Project Title: Evaluation of phytotoxicity of Sulfentrazone on American Arborvitae (Thuja occidentalis Emerald Green ) IR4 PR#: 25362 Report date: November 21, 26 Authors: Heiner Lieth and Linda Dodge Department of Plant Sciences University of California, Davis Davis, CA 95616 Narrative Summary: Thuja occidentalis Emerald Green plants growing in 1-gallon containers received two applications of Sulfentrazone at.125 lb ai/acre (1X),.25 lb ai/acre (2X) or.5 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 Sulfentrazone. The trial was conducted over 8 weeks from April 14, 26 to June 6, 26. Sulfentrazone caused no phytotoxicity or growth retardation on Thuja occidentalis Emerald Green plants. 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 Melaku Sebhatu (plant culture, data collection). The materials being tested were supplied by the manufacturer/distributor. Plants were provided by Matsuda s Nursery, Sacramento CA. 1
Overview of Trial and Protocol: The trial was conducted according to the IR4 protocol # 6-1 (Appendix A). The details are listed in the section, below, entitled Materials and Methods/Recordkeeping. Phytotoxicity ratings were recorded at weeks, 1, 2, 4, 5, 6 and 8. Phytotoxicity was evaluated using a Phytotoxicity index, consisting of a scale where values of 1 or below represent negligible blemishes and values above 3 represent damage that renders the plant unmarketable. Plant height and width measurements were taken at the beginning and end of the trial. Plant growth evaluations include a calculated Volume index which is proportional to the canopy volume. Results: Phytotoxicity index levels for all Thuja occidentalis Emerald Green plants treated with Sulfentrazone were no different from the controls and all means were below 1 at all observation dates (Tables 1 and 3, Figure 1). Thuja occidentalis Emerald Green plants in all treatments grew during the trial (Tables 2 and 3, Figures 1 and 2). The height, width and volume index increases were not significantly different. Discussion: Sulfentrazone caused no phytotoxicity or growth retardation on Thuja occidentalis Emerald Green plants. 2
Materials & Methods/Recordkeeping: Crop History Crop Cultivar/Variety: Date of Seeding: Date of Emergence: Date of Transplanting: Potting Mix: Pot size & spacing: Row spacing: American Arborvitae (Thuja occidentalis Emerald Green ) liners received from Matsuda s Nursery 3/1/6, transplanted 3/2/6 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 Application Crop Growth Stage Application Volume Osmocote 15-9-12 1 tsp./pot Manual 4/4/6 Actively growing NA Experiment Information Experimental Design: Number of Reps: Randomized complete block 9 (3 blocks x 3 reps per block) Materials & Methods: Plant Material and Culture. Liners of Thuja occidentalis Emerald Green were received from Matsuda s Nursery, Sacramento CA, on March 1, 26. The plants were transplanted to 1-gallon pots containing UC Mix on March 21, 26. The experiment ran from April 14, 26 to June 6, 26 in an outdoor nursery under 5% shade (Table 4). The plants were irrigated 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 below). Experimental Procedure. Thirty-six plants were randomly chosen and individually tagged for treatment with (Control),.125 lb ai/acre (1X),.25 lb ai/acre (2X) or.5 lb ai/acre (4X) Sulfentrazone with 9 replicates per treatment. These dosages were prescribed in IR4 Ornamental Protocol 6-1 (Appendix A). The plants received the first granular application on April 14, 26 and the second application 4 weeks later on May 12, 26. 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. 3
Application Equipment: Manual shaker container for Sulfentrazone Product(s) applied during experiment (including treatments, fertilizers, etc): Product Rate(s) Application Type Date of Application Crop Growth Stage Sulfentrazone.125,.25, Granular 4/4/6 Actively growing.5 lb ai/acre Sulfentrazone.125,.25, Granular 5/4/6 Actively growing.5 lb ai/acre Application Volume Data Collected: Data Collection. Phytotoxicity ratings were taken at week, 1, 2, 4, 5, 6 and 8, (April 1, 18 and 25, 26; May 9, 15 and 24, 26; June 6, 26). Visual phytotoxicity evaluations were based on a numerical rating scale ranging from (no injury) to 1 (complete kill) (Table 5). Plant height and width were measured at week (April 1, 26) and week 8 (June 6, 26). 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. 4
Table 1. Phytotoxicity changes over 8 weeks for Thuja occidentalis Emerald Green treated with (Control),.125 (1X),.25 (2X) or.5 (4X) lb ai/acre Sulfentrazone at weeks and 4. Different letters within a column indicate significant differences between treatments (P <.5). Yes / No designations refer to significant treatment effects at the 5% level. Means ± SE (n=9) Phytotoxicity Effect of Sulfentrazone on Thuja Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week 2 weeks (NA) 4 weeks no (NA) X. ±. a. ±. a. ±. a 1X. ±. a. ±. a.11 ±.11 a 2X. ±. a. ±. a. ±. a 4X. ±. a. ±. a.33 ±.24 a Phytotoxicity Index increase from beginning of trial until: Treatment 5 weeks no 6 weeks no 8 weeks no X. ±. a.44 ±.18 a.67 ±.17 a 1X.22 ±.22 a.67 ±.24 a.44 ±.18 a 2X. ±. a.67 ±.24 a.78 ±.15 a 4X.33 ±.24 a.44 ±.24 a.33 ±.17 a Table 2. Plant height, width and volume changes over 8 weeks for Thuja occidentalis Emerald Green treated with (Control),.125 (1X),.25 (2X) or.5 (4X) lb ai/acre Sulfentrazone at weeks and 4. Different letters within a column indicate significant differences between treatments (P <.5). Yes / No designations refer to significant treatment effects at the 5% level. Means ± SE (n=9) Growth Effect of Sulfentrazone on Thuja Increase by week 8 of: Treatment Height (cm) no Average no Volume Index no Width (cm) X 6.94 ±.47 a 1.44 ±.3 a 1448.44 ± 147.97 a 1X 6.56 ±.31 a 2.42 ±.4 a 1884.67 ± 215.44 a 2X 7.17 ±.35 a 1.31 ±.52 a 148. ± 284.46 a 4X 7.22 ±.26 a 2.22 ±.38 a 1984.28 ± 213.52 a 5
Raw Data: Table 3. Phytotoxicity and plant growth data collected for plants of Thuja occidentalis Emerald Green treated with two applications of (Control),.125 (1X),.25 (2X) or.5 (4X) lb ai/acre Sulfentrazone at weeks and 4 of an 8-week experiment. Phytotoxicity Report Form Thuja Sulfentrazone Phytotoxicity at week Plant Size at week Plant Size at week 8 Height Width1 Width 2 Height Width1 Width 2 Treatment Block Rep 1 2 4 5 6 8 (cm) (cm) (cm) (cm) (cm) (cm) Control A 1 19 12 11 28.5 14 9.5 Control A 2 17.5 12 8 24 13.5 9 Control A 3 1 1 22.5 15 11 29.5 16.5 1.5 Control B 1 1 1 16.5 11 9 21.5 15.5 1 Control B 2 1 1 22 12.5 12 3 13 13 Control B 3 18 9 7 25.5 11.5 7.5 Control C 1 1 21 9 7 28.5 13 7.5 Control C 2 1 18 1 8 23 13 7.5 Control C 3 1 1 22 12 9 28.5 15 11 Mean......4.7 19.6 11.4 9.1 26.6 13.9 9.5 1X A 1 1 2 2 1 16 8 7 23 15.5 9.5 1X A 2 1 1 19 13 9 24 13.5 11 1X A 3 1 1 21 1 9 29 12.5 12.5 1X B 1 16 13 9 22 16.5 11 1X B 2 1 1 15 13 8 22 13 11.5 1X B 3 17 1 9 23 13 8 1X C 1 21 12 9 28.5 14 12 1X C 2 17 11 9 23.5 14 11.5 1X C 3 1 17 9 8 23 11.5 9 Mean....1.2.7.4 17.7 11. 8.6 24.2 13.7 1.7 2X A 1 13 9 9 2 1 9 2X A 2 1 1 17 1 1 23.5 11.5 9 2X A 3 24.5 15 12 32 15.5 9.5 2X B 1 1 2 11 1 29 14 9 2X B 2 1 1 21 13 1 27.5 14 9.5 2X B 3 1 1 19 11 9 27 12.5 13 2X C 1 1 23 9 1 29.5 13 8.5 2X C 2 1 1 18 1 7 26 14 11 2X C 3 2 1 19 1 1 24.5 13.5 12 Mean......7.8 19.4 1.9 9.7 26.6 13.1 1.1 4X A 1 21 11 8 28 12.5 11 4X A 2 21 9 8 28 11 8 4X A 3 21 13 1 29 15.5 12.5 4X B 1 1 1 17.5 8 8 25 13 12 4X B 2 2 2 2 1 22 11 9 28 15 9.5 4X B 3 2 9 9 28 13.5 11 4X C 1 15 13 9 21 13.5 12.5 4X C 2 19 11 1 27 11 12 4X C 3 1 1 1 1 21 11 1 28.5 12 11.5 Mean....3.3.4.3 19.7 1.7 9. 26.9 13. 11.1 6
Environmental conditions during the experiment: Table 4. Environmental conditions during the experiment to determine phytotoxicity of Sulfentrazone on Thuja occidentalis Emerald Green. Date Sol Rad (Ly/day) Max Air Temp ( F) Min Air Temp ( F) Avg Vap (mbars) Avg wspd (MPH) Precip (in) CIMIS ETo (in) Avg Rel Hum (%) 4/14/26 429 71.2 51.4 13.5 6.9.14 77 4/15/26 311 59.2 48.5 1.6 1.7.1 76 4/16/26 278 58.2 44.3 9.8 8.6.21.8 77 4/17/26 563 59 37.4 7.5 5.1.16 63 4/18/26 594 67.1 44.8 7.7 7.8.2 52 4/19/26 592 75.1 4.6 9.4 4.3.19 57 4/2/26 555 74 43 11.2 4.4.18 67 4/21/26 297 68.9 45.1 11.8 5.2.9 77 4/22/26 411 65.8 49.6 11.8 6.8.4.13 74 4/23/26 426 67.6 52.2 12.4 6.4.5.13 75 4/24/26 297 6.7 48.4 11.2 6.2.8 75 4/25/26 368 66 46.2 11.9 4.3.1 79 4/26/26 585 8 48 13.1 6.5.21 68 4/27/26 67 85.6 52 12.9 7.4.26 54 4/28/26 64 81.4 5.2 14.7 4.5.21 7 4/29/26 512 74.5 51.5 14.5 5.1.16 77 4/3/26 626 85.3 52.6 11.4 6.27 46 5/1/26 625 86.4 45.7 11.4 4.6.25 5 5/2/26 624 85.4 51.7 9.6 7.3.28 4 5/3/26 615 73.2 5.1 11.7 6.6.22 64 5/4/26 613 74.3 47.2 12.3 6.4.21 67 5/5/26 595 73.1 48.7 12.4 6.7.2 71 5/6/26 567 74 47.6 11.9 5.6.18 7 5/7/26 614 83.5 47 13.3 3.6.21 6 5/8/26 625 84.6 52.8 11 5.1.25 46 5/9/26 638 87.8 51.6 7.7 8.2.32 3 5/1/26 625 89.9 54.4 9 5.3.28 32 5/11/26 647 89.1 54.8 11.1 4.7.26 43 5/12/26 62 87.9 5.3 12 4.9.25 48 5/13/26 648 84.7 52.6 12.7 4.7.24 56 5/14/26 649 95.9 51.5 11.7 5.8.3 39 5/15/26 628 91.5 6.5 13.8 5.5.28 46 5/16/26 66 9.7 54 14.9 4.3.25 56 5/17/26 665 92.4 54.4 15.2 4.7.25 58 5/18/26 668 93.9 53.8 12.4 5.9.26 49 5/19/26 365 76.3 5.9 12 6.2.2.13 65 5/2/26 532 74.9 5.8 13.5 4.9.18 68 5/21/26 252 68.9 55.6 14.9 5.6.23.7 79 5/22/26 63 69.3 52.9 12 7.8.2.21 67 5/23/26 524 73.7 56.8 12.2 6.3.18 6 5/24/26 638 75.5 53.4 12.4 5.7.23 6 5/25/26 682 78.2 48.1 11.6 4.8.24 58 5/26/26 639 73.1 49.3 8.6 6.7.24 47 5/27/26 632 7 44 8.1 5.1.2 49 5/28/26 59 75.6 44.2 9.7 4.6.21 54 5/29/26 631 8.6 44.3 9.1 3.8.22 45 5/3/26 64 84.7 46.3 1.1 4.6.25 44 5/31/26 64 87.9 51.9 13.3 4.2.25 53 6/1/26 477 86.5 57.1 14.9 4.6.19 55 6/2/26 623 86.1 6.6 16.3 5.6.24 6 6/3/26 662 92.3 55 14.3 4.8.27 48 6/4/26 697 85.9 58.2 13.8 7.6.3 48 6/5/26 715 87.7 52.2 13.9 4.9.27 55 6/6/26 688 89 54.8 13.9 4.6.26 52 6/7/26 688 9.3 55 12.4 5.9.29 47 7
Table 5. 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 8
Species: Thuja -- Material: Sulfentrazone Height (cm) 3 25 2 15 1 5 15 Ctrl 1X 2X 4X 1 2 3 4 5 6 Day of trial 1 5 Change (cm) Phytotoxicity Index 1 8 6 4 2 4 Control 1X 2X 4X 1 2 3 4 5 6 Day of trial Width (cm) 1 5 6 4 2 Change (cm) Volume Index 3 2 1 3 2 1 Change Ctrl 1X 2X 4X 1 2 3 4 5 6 Day of trial Ctrl 1X 2X 4X 1 2 3 4 5 6 Day of trial Figure 1. Summary of results for Thuja occidentalis Emerald Green treated with (Control),.125 (1X),.25 (2X) or.5 (4X) lb ai/acre Sulfentrazone at weeks and 4. 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 = 9) 9
Block A Block B CONTROL 1X 2X 4X Block C Figure 2. Thuja occidentalis Emerald Green 8 weeks after two applications of (Control),.125 (1X),.25 (2X) or.5 (4X) lb ai/acre Sulfentrazone at weeks and 4. 1
APPENDIX A Phytotoxicity to ornamental horticulture plants from tools to manage broadleaf weeds and sedges. Ornamental Protocol Number: 6-1 Objective: Determine phytotoxicity of Manage (halosulfuron), Sulfentrazone.2G, and V-1142 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: Apply first application over the top of plants just breaking dormancy or, under climates where plants do not go totally dormant, apply prior to active growth in the spring. See table for product specific information. 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. If different application methods or evaluations are made, please clearly specify differences in final report and explain how they enhanced results. 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 Rates Special Instructions Contact Information to obtain materials and any needed adjuvants Sedgehammer 75WG (halosulfuron) Sulfentrazone.2G (sulfentrazone.2% active) 1 oz per acre (.47 lb ai) 2 oz per acre (.94 lb ai) 4 oz per acre (.188 lb ai).125 lb ai/acre.25 lb ai/acre.5 lb ai/acre V-1142 75WG.5 lb ai/acre 1. lb ai/acre 2. lb ai/acre Untreated ------ ------ 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. Always use.25% v/v of a non ionic surfactant. If severe phyto symptoms do not occur and where feasible apply a second application 4-6 weeks later at identical rates. 2 applications on a 4 week interval 2 applications on a 4 week interval Kory Wheeler 928-819-1592 Kwheeler@gowanco.com FMC, Bobby Walls, 919-735-3862, bobby_walls@fmc.com Valent, Joe Chamberlin, 77-985-33, jcham@valent.com 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 892-339, Phone 732-932-9575 x629, palmer@aesop.rutgers.edu OR Ely Vea, 38 Aston Forest Lane, Crownsville, MD 2132, Phone & FAX#: 41-923-488, E-mail: evvea@comcast.net. 11