IR-4 Ornamental Horticulture Program Research Report Form

Transcription

1 Project Title: Phytotoxicity of BroadStar 0.25G (VC1604) applied over the top to Nandina, Nepeta and Potentilla Protocol #: Narrative Summary (Results/Discussion) Note: Because the plant root balls for these species were less than 4 inches in diameter, the single application protocol was chosen for these trials. Nandina domestica Phytotoxicity. The phytotoxicity rating increases for Nandina plants treated with 1X or 4X levels of BroadStar were significantly greater than those for plants treated with 2X BroadStar by week 4 (Tables 1 and 6a, Figures 1, 2a and 3). The control plants showed some blemishes by week 4 but the level was significantly lower than that for all plants treated with BroadStar. Symptoms of BroadStar phytotoxicity on Nandina plants consisted of chlorosis and distortion of leaflets and red to purple coloration of leaflet veins (Figure 3). Plant Growth. No significant treatment effect of BroadStar on Nandina was noted for height or width increase (Tables 2 and 6a, Figure 2a). BroadStar had a phytotoxicity effect on Nandina, suggesting that the product should not be used on this plant. Nepeta cataria Phytotoxicity. The phytotoxicity rating increases for Nepeta plants treated with the 1X, 2X or 4X levels of BroadStar were significantly greater than those for the control plants at week 2 (Tables 1 and 6b, Figure 1). At that time, the symptoms appeared as bronzing of leaves and necrosis of older leaves. By week 4, however, all plants were flowering and setting seed and some older leaves on all plants were beginning to senesce. This was reflected in elevated ratings for the control plants such that increases were not significantly different for the control and 1X BroadStar treated plants (Figure 1). By week 4 all plants showed symptoms of leaf chlorosis, bronzing and necrosis (Figures 2b and 3). Plant Growth. There was a significant effect of BroadStar on canopy volume increase for Nepeta with plants in the 1X, 2X, and 4X treatment groups being 23%, 17%, and 38% smaller, respectively, than the control plants (Tables 2 and 6b, Figure 2b). The plant growth reduction and phytotoxicity due to BroadStar suggests that the product is not safe on Nepeta. Potentilla fruticosa Abbotswood Phytotoxicity. There were slight but statistically significant treatment effects from BroadStar on Potentilla. After the first and second weeks the effect was minor with phytotoxicity ratings below 1.5 (Tables 1 and 6c, Figure 1). At week 4 the plants in the 2X and 4X BroadStar treatments Researcher(s): Heiner Lieth, UC Davis 1

2 showed significantly greater phytotoxicity index levels compared with the control plants. Phytotoxicity symptoms included leaf chlorosis, leaf necrosis and red coloration of leaf veins (Figure 3). Plant Growth. Height was not affected by BroadStar. Width increase over the experiment, however, was significantly reduced by BroadStar (Tables 2 and 6c, Figure 2c). The volume index, representing overall growth was significantly reduced at all levels. BroadStar resulted in slight phytotoxicity and significant growth suppression, suggesting that this product is not safe on Potentilla. Materials & Methods Plant Material and Culture. The plants for these trials were grown as indicated in Table 3. The experiment ran from July 14, 2009 to August 11, 2009 in an outdoor nursery with full sun exposure. The plants were irrigated daily during the 4-week experiment using an automatic drip irrigation system delivering 2L per hour. Environmental conditions during the trial are summarized 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 material was applied on July 14, Data Collection. Phytotoxicity ratings were taken at week 0, 1, 2, and 4. The dates for those observations were July 14, 21 and 28 and August 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 (July 14, 2009) and week 4 (August 11, 2009). 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 Researcher(s): Heiner Lieth, UC Davis 2

3 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), David La, Maria Contador and Ho-Yun Kim (plant culture, data collection). The materials being tested were supplied by the manufacturer/distributor. The Nandina plants were supplied by Hines Nurseries, Winters CA. The Nepeta plants were grown from seed (Lake Valley Seed, Boulder CO). The Potentilla plants were supplied by Village Nurseries, Sacramento CA. Table 1. Phytotoxicity changes over 4 weeks for plants treated with 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb. per acre BroadStar 0.25G at week 0. 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 ± SE (n=9) Phytotoxicity Effect of BroadStar on Nandina Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week yes 2 weeks yes 4 weeks yes 0X 0.00 ± 0.00 b 0.22 ± 0.15 c 0.67 ± 0.24 c 1X 0.33 ± 0.17 a 1.11 ± 0.26 ab 2.78 ± 0.22 a 2X 0.00 ± 0.00 b 0.67 ± 0.37 bc 1.67 ± 0.47 b 4X 0.33 ± 0.17 a 1.78 ± 0.40 a 2.89 ± 0.31 a Phytotoxicity Effect of BroadStar on Nepeta Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week yes 2 weeks yes 4 weeks yes 0X 0.00 ± 0.00 c 0.00 ± 0.00 c 3.00 ± 0.00 c 1X 0.67 ± 0.24 b 1.11 ± 0.26 b 3.22 ± 0.15 c 2X 0.11 ± 0.11 c 0.89 ± 0.31 b 3.67 ± 0.17 b 4X 1.11 ± 0.11 a 2.22 ± 0.22 a 4.33 ± 0.17 a Phytotoxicity Effect of BroadStar on Potentilla Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week yes 2 weeks yes 4 weeks yes at 10% 0X 0.00 ± 0.00 b 0.00 ± 0.00 b 0.22 ± 0.22 b 1X 0.44 ± 0.24 ab 0.44 ± 0.24 b 0.89 ± 0.35 ab 2X 0.44 ± 0.24 ab 0.67 ± 0.29 ab 1.56 ± 0.50 a 4X 1.11 ± 0.31 a 1.33 ± 0.37 a 1.78 ± 0.49 a Researcher(s): Heiner Lieth, UC Davis 3

4 Phytotoxicity Index Material: BroadStar Control 1X 2X 4X Species: Nandina Phytotoxicity Index Material: BroadStar Control 1X 2X 4X Species: Nepeta Day of trial Day of trial Phytotoxicity Index Material: BroadStar Control 1X 2X 4X Species: Potentilla Day of trial Figure 1. Phytotoxicity ratings for plants exposed to one application of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb. per acre BroadStar 0.25G at week 0 (arrow). See Table 5 for explanation of ratings. Researcher(s): Heiner Lieth, UC Davis 4

5 Table 2. Growth changes over 4 weeks for plants treated with 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb. per acre BroadStar 0.25G at week 0. 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 ± SE (n=9) Growth Effect of BroadStar on Nandina Increase by week 4 of: Treatment Height (cm) no Average Width (cm) no Volume Index no 0X 3.72 ± 1.04 a 3.75 ± 0.92 a ± a 1X 1.00 ± 1.12 a 1.94 ± 0.82 a ± a 2X 2.78 ± 1.40 a 3.81 ± 0.74 a ± a 4X 0.61 ± 0.96 a 2.69 ± 1.00 a ± a Growth Effect of BroadStar on Nepeta Increase by week 4 of: Treatment Height (cm) yes at 10% Average Width (cm) no Volume Index yes 0X ± 1.65 a ± 1.87 a ± a 1X ± 1.95 ab ± 1.40 ab ± ab 2X ± 2.62 a ± 1.12 ab ± ab 4X ± 2.05 b ± 2.76 b ± b Growth Effect of BroadStar on Potentilla Increase by week 4 of: Treatment Height (cm) no Average Width (cm) yes Volume Index yes at 10% 0X ± 2.24 a ± 3.04 a ± a 1X 9.11 ± 2.89 a ± 1.23 ab ± b 2X ± 1.50 a ± 2.92 bc ± b 4X ± 1.31 a ± 1.22 c ± b Researcher(s): Heiner Lieth, UC Davis 5

6 Block A Block B CONTROL 1X 2X 4X Block C Figure 2a. Nandina plants 4 weeks after one application of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb. per acre BroadStar 0.25G at week 0. Researcher(s): Heiner Lieth, UC Davis 6

7 Block A Block B CONTROL 1X 2X 4X Block C Figure 2b. Nepeta plants 4 weeks after one application of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb. per acre BroadStar 0.25G at week 0. Researcher(s): Heiner Lieth, UC Davis 7

8 Block A Block B CONTROL 1X 2X 4X Block C Figure 2c. Potentilla plants 4 weeks after one application of 0 (Control), 150 (1X), 300 (2X) or 600 (4X) lb. per acre BroadStar 0.25G at week 0. Researcher(s): Heiner Lieth, UC Davis 8

9 Nandina Nepeta Potentilla Figure 3. Phytotoxicity symptoms seen on plants at 4 weeks that had been treated with 150 lb. per acre (1X) BroadStar 0.25G at week 0. Researcher(s): Heiner Lieth, UC Davis 9

10 Table 3. Materials & Methods/Recordkeeping Protocol number Product Short Name BroadStar 0.25G (VC1604) BroadStar 0.25G (VC1604) BroadStar 0.25G (VC1604) Production Field Container Field Container Field Container Site Description PR Number Crop Latin Nandina domestica Nepeta cataria Potentilla fruticosa Name Crop Common Heavenly Bamboo Catnip Shrubby Cinquefoil Name Crop Cultivar Abbotswood Plant Source Liners from Hines Nurseries Grown from seed (Lake Valley Seed) Sown Liners from Village Nurseries Transplant Date Potting Mix UC Mix UC Mix UC Mix Pot Size 1-gallon 1-gallon 1-gallon Spacing Pot-to-pot Pot-to-pot Pot-to-pot Expt. Design 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 Fertilizer Type Osmocote Osmocote Osmocote Fertilizer Application Date Irrigation type and frequency First Application and Measurements Date Final Measurements Date automatic drip automatic drip automatic drip irrigation daily irrigation daily irrigation daily Researcher(s): Heiner Lieth, UC Davis 10

11 Table 4. Environmental conditions during the experiment from to Max Air Temp ( F) Min Air Temp ( F) Avg Air Temp ( F) Avg Vap (mbars) PM ETo (in) Avg Rel Hum (%) Date Sol Rad (Ly/day) Precip (in) 7/14/ /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/ Researcher(s): Heiner Lieth, UC Davis 11

12 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 Researcher(s): Heiner Lieth, UC Davis 12

13 Table 6a Raw Data for Nandina Phytotoxicity Report Form Nandina IR4 Trial BroadStar Phytotoxicity at week Plant Size at week 0 Plant Size at week 4 Width Height Width1 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 Researcher(s): Heiner Lieth, UC Davis 13

14 Table 6b Raw Data for Nepeta Phytotoxicity Report Form Nepeta IR4 Trial BroadStar Phytotoxicity at week Plant Size at week 0 Plant Size at week 4 Width Height Width1 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 Researcher(s): Heiner Lieth, UC Davis 14

15 Table 6c Raw Data for Potentilla Phytotoxicity Report Form Potentilla IR4 Trial BroadStar Phytotoxicity at week Plant Size at week 0 Plant Size at week 4 Width Height Width1 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 Researcher(s): Heiner Lieth, UC Davis 15

16 Appendix A 2009 Crop Safety with Over-the-top Applications of Select Herbicide Materials Ornamental Protocol Number: Objective: Determine phytotoxicity of BroadStar 0.25G VC1604, Freehand, Snapshot, sulfosulfuron, Tower EC, and V G and to ornamental horticulture plants. 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 0.25G VC1604. 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. Treatments: See table on next page. 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, soiltype or soil-less media, application equipment, irrigation, liner size, plant height & width, and plant growth stage at application and data collection dates. Reports: Reports submitted electronically on the standard IR-4 Ornamental Horticulture are preferred. 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 x4629, palmer@aesop.rutgers.edu OR Ely Vea, 308 Aston Forest Lane, Crownsville, MD 21032, Phone & FAX#: , evvea@comcast.net. Draft Date: 3/23/09 Revised By: CLP Researcher(s): Heiner Lieth, UC Davis 16

17 Treatments: Product Priority Rate Product ( per acre BroadStar 0.25G VC1604 (flumioxazin) Freehand 1.75G (dimethenamid-p + pendimethalin) A/B A/B 150 lb (0.375 lb 300 lb (0.75 lb 600 lb (1.5 lb 150 lb (2.65 lb 300 lb (5.3 lb 600 lb (10.6 lb Mesotrione SC C 6 oz (0.187 lb 8 oz (0.25 lb 12 oz (0.37 lb Snapshot B/C 100 lb (2.5 lb (trifluralin + isoxaben) 200 lb (5.0 lb 400 lb (10.0 lb Sulfosulfuron C 1.25 oz Special Instructions Test only on woody ornamentals. If root ball of liner is less than 4 in diameter, only apply at second application timing. If root ball is 4 or greater in diameter, apply at both application timings. Certain woody ornamentals and ornamental grasses only 2.5 oz 5.0 oz Tower 63.9%EC A/B 21 fl oz (0.97 lb (dimethenamid-p) 42 fl oz (1.94 lb 84 fl oz (3.88 lb V G A/B 150 lb (0.75 lb Test only on Conifers and (imazosulfuron) finish ongoing woody 300 lb (1.5 lb ornamentals species trials. 600 lb (3.0 lb Untreated Contact Information to obtain materials Valent, Joe Chamberlin, , jcham@valent.com BASF, Kathie Kalmowitz, , kathie.kalmowitz@basf.com Syngenta, Nancy Rechsigl, , nancy.rechcigl@syngenta.com Dow Agrosciences, Raymond Miller, (817) , RCMiller2@dow.com Monsanto, James Cole, , james.t.cole@monsanto.com BASF, Kathie Kalmowitz, , kathie.kalmowitz@basf.com Valent, Joe Chamberlin, , jcham@valent.com Researcher(s): Heiner Lieth, UC Davis 17