Potential for Phytotoxicity of Pennant Magnum 7.62 EC (s-metalochlor) on Lavender Cotton (Santolina chamaecyparissus Compacta )

Transcription

1 Potential for Phytotoxicity of Pennant Magnum 7.62 EC (s-metalochlor) on Lavender Cotton (Santolina chamaecyparissus Compacta ) By Heiner Lieth, Director Linda Dodge Ron Lane Dylan Hodgkiss Project Interregional Research Project #4 Project Number A September 3, 25 Donors/Supporters High Ranch Nursery, Loomis, CA UC Davis Environmental Horticulture IR4 Center Department of Plant Sciences University of California One Shields Ave. Davis, CA http//envhort.ucdavis.edu/ir4

2 TRIAL DATE 9/3/5 Investigator (Name, Address, Phone#, e- mail, etc) Dr. Heiner Lieth Department of Plant Sciences University of California One Shields Ave. Davis, CA Ph FAX Location of Trial TRIAL TYPE (field, container, greenhouse, etc) University of California, Davis CA Field Container Chemical - Common Name s-metalochlor - Formulation 7.62% EC - Batch Number - Product Pennant Magnum 7.62 EC - EPA Registration Number Manufacture Syngenta USE INFORMATION - Plant Common Name Lavender Cotton - Plant Scientific Name Santolina chamaecyparissus Compacta - Pest (s) Weeds Soil Type or Type of Potting Mix Grower s Mix a)%sand b)%silt c)%clay d)%om e)%ph Enter each DATE for Seedling Emergence Transplanting Enter each SPACING for Enter each SIZE for Experimental Design Number of Reps Plant or Pot 6 inches Row 6 inches Pot 1-gallon (15 cm) Plot 5 sq ft Completely randomized design 4 reps per treatment 2

3 TRIAL DATE 9/3/5 APPLICATION PARAMETERS1 Type of Application (aerial, ground, foliar, drench, ppi, chemigation, broadcast, directed, etc) Number of Applications Application Type Foliar spray 2, 3 days apart Manual spray bottle Nozzle Type/Size Nozzle Pressure Delivery Rate Calibration Date(s) APPLICATION SUMMARY APPLICATION DATE RATES (a.i./a) (Be sure to provide units) Brief Description of Growth Stage (Dormant, New Growth Present, Bud, etc) August 5, 25, 2.5, 5, 1 lb. a.i./a Vegetative, actively growing September 2, 25, 2.5, 5, 1 lb. a.i./a Vegetative, actively growing 1 RAINFALL/IRRIGATION RECORDS INCLUDE RAINFALL/IRRIGATION INFORMATION (printouts, IR-4 forms, etc.) See Table 1 for environmental conditions. The plants were watered daily with tap water using a drip irrigation system delivering 1 gallon per hour. 3

4 TRIAL DATE 9/3/5 OTHER PESTICIDES, FERTILIZER, LIME AND ADJUVANTS USED PRODUCT AMOUNT DATE Pounce.16 oz/2 gal 8/26/25 Marathon II 2.4 oz/2 gal 8/26/25 NARRATIVE SUMMARY OF METHODS AND RESULTS Materials and Methods Plant Material and Culture. One-gallon plants of Santolina chamaecyparissus Compacta were received from High Ranch Nursery on July 19, 25. The plants remained in the 1-gallon pots containing the grower s mix and controlled release fertilizer. The 8-week experiment took place in an outdoor nursery and began on August 5, 25. Environmental conditions during the experiment are summarized in Table 1. The plants were watered daily during the 8-week experiment with tap water using a drip irrigation system delivering 1 gallon per hour. Applications of pesticides as part of a normal pest management program were made as needed (see above). Experimental Procedure. Sixteen plants were randomly chosen and individually tagged for treatment with (Control), 2.5 (1X), 5 (2X), or 1 (4X) lb. ai/a Pennant Magnum 7.62 EC with 4 replicates per treatment. These dosages were prescribed in IR4 Ornamental Protocol 5-1 dated 1/5 (Appendix A). The plants received the first foliar spray application on August 5, 25 and the second application 4 weeks later on September 2, 25. The plants were arranged in a completely randomized design with 4 replicates per treatment. Phytotoxicity ratings and plant height and width measurements were taken at day, 3, 7, 14, 28, 31, 35, 42 and 56. Visual phytotoxicity evaluations were based on a numerical rating scale ranging from (no injury) to 1 (complete kill) (Table 2). Plant height (cm) was measured from the container soil surface to the top of the canopy. Plant width (cm) was measured twice along perpendicular lines at the widest part of the plant, resulting in W 1 and W 2. For each observation a canopy volume index was calculated so as to be able to determine if canopy volume was affected by the application of Pennant Magnum 7.62 EC. The calculation was made as H*W 1 *W 2, where H is the height and W 1 and W 2 are two width measurements. The usefulness of this index is based on the fact that many of the models for such a volume calculation are of the form a*h*w 1 *W 2. The constant a depends on the assumption of the shape of the canopy. Since analyses of variance are scale-independent, the conclusion will thus be for the volume of the plant canopy. Statistical Analysis. The data were analyzed using Proc GLM of the Statistical Analysis System (SAS). The phytotoxicity and change in mean value from the starting plant height, width and volume index were analyzed for significant differences using t-tests. 4

5 TRIAL DATE 9/3/5 Results Virtually no blemishes were observed on any plants in the control at any time, resulting in phytotoxicity index values of for all observations of control plants. In fact, during the first half of the trial no blemishes were observed on any plants in any of the treatments, resulting in phytotoxicity index values of for all observations prior to week 4 (Table 3, Figure 2, Appendix B). As such no statistical analysis was needed (or possible) to show that there were no differences over time among any of the treatments up to week 4. After week 4 some slight blemishes were observed on the plants treated with Pennant, but the overall level was very minor in the 1X treatment. Significant phytotoxicity index increases were noted for the 4X treatment after week 4 (Figure 1). The level of phytotoxicity in the 2X treatment was greater than the control, but less than the 4X treatment. The phytotoxicity index value for the 2X treatment was around 2, which is still acceptable. The level in the 4X Pennant treatment at week 8 was unacceptable. The Santolina plants in all treatments grew in height and width (Table 4, Figures 2 and 3, Appendix B). No treatment effects due to Pennant were noted. Discussion Pennant had no deleterious effect on Santolina at the 1X rate and the product is safe for this plant at the proposed labeled rate. No appreciable phytotoxicity was observed at this rate. At the 2X rate, some phytotoxicity was present, but the level was found to be relatively low; these plants were still marketable. At the 4X level, plants were damaged after the second application. This high rate is not safe for plants. GOOD RESEARCH PRACTICE STATEMENT I acknowledge that I have read and followed the IR-4 Research protocol and completed this trial following good agricultural practice, or reported any deviations (note any changes from authorized protocol in narrative). SIGNATURE (PRINCIPAL INVESTIGATOR) Date Completed If submitted, using , please provide address and send confirming receipt. 5

6 TRIAL DATE 9/3/5 Table 1. Environmental conditions during the experiment to evaluate the phytotoxicity of Pennant Magnum 7.62 EC on Santolina chamaecyparissus Compacta. Date Sol Rad (Ly/day) Max Air Temp ( F) Min Air Temp ( F) Avg Air Temp ( F) Avg Vap (mbars) Avg wspd (MPH) Precip (in) CIMIS ETo (in) Avg Rel Hum (%) Dew Pt ( F) 8/5/ /6/ /7/ /8/ /9/ /1/ /11/ /12/ /13/ /14/ /15/ /16/ /17/ /18/ /19/ /2/ /21/ /22/ /23/ /24/ /25/ /26/ /27/ /28/ /29/ /3/ /31/ /1/ /2/ /3/ /4/ /5/ /6/ /7/ /8/ /9/ /1/ /11/ /12/ /13/ /14/ /15/ /16/ /17/ /18/ /19/ /2/ /21/ /22/ /23/ /24/ /25/ /26/ /27/ /28/ /29/ /3/

7 TRIAL DATE 9/3/5 Table 2. Numerical plant damage rating scale used for phytotoxicity determinations. Rating Description of plant damage No damage 1 No visible damage but unintended (non-permanent) impact 2 Slight leaf/tissue damage (curling leaves, necrosis, etc.) 3 Marginal chlorosis on some leaves (damage on up to 1% of plant) 4 1% 2% of plant damaged 5 Significant damage to much of plant (3% - 4%) 6 4% 6% of plant damaged 7 Chlorosis or necrosis on most of plant (6% - 7%) 8 Abscised leaves, branch dieback 9 Tissue severely damaged (8% - 1% of plant) 1 Complete kill Table 3. Phytotoxicity ratings over 8 weeks for Santolina chamaecyparissus Compacta treated with (Control), 2.5 (1X), 5 (2X), or 1 (4X) lb. ai/a Pennant Magnum 7.62 EC, applied at weeks and 4. Different letters within a column indicate significant differences between treatments (P <.5). Yes / No refer to significant treatment effects at the 5% level. Means ± SE (n = 4) Phytotoxicity Effect of Pennant on Santolina Phytotoxicity Index Increase from beginning of trial until Treatment Day 3 (NA) 1 week (NA) 2 weeks (NA) 4 weeks yes X. ±. a. ±. a. ±. a. ±. b 1X. ±. a. ±. a. ±. a. ±. b 2X. ±. a. ±. a. ±. a. ±. b 4X. ±. a. ±. a. ±. a.75 ±.25 a Phytotoxicity Index increase from beginning of trial until Treatment 5 week yes 6 weeks yes 8 weeks yes X. ±. b. ±. c. ±. c 1X.25 ±.25 b.25 ±.25 c. ±. c 2X 1.5 ±.29 a 1.5 ±.29 b 2. ±. b 4X 2. ±. a 2.25 ±.25 a 3.25 ±.25 a Table 4. Plant height, width and volume changes over 8 weeks for Santolina chamaecyparissus Compacta treated with (Control), 2.5 (1X), 5 (2X), or 1 (4X) lb. ai/a Pennant Magnum 7.62 EC, applied at weeks and 4. Different letters within a column indicate significant differences between treatments (P <.5). Yes / No refer to significant treatment effects at the 5% level. Means ± SE (n = 4) Growth Effect of Pennant on Santolina Increase by week 8 of Treatment Height (cm) no Average Width (cm) no Volume Index no X 4.38 ±.38 a 4.25 ±.68 a ± a 1X 4.13 ±.31 a 3.31 ±.48 a ± a 2X 4.25 ±.48 a 4.13 ±.39 a ± a 4X 3.25 ±.32 a 3.88 ± 1.16 a ± 839. a 7

8 TRIAL DATE 9/3/5 CONTROL 4X Pennant Magnum Figure 1. Phytotoxicity symptoms seen on Santolina chamaecyparissus Compacta plants 8 weeks after treatment with 1 lb. ai/a (4X rate) of Pennant Magnum 7.62 EC. Foliar spray applications were made at week and week 4. Symptoms included distorted stem tips. 8

9 TRIAL DATE 9/3/5 Species Santolina -- Material Pennant Height (cm) Change (cm) Phytotoxicity Index Control 1X 2X 4X 3 Ctrl 1X 2X 4X Day of trial Day of trial Width (cm) Change (cm) Volume Index Change Ctrl 1X 2X 4X Day of trial Ctrl 1X 2X 4X Day of trial Figure 2. Summary of results for Santolina chamaecyparissus Compacta treated with (Control), 2.5 (1X), 5 (2X), or 1 (4X) lb. ai/a Pennant Magnum 7.62 EC, applied at weeks and 4 (arrows). Both means and cumulative changes over time are plotted for phytotoxicity index, plant height, plant width and plant volume index. Histograms show changes over the 8-week trial period. SE bars shown. (n = 4) 9

10 TRIAL DATE 9/3/5 CONTROL 1X 2X 4X Figure 3. Santolina chamaecyparissus Compacta plants 8 weeks after treatment with (Control), 2.5 (1X), 5 (2X), or 1 (4X) lb. ai/a Pennant Magnum 7.62 EC, applied at weeks and 4. 1

11 TRIAL DATE 9/3/5 Appendix A Phytotoxicity to herbaceous perennial plants with pre-emergent applications of Pendulum, Pennant Magnum, and Snapshot Ornamental Protocol Number 5-1 Objective Determine phytotoxicity of Pendulum, Pennant Magnum, and Snapshot to unlabelled perennial plants commonly grown in nurseries. Experimental Design Plot Size Must be adequate to reflect actual use conditions. Replicates Minimum of 3 replications (preferably 4) with 3 pots per replicate Application Instructions Two applications made approximately 4 weeks apart with the first application within 7 days of potting. Plant materials must have broken dormancy prior to first application. For liquid applications, use a minimum of 2 gal per acre. Applications should be made over the top of the plants using application equipment consistent with conventional commercial equipment. Please see table below for instructions for post-application irrigation. Plant Materials See attached list of plant materials. Plants grown in field containers are preferred to in-ground. Evaluations Record phytotoxicity on a scale of to 1 ( = No phytotoxicity; 1 = Complete kill)at 3, 7, 14, and 28 days after each application. If phytotoxicity is observed in treated plants, take pictures comparing treated and untreated plant material. Recordkeeping Keep detailed records of weather conditions including temperature and precipitation, soil-type or soil-less media, application equipment, application volume per acre, irrigation, liner size, plant height & width, and plant growth stage at application and data collection dates. Treatments Product Rate Post-Application Irrigation Instructions Pendulum 2G (pendimethalin) 2. lb ai/a Follow with sufficient overhead irrigation to 4. lb ai/a 8. lb ai/a wash Pendulum from the foliage to reduce the chance of injury Pennant MAGNUM 7.62EC (s-metalochlor) 2.5 lb ai/a 5. lb ai/a Follow with sufficient overhead irrigation to wash Pennant Magnum from the foliage to 1. lb ai/a reduce the chance of injury Snapshot 2.5TG (isoxaben+trifluralin) 2.5 lb ai/a Follow with sufficient overhead irrigation to 5. lb ai/a 1. lb ai/a wash Snapshot from the foliage to reduce the chance of injury Untreated For labels, materials, and any required adjuvants contact Pendulum - BASF, Kathie Kalmowitz, , kalmowk@basf-corp.com Pennant Magnum - Syngenta, Dave Ross, , david.ross@syngenta.com Snapshot - Dow AgroSciences, Mike Melichar, , mwmelichar@dow.com Reports Report must include a brief summary paragraph of results, a summary table with appropriate statistical analyses, a section on experimental design and materials and methods, with raw data and recordkeeping information as listed above included as appendices. If pictures were taken, please include them. An electronic report is preferred but not required. If the report is provided electronically, the basic report can be sent in MS Word or WordPerfect, the recordkeeping information as pdf or other electronic documents, and the raw data in MS Excel or other suitable program such as ARM. Please direct questions to Cristi Palmer, IR-4 HQ, Rutgers University, 681 US Hwy 1 S, North Brunswick, NJ , Phone x629, palmer@aesop.rutgers.edu OR Ely Vea, 38 Aston Forest Lane, Crownsville, MD 2132, Phone & FAX# , evvea@comcast.net. 11

12 TRIAL DATE 9/3/5 Appendix B Phytotoxicity Report Form for Pennant on Santolina Phytotoxicity at week Plant Size at week Plant Size at week 8 day day Height Width1 Width 2 Height Width1 Width 2 Treatment Block Rep (cm) (cm) (cm) (cm) (cm) (cm) Control Control Control Control Control Control Control Control Control Mean X X X X X 1X 1X 1X 1X Mean X X X X X 2X 2X 2X 2X Mean X X X X X 4X 4X 4X 4X Mean