisory A Rutgers Cooperative Extension Publication Vol. 16 No. 15 INSIDE Packinghouse Pest Control...1 Pest Notes...2 IPM Update...3 Extreme Heat and