Progress Report. Evaluation of Aminocyclopyrachlor for Saltcedar Control

Transcription

1 Progress Report Evaluation of Aminocyclopyrachlor for Saltcedar Control Site Locations: Cooperators: Authors: Howard, Williamson, Stonewall and Childress Counties McDowell Ranch, Lake Georgetown, Childress County Judge and Baylor Lake Charles Hart, Extension Range Specialist, Stephenville Will Hatler, Extension Program Specialist, Stephenville Tommy Yeater, County Extension Agent, Howard County Dustin Coufal, County Extension Agent, Williamson County County Extension Agent, Stonewall County Lonnie Jenschke, County Extension Agent, Childress County Summary Experimental plots were set up in order to test a new DuPont herbicide (aminocyclopyrachlor) in several different formulations and tank mix combinations using different application methods on saltcedar. Plots were established in September of 2007 and 2008 in Howard County, September 2009 in Williamson County, October 2009 in Stonewall County and September 2010 in Childress County. Final results are available for trials established in 2007 and 2008, and 2009 and initial apparent mortality has been estimated on treatments established in Objective Saltcedar continues to be an issue along waterways and drainage ditches in the western portion of Texas. Aminocyclopyrachlor, currently named MAT28 or KJM44, has been in the testing phase for several years and has the potential to be a very effective product for controlling invasive brush and weed species in non-cropland settings. The objective of this project is to evaluate the efficacy of aminocyclopyrachlor for control of saltcedar. Materials and Methods This study was initiated in September of 2007 in Howard County. Plots were located on the Morrow property near Big Spring, Texas. Seven ground broadcast treatments were applied using a pole sprayer equipped with a KLC-9 boomless spray nozzle delivering an effective swath width of 25 feet at a spray volume of 15 gallons per acre. Each plot measured 25 by 50 feet and methylated seed oil was added to each treatment at a 1% v/v rate. Herbicides and rates for 2007 plots are presented in Table 2. Plots were also established in September of 2008 on the McDowell Ranch near Big Spring, Texas. A variety of application methods were used, including; ground broadcast, basal individual plant treatment

2 (IPT), and foliar IPT. Herbicides and rates for 2008 plots are presented in Tables 3 and 4. Two reps of ground broadcast treatments were made, each using different nozzles. Rep 1 was treated using a pole sprayer equipped with a KLC-18 boomless spray nozzle delivering an effective swath width of 20 feet at a spray volume of 20 gallons per acre. Rep 2 was treated using a hand boom equipped with XR8003 nozzles delivering a swath width of 10 feet at 20 gallons per acre. Each plot measured 20 by 50 feet or acres. Methylated seed oil was added to each treatment at a 1% v/v rate. Basal IPT plots were treated using a manual pump sprayer equipped with a ConeJet X3 nozzle. Total spray volume was 1 quart per plot, with basal oil used as the carrier. The entire circumference of each grounded stem within the plots was sprayed to wet up to at least 12 inches above the ground. Foliar IPT plots were treated using a battery powered backpack sprayer equipped with a ConeJet X8 nozzle. Total spray volume for foliar IPT plots was 1 gallon, with methylated seed oil added to each treatment at a 1% v/v rate. Foliage was sprayed to glisten but not to the point of run-off. Ground broadcast treatments were also established on September 21, 2009 at Russell and Jim Hogg Parks on Lake Georgetown in Williamson County. Treatments were applied using a CO 2 powered hand boom equipped with TT11003 nozzles delivering an effective swath width of 10 feet at 20 gallons per acre (Table 5). Plot sizes measured 10 by 40 feet and plant stage of growth ranged from seedlings to 5 feet tall. Additional plots were established October 16, 2009 on the Salt Fork Brazos River in Stonewall County. A replication of the 2008 basal IPT protocol was installed, along with adjusted rates of the foliar IPT treatments. Basal IPT plots were treated using a hand-pump garden sprayer equipped with a ConeJet X3 nozzle, with 1 quart total spray volume. Foliar IPT plots were treated using a hand-pump backpack sprayer equipped with a ConeJet X8 nozzle, with 1 gallon total spray volume. Methylated seed oil was added at 1% v/v to all foliar IPT (Table 6). Foliar IPT trials were installed on September 30, 2010 at Baylor Lake in Childress County (Table 7). Plots were treated using hand-pump backpack sprayers equipped with ConeJet X8 nozzles, spraying all foliage to wet. Plant sizes ranged from 1-10 feet tall, with many of them exhibiting significant foliage yellowing or defoliation. Environmental conditions on the day of application for all trials are detailed in Table 1 and herbicides, rates, and application data are presented in Tables 2-7. Table 1. Environmental conditions on the day of application for saltcedar trials established Site Date Spray Time Wind Speed/ Direction Soil Temp. Air Temp. Soil Type/ Moisture RH Howard Co. 9/23/07 12:00-12: mph/ssw 79⁰F 78⁰F Clay Loam/High 55% 1 Howard Co. 9/9/08 5:00-6: mph/e - 65⁰F Clay Loam/High 99% 2 Howard Co. 9/19/08 10:00-3: mph/s ⁰F Sand/Mod % 3 Howard Co. 9/19/08 10:00-11: mph/s - 71⁰F Sand/Mod. 35% Stonewall Co. 10/16/09 10:30-12: mph/ne 64⁰F 68⁰F Sandy Loam/Mod. 45% Childress Co. 9/30/10 3:00-6: mph/nw 74⁰F 78⁰F Loam/Low 46% 1 basal IPT plots, 2 foliar IPT & ground broadcast rep 1 plots, 3 ground broadcast rep 2 plots

3 Table 2. Herbicide, rate, and total spray volume for ground broadcast saltcedar plots treated September 12, 2007 in Howard County. MSO at 1% v/v was added to all treatments. Plot No. Herbicide Rate a.i./acre Rate product/acre TSV/acre 1 DPX-KJM oz. 7.2 oz. 15 gal. 2 DPX-KJM oz oz. 15 gal. 3 DPX-KJM oz oz. 15 gal. 4 DPX-KJM oz oz. 15 gal. 5 DPX-MAT oz oz. 15 gal. 6 DPX-MAT oz oz. 15 gal oz oz. 15 gal. 8 Control Table 3. Herbicide, rate, and total spray volume for saltcedar ground broadcast plots treated in September 2008 in Howard County. MSO at 1% v/v was added to all treatments. Plot No. Herbicide Rate a.i./acre Rate product/acre TSV/acre 1 DPX-MAT oz. 6.0 oz. 2 DPX-MAT oz. 8.0 oz. 3 DPX-MAT oz oz. 4 DPX-MAT oz. 6.0 oz. 0.9 oz. 1.5 oz. 5 DPX-MAT oz. 8.0 oz. 1.2 oz. 2.0 oz. 6 DPX-MAT oz oz. 1.5 oz. 2.5 oz. 7 DPX-MAT oz. 6.0 oz. 3.9 oz oz. 0.9 oz. 1.5 oz. 8 DPX-MAT oz. 8.0 oz. 5.2 oz oz. 1.2 oz. 2.0 oz. 9 DPX-MAT oz oz. 6.5 oz oz. 1.5 oz. 2.5 oz. 10 DPX-MAT oz. 9.0 oz. Garlon oz oz. 11 DPX-MAT oz. 9.0 oz. 1.5 oz. 2.5 oz. 12 Clearstand 18.2 oz oz. 13 Powerline 16.0 oz oz.

4 Table 4. Herbicide, rate, and total spray volume for saltcedar IPT plots treated in September 2008 in Howard County. MSO at 1% v/v was added to all foliar IPT plots. Plot No. Herbicide IPT Rate TSV/plot Foliar IPT 1 DPX-MAT g/gal 1 gal 2 DPX-MAT g/gal 1 gal 3 DPX-MAT g/gal 1 gal 4 DPX-MAT g/gal 1 gal Basal IPT 1 DPX-KJM % v/v 1 quart 95.0 % v/v 1 quart 2 DPX-KJM % v/v 1 quart 90.0 % v/v 1 quart 3 DPX-KJM % v/v 1 quart 85.0 % v/v 1 quart 4 Garlon % v/v 1 quart 75.0 % v/v 1 quart 5 Garlon % v/v 1 quart Stalker 1.0 % v/v 1 quart 79.0 % v/v 1 quart 6 DPX-KJM % v/v 1 quart Stalker 1.0 % v/v 1 quart 89.0 % v/v 1 quart Table 5. Herbicide, rate, and total spray volume for saltcedar ground broadcast plots treated September 2009 in Williamson County. MSO at 1% v/v was added to all treatments. Plot No. Herbicide Rate a.i./acre Rate product/acre TSV/acre 1 DPX-MAT oz oz. 0.9 oz oz. 2 DPX-MAT oz oz. 3 DPX-MAT28 4 DPX-MAT28 5 DPX-MAT28 6 DPX-MAT oz oz. 0.3 oz. 1.3 oz oz. 0.6 oz. 2.6 oz oz. 0.9 oz. 3.9 oz oz. 1.2 oz. 5.2 oz oz oz oz oz oz oz oz oz oz oz oz oz oz. 7 DPX-MAT oz oz. 0.3 oz oz. 8 DPX-MAT oz oz. 0.6 oz oz oz oz.

5 Table 6. Herbicide, rate, and total spray volume for saltcedar IPT plots treated September 2009 in Stonewell County. MSO at 1% v/v was added to all foliar IPT plots. Plot No. Herbicide IPT Rate TSV/plot Foliar IPT 1 DPX-MAT g/gal 1 gal 2 DPX-MAT g/gal 1 gal 3 DPX-MAT g/gal 1 gal 4 DPX-MAT g/gal 1 gal Basal IPT 1 DPX-KJM % v/v 1 quart 95.0 % v/v 1 quart 2 DPX-KJM % v/v 1 quart 90.0 % v/v 1 quart 3 DPX-KJM % v/v 1 quart 85.0 % v/v 1 quart 4 Garlon % v/v 1 quart 75.0 % v/v 1 quart 5 Garlon % v/v 1 quart Stalker 1.0 % v/v 1 quart 79.0 % v/v 1 quart 6 DPX-KJM % v/v 1 quart Stalker 1.0 % v/v 1 quart 89.0 % v/v 1 quart Table 7. Herbicide, rate, and total spray volume for saltcedar IPT foliar plots treated September 2010 in Childress County. Plot No. Herbicide IPT Rate TSV/plot Protocol #1 NIS at 0.5% v/v was added to all treatments. 1 MAT28 (50% SG) 4.7 g/gal 2.93 gal 1.2 g/gal 2 MAT28 (50% SG) 8.5 g/gal 3.00 gal 2.3 g/gal 3 MAT28 (50% SG) 15.3 g/gal 2.74 gal 4 MAT28 (50% SG) 5 MAT28 (50% SG) 6 MAT28 (50% SG) 4.1 g/gal 3.3 g/gal 3.0 g/gal 0.9 g/gal 6.5 g/gal 6.0 g/gal 1.8 g/gal 13.1 g/gal 12.0 g/gal 3.5 g/gal 1.74 gal 1.74 gal 2.47 gal 7 Glyphosate 0.5% v/v 0.5% v/v 2.50 gal Protocol #2 MSO at 1% v/v was added to all treatments 1 MAT28 (50% SG) 10.0 g/gal 1.0 gal 2 MAT28 (50% SG) 5.0 g/gal 1.0 gal 3 MAT28 (50% SG) 3.0 g/gal 1.0 gal 4 MAT28 (50% SG) 1.0 g/gal 1.0 gal

6 Results and Discussion 2007 Treatments Visual percent defoliation at 60 days and percent apparent mortality at 1 and 2 years post-treatment were estimated on plots established in At 60 days, defoliation ranged from 20-50% with (imazapyr) showing the most activity. After 1 year, activity declined in all treatments but which had 63% apparent mortality. The treatment apparent mortality increased to 80% in the final 2-year evaluation, whereas all others had completely recovered or had negligible apparent mortality (Table 8). Table 8. Percent defoliation at 60 DAT and percent mortality at 1 and 2 YAT of ground broadcast saltcedar plots installed in September 2007 in Howard County. MSO at 1% v/v was added to all treatments. Plot No. Herbicide Rate a.i. / acre % Defoliation 60 DAT % Mortality 1 YAT % Mortality 2 YAT 1 DPX-KJM oz DPX-KJM oz DPX-KJM oz DPX-KJM oz DPX-MAT oz DPX-MAT oz oz Control Treatments Percent apparent mortality at 2 years post-treatment was estimated on plots established in 2008 (Tables 9 & 10). Apparent mortality estimates for ground broadcast plots at two years ranged from 5 100%, with treatments including imazapyr having the best results. Broadcast treatments using DPX-MAT28 alone had notably lower efficacy. All foliar IPT plots had 100% apparent mortality, with the exception of the lowest rate of MAT28 at 14.2 g/gal which was estimated at 95%. All basal IPT plots showed 100% apparent mortality at 2 years after treatment. It should be noted that saltcedar leaf beetles were present on the site for an undetermined amount of time between the 1 and 2 year evaluations, which may have caused the dramatic increase in apparent mortality for some of the treatments.

7 Table 9. Percent apparent mortality at 1 and 2 YAT of ground broadcast saltcedar plots installed in September 2008 in Howard County. MSO at 1% v/v was added to all treatments. Plot No. Herbicide Rate a.i. / acre % Apparent Mortality 1 YAT % Apparent Mortality 2 YAT Rep 1 Rep 2 AVG Rep 1 Rep 2 AVG 1 DPX-MAT oz DPX-MAT oz DPX-MAT oz DPX-MAT oz oz. 5 DPX-MAT oz oz. 6 DPX-MAT oz oz. 7 DPX-MAT oz oz. 0.9 oz. 8 DPX-MAT oz oz. 1.2 oz. 9 DPX-MAT oz oz. 1.5 oz. 10 DPX-MAT oz Garlon oz. 11 DPX-MAT oz oz. 12 Clearstand 18.2 oz Powerline 16.0 oz

8 Table 10. Herbicide, rate, and percent apparent mortality at 1 and 2 YAT for saltcedar IPT plots treated in September 2008 in Howard County. MSO at 1% v/v was added to all foliar IPT plots. % Apparent Mortality Plot No. Herbicide Rate 1 YAT 2 YAT Foliar IPT 1 DPX-MAT g/gal DPX-MAT g/gal DPX-MAT g/gal DPX-MAT g/gal Basal IPT 1 DPX-KJM % v/v % v/v 2 DPX-KJM % v/v % v/v 3 DPX-KJM % v/v % v/v 4 Garlon % v/v % v/v 5 Garlon % v/v Stalker 1.0 % v/v 79.0 % v/v 6 DPX-KJM % v/v Stalker 1.0 % v/v 89.0 % v/v 2009 Treatments Treatments applied in Williamson County in 2009 were flooded shortly after installation and remained as such throughout the year, eliminating the possibility of evaluation. Initial apparent mortality at 9 months after treatment was estimated on plots established in Stonewall County in 2009 (Table 11). All foliar treatments were at or above 91% initial apparent mortality, with the exception of the lowest rate of MAT28 at 1.0 g/gal which was estimated at 46%. This may indicate that the threshold for adequate efficacy lies between 1.0 and 5.0 g/gal. Basal IPT plots treated with the highest rates of KJM44 or Garlon 4 had 100% initial apparent mortality at 1 year. The lowest basal rate of KJM44 correspondingly had the lowest estimated initial apparent mortality at 75%. The Stonewall County site was burned by wildfire previous to the 2 year site visit making evaluation impossible.

9 Table 11. Herbicide, rate, and percent apparent mortality at 9 MAT for saltcedar IPT plots treated September 2009 in Stonewell County. MSO at 1% v/v was added to all foliar IPT plots. % Apparent Mortality Plot No. Herbicide Rate 9 MAT 2 YAT Foliar IPT 1 DPX-MAT g/gal DPX-MAT g/gal DPX-MAT g/gal DPX-MAT g/gal Basal IPT 1 DPX-KJM % v/v % v/v 2 DPX-KJM % v/v % v/v 3 DPX-KJM % v/v % v/v 4 Garlon % v/v % v/v 5 Garlon % v/v Stalker 1.0 % v/v 79.0 % v/v 6 DPX-KJM % v/v Stalker 1.0 % v/v 89.0 % v/v 2010 Treatments Initial apparent mortality evaluations were conducted on the Childress County site at one year after treatment (Table 12). MAT28 plus at g/gal. performed the poorest initially with only 11% apparent mortality. This was a confounding result considering that MAT28 applied alone at 1.0 g/gal. and 3.0 g/gal. had significantly higher initial apparent mortality. Plant condition was relatively poor in some of the plots which may have negatively impacted the plot treated with the low rate of MAT28 plus. The two plots treated with higher rates of MAT28 plus had very high initial apparent mortality. All rates of the MAT28 plus and imazapyr provided very high initial apparent mortality, as did the combination of and glyphosate. MAT28 applied alone at 5.0 and 10.0 g/gal. had similar initial apparent mortality to comparable rates of MAT28 mixed with, indicating that the addition of may not provide any advantage. Final evaluation of the Childress County site will be completed in 2012.

10 Table 12. Herbicide, rate and percent apparent mortality at 1 year after treatment for saltcedar IPT foliar plots treated September 2010 in Childress County. % Apparent Mortality Plot No. Herbicide IPT Rate 1 YAT Protocol #1 NIS at 0.5% v/v was added to all treatments. 1 MAT28 (50% SG) 4.7 g/gal g/gal 2 MAT28 (50% SG) 8.5 g/gal g/gal 3 MAT28 (50% SG) 15.3 g/gal g/gal 4 MAT28 (50% SG) 3.3 g/gal 3.0 g/gal 0.9 g/gal 90 5 MAT28 (50% SG) 6 MAT28 (50% SG) 6.5 g/gal 6.0 g/gal 1.8 g/gal 13.1 g/gal 12.0 g/gal 3.5 g/gal 7 Glyphosate 0.5% v/v 0.5% v/v 96 Protocol #2 MSO at 1% v/v was added to all treatments 1 MAT28 (50% SG) 10.0 g/gal 78 2 MAT28 (50% SG) 5.0 g/gal 74 3 MAT28 (50% SG) 3.0 g/gal 65 4 MAT28 (50% SG) 1.0 g/gal Acknowledgements This project was supported by DuPont Crop Protection, Howard, Williamson, Stonewall and Childress Counties and the cooperating landowners. Trade names of commercial products used in this report is included only for better understanding and clarity. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by Texas AgriLife Extension Service and the Texas A&M University System is implied. Readers should realize that results from one experiment do not represent conclusive evidence that the same response would occur where conditions vary.