How To Test Phytotoxicity Of Snapshot 2.Tg

Transcription

1 Project Title: Evaluation of phytotoxicity of Snapshot 2.TG (trifluralin+isoxaben) on Spiderwort (Tradescantia Baby Bunny Bellies ) Protocol #: 6-9 Report date: June 22, 27 Authors: Heiner Lieth and Linda Dodge Department of Plant Sciences University of California, Davis Davis, CA 9616 Narrative Summary: Tradescantia Baby Bunny Bellies plants growing in 1-gallon containers received two applications of Snapshot 2.TG at 2. lb/acre (1X), lb/acre (2X) or 1 lb/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. The trial was conducted outdoors over 8 weeks from January, 27 to March, 27. The plants were then grown on in a greenhouse for 4 weeks from March, 27 to April 4, 27. Results The Tradescantia plants used in this trial all showed some blemishes during the first 8 weeks due to occasional cold temperatures in the nursery. The plants treated with Snapshot had slightly higher phytotoxicity index values than the controls by week 8 (Tables 1 and 4; Figures 1, 2 and 4a). It should be noted that the mean values were generally still less than 3 which is a relatively minor response. Also by the end of the trial, all plants had grown out of the phytotoxic response. It should be noted that Tradescantia has a creeping growth habit; consequently the height and volume data are not as relevant as the width data. The width data show that the plants which received Snapshot had widths at week 12 which were generally 2% smaller than the control (Tables 1 and 4; Figures 3 and 4b). Discussion While the Tradescantia has the ability to overcome the negative effects of Snapshot, the extra time required to produce a potted plant to marketing specifications (i.e. to achieve a particular width) will be significant. Thus we find that Snapshot is not safe when applied over Tradescantia. 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 provided by EuroAmerican Propagators, Bonsall CA. 1

2 Results Table IR-4 Ornamental Horticulture Program Table 1. Phytotoxicity and growth changes over 12 weeks for Tradescantia Baby Bunny Bellies 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 Tradescantia Phytotoxicity Index Increase from beginning of trial until: Treatment 2 week no 4 weeks yes at 1% weeks yes X 1.22 ±.43 a 2. ±.47 a 1.89 ±.2 b 1X 2.11 ±.9 a 3.22 ±.49 a 3.11 ±.1 a 2X 1.67 ±.44 a 2.33 ±.41 a 2.11 ±.3 ab 4X 1.22 ±.32 a 2.33 ±.44 a 1.78 ±.36 b Phytotoxicity Index increase from beginning of trial until: Treatment 6 weeks yes at 1% 8 weeks yes 12 week (NA) X 1.44 ±.34 b 1.22 ±.28 b. ±. a 1X 2.67 ±. a 2.22 ±.36 a. ±. a 2X 2.11 ±.31 ab 2.11 ±.11 a. ±. a 4X 2.11 ±.39 ab 1.78 ±.1 ab. ±. a Growth Effect of Snapshot on Tradescantia Increase by week 8 of: Treatment Height (cm) no Average Width (cm) no Volume Index no X 6.67 ±. a.28 ±.9 a ± a 1X.22 ± 1.18 a 4.42 ± 1.13 a ± 63.4 a 2X.78 ±.83 a 6. ±.71 a ± a 4X 6.6 ±.71 a.81 ± 1.28 a ± a Increase by week 12 of: Treatment Height (cm) no Average Width (cm) yes Volume Index yes X 17. ± 1.12 a ±.79 a ± a 1X 1.33 ± 1.42 a ±.61 b ± b 2X ±.7 a 17.6 ±.71 b ±11.13 b 4X ± 1.47 a ± 2.2 b ±371.8 ab 2

3 Species: Tradescantia -- Material: Snapshot Phytotoxicity Index Control 1X 2X 4X Day of trial Figure 1. Phytotoxicity index ratings for Tradescantia Baby Bunny Bellies 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 Phyto rating = 2 Phyto rating = 4 Figure 2. Examples of phytotoxicity ratings given to plants of Tradescantia Baby Bunny Bellies 8 weeks after 2 applications of 1X (2. lb/acre) Snapshot 2.TG at weeks and 4. Symptoms included necrosis of older leaves. 4

5 Species: Tradescantia -- Material: Snapshot Width (cm) Height (cm) Volume Index Day of trial Day of trial Day 9 Ctrl 1X 2X 4X Day 89 Ctrl 1X 2X 4X Day 9 Ctrl 1X 2X 4X Day 89 Ctrl 1X 2X 4X Change (cm) Change (cm) Change (cm) Change (cm) 6 Day Ctrl 1X 2X 4X 3 Day Change Change Day of trial Ctrl 1X 2X 4X Figure 3. Plant height, plant width and plant volume index results for Tradescantia Baby Bunny Bellies 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. Tradescantia Baby Bunny Bellies 8 weeks after two applications of (Control), 2. (1X), (2X) or 1 (4X) lb/acre Snapshot 2.TG at weeks and 4. 6

7 Block A Block B CONTROL 1X 2X 4X Block C Figure 4b. Tradescantia Baby Bunny Bellies 12 weeks after two applications of (Control), 2. (1X), (2X) or 1 (4X) lb/acre Snapshot 2.TG at weeks and 4. 7

8 Materials & Methods/Recordkeeping: Crop History Crop Cultivar/Variety: Date of Seeding: Date of Emergence: Date of Transplanting: Potting Mix: Pot size & spacing: Row spacing: Spiderwort (Tradescantia Baby Bunny Bellies ) Liners received from EuroAmerican 12/22/6, transplanted 12/28/6 UC Mix: 1/3 sand, 1/3 peat, 1/3 bark (by volume) 1-gallon pots spaced on 12-inch centers Product(s) applied prior to start of experiment: Product Rate Application Type Date of Crop Growth Application Stage Osmocote tbs./pot Topdress 12/28/6 Actively growing NA Experiment Information Application Volume Experimental Design: Number of Reps: Randomized complete block 9 (3 blocks x 3 reps per block) Application Equipment: shaker containers for Snapshot 2.TG 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 Granular OTT 1//7 Actively growing 2.TG lb/acre Snapshot 2.TG 2.,, 1 lb/acre Granular OTT 2//7 Actively growing Materials & Methods: Plant Material and Culture. Liners of Tradescantia Baby Bunny Bellies were received from EuroAmerican Propagators (Bonsall CA) on December 22, 26. The plants were transplanted to 1-gallon pots containing UC Mix on December 28, 26. The experiment ran from January, 27 to March, 27 in an outdoor nursery under % shade (Table 3). The plants were then transferred to a greenhouse with day/night temperatures of 7 /6 F for 4 additional weeks (Figure ). The plants were irrigated as needed during the 12-week experiment by hand with tap 8

9 water. 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. lb/acre (1X), lb/acre (2X) or 1 lb/acre (4X) Snapshot 2.TG 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 January, 27 and the second application 4 weeks later on February, 27. Data Collection. Phytotoxicity ratings were taken at week, 1, 2, 4,, 6, 8 and 12, (January, 12, 18 and 31, February 12 and 19, March and April 4, 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 (January, 27), week 8 (March, 27) and week 12 (April 4, 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 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. 9

10 Environmental conditions during the experiment: Table 3. Environmental conditions during the first 8 weeks of the experiment to determine phytotoxicity of Snapshot 2.TG on Tradescantia Baby Bunny Bellies. Date Sol Rad (Ly/day) Max Air Temp ( F) Min Air Temp ( F) Avg wspd (MPH) Precip (in) CIMIS ETo (in) Avg Rel Hum (%) 1/4/ // /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/ /1/ /16/ /17/ /18/ /19/ /2/ /21/ /22/ /23/ /24/ /2/ /26/ /27/ /28/ /1/ /2/ /3/ /4/ // /6/

11 Air Temperature - Greenhouse Air Temperature (F) /27/27 3/4/27 3/9/27 3/14/27 3/19/27 3/24/27 3/29/27 4/3/27 4/8/27 Figure. Environmental conditions during weeks 9-12 of the experiment to determine phytotoxicity of Snapshot 2.TG (Trifluralin + Isoxaben) on Tradescantia Baby Bunny Bellies. 11

12 Raw Data: Table 4. Phytotoxicity and plant growth data collected for plants of Tradescantia Baby Bunny Bellies treated with two applications of (Control), 2. (1X), (2X) or 1 (4X) lb/acre Snapshot 2.TG at weeks and 4 of a 12-week experiment. Phytotoxicity Report Form Tradescantia 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, Snapshot 2.TG, and Pennant Magnum 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 soilless 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) Pennant Magnum 7.62E C (s-metalochlor) Snapshot 2.TG (trifluralin+isoxaben) 2. lb ai/a 4. lb ai/a 8. lb ai/a 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 Snapshot 2.TG 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: 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