IR-4 Ornamental Horticulture Program Research Report Form

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1 Project Title: Phytotoxicity of BAS 659h G applied over the top to selected herbaceous and woody ornamental plants (May 2008 trials) Protocol #: Narrative Summary (Results/Discussion) Agapanthus Phytotoxicity. All phytotoxicity index values were zero for all plants prior to week 6 so that the averages were all zero and obviously there were no differences (Tables 1 and 6a, Figure 1). Between week 6 and 7 leaf tip burn appeared on all plants resulting in mean phytotoxicity index levels averaging around 1.0 in all treatments with no differences between treatments on any of the observations at week 7, 8, or 10. BAS 659h G applied to Agapanthus resulted in no phytotoxicity at any of the rates. Plant Growth. Growth was based on leaf biomass, with the exclusion of any flower biomass. Flowers were present in each treatment but not uniformly on all plants; so this was not used in calculations. Thus height is to the top of the leaves with plants in the control increasing by 2.4 cm over 10 weeks (Tables 2 and 6a, Figure 2a). The plants in the 4X treatment showed a decline in height by 2.5 cm. A declining trend with concentration was evident and the photos show that the density of foliage (number of leaves was not tracked) at the end of the trial decreased with increasing concentration (Figure 2a). While the mean height increases in the 1X and 2X treatments were not significantly different from the control, the plants in the 4X treatment actually showed a decrease in growth which was significant with respect to the control. The same pattern was evident in the width so that the volume index also showed a declining trend, suggesting a significant growth reduction in the 2X and 4X treatments. No significant differences were noted between the control plants and those treated at the 1X rate. While the overall diagnosis is that the material is safe on Agapanthus based on the quantitative data, it should be noted that the photos show an effect that is not quantified in this study. The photos suggest that fewer leaves were being produced on plants treated with the herbicide. For many growers this would result in a delay before the plants were marketable or a slight reduction in economic value of the product. Berberis Phytotoxicity. None of the average phytotoxicity index values in any of the treatments on any of the observation dates were above 0.5 (Tables 1 and 6b, Figure 1). There were never any significant trends with application rate of the herbicide. No phytotoxicity could be attributed to BAS 659h G. Plant Growth. The Berberis plants in the control group grew by an average of 3.2 cm in height and 17.1 cm in width (Tables 2 and 6b, Figure 2b). There was considerable variability in plant height and width so that the average height measurements did not reflect significant differences. While large differences did occur, the means did not show a linear pattern with application rate. 1

2 The only significant difference between control and any other treatment was with the averaged width in the control and 4X treatment. The growth data were subject to considerable variability and we cannot conclude that the control plants were significantly different in size from those of the 1X and 2X treatment. Thus we conclude that BAS 659h G is safe on Berberis. Cotoneaster Phytotoxicity. Cotoneaster showed no blemishes during the first 6 weeks of the experiment with all phytotoxicity index values zero (Tables 1 and 6c, Figure 1). After the second application all plants showed increases in leaf burn, probably due to the summer heat. There were no treatment differences in these levels on any observation date. No phytotoxicity could be attributed to BAS 659h G. Plant Growth. The Cotoneaster plants in the control group grew in height by an average of 13.6 cm while the plants treated with BAS 659h G grew only between 10.1 and 10.9 cm with no significant differences between treatments (Tables 2 and 6c, Figure 2c). Average width increases and volume index increases also showed a declining pattern with increasing application rate. Due to this reduction in growth, BAS 659h G should not be used over the top on Cotoneaster. Ligustrum Phytotoxicity. All phytotoxicity index means were less than 0.7 in all treatments and on every observation date (Tables 1 and 6d, Figure 1). No phytotoxicity could be attributed to BAS 659h G. Plant Growth. The plants in the control group grew by 10.4 cm in height and by 9.2 cm in width on average (Tables 2 and 6d, Figure 2d). The plants in the 1X treatment grew the same, but in the 2x and 4X treatments, plant height increases were only 5.2 and 4.6 cm respectively. The plants in the 2X and 4X treatments put on significantly less height than the control plants suggesting that growers will have to be very careful not to exceed the 1X rate or risk having stunted plants. At the 1X rate, BAS 659h G was found to be safe on Ligustrum. Materials & Methods: Plant Material and Culture. The plants for these trials were grown as indicated in Table 3. The experiment ran from May 2, 2008 to July 11, 2008 in an outdoor nursery under 50% shade. The plants were irrigated daily during the 10-week experiment using an automatic drip system delivering 2L per hour. Environmental conditions during the trial are indicated in Table 4. Experimental Procedure. Thirty-six plants were randomly chosen and individually tagged for treatment with 0 (Control), 1X, 2X or 4X rates of the herbicide with 9 replicates per treatment. These dosages were prescribed in IR4 Ornamental Protocol (Appendix A). The plants received the first application on May 2, 2008 and the second application 6 weeks later on June 13,

3 Data Collection. Phytotoxicity ratings were taken at week 0, 1, 2, 4, 6, 7, 8, and 10.The dates for those observations were May 2, 9, 16, 30, June 13, 20, 27, and July 11, Visual phytotoxicity evaluations were based on a numerical rating scale ranging from 0 (no injury) to 10 (complete kill) (Table 5). Plant height and width were measured at week 0 (May 2, 2008) and week 10 (July 11, 2008). 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. 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 Linda Dodge (trial coordination, data collection, report compilation), Ron Lane (pesticide application, pest management), Marian Shahid, Jennifer Orsi, Katie Gross, Hsin Yi Cheng, Yan Zhaung and Dylan Portnoff (plant culture, data collection). The materials being tested were supplied by the manufacturer/distributor. The plants were supplied by Monrovia Nursery, Visalia CA. 3

4 Table 1. Phytotoxicity changes over 10 weeks for plants treated with 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 6. Differing letters a, b, c designate significant differences among the four means; "Yes" or "no" indicates whether there was an overall significant treatment effect at the 5% level (NA means no variation in data; "yes at 10%" means treatment effect was significant at 10% but not at the 5% level). Means ± SD (n=9) Phytotoxicity Effect of BAS 659H G Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week (NA) 2 weeks (NA) 4 weeks (NA) 6 weeks (NA) 7 weeks no 8 weeks no 10 weeks no Agapanthus 0X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 1.00 ± 0.00 a 1.11 ± 0.11 a 1.22 ± 0.15 a PR# X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.89 ± 0.20 a 1.11 ± 0.11 a 1.33 ± 0.17 a 2X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 1.00 ± 0.00 a 1.11 ± 0.11 a 1.44 ± 0.18 a 4X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 1.11 ± 0.11 a 1.00 ± 0.00 a 1.56 ± 0.18 a Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week (NA) 2 weeks (NA) 4 weeks no 6 weeks no 7 weeks no 8 weeks no 10 weeks no Berberis 0X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 b 0.00 ± 0.00 a 0.00 ± 0.00 a PR# X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.11 ± 0.11 a 0.11 ± 0.11 a 0.11 ± 0.11 ab 0.00 ± 0.00 a 0.00 ± 0.00 a 2X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.11 ± 0.11 ab 0.22 ± 0.22 a 0.22 ± 0.15 a 4X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.33 ± 0.24 a 0.33 ± 0.24 a 0.44 ± 0.24 a 0.44 ± 0.24 a 0.22 ± 0.22 a Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week (NA) 2 weeks (NA) 4 weeks (NA) 6 weeks (NA) 7 weeks no 8 weeks no 10 weeks no Cotoneaster 0X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.56 ± 0.24 a 0.89 ± 0.20 a 1.00 ± 0.17 ab PR# X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.67 ± 0.29 a 1.11 ± 0.31 a 1.56 ± 0.24 a 2X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.33 ± 0.17 a 0.78 ± 0.15 a 1.00 ± 0.24 ab 4X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.11 ± 0.11 a 0.67 ± 0.24 a 0.89 ± 0.20 b Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week (NA) 2 weeks (NA) 4 weeks yes at 10% 6 weeks yes at 10% 7 weeks yes 8 weeks yes at 10% 10 weeks no Ligustrum 0X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 b 0.11 ± 0.11 a 0.00 ± 0.00 a PR# X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.22 ± 0.15 a 0.22 ± 0.15 a 0.67 ± 0.29 a 0.56 ± 0.24 a 0.22 ± 0.22 a 2X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 b 0.22 ± 0.15 a 0.00 ± 0.00 a 4X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.11 ± 0.11 a 0.11 ± 0.11 a 0.11 ± 0.11 b 0.56 ± 0.18 a 0.11 ± 0.11 a 4

5 Species: Agapanthus Material: BAS 659H G 10 Control 1X 8 2X 4X 6 Phytotoxicity Index 4 2 Species: Berberis Material: BAS 659H G 10 Control 1X 8 2X 4X 6 Phytotoxicity Index Day of trial Day of trial Species: Cotoneaster Material: BAS 659H G 10 Control 1X 8 2X 4X 6 Phytotoxicity Index 4 2 Species: Ligustrum Material: BAS 659H G 10 Control 1X 8 2X 4X 6 Phytotoxicity Index Day of trial Day of trial Figure 1. Phytotoxicity ratings for plants exposed to two applications of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 6 (arrows). See Table 5 for explanation of ratings. 5

6 Table 2. Growth changes over 10 weeks for plants treated with 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 6. Differing letters a, b, c designate significant differences among the four means; "Yes" or "no" indicates whether there was an overall significant treatment effect at the 5% level (NA means no variation in data; "yes at 10%" means treatment effect was significant at 10% but not at the 5% level). Means ± SD (n=9) Growth Effect of BAS 659h G Crop Increase by week 10 of: Treatment Height (cm) yes Average Width (cm) no Volume Index yes Agapanthus 0X 2.39 ± 0.68 a ± 1.82 a ± a 1X 0.67 ± 0.73 a ± 1.19 ab ± ab 2X ± 0.93 ab 9.22 ± 0.86 ab ± bc 4X ± 1.65 b 8.75 ± 1.42 b ± c Treatment Height (cm) no Average Width (cm) yes Volume Index yes Berberis 0X 3.22 ± 1.79 a ± 0.96 a ± ab 1X 1.17 ± 1.31 a ± 1.24 ab ± b 2X 4.67 ± 1.11 a ± 3.67 a ± a 4X 2.11 ± 1.09 a 9.67 ± 2.01 b ± b Treatment Height (cm) yes Average Width (cm) yes Volume Index yes Cotoneaster 0X ± 0.68 a ± 1.74 a ± a 1X ± 0.79 b ± 1.95 ab ± ab 2X ± 0.96 b ± 1.94 ab ± ab 4X ± 0.72 b ± 1.52 b ± b Treatment Height (cm) yes Average Width (cm) no Volume Index no Ligustrum 0X ± 2.50 ab 9.17 ± 1.25 a ± a 1X ± 2.33 a 9.17 ± 2.28 a ± a 2X 6.17 ± 2.29 ab 6.06 ± 1.66 a ± a 4X 4.56 ± 1.90 b 9.78 ± 1.76 a ± a 6

7 Block A Block B CONTROL 1X 2X 4X Block C Figure 2a. Agapanthus plants 10 weeks after two applications of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 6. 7

8 Block A Block B CONTROL 1X 2X 4X Block C Figure 2b. Berberis plants 10 weeks after two applications of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 6. 8

9 Block A Block B CONTROL 1X 2X 4X Block C Figure 2c. Cotoneaster plants 10 weeks after two applications of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 6. 9

10 Block A Block B CONTROL 1X 2X 4X Block C Figure 2d. Ligustrum plants 10 weeks after two applications of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 6. 10

11 Table 3. Materials & Methods/Recordkeeping Protocol number Product Short Name BAS 659h G (dimethenamid + pendimethalin) BAS 659h G (dimethenamid + pendimethalin) BAS 659h G (dimethenamid + pendimethalin) BAS 659h G (dimethenamid + pendimethalin) Production Site Field Container Field Container Field Container Field Container Description PR Number Crop Latin Name Agapanthus sp. Berberis thunbergii Cotoneaster horizontalis Ligustrum japonicum Crop Common Name Lily-Of-The-Nile Barberry Cotoneaster Privet Crop Cultivar Peter Pan Crimson Pygmy Perpusillus Texanum Plant Source Liners from Monrovia 2008_03_18 Liners from Monrovia 2008_03_18 Liners from Monrovia 2008_03_18 propagated from UCD stock plants Transplant Date 2008_04_ _04_ _04_ _04_28 Potting Mix UC Mix UC Mix UC Mix UC Mix Pot Size 1-gallon 1-gallon 1-gallon 1-gallon Spacing Pot-to-pot Pot-to-pot Pot-to-pot Pot-to-pot Expt. Design RCB RCB RCB RCB Number of Reps 3 blocks with 3 reps per block = 9 3 blocks with 3 reps per block = 9 3 blocks with 3 reps per block = 9 3 blocks with 3 reps per block = 9 Fertilizer Type Osmocote Osmocote Osmocote Osmocote Fertilizer 2008_05_ _05_ _05_ _05_02 Application Date Irrigation type and frequency automatic drip daily automatic drip daily automatic drip daily automatic drip daily First Application and Measurements Date 2008_05_ _05_ _05_ _05_02 Second Application Date Final Measurements Date 2008_06_ _06_ _06_ _06_ _07_ _07_ _07_ _07_11 11

12 Table 4. Environmental conditions during the experiment from 2008_05_02 to 2008_07_11 Date Net Rad (Ly/day) Precip (in) Max Air Temp ( F) Min Air Temp ( F) Avg Vap (mbars) Avg wspd (MPH) CIMIS ETo (in) Avg Rel Hum (%) 5/2/ /3/ /4/ /5/ /6/ /7/ /8/ /9/ /10/ /11/ /12/ /13/ /14/ /15/ /16/ /17/ /18/ /19/ /20/ /21/ /22/ /23/ /24/ /25/ /26/ /27/ /28/ /29/ /30/ /31/ /1/ /2/ /3/ /4/ /5/ /6/ /7/ /8/ /9/ /10/ /11/ /12/ /13/ /14/ /15/

13 Date Net 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 (%) 6/16/ /17/ /18/ /19/ /20/ /21/ /22/ /23/ /24/ /25/ /26/ /27/ /28/ /29/ /30/ /1/ /2/ /3/ /4/ /5/ /6/ /7/ /8/ /9/ /10/ /11/ Table 5. Numerical plant damage rating scale used for phytotoxicity determinations. Rating Description of plant damage 0 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 10% of plant) 4 10% 20% of plant damaged 5 Significant damage to much of plant (30% - 40%) 6 40% 60% of plant damaged 7 Chlorosis or necrosis on most of plant (60% - 70%) 8 Abscised leaves, branch dieback 9 Tissue severely damaged (80% - 100% of plant) 10 Complete kill 13

14 Table 6a Raw Data for Agapanthus Phytotoxicity Report Form Agapanthus BAS 659h G IR4 Trial Phytotoxicity at week Plant Size at week 0 Plant Size at week 10 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

15 Table 6b Raw Data for Berberis Phytotoxicity Report Form Berberis BAS 659h G IR4 Trial Phytotoxicity at week Plant Size at week 0 Plant Size at week 10 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

16 Table 6c Raw Data for Cotoneaster Phytotoxicity Report Form Cotoneaster BAS 659h G IR4 Trial Phytotoxicity at week Plant Size at week 0 Plant Size at week 10 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

17 Table 6d Raw Data for Ligustrum Phytotoxicity Report Form Ligustrum BAS 659h G IR4 Trial Phytotoxicity at week Plant Size at week 0 Plant Size at week 10 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

18 Appendix A 2008/2009 Crop Safety with Over-the-top Applications of Select Herbicide Materials Ornamental Protocol Number: Objective: Determine phytotoxicity of BAS 656EC, BAS 659G, Broadstar 0.25G VC1604, Mesotrione G, and V G to woody ornamental plants and BAS 659G on herbaceous perennials. 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: Depending upon research site and plant materials, various experiments can be established. Two applications are to be made approximately 6 weeks apart, with the first application within 7 days after potting, preferable between 24 and 48 hours. However, plant materials must have broken dormancy prior to first application. See notes below for Broadstar New Formulation. For liquid applications, use a minimum of 20 gal per acre. Applications should be made over the top of the plants using application equipment consistent with conventional commercial equipment. For all materials, target dry foliage. If dew is present at the time of application, note it. Irrigate with ½ inch water between 1 and 4 hours after application. Note: Liquid materials need at least 1 hour drying time prior to irrigation. Plant Materials: Contact your Regional Coordinator for an up-to-date list. Plants grown in field containers are preferred to in-ground. Evaluations: Record plant height & width at initial and final evaluations only. At 1, 2, and 4 weeks after each application, record phytotoxicity on a scale of 0 to 10 (0 = No phytotoxicity; 10 = Complete kill). If appropriate, also include ratings for chlorosis, defoliation, stunting or other growth effects on a scale of 0 to 10 (0 = No effect; 10 = 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 Special Instructions Contact Information to obtain materials BAS 656h 63.9%EC (dimethenamid-p) BAS 659h 1.75G (dimethenamid-p + pendimethalin) Broadstar 0.25G VC1604 Mesotrione G 21 fl oz per acre (0.97 lb ai) 42 fl oz per acre (1.94 lb ai) 84 fl oz per acre (3.88 lb ai) 150 lb per acre (2.65 lb ai 300 lb per acre (5.3 lb ai) 600 lb per acre (10.6 lb ai) 150 lb per acre (0.375 lb ai) 300 lb per acre (0.75 lb ai) 600 lb per acre (1.5 lb ai) 100 lb product per acre (2.1 lb ai/a) 200 lb product per acre (4.2 lb ai/a 300 lb product per acre (6.3 lb ai/a) Woody ornamentals only BASF, Kathie Kalmowitz, , kathie.kalmowitz@basf.com Do not apply at the first application timing within 7 days after potting; only apply at the second application timing. BASF, Kathie Kalmowitz, , kathie.kalmowitz@basf.com Valent, Joe Chamberlin, , jcham@valent.com Woody ornamentals only Syngenta, Nancy Rechsigl, , nancy.rechcigl@syngenta.com V G 150 lb per acre (0.75 lb ai/acre) 300 lb per acre (1.5 lb ai/acre) 600 lb per acre (3.0 lb ai/acre) Untreated Valent, Joe Chamberlin, , jcham@valent.com 18