IR-4 Ornamental Horticulture Program Trial Report

Transcription

1 Project Title: Evaluation of phytotoxicity of Snapshot 2.TG (Trifluralin + Isoxaben) on Shasta Daisy (Leucanthemum maximum Snow Lady ) Protocol #: 6-9 Report date: July 9, 27 Authors: Heiner Lieth and Linda Dodge Department of Plant Sciences University of California, Davis Davis, CA 9616 Narrative Summary: Leucanthemum maximum Snow Lady plants growing in 1-gallon containers received two applications of Snapshot 2.TG (Trifluralin + Isoxaben) at 2. lb. ai/acre (1X), lb. ai/acre (2X) or 1 lb. ai/acre (4X) rates as described in the Materials and Methods section of this report. The interval between applications was 4 weeks. The plants in the Control group received no Snapshot 2.TG (Trifluralin + Isoxaben). The trial was conducted over 8 weeks outdoors from December 22, 26 to February 14, 27. The plants were then transferred to a greenhouse and the trial was continued for 4 weeks from February 14, 27 to March 12, 27. Results All the plants in the trial showed blemishes at various times that were unrelated to the application of any material. This resulted in average phytotoxicity index levels of around 2 for all treatments at day 4 (Tables 1 and 4, Figure 1). While there seem to be significant differences at weeks and 8, the differences are not significant at the other weeks (Figure 2). Over the period from the start to week 8 there was a decline in plant height due to the leaves being initially more upright (Tables 1 and 4, Figures 3 and 4a). Thus this apparent decline is not actually a decrease in plant size. By week 12 only very small differences were evident between treated and untreated plants (Figure 4b). These differences were not significant at the 9% level. Discussion The observed values suggest that Snapshot is safe on Leucanthemum at the 1X rate. Caution should be used at higher rates since these could result in smaller plants with slight blemishes. Acknowledgements: The research was supported through funding from the USDA IR-4 Program, Western Region based at UC Davis, Davis, CA. Personnel involved in this project included: Ron Lane (pesticide application, pest management) and Priyasheila Singh (plant culture, data collection). The materials being tested were supplied by the manufacturer/distributor. Plants were purchased from Capital Nursery, Sacramento CA. 1

2 Results Table IR-4 Ornamental Horticulture Program Table 1. Phytotoxicity and growth changes over 12 weeks for Leucanthemum maximum Snow Lady treated with (Control), 2. (1X), (2X) or 1 (4X) lb/acre Snapshot 2.TG (Trifluralin + Isoxaben) at weeks and 4. Differing letters a, b, c designate significant differences among the four means; "Yes" and "no" indicates whether there was an overall significant treatment effect at the % level (NA means no variation in data; "yes at 1%" means treatment effect was significant at 1% but not at the % level). Means ± SE (n=9) Phytotoxicity Effect of Snapshot on Leucanthemum Phytotoxicity Index Increase from beginning of trial until: Treatment 2 week no 4 weeks no weeks yes X.33 ±.17 a.44 ±.18 a.78 ±.22 b 1X.11 ±.11 ab.22 ±.1 a 1.6 ±.18 a 2X.11 ±.11 ab.11 ±.11 a 1.89 ±.2 a 4X. ±. b.11 ±.11 a 1.44 ±.29 a Phytotoxicity Index increase from beginning of trial until: Treatment 6 weeks no 8 weeks yes 12 week no X 1.78 ±.46 a.33 ±.24 b.78 ±.32 ab 1X 2. ±.24 a 1.11 ±.11 a.6 ±.38 b 2X 2.33 ±.24 a 1.78 ±.32 a 1.67 ±.24 a 4X 1.89 ±.26 a 1.67 ±.24 a 1.67 ±.37 a Growth Effect of Snapshot on Leucanthemum Increase by week 8 of: Treatment Height (cm) yes Average Width (cm) no Volume Index no X ±.82 a 1.44 ±.66 a ± a 1X -7. ±.48 b.86 ±.62 a ± b 2X ±.4 b -.7 ±.84 a -21. ± 47.9 ab 4X ±.7 b.94 ±.91 a ± ab Increase by week 12 of: Treatment Height (cm) yes at 1% Average Width (cm) yes Volume Index yes at 1% X 2.83 ±.77 a.47 ±.68 a ± 623. a 1X 3.33 ± 1.9 a 2.97 ± 1.2 b ± ab 2X 4.33 ±.71 a 3.31 ± 1.23 ab ± ab 4X 3.28 ± 1.17 a 2.17 ±.47 b ± b 2

3 Species: Leucanthemum -- Material: Snapshot Phytotoxicity Index Control 1X 2X 4X Day of trial Figure 1. Phytotoxicity index ratings for Leucanthemum maximum Snow Lady treated with (Control), 2. (1X), (2X) or 1 (4X) lb/acre Snapshot 2.TG (Trifluralin + Isoxaben) at weeks and 4. SE bars shown. (n = 9) 3

4 Figure 2. Phytotoxicity symptoms seen on plants of Leucanthemum maximum Snow Lady treated with 2X ( lb/acre) Snapshot 2.TG at weeks and 4 of a 12- week experiment. Symptoms included marginal burning of leaves. 4

5 Species: Leucanthemum -- Material: Snapshot IR-4 Ornamental Horticulture Program Width (cm) Height (cm) Day of trial Day 4 Ctrl 1X 2X 4X Day 8 Ctrl 1X 2X 4X Day 4 Ctrl 1X 2X 4X Day Change (cm) Change (cm) Change (cm) Change (cm) Volume Index Day of trial Day of trial Ctrl 1X 2X 4X Day 4 Ctrl 1X 2X 4X Day 8 Ctrl 1X 2X 4X Change Change Figure 3. Plant height, plant width and plant volume index results for Leucanthemum maximum Snow Lady treated with (Control), 2. (1X), (2X) or 1 (4X) lb/acre Snapshot 2.TG (Trifluralin + Isoxaben) at weeks and 4 (see Figure 1 for treatment legend). Histograms show changes over the 12-week trial period. SE bars shown. (n = 9)

6 Block A Block B CONTROL 1X 2X 4X Block C Figure 4a. Leucanthemum maximum Snow Lady 8 weeks after two applications of (Control), 2. (1X), (2X) or 1 (4X) lb ai/acre Snapshot 2.TG (Trifluralin + Isoxaben) at weeks and 4. 6

7 Block A Block B CONTROL 1X 2X 4X Block C Figure 4b. Leucanthemum maximum Snow Lady 12 weeks after two applications of (Control), 2. (1X), (2X) or 1 (4X) lb ai/acre Snapshot 2.TG (Trifluralin + Isoxaben) at weeks and 4. 7

8 Materials & Methods/Recordkeeping: Crop History Crop Cultivar/Variety: Date of Seeding: Date of Emergence: Shasta Daisy (Leucanthemum maximum Snow Lady ) Date of Transplanting: Liners from Capital 12/1/6, transplanted 12/19/6 Potting Mix: Pot size & spacing: Row spacing: Product(s) applied prior to start of experiment: Product Rate Application Type UC Mix: 1/3 sand, 1/3 peat, 1/3 bark (by volume) 1-gallon pots spaced on 12-inch centers Date of Crop Growth Application Stage Osmocote tps./pot Topdress 12/19/6 At transplanting NA Application Volume Experiment Information Experimental Design: Number of Reps: Randomized complete block 9 (3 blocks x 3 reps per block) Application Equipment: Manual shaker containers for Snapshot 2.TG (Trifluralin + Isoxaben) Product(s) applied during experiment (including treatments, fertilizers, etc): Product Rate(s) Application Type Date of Application Crop Growth Stage Application Volume Snapshot 2.,, 1 lb. Granular OTT 12/22/6 Actively growing 2.TG ai/acre Snapshot 2.TG 2.,, 1 lb. ai/acre Granular OTT 1/17/7 Actively growing Materials & Methods: Plant Material and Culture. Liners of Leucanthemum maximum Snow Lady were purchased from Capital Nursery (Sacramento CA) on December 1, 26. The plants were transplanted to 1-gallon pots containing UC Mix on December 19, 26. The experiment ran from December 22, 26 to February 14, 27 in an outdoor nursery under % shade (Table 3). The plants were irrigated as needed during the 8-week experiment by hand with tap water. Applications of pesticides as part of a normal pest management program were made as needed (see above). The plants were transferred to a greenhouse on February 14, 27 and held for 4 weeks for observation under warmer conditions (Figure ). Experimental Procedure. Thirty-six plants were randomly chosen and individually tagged for treatment with (Control), 2. lb. ai/acre (1X), lb. ai/acre (2X) or 1 lb. ai/acre (4X) Snapshot 8

9 2.TG (Trifluralin + Isoxaben) with 9 replicates per treatment. These dosages were prescribed in IR4 Ornamental Protocol 6-9 (Appendix A). The plants received the first granular application on December 22, 26 and the second application 4 weeks later on January 17, 27. Data Collection. Phytotoxicity ratings were taken at week, 1, 2, 4,, 6, 8 and 12 (December 22 and 29, 26; January, 17, 24 and 31, 27; February 14, 27; March 12, 27). Visual phytotoxicity evaluations were based on a numerical rating scale ranging from (no injury) to 1 (complete kill) (Table 2). 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 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 Plant height and width were measured at week (December 22, 26), week 8 (February 14, 27) and week 12 (March 12, 27). 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 herbicide. 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 scaleindependent, 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. 9

10 Environmental conditions during the experiment: Table 3. Environmental conditions during the experiment to determine phytotoxicity of Snapshot 2.TG (Trifluralin + Isoxaben) on Leucanthemum maximum Snow Lady. Date Sol Rad (Ly/day) Max Air Temp ( F) Min Air Temp ( F) Avg wspd (MPH) Precip (in) CIMIS ETo (in) Avg Rel Hum (%) 12/22/ /23/ /24/ /2/ /26/ /27/ /28/ /29/ /3/ /31/ /1/ /2/ /3/ /4/ // /6/ /7/ /8/ /9/ /1/ /11/ /12/ /13/ /14/ /1/ /16/ /17/ /18/ /19/ /2/ /21/ /22/ /23/ /24/ /2/ /26/ /27/ /28/ /29/ /3/ /31/ /1/ /2/ /3/ /4/ // /6/ /7/ /8/ /9/ /1/ /11/ /12/ /13/ /14/

11 Greenhouse Air Temperature (F) /12/27 2/17/27 2/22/27 2/27/27 3/4/27 3/9/27 3/14/27 3/19/27 Figure. Environmental conditions during weeks 9-12 of the experiment to determine phytotoxicity of Snapshot 2.TG (Trifluralin + Isoxaben) on Leucanthemum maximum Snow Lady. 11

12 Raw Data: Table 4. Phytotoxicity and plant growth data collected for plants of Leucanthemum maximum Snow Lady treated with two applications of (Control), 2. (1X), (2X) or 1 (4X) lb ai/acre Snapshot 2.TG (Trifluralin + Isoxaben) at weeks and 4 of a 12-week experiment. Phytotoxicity Report Form Leucanthemum Snapshot IR4 Trial Phytotoxicity at week Plant Size at week Plant Size at week 8 Plant Size at week 12 Height Width1 Width 2 Height Width1 Width 2 Height Width1 Width 2 Treatment Block Rep (cm) (cm) (cm) (cm) (cm) (cm) (cm) (cm) (cm) Control A Control A Control A Control B Control B Control B Control C Control C Control C Mean X A X A X A X B X B X B X C X C X C Mean X A X A X A X B X B X B X C X C X C Mean X A X A X A X B X B X B X C X C X C Mean

13 APPENDIX A Phytotoxicity to herbaceous perennial plants with pre-emergent applications of Pendulum, Pennant Magnum, and Snapshot. Ornamental Protocol Number: 6-9 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 plants 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 plant height & width at initial and final evaluations. At 1, 2, and 4 weeks after each application, record phytotoxicity on a scale of to 1 ( = No phytotoxicity; 1 = Complete kill). If appropriate, also include ratings for chlorosis, defoliation, stunting or other growth effects on a scale of to 1 ( = No effect; 1 = Complete plant affected). If any 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, 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 4. lb ai/a 8. lb ai/a Pennant MAGNUM 7.62EC (s-metalochlor) Snapshot 2.TG (trifluralin+isoxaben) 2. lb ai/a. lb ai/a 1. lb ai/a 2. lb ai/a. lb ai/a 1. lb ai/a Untreated Follow with sufficient overhead irrigation to wash Pennant Magnum from the foliage to reduce the chance of injury Follow with sufficient overhead irrigation to wash Snapshot from the foliage to reduce the chance of injury Contact Information to obtain materials and any needed adjuvants BASF, Kathie Kalmowitz, kalmowk@basf-corp.com Syngenta, Dave Ross, david.ross@syngenta.com Dow AgroSciences Mike Melichar, , mwmelichar@dow.com Reports must include: Results summary (no more than one page) Summary table with appropriate statistical analyses Experimental design and materials and methods Appendices: raw data and recordkeeping information as listed above If pictures were taken, please include them. A report submitted electronically 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. Draft Date: 1/ Revised By: CLP 13