Potential for Phytotoxicity of Pennant Magnum 7.62 EC (s-metalochlor) on Candytuft (Iberis sempervirens Snowflake )

Transcription

1 Potential for Phytotoxicity of Pennant Magnum 7.62 EC (s-metalochlor) on Candytuft (Iberis sempervirens Snowflake ) By Heiner Lieth, Director Linda Dodge Ron Lane Dylan Hodgkiss Project Interregional Research Project #4 Project Number A November 18, 25 Donors/Supporters Hines Horticulture, Vacaville 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 11/18/5 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 Candytuft - Plant Scientific Name Iberis sempervirens Snowflake - Pest (s) Weeds Soil Type or Type of Potting Mix UC Mix a)%sand 35 b)%silt c)%clay d)%om 65 e)%ph 6.5 Enter each DATE for Seedling Emergence Transplanting 8/3/25 Enter each SPACING for Enter each SIZE for Experimental Design Number of Reps Plant or Pot 6 inches Row 6 inches Pot 6-inch Plot 5 sq ft Completely randomized 7 replicates per treatment 2

3 TRIAL DATE 11/18/5 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) September 15, 25, 2.5, 5, 1 lb. a.i./a Vegetative, actively growing October 18, 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 11/18/5 OTHER PESTICIDES, FERTILIZER, LIME AND ADJUVANTS USED PRODUCT AMOUNT DATE Osmocote tsp per 6-inch pot 9/19/25 NARRATIVE SUMMARY OF METHODS AND RESULTS Materials and Methods Plant Material and Culture. Liners of Iberis sempervirens Snowflake were received from Hines Horticulture on April 22, 25. Cuttings from these plants were re-propagated, transplanted to 6-inch pots containing UC Mix on August 3, 25 and grown on in a greenhouse for 2 weeks. The 8-week experiment took place in an outdoor nursery and began on September 15, 25. Environmental conditions during the experiment are summarized in Table 1. Osmocote ( ) controlled release fertilizer was added on September 19, 25 at the rate of.5 teaspoon per 6-inch pot. The plants were watered daily 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. Thirty-six 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 7 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 September 15, 25 and the second application 4 weeks later on October 18, 25. The plants were arranged in a completely randomized design with 7 replicates per treatment (Figure 1). 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 leaf 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 11/18/5 Results The Iberis plants in the 1X treatment of Pennant did not show any significantly greater increases in phytotoxicity index relative to the control (Table 3, Figure 2, Appendix B). None of the average phytotoxicity index values in either the control or 1X treatment represented significant phytotoxicity throughout the trial. At weeks 6 and 8 some differences between the control and the plants treated with 2X and 4X rates were evident, but even here the level of phytotoxicity was relatively small. The growth of Iberis plants was affected by Pennant (Table 4, Figures 2 and 3, Appendix B). Height and width increased in the control by 3.9 and 1 cm respectively. While the height increase of the 1X treated plants (3.4 cm) was not significantly different from that of the control, the height increase in the 2X and 4X treated plants were significantly lower (1.1 and cm, respectively). The width increases in all Pennant treatments were significantly lower than in the control. The canopy volume was significantly lower in all the Pennant treatments. Discussion Although Pennant did not cause a significant amount of phytotoxicity, it had a dramatic effect on the growth of the Iberis plants. Growth suppression due to Pennant at the 1X rate suggests that this product should not be used over the top of Iberis 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 11/18/5 Table 1. Environmental conditions during the experiment to evaluate the phytotoxicity of Pennant Magnum 7.62 EC on Iberis sempervirens Snowflake. 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) 9/15/ /16/ /17/ /18/ /19/ /2/ /21/ /22/ /23/ /24/ /25/ /26/ /27/ /28/ /29/ /3/ /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/ /31/ /1/ /2/ /3/ /4/ /5/ /6/ /7/ /8/ /9/ /1/ /11/ /12/ /13/ /14/

7 TRIAL DATE 11/18/5 11/15/ 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 Iberis sempervirens Snowflake 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 = 7) Phytotoxicity Index Increase from beginning of trial until Treatment Day 3 yes at 1% 1 week yes at 1% 4 weeks no X. ±. b. ±. b. ±. a 1X. ±. b. ±. b.14 ±.14 a 2X.29 ±.18 a.29 ±.18 a.14 ±.14 a 4X. ±. b. ±. b. ±. a Phytotoxicity Index increase from beginning of trial until Treatment Day 3 of week4 no 5 week no 6 weeks yes 8 weeks yes at 1% X. ±. a. ±. a 1. ±.38 b.29 ±.18 ab 1X. ±. a. ±. a 1.43 ±.37 b.14 ±.14 b 2X.29 ±.29 a.57 ±.37 a 2.71 ±.18 a.86 ±.26 a 4X.43 ±.3 a.29 ±.18 a 2.43 ±.2 a.71 ±.18 ab Table 4. Plant height, width and volume changes over 8 weeks for Iberis sempervirens Snowflake 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 = 7) Growth Effect of Pennant on Iberis Increase by week 8 of Treatment Height (cm) yes Average Width (cm) yes Volume Index yes X 3.86 ±.7 a 1. ± 1.8 a ±131.7 a 1X 3.36 ± 1.81 a 5.57 ±.83 b ± b 2X 1.14 ±.4 ab 3.7 ±.5 bc ± b 4X. ±.44 b 1.93 ± 1. c ± b 7

8 TRIAL DATE 11/18/5 Figure 1. Iberis sempervirens Snowflake plants were arranged in a completely randomized design with 7 replicates per treatment for the experiment to evaluate the phytotoxicity of Pennant Magnum 7.62 EC. 8

9 TRIAL DATE 11/18/5 Species Iberis -- Material Pennant Height (cm) Change (cm) Phytotoxicity Index Control 1X 2X 4X Ctrl 1X 2X 4X Day of trial Day of trial Width (cm) Ctrl 1X 2X 4X Day of trial Change (cm) Volume Index Ctrl 1X 2X 4X Day of trial Change Figure 2. Summary of results for Iberis sempervirens Snowflake 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 = 7) 9

10 TRIAL DATE 11/18/5 CONTROL 1X 2X 4X Figure 3. Iberis sempervirens Snowflake 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 11/18/5 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 11/18/5 Appendix B Phytotoxicity Report Form for Pennant on Iberis 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 Mean X X X X X X X Mean X X X X X X X Mean X X X X X X X Mean