IR-4 Ornamental Horticulture Program Trial Report

Transcription

1 Project Title: Phytotoxicity on Arborvitae (Thuja occidentalis Emerald Green ) with over the top applications of select sedge control materials Protocol #: Report date: October 2, 2007 Authors: Heiner Lieth and Linda Dodge Department of Plant Sciences University of California, Davis Davis, CA Narrative Summary: Thuja occidentalis Emerald Green plants growing in 1-gallon containers received two applications of BAS 656h EC (dimethenamid), BAS 659h 1.75G (dimethenamid + pendimethalin) or F6875 (Sulfentrazone + unknown proprietary material) at 1X, 2X or 4X the recommended rates as described in the Materials and Methods section of this report. The interval between applications was 8 weeks. Another group of plants received two applications of Mesotrione at 1X, 1.33X or 2X the recommended rate. The interval between applications was 4 weeks. The plants in the Control group received no herbicide. The trial was conducted outdoors over 8-12 weeks from May 31, 2007 to August 22, Results During the first two weeks, the phytotoxicity values for Thuja plants treated with BAS 656h EC (dimethenamid) were zero for all rates (Tables 1 and 2, Figures 1,2 and 6). At week 4 all plants treated with dimethanamid averaged phytotoxicity index levels of 1. This was due to tip burn (Figure 6). The second application of dimethanamid was on week 8 and subsequent to that there was a significant increase in phytotoxicity values due to the material at weeks 9 and 10. By week 12, the plants in the 4X treatment reached a phytotoxicity mean of 2.9; the mean phytotoxicity index values for the 1X and 2X treatments were both 1.9. The Thuja plants grew substantially during the study but there were no significant treatment effects for the change in height. Width changes, on the other hand, were positive 2.4 and 1.3 cm, respectively, in the control and 1X treatment and near zero in the 2X and 4X treatments. The volume index showed significant treatment effects. In particular the mean volume index appeared to decline with increasing dosage. During the first four weeks, the phytotoxicity values for Thuja plants treated with BAS 659h 1.75G (dimethenamid + pendimethalin) were zero for all rates (Tables 1 and 3, Figures 1 and 3). The second application of this herbicide was on week 8 and subsequent to that there was a significant increase in phytotoxicity values due to the material at weeks 9 and 10. The mean value was 1 in all treatments. By week 12, the plants in the 4X treatment reached a phytotoxicity mean of 1.9; the mean phytotoxicity index values of the 1X and 2X treatments were both

2 The Thuja plants grew substantially during the study but there were no significant treatment effects for the change in height, width or volume index. During the first four weeks, the phytotoxicity index values for Thuja plants treated with F6875 were zero for all rates (Tables 1 and 4, Figures 1 and 4). At week 9 and thereafter all plants treated with F6875 averaged phytotoxicity index levels of 1. This was due to chlorosis of shoot tips. The Thuja plants grew substantially during the study; there were no significant treatment effects for the change in height at the 5% level. At the 10% level significant differences suggested more growth in the treatments that received the herbicide. Width changes and volume index changes showed no significant treatment effects. The Thuja plants treated with Mesotrione at all rates exhibited significantly greater phytotoxicity index levels after 4 weeks (Tables 1 and 5, Figures 1,5 and 7). This situation got slightly worse with the second application (Figure 7). The control plants grew 4.4 cm in height and 1.4 cm in width over the 8 week period. The plants in the 1X treatment grew significantly less, increasing in height only 3 cm and in width only 0.4 cm. The increase in volume index for the plants treated with Mesotrione at the 1X level was less than half of the control plants. The plants treated at the 2X level had height, width and volume index increases that were not significantly different from the 1X treatment. Discussion BAS 656h EC (dimethenamid) is not safe for over the top application on Thuja because the material causes burning of shoot tips and subsequent distorted growth. This is especially true for multiple applications. BAS 659h 1.75G (dimethenamid + pendimethalin) is safe at the recommended rate for over the top application on Thuja. Higher phytotoxicity levels in the form of chlorotic shoot tips on week 12 at the 4X rate suggest that while the material is safe at 1X, growers should be careful to not exceed the labeled rate. F6875 is safe for over the top application on Thuja. Mesotrione is not safe for over the top application on Thuja. The material causes bleaching of shoot tips, which develops into necrosis. Subsequent growth is delayed and distorted. 2

3 Results Table Table 1. Phytotoxicity and growth changes over 12 weeks for Thuja occidentalis Emerald Green treated with 0 (Control), 1X, 2X or 4X BAS 656h EC (dimethenamid), BAS 659h 1.75G (dimethenamid + pendimethalin) or F6875 (sulfentrazone+) at weeks 0 and 8. Changes over 8 weeks for plants treated with 0 (Control), 1X, 1.33X or 2X Mesotrione at weeks 0 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 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 Dimethanamid on Thuja Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week (NA) 2 weeks (NA) 4 weeks yes 0X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 b 1X 0.00 ± 0.00 a 0.00 ± 0.00 a 1.00 ± 0.00 a 2X 0.00 ± 0.00 a 0.00 ± 0.00 a 1.00 ± 0.00 a 4X 0.00 ± 0.00 a 0.00 ± 0.00 a 1.00 ± 0.00 a Phytotoxicity Index increase from beginning of trial until: Treatment 9 weeks yes 10 weeks yes 12 week yes 0X 0.00 ± 0.00 c 0.00 ± 0.00 d 0.00 ± 0.00 c 1X 1.11 ± 0.11 b 1.22 ± 0.15 b 1.89 ± 0.11 b 2X 1.00 ± 0.00 b 1.00 ± 0.00 c 1.89 ± 0.11 b 4X 2.00 ± 0.00 a 2.00 ± 0.00 a 2.89 ± 0.11 a Growth Effect of Dimethanamid on Thuja Increase by week 12 of: Treatment Height (cm) no Average Width yes Volume Index yes (cm) 0X 5.56 ± 0.36 b 2.42 ± 0.32 a ± a 1X 6.67 ± 0.63 ab 1.28 ± 0.36 ab ± ab 2X 7.33 ± 0.52 a ± 0.71 c ± b 4X 5.89 ± 0.80 ab 0.14 ± 0.33 bc ± b Phytotoxicity Effect of Dimethanamid + Pendimethalin on Thuja Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week (NA) 2 weeks (NA) 4 weeks (NA) 0X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 1X 0.00 ± 0.00 a 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 4X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a Phytotoxicity Index increase from beginning of trial until: Treatment 9 weeks yes 10 weeks yes 12 week yes 0X 0.00 ± 0.00 b 0.00 ± 0.00 b 0.00 ± 0.00 c 1X 1.00 ± 0.00 a 1.00 ± 0.00 a 1.00 ± 0.00 b 2X 1.00 ± 0.00 a 1.00 ± 0.00 a 1.00 ± 0.00 b 4X 1.00 ± 0.00 a 1.00 ± 0.00 a 1.89 ± 0.11 a Growth Effect of Dimethanamid + Pendimethalin on Thuja Increase by week 12 of: Treatment Height (cm) no Average Width (cm) no Volume Index no 0X 5.56 ± 0.36 a 2.42 ± 0.32 a ± a 1X 5.56 ± 0.80 a 1.44 ± 0.84 a ± a 2X 5.67 ± 0.72 a 2.50 ± 0.48 a ± a 4X 5.83 ± 0.82 a 1.94 ± 0.89 a ± a 3

4 Phytotoxicity Effect of F6875 on Thuja Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week (NA) 2 weeks (NA) 4 weeks (NA) 0X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 1X 0.00 ± 0.00 a 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 4X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a Phytotoxicity Index increase from beginning of trial until: Treatment 9 weeks yes 10 weeks yes 12 week yes 0X 0.00 ± 0.00 b 0.00 ± 0.00 b 0.00 ± 0.00 c 1X 1.00 ± 0.00 a 1.00 ± 0.00 a 1.00 ± 0.00 b 2X 1.00 ± 0.00 a 1.00 ± 0.00 a 1.00 ± 0.00 b 4X 1.00 ± 0.00 a 1.11 ± 0.11 a 1.33 ± 0.24 a Growth Effect of F6875 on Thuja Increase by week 12 of: Treatment Height (cm) yes at Average Width (cm) no Volume Index no 10% 0X 5.56 ± 0.36 b 2.42 ± 0.32 a ± a 1X 7.94 ± 1.11 a 2.00 ± 0.60 a ± a 2X 7.72 ± 0.74 ab 1.67 ± 0.82 a ± a 4X 6.94 ± 0.74 ab 0.97 ± 0.83 a ± a Phytotoxicity Effect of Mesotrione on Thuja Phytotoxicity Index Increase from beginning of trial until: Treatment 1 week (NA) 2 weeks yes at 4 weeks yes 10% 0X 0.00 ± 0.00 a 0.00 ± 0.00 b 0.00 ± 0.00 c 1X 0.00 ± 0.00 a 0.44 ± 0.18 ab 1.11 ± 0.31 b 1.33X 0.00 ± 0.00 a 0.56 ± 0.18 a 2.00 ± 0.37 ab 2X 0.00 ± 0.00 a 0.89 ± 0.26 a 2.11 ± 0.39 a Phytotoxicity Index increase from beginning of trial until: Treatment 5 weeks yes 6 weeks yes 8 week yes 0X 0.00 ± 0.00 c 0.00 ± 0.00 c 0.00 ± 0.00 c 1X 1.33 ± 0.33 b 1.33 ± 0.29 b 1.56 ± 0.29 b 1.33X 2.22 ± 0.28 a 2.44 ± 0.24 a 2.67 ± 0.17 a 2X 2.11 ± 0.31 ab 2.56 ± 0.18 a 2.67 ± 0.17 a Growth Effect of Mesotrione on Thuja Increase by week 8 of: Treatment Height (cm) yes Average Width (cm) no Volume Index no 0X 4.39 ± 0.33 a 1.36 ± 0.23 a ± a 1X 3.00 ± 0.34 b 0.42 ± 0.34 b ± b 1.33X 2.50 ± 0.20 b 0.64 ± 0.36 ab ± ab 2X 2.28 ± 0.28 b 0.72 ± 0.29 ab ± b 4

5 Raw Data: Table 2. Phytotoxicity and plant growth data collected for plants of Thuja occidentalis Emerald Green treated with two applications of 0 (Control), 0.97 (1X), 1.94 (2X) or 3.88 (4X) lb ai/acre BAS 656h EC (dimethenamid) at weeks 0 and 8 of a 12-week experiment. Phytotoxicity Report Form Thuja Dimethanamid IR4 Trial Phytotoxicity at week Plant Size at week 0 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

6 Table 3. Phytotoxicity and plant growth data collected for plants of Thuja occidentalis Emerald Green treated with two applications of 0 (Control), 2.65 (1X), 5.3 (2X) or 10.6 (4X) lb ai/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 8 of a 12-week experiment. Phytotoxicity Report Form Thuja Dimethanamid + Pendimethalin IR4 Trial Phytotoxicity at week Plant Size at week 0 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

7 Table 4. Phytotoxicity and plant growth data collected for plants of Thuja occidentalis Emerald Green treated with two applications of 0 (Control), (1X), 0.75 (2X) or 1.5 (4X) lb ai/acre F6875 (sulfentrazone+) at weeks 0 and 8 of a 12-week experiment. Phytotoxicity Report Form Thuja F6875 IR4 Trial Phytotoxicity at week Plant Size at week 0 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

8 Table 5. Phytotoxicity and plant growth data collected for plants of Thuja occidentalis Emerald Green treated with two applications of 0 (Control), (1X), 0.25 (1.33X) or 0.37 (2X) lb ai/acre Mesotrione at weeks 0 and 4 of an 8-week experiment. Phytotoxicity Report Form Thuja Mesotrione IR4 Trial Phytotoxicity at week Plant Size at week 0 Plant Size at week 8 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

9 Phytotoxicity Index Species: Thuja Material: Dimethanamid 10 Control 1X 8 2X 4X IR-4 Ornamental Horticulture Program Phytotoxicity Index Species: Thuja Material: Dimethanamid + Pendimethalin 10 Control 1X 8 2X 4X Day of trial Day of trial Phytotoxicity Index Species: Thuja Material: F Control 1X 8 2X 4X Species: Thuja Material: Mesotrione 10 Control 1X X 2X 6 Phytotoxicity Index Day of trial Day of trial Figure 1. Phytotoxicity ratings for Thuja occidentalis Emerald Green plants exposed to two applications of 0 (Control), 1X, 2X or 4X BAS 656h EC (dimethenamid), BAS 659h 1.75G (dimethenamid + pendimethalin) or F6875 (sulfentrazone+) at weeks 0 and 8. Phytotoxicity ratings over 8 weeks for plants treated with 0 (Control), 1X, 1.33X or 2X Mesotrione at weeks 0 and 4. Arrows indicate application dates. See Table 6 for explanation of ratings. 9

10 Block A Block B CONTROL 1X 2X 4X Block C Figure 2. Thuja occidentalis Emerald Green plants 12 weeks after two applications of 0 (Control), 0.97 (1X), 1.94 (2X) or 3.88 (4X) lb ai/acre BAS 656h EC (dimethenamid) at weeks 0 and 8. 10

11 Block A Block B CONTROL 1X 2X 4X Block C Figure 3. Thuja occidentalis Emerald Green plants 12 weeks after two applications of 0 (Control), 2.65 (1X), 5.3 (2X) or 10.6 (4X) lb ai/acre BAS 659h 1.75G (dimethenamid + pendimethalin) at weeks 0 and 8. 11

12 Block A Block B CONTROL 1X 2X 4X Block C Figure 4. Thuja occidentalis Emerald Green plants 12 weeks after two applications of 0 (Control), (1X), 0.75 (2X) or 1.5 (4X) lb ai/acre F6875 (sulfentrazone+) at weeks 0 and 8. 12

13 Block A Block B CONTROL 1X 2X 4X Block C Figure 5. Thuja occidentalis Emerald Green plants 8 weeks after two applications of 0 (Control), (1X), 0.25 (1.33X) or 0.37 (2X) lb ai/acre Mesotrione at weeks 0 and 4. 13

14 Control 1X Dimethenamid 2X Dimethenamid 4X Dimethenamid Figure 6. Phytotoxicity symptoms seen on Thuja occidentalis Emerald Green plants 12 weeks after two applications of 0 (Control), 0.97 (1X), 1.94 (2X) or 3.88 (4X) lb ai/acre BAS 656h EC (dimethenamid) at weeks 0 and 8. 14

15 Control 1X Mesotrione 2X Mesotrione 4X Mesotrione Figure 7. Phytotoxicity symptoms seen on Thuja occidentalis Emerald Green plants 8 weeks after two applications of 0 (Control), (1X), 0.25 (1.33X) or 0.37 (2X) lb ai/acre Mesotrione at weeks 0 and 4. 15

16 Materials & Methods/Recordkeeping: Crop History Crop Cultivar/Variety: Date of Cuttings: 1/24/2007 Date of Emergence: Date of Transplanting: 5/23/07 Potting Mix: Pot size & spacing: Row spacing: Product(s) applied prior to start of experiment: Product Rate Application Type IR-4 Ornamental Horticulture Program Arborvitae (Thuja occidentalis Emerald Green ) UC Mix: 1/3 sand, 1/3 peat, 1/3 bark (by volume) 1-gallon pots spaced on 12-inch centers Date of Crop Growth Application Stage Osmocote tsp./pot Topdress 5/23/07 At transplanting NA Application Volume Experiment Information Experimental Design: Number of Reps: Randomized complete block 9 (3 blocks x 3 reps per block) Application Equipment: manual spray bottles or shaker containers Product(s) applied during experiment (including treatments, fertilizers, etc): Product Rate(s) Application Type Date of Application Crop Growth Stage BAS 656h EC 0.97, 1.94, Spray OTT 5/31/07 Actively growing (dimethenamid) 3.88 lb BAS 659h 1.75G (dimethenamid + pendimethalin) F6875 ai/acre 2.65, 5.3, 10.6 lb ai/acre 0.375, 0.75, (sulfentrazone+) 1.5 lb ai/acre Mesotrione 0.187, 0.25, 0.37 lb ai/acre Mesotrione 0.187, 0.25, 0.37 lb ai/acre BAS 656h EC (dimethenamid) BAS 659h 1.75G (dimethenamid + pendimethalin) F6875 (sulfentrazone+) 0.97, 1.94, 3.88 lb ai/acre 2.65, 5.3, 10.6 lb ai/acre 0.375, 0.75, 1.5 lb ai/acre Ganular OTT 5/31/07 Actively growing Ganular OTT 5/31/07 Actively growing Spray OTT 5/31/07 Actively growing Spray OTT 6/27/07 Actively growing Spray OTT 7/25/07 Actively growing Granular OTT 7/25/07 Actively growing Granular OTT 7/25/07 Actively growing Application Volume 16

17 Materials & Methods: Plant Material and Culture. Cuttings of Thuja occidentalis Emerald Green were taken from UCD stock plants on January 24, 2007 and rooted in a medium of 50% perlite and 50% vermiculite. The cuttings were allowed to root in a mist bench for 2 months and then grown on in a greenhouse under natural day length and day/night temperatures of 75 /65 F. The plants were transplanted to 1-gallon pots containing UC Mix on May 23, The experiment ran from May 31, 2007 to August 22, 2007 in an outdoor nursery under 50% shade (Table 7). The plants were irrigated daily during the 12-week experiment using an automatic drip system delivering 2L 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 0 (Control), 1X, 2X or 4X rates of 3 herbicides with 9 replicates per treatment. Thirty-six plants were randomly chosen and individually tagged for treatment with 0 (Control), 1X, 1.33X or 2X rates of Mesotrione with 9 replicates per treatment. These dosages were prescribed in IR4 Ornamental Protocol (Appendix A). The plants received the first application on May 31, 2007, the second application of Mesotrione 4 weeks later on June 27, 2007 and the second application of the other three materials 8 weeks later on July 25, Data Collection. Phytotoxicity ratings were taken at week 0, 1, 2, 4, 8, 9, 10 and 12 for three of the herbicides and at week 0, 1, 2, 4, 5, 6, and 8 for Mesotrione. Visual phytotoxicity evaluations were based on a numerical rating scale ranging from 0 (no injury) to 10 (complete kill) (Table 6). Table 6. 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 Plant height and width were measured at week 0 (May ), at week 8 for Mesotrione ( July 25, 2007) and at week 12 (August 22, 2007) for the other herbicides. 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 17

18 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: Ron Lane (pesticide application, pest management) and Priyasheila Singh (plant culture, data collection). The materials being tested were supplied by the manufacturer/distributor. The plants were propagated from plants provided by Monrovia Nursery, Visalia CA. 18

19 Environmental conditions during the experiment: Table 7. Environmental conditions during the 12 weeks of the experiment to determine phytotoxicity of BAS 656h EC (dimethenamid), BAS 659h 1.75G (dimethenamid + pendimethalin), F6875 (sulfentrazone+) or Mesotrione on Thuja occidentalis Emerald Green. (continued on next page) Max Air Temp ( F) Min Air Temp ( F) Date Sol Rad (Ly/day) Precip (in) CIMIS ETo (in) Avg Rel Hum (%) 5/30/ /31/ /1/ /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/ /1/ /2/ /3/ /4/ /5/ /6/ /7/ /8/ /9/ /10/ /11/ /12/ /13/ /14/

20 Max Air Temp ( F) IR-4 Ornamental Horticulture Program Min Air Temp ( F) Date Sol Rad (Ly/day) Precip (in) CIMIS ETo (in) Avg Rel Hum (%) 7/15/ /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/ /16/ /17/ /18/ /19/ /20/ /21/ /22/

21 APPENDIX A Phytotoxicity with over the top applications of select sedge control materials Ornamental Protocol Number: Objective: Determine phytotoxicity of dimethenamid-p + pendimethalin G, F6875, and mesotrione to certain herbaceous ornamental plants, and these three plus dimethenamid-p EC on woody ornamental 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: Two applications made approximately 4 weeks apart for Mesotrione and 8 weeks apart for F6875 and dimethenamid formulations, with the first application 7 days after potting. However, plant materials must have broken dormancy prior to first application. 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. Please see table below for instructions for post-application irrigation. Plant Materials: Contact your Regional Coordinator for an up-to-date list. Plants grown in field containers are preferred to in-ground. PR Numbers in the attached table refer to only those plants grown in field containers. Additional new PR Numbers will be assigned to plant material grown 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 and any needed adjuvants BAS 656h 63.9%EC (dimethenamid-p) BAS 659h 1.75G (dimethenamid-p + pendimethalin) F6875 (sulfentrazone +) Mesotrione Untreated 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) lb ai per acre 0.75 lb ai per acre 1.5 lb ai per acre lb ai per acre (6 oz/a) 0.25 lb ai per acre (8 oz/a) 0.37 lb ai per acre (12oz/A) Woody ornamentals only. Irrigate within 1 and 4 hours after application. Shipments planned for March/April Irrigate within 1 and 4 hours after application. BASF, Kathie Kalmowitz, , kathie.kalmowitz@basf.com BASF, Kathie Kalmowitz, , kathie.kalmowitz@basf.com FMC, Bobby Walls, , bobby_walls@fmc.com Syngenta, Nancy Rechsigl, , nancy.rechcigl@syngenta.com Reports: Reports submitted on the standard IR-4 Ornamental Horticulture Research Report Form 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. Draft Date: 3/14/7 Revised By: CLP 21