Potential for Phytotoxicity of Mogeton 25 WP (Quinoclamine) on Shasta Daisy (Leucanthemum X superbum)

Transcription

1 Potential for Phytotoxicity of Mogeton 25 WP (Quinoclamine) on Shasta Daisy (Leucanthemum X superbum) By Heiner Lieth, Director Linda Dodge Ron Lane Dylan Hodgkiss Project Interregional Research Project #4 Project Number A November 17, 25 Donors/Supporters 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 1 DATE 11/17/25 Investigator (Name, Address, Phone#, e- mail, etc) Dr. Heiner Lieth Department of Plant Sciences University of California One Shields Ave. Davis, CA Ph FAX jhlieth@ucdavis.edu Location of Trial TRIAL TYPE (field, container, greenhouse, etc) Chemical - Common Name UC Davis Greenhouse containers Quinoclamine - Formulation Wettable Powder 25% - Batch Number - Product Mogeton - EPA Registration Number CAS number Manufacture Crompton USE INFORMATION - Plant Common Name Shasta Daisy - Plant Scientific Name Leucanthemum X superbum (Chrysanthemum maximum) - Pest (s) / Pathogen(s) / Weed(s) Liverworts Soil Type or Type of Potting Mix UC Mix % Sand % Silt % Clay % OM ph Enter each DATE for Seeding 7/7/25 Emergence Transplanting 8/22/25 Enter each SPACING for Plant or Pot 6 inches Row 6 inches Enter each SIZE for Pot 6-inch Plot 45 feet 2 Experimental Design Randomized Complete Block Number of Reps 3 blocks X 3reps/block = 9 replicates total for each treatment 2

3 TRIAL 1 DATE 11/17/25 APPLICATION PARAMETERS1 Type of Application (aerial, ground, foliar, drench, ppi, chemigation, broadcast, directed, etc) Number of Applications Application Type Nozzle Type/Size Foliar spray 2, four weeks apart Over the top Manual spray bottles Nozzle Pressure Delivery Rate Calibration Date(s) APPLICATION SUMMARY APPLICATION DATE RATES (a.i./1 gallons water) (Be sure to provide units) Brief Description of Growth Stage (Dormant, New Growth Present, Bud, etc) 9/7/25, 2, 4, 8 oz./gal Vegetative, 2 weeks post-transplant 1/5/25, 2, 4, 8 oz./gal Vegetative, 6 weeks post-transplant RAINFALL/IRRIGATION RECORDS INCLUDE RAINFALL/IRRIGATION INFORMATION (printouts, IR-4 forms, etc.) The plants were watered daily during the 1-week experiment with half-strength Hoagland s solution using a drip irrigation system delivering 1 gallon per hour. 3

4 TRIAL 1 DATE 11/17/25 OTHER PESTICIDES, FERTILIZER, LIME AND ADJUVANTS USED PRODUCT AMOUNT DATE Dursban 5W 2.5 g/1 gal 9/23/25 Pylon 1.5 ml/1 gal 9/23/25 Silwett.5 tsp/1 gal 9/23/25 Avid 7 ml/3 gal 1/7/25 Sevin 5W 6 tsp/3 gal 1/7/25 Tame 2.4EC.5 oz/3 gal 1/21/25 Heritage 18 g/3 gal 1/21/25 Silwett.25 oz/ 3 gal 1/21/25 Safari.32 oz/ 4 gal 1/24/25 Avid.32 oz/4 gal 1/24/25 NARRATIVE SUMMARY OF METHODS AND RESULTS (Use more pages if needed) Materials and Methods Plant Material and Culture. Seeds of Leucanthemum X superbum (Botanical Interests, Broomfield CO) were planted on July 7, 25 and allowed to germinate in a mist bench for 3 weeks. The seedlings were transplanted to 6-packs and grown on for 5 weeks. The young plants were transplanted into 6-inch pots containing UC Mix on August 22, 25 and maintained in a greenhouse under natural day length for 2 weeks until the experiment began on September 7, 25. For the experiment, the plants were transferred to a greenhouse under natural day length with day/night temperatures of 75 /62 F (24 /16 C) (Figure 1). The plants were watered daily during the 1-week experiment with half-strength Hoagland s solution 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 (1X), 4 (2X), or 8 (4X) oz./gal Mogeton with 9 replicates per treatment. These dosages were prescribed in IR4 Ornamental Protocol 5-4 dated 5/5 (Appendix A). The plants received the first foliar spray application on September 7, 25 and the second application 4 weeks later on October 5, 25. The plants were arranged in a randomized complete block design with 3 blocks and 3 treatment replicates per block. The plants outgrew their containers by week 1 and the experiment was terminated 2 weeks earlier than specified in the protocol. Phytotoxicity ratings and plant height and width measurements were taken at week, 1, 2, 4, 8, and 1. Visual phytotoxicity evaluations were based on a numerical rating scale ranging from (no injury) to 1 (complete kill) (Table 1). 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 Mogeton. 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

5 TRIAL 1 DATE 11/17/25 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. Results During the 1-week trial, all Leucanthemum plants suffered from stress due to the fact that the plants rapidly outgrew the containers and the normal horticultural practices were not adequate to prevent blemishes on the foliage. Thus, in this experiment, elevated phytotoxicity index readings reflect this damage as well as any impact from the Mogeton. Over the first 4 weeks, the plants in the control showed a steady increase in the phytotoxicity index indicating that these plants experienced some stress early in the trial (Table 2, Figure 2, Appendix B). During this time, there were no significant differences between the phytotoxicity indexes observed in the control and those observed in the 2 oz/gal (1X) and 4 oz/gal (2X) treatments. In the 8 oz/gal (4X) treatment, significantly greater phytotoxicity index values were noted already at week 1, although the level was still very low. After that, the phytotoxicity index values increased significantly in all treatments including the control. Visual observations showed that the types of blemishes that were due to Mogeton were burning of new leaf tips and distorted growth of leaves (Figure 3). During the second half of the trial (after the second application), the phytotoxicity index values continued to rise in the Mogeton treatments, while leveling off in the control (Figure 2). The phytotoxicity index increases over the 1 weeks of the trial resulted in significantly greater levels in the 1X, 2X and 4X treatments. While the statistical analysis showed a significant trend in the effect of treatment concentration of Mogeton on the increase in height and relative volume index, the lowest increase was observed in the 2 oz/gal treatment while the greatest increase was noted in the 8 oz/gal treatment (Table 3, Figures 2 and 4, Appendix B). At the same time none of the individual treatment means within the variables of height increase, width increase and volume index increase were significantly different from any other mean. Discussion On the whole the data are not as conclusive as would be desired. Clearly there is an increasing pattern of phytotoxicity index with the date of the trial, but we also see this pattern in the control although to a lesser degree. We do know that at the 8 oz/gal treatment, Mogeton generates leaf distortion damage on the Leucanthemum plants; less so at the 2 oz/gal and 4 oz/gal treatments. At the proposed labeled rate, the differences in increase of phytotoxicity index between it and the control were not significant. Thus we cannot be sure from the experiment whether the product is safe at the 1X rate (2 oz/gal); we are fairly certain that it is not safe at the 4X rate (8 oz/gal). It would be advisable to repeat this trial in a way that avoids the horticultural problems that resulted from the 12-week protocol. Thus a protocol should be developed that tests Mogeton on Leucanthemum over a shorter period of time and in larger containers so as to avoid water stress. 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) 5

6 TRIAL 1 DATE 11/17/25 Date Completed 6

7 TRIAL 1 DATE 11/17/25 Greenhouse Air Temperature (F) /1/25 9/11/25 9/21/25 1/1/25 1/11/25 1/21/25 1/31/25 11/1/25 11/2/25 11/3/25 12/1/25 Figure 1. Greenhouse air temperatures during the experiment to evaluate the phytotoxicity of Mogeton on Leucanthemum X superbum. Table 1. 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 7

8 TRIAL 1 DATE 11/17/25 Table 2. Phytotoxicity ratings over 1 weeks for Leucanthemum X superbum treated with (Control), 2 (1X), 4 (2X), or 8 (4X) oz./gallon Mogeton, 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 = 9) Mogeton on Leucanthemum Phytotoxicity Increase at/after Treatment Week 1 yes Week 2 yes at Week 4 no Week 8 yes Week 1 yes (oz/gal) 1% level (Control).22 ±.15 a.67 ±.17 a 1.33 ±.44 ab.44 ±.18 a 2.11 ±.31 a 2 (1X).33 ±.37 a 1.22 ±.4 ab 1.56 ±.38 ab 2.11 ±.35 b 3. ±.47 ab 4 (2X).33 ±.24 a 1.33 ±.37 ab 1.22 ±.4 a 3. ±.41 b 3.33 ±.37 b 8 (4X) 1.22 ±.15 b 2.11 ±.26 b 2.33 ±.24 b 4.33 ±.33 c 4.89 ±.31 c Table 3. Plant height, width and volume changes over 1 weeks for Leucanthemum X superbum treated with (Control), 2 (1X), 4 (2X), or 8 (4X) oz./gallon Mogeton, 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 = 9) Treatment Height Increase after 1 yes Width Increase after 1 no Relative Volume Index Increase after yes (oz/gal) weeks weeks 1 weeks (Control) ± 1.99 a ± 2.5 a ± a 2 (1X) ± 1.91 a ± 2.33 a ± a 4 (2X) ± 1.75 a ± 1.51 a ± a 8 (4X) ± 1.4 a 26.6 ± 2.24 a ± a 8

9 TRIAL 1 DATE 11/17/25 Species Leucanthemum -- Material Mogeton Height (cm) Ctrl 1X 2X 4X week of trial Change (cm) Phytotoxicity Index Control 1X 2X 4X week of trial 5 1 Width (cm) Ctrl 1X 2X 4X week of trial Volume Index Change (cm) Ctrl 1X 2X 4X week of trial Change Figure 2. Summary of results for Leucanthemum X superbum treated with (Control), 2 (1X), 4 (2X), or 8 (4X) oz./gallon Mogeton, applied 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 1-week trial period. SE bars shown. (n = 9) 9

10 TRIAL 1 DATE 11/17/25 Control at 1 weeks 4X at 1 weeks Figure 3. Phytotoxicity symptoms seen on Leucanthemum X superbum one week after the first foliar application of 8 oz./gallon (4X) Mogeton (top). Symptoms included burning of leaf tips. By week 1 (bottom) the Mogeton-treated plants showed distorted growth of leaves compared to the control plants. 1

11 TRIAL 1 DATE 11/17/25 Block A Block B CONTROL 1X 2X 4X Block C Figure 4. Leucanthemum X superbum plants 1 weeks after treatment with (Control), 2 (1X), 4 (2X), or 8 (4X) oz./gallon Mogeton, applied at weeks and 4. 11

12 TRIAL 1 DATE 11/17/25 APPENDIX A Phytotoxicity to herbaceous perennial plants with applications of Mogeton 25WP Ornamental Protocol Number 5-4 REVISED DATE 5/5 Objective Determine phytotoxicity of Mogeton 25WP to perennial plants commonly grown in greenhouse and/or 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. Plant materials must be established in containers and have broken dormancy prior to first application. Use 2 qts of final spray solution per 1 sq ft or about 218 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 must be growing in containers and not field grown. Evaluations Record phytotoxicity on a scale of to 1 ( = No phytotoxicity; 1 = Complete kill) at 1, 2, 4, 8, and 12 weeks after initial application. 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, 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 Mogeton 25WP (quinoclamine) 2. oz/gal Do not overhead water for 24 h after application. 4. oz/gal 8. oz/gal Untreated For labels, materials, and any required adjuvants contact Mogetan - Crompton, Kevin Donovan, x 228, kevin.donovan@cromptoncorp.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. 12

13 TRIAL 1 DATE 11/17/25 APPENDIX B Phytotoxicity Report Form Phytotoxicity at week Plant Size at week Plant Size at week 12 Height Width1 Width 2 Height Width1 Width 2 Treatment Block Rep (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