RANGELAND RESEARCH AND DEMONSTRATIONS HANDBOOK CENTRAL DISTRICT VIII

Transcription

1 RANGELAND RESEARCH AND DEMONSTRATIONS HANDBOOK CENTRAL DISTRICT VIII 2007

2 Table of Contents Aerial Application of Selected Herbicides for Saltcedar Control. 1 Aerial Applications on Cholla Cactus Final Report.. 15 Aerial Application Trials on Mesquite Control of Mesquite-Pricklypear Complex with Aerial Application of Herbicides, High Volume Aerial Applications on Redberry Juniper 36 Individual Plant Foliar Sprays on Blackberry 46 Individual Plant Foliar Sprays on Greenbriar 48 Individual Plant Basal Sprays on Selected Brush Species. 52 Mesquite IPT Treatments using Dow AgroSciences Products.. 54 Individual Plant Leaf Sprays on Mesquite. 57 Comparison of Herbicide Options for IPT Mesquite Control Comparison of Individual Plant Pad Sprays for Pricklypear Control 63 Generic Herbicide Efficacy for Weed Control.. 65 Generic Herbicide Efficacy for Mesquite Management, 2007 Goldmine Applied Research Progress Report.. 70 Comparison of Picloram Options for Prickleypear Control... 73

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4 2007 SUMMARY Aerial Application of Selected Herbicides for Saltcedar Control Charles R. Hart, Extension Range Specialist, Fort Stockton Tommy Yeater, County Extension Agent, Howard County County Extension Agent, Midland County Saltcedar infestations along major waterways and springs continue to be a major problem in Texas. Mechanical control practices tend to be very expensive. The efficacy of varying rates and tank mixes of Arsenal, Roundup Pro, Escort, Cimarron Max, Krenite, Tordon 22K, Pasturegard and Arsenal Power Line herbicides were evaluated for saltcedar control along various sites in Howard, Glasscock, Midland and Stephens Counties in These plots will be evaluated 1 and 2 years after treatment. OBJECTIVES Saltcedar (Tamarix spp.) is an ever increasing problem along waterways and drainage ditches in the Western half of Texas. There are seven species of Tamarix listed in Texas with T. gallica, T. aphylla, and T. ramosissima found in the western portion of the state. Saltcedar may grow as a short shrub or tall tree. It was introduced into North America in the early 1800's from Europe, Africa, and Asia. It has been recorded growing in 15 western states. In West Texas, it is typically found in dense thickets along major waterways but can also be a nuisance along drainage ditches, irrigation ditches, and frequently flooded areas. It is also invading areas such as CRP fields. In addition to forming dense thickets, saltcedar is also an excessive water user and is commonly referred to as a facultative phreatophyte. As the name implies, the plant is capable of growing in highly saline soils and can actually cause the soil surface to increase in salinity. Because of these reasons, saltcedar is considered a major threat to the conservation of waterways in Texas. Control of saltcedar in the past has been expensive and confined to mechanical removal of the plant. Treatments to effectively control saltcedar through mechanical means have cost in excess of $500 per acre. This research trial was established to evaluate several tank mixes of Arsenal, Roundup Pro, Escort and Cimarron Max herbicides for efficacy in controlling saltcedar. Page 1

5 MATERIALS AND METHODS Two sets of herbicide treatments were established along Mustang Draw in The first site was located in the northern end of Glasscock County on the McDowell property at the intersection of mustang draw and Hilger road (Figure 1). Plots were established on August 27, This site evaluated treatments of Arsenal, Escort, Arsenal + Escort and Cimarron Max herbicides for saltcedar control. The second site, established on August 28, 2003, was located in the southern end of Howard County on the Lowder property along the intersection of Mustang Draw and FM 818 (Figure 2). The herbicide treatments of Arsenal and Arsenal + Roundup Pro were evaluated for saltcedar control at this site. Both sites contained dense stands of healthy, mature saltcedar in the post-bloom stage. Plots were established in 2004 with seven treatments replicated across two sites. The first site was the Wilkinson Ranch (Figure 3) on the west side of Big Spring just north of I-20 and the second was the Cloud Ranch (Figure 4) east of Big Spring on Beals Creek. Both sites were treated on September 9, Additional plots were established in 2005 with 6 treatments. Treatments were established on the Tim Spivey property near Big Spring on September 6, 2005 (Figure 5) and on the Bill Wight property south of Midland on September 7, 2005 (Figure 6). Additional plots were established on Hubbard Creek Lake in Stephens County on August 13, 2006 (Figure 7), on the Chandler farm in Midland County on September 26, 2006 (Figure 8) and on the Buchannan Ranch in Midland County on September 26, 2006 (Figure 9). In 2007 new plots were established in Midland County. On September 23, 2007 sites were treated on the Chandler farm and on September 24, 2007, on the John Hopkins property. Applications were made on each site with a rotary wing aircraft. Accuflo nozzles with a.028 orifice were used to deliver 15 gallons per acre of total spray volume with a course spray droplet ( microns). Treatment rates and plot sizes are summarized in Table 1. The helicopter was equipped with a GPS system for precise calculation of acres and areas sprayed. Evaluations will be made at one and two years post treatment to determine percent mortality of saltcedar. Page 2

6 Table 1. Herbicides, rates and application data for aerial saltcedar control treatments on two sites in Glasscock and Howard Counties applied in August Treatment No. Herbicide Rate (a.i./acre) Total Spray Volume (gpa) Acres Treated McDowell Site, Arsenal 1.0 lbs Arsenal + Escort 0.5 lbs oz Escort 2.4 oz Cimarron Max 0.6 oz. + 4 pints 15 5 Lowry Site, Roundup Pro + Arsenal 1.0 lbs lbs Arsenal 0.75 lbs 15 3 Wilkinson and Cloud Sites, Arsenal 1.0 lbs Arsenal + Pasturegard 0.25 lbs lbs Arsenal + Pasturegard 0.5 lbs lbs Arsenal + Escort 0.25 lbs oz Escort + Krenite 1.8 oz lbs Escort + Roundup 1.8 oz lbs Escort + Remedy 1.8 lbs + 3 lbs Wight and Spivey Sites, Escort+Arsenal 1.8oz+0.5lbs Escort+Krenite 1.8oz+12lbs Escort+Krenite+Tordon 1.2oz+6lbs+0.5lbs Arsenal 1.0lbs Escort+Krenite+Arsenal 1.8oz+12lbs+0.5lbs Escort+Tordon 1.8oz+0.5lbs Hubbard, Chandler and Buchannan Sites, Arsenal 1.0 lbs Arsenal 0.75 lbs Arsenal 0.5 lbs Powerline 1.0 lbs Powerline 0.75 lbs Powerline 0.5 lbs Escort 2.4 oz Note: Buchannan site only includes treatments 1 and 7 and Hubbard site does not include Treatment 7. Chandler and Hopkins, Arsenal 64 oz Arsenal 48 oz Arsenal 32 oz Arsenal Power line 64 oz Arsenal Power line 48 oz Arsenal Power line 32 oz Arsenal Power line+rodeo 48 oz + 32 oz Escort 4 oz Note: Hopkins Site did not have treatment 8 and plot sizes were 4 ac Page 3

7 Figure 1. Plot location and layout of treatments applied for saltcedar control in northern Glasscock County on the McDowell property. Figure 2. Plot location and layout of treatments applied for saltcedar control in southern Howard County on the Lowry property. Page 4

8 Figure 3. Plot location and layout of treatments applied for saltcedar control in Howard County on the Wilkinson Ranch property in Figure 4. Plot location and layout of treatments applied for saltcedar control in Howard County on the Cloud Ranch property in Page 5

9 Figure 5. Plot location and layout of treatments applied for saltcedar control in Howard County on the Spivey Ranch property in Figure 6. Plot location and layout of treatments applied for saltcedar control in Midland County on the Wight Ranch property in Page 6

10 Figure 7. Plot location and layout of treatments applied for saltcedar control in Stephens County on the Hubbard Creek Reservoir in Figure 8. Plot location and layout of treatments applied for saltcedar control in Midland County on the Chandler Ranch property in Page 7

11 Figure 9. Plot location and layout of treatments applied for saltcedar control in Midland County on the Buchanan Ranch property in Figure 10. Plot location and layout of treatments applied for Saltcedar control in Midland County on the Hopkins property in Page 8

12 Figure 11. Plot location and layout of treatments applied for Saltcedar control in Midland County on the Chandler property in Page 9

13 RESULTS AND DISCUSSION Final results from each site will not be available until two years post treatment. Preliminary leaf brown-out and leaf drop were estimated on the McDowell property 60 days after treatment. Additional 1 year mortality and canopy reduction estimates were made in 2004 and 2 year mortality data in 2005 on both the Lowder and McDowell property. Two year evaluations are available on the 2004 plots established on the Cloud and Wilkinson sites and also available on the Spivey and Wight sites from One year results are available for the Buchannan and Chandler sites from Table 2 summarizes these results. Figure 12 shows results on 2004 plots two years after treatment and Figures 13 and 14 show one and two year results on 2005 plots. Arsenal and Arsenal + Escort provided adequate mortality on the McDowell site treated in The Lowder site was established to evaluate the Arsenal + Roundup mixture and an equivalent amount of Arsenal without the Roundup. Results indicate that the Roundup added to the mix, may not provide any additional mortality over the same rate of Arsenal. To date, only two treatments have provided satisfactory results: Arsenal at 1.0 lbs a.i./acre has provided an average of 70% mortality across years. The Wilkinson site in 2004 and Spivey site in 2005 had mortality on the Arsenal plot below the average, but all other treatments were significantly lower as well. We attribute this to extremely dry conditions combined with marginal habitat. Arsenal +Escort at 0.5 lbs.+2.4oz/acre has provided some level of control averaging 42% across years, but does show significant variability among years. Escort applied alone at 2.54 oz a.i./acre on one site showed 56% mortality. As a result, the tank mix of Arsenal and Escort appears to have no advantage. Tests with the 2.4 oz rate of Escort were again established in 2006 to further evaluate this treatment; one year evaluations showed a 22% mortality (Table 2). Even with somewhat reduced mortality of saltcedar when compared to Arsenal applied alone, Escort may have a use on areas of scattered saltcedar where grasses dominate, by allowing using herbicide application that has less damage to desirable grasses. In 2006, BASF introduced the new Arsenal Powerline herbicide. Evaluations are currently being conducted to determine efficacy rates for this product. To date, only one set of plots have been evaluated one year post-treatment. The second set of plots established in 2006 on the Hubbard Creek Reservoir were lost do to lake levels rising and flooding of plots. Additional Powerline plots established in 2007 have not yet been evaluated. Table 2. Evaluations of percent mortality and canopy reduction one and two years post treatment following aerial treatments on saltcedar. Trt no. Treatment Rate (a.i./acre) 1Y Mortality 1Y Canopy Reduction 2Y Mortality 2003 McDowell Site 1 Arsenal 1.0 lbs 84.7% 99% 84% 2 Arsenal + Escort 0.5 lbs oz. 54.3% 93% 64% 3 Escort 2.4 oz 52.0% 90% 56% 4 Cimarron Max 0.6 oz + 4 pints 10.0% 38% 7% 2003 Lowder Site 1 Roundup+Arsenal lbs. 70% 2 Arsenal 0.75 lbs. 70% Page 10

14 Table 2. Evaluations of percent mortality and canopy reduction one and two years post treatment following aerial treatments on saltcedar. Trt no. Treatment Rate (a.i./acre) 1Y Mortality 1Y Canopy Reduction 2Y Mortality 2004 Cloud Site 1 Arsenal 1.0 lbs. 97% 96% 83% 2 Arsenal +PG 0.25 lbs lbs 6% 53% 14% 3 Arsenal + PG 0.5 lbs lbs 14% 68% 10% 4 Arsenal + Escort 0.25 lbs oz. 26% 84% 21% 5 Escort + Krenite 1.8 oz lbs. 11% 67% 11% 6 Escort + Roundup 1.8 oz lbs 5% 50% 16% 7 Escort + Remedy 1.8 lbs + 3 lbs 0% 18% 0% 2004 Wilkinson Site 1 Arsenal 1.0 lbs. 59% 92% 50% 2 Arsenal +PG 0.25 lbs lbs 17% 69% 9% 3 Arsenal + PG 0.5 lbs lbs 7% 58% 8% 4 Arsenal + Escort 0.25 lbs oz. 17% 65% 17% 5 Escort + Krenite 1.8 oz lbs. 33% 70% 22% 6 Escort + Roundup 1.8 oz lbs 7% 20% 10% 7 Escort + Remedy 1.8 lbs + 3 lbs 3% 43% 2% 2005 Wight Site 1 Escort + Arsenal 1.8oz+0.5lbs. 95% 58% 60% 2 Escort + Krenite + 1.2oz+6lbs+0.5lbs 50% 15% Tordon 10% 3 Arsenal 1.0lbs 95% 83% 85% 4 Escort + Krenite 1.8oz+12lbs 75% 34% 20% 5 Escort + Krenite + 1.8oz+12lbs+0.5lbs 80% 43% Arsenal 45% 6 Escort + Tordon 1.8oz+0.5lbs 20% 6% 0% 2005 Spivey Site 1 Escort + Arsenal 1.8oz+0.5lbs. 95% 31% 57% 2 Escort + Krenite 1.8oz+12lbs 50% 18% 17% 3 Escort + Krenite + 1.2oz+6lbs+0.5lbs 10% 2% Tordon 4% 4 Arsenal 1.0lbs 80% n/a n/a 5 Escort + Krenite + 1.8oz+12lbs+0.5lbs 75% 33% Arsenal 49% 6 Escort + Tordon 1.8oz+0.5lbs 10% 1% 0% 2006 Hubbard Site 1 Arsenal 1.0 lbs 2 Arsenal 0.75 lbs 3 Arsenal 0.5 lbs 4 Powerline 1.0 lbs 5 Powerline 0.75 lbs 6 Powerline 0.5 lbs Plots Flooded Page 11

15 Table 2. Evaluations of percent mortality and canopy reduction one and two years post treatment following aerial treatments on saltcedar. Trt no. Treatment Rate (a.i./acre) 1Y Mortality 1Y Canopy Reduction 2Y Mortality 2006 Chandler Site 1 Arsenal 1.0 lbs 64% 2 Arsenal 0.75 lbs 64% 3 Arsenal 0.5 lbs 50% 4 Powerline 1.0 lbs 92% 5 Powerline 0.75 lbs 81% 6 Powerline 0.5 lbs 20% 7 Escort 2.4 oz. 22% 2006 Buchannan Site 1 Arsenal 1.0 lbs 78% 2 Escort 2.4 oz. 45% 2004 Saltcedar Aerial Herbicide Applications Cloud and Wilkinson Sites Two Years After Treatment 100% 80% % Mortality 60% 40% 20% 0% oz oz. 64 oz oz oz oz oz. Arsenal+PG Arsenal+PG Arsenal Arsenal+Escort Escort+Krenite Escort+Roundup Escort+Remedy Cloud Treatment Wilkinson Figure 12. Percent apparent mortality estimates two years after treatment on aerial saltcedar plots established on the Cloud and Wilkinson sites in Page 12

16 Figure 13. Percent apparent mortality estimates on aerial saltcedar treatments applied on the Spivey and Wight sites in Data is preliminary at one year after treatment. Figure 14. Percent apparent mortality estimates two years after treatment on aerial saltcedar treatments applied on the Spivey and Wight sites in Page 13

17 Figure 15. Percent apparent mortality estimates on aerial Saltcedar treatments applied on the Chandler and Buchannan sites in Data is preliminary at one year after treatment. ACKNOWLEDGMENTS This project was supported by BASF, DuPont, Dow AgroSciences, Monsanto, North Star Helicopters and cooperating counties and landowners. The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by AgriLIFE Extension is implied. Page 14

18 2007 SUMMARY Aerial applications on Cholla Cactus Final Report Charles R. Hart, Extension Range Specialist, Stephenville Tommy Yeater, County Extension Agent Ag, Howard County William Hatler, Extension Assistant, Stephenville Aerial application trials on cholla cactus were initiated in Three herbicides and two droplet sizes were tested by aerial applications with helicopter. Aerial broadcast applications were established in Howard County on the Morgan Ranch during fall Two year posttreatment evaluations showed Surmount provided satisfactory control, regardless of nozzle type. Tordon 22K and Tordon 22K + Reclaim provided adequate control with the accuflo nozzle but showed lower control ratings with the CP nozzle. OBJECTIVES Cholla cactus can be a significant problem on many rangeland areas of western Texas. Plant densities can become dense enough to decrease forage production and limit accessibility. Broadcast treatments with Tordon 22K have been used for pricklypear the past several years with good results. Aerial applications of Tordon 22K on cholla cactus have historically shown extremely variable results. A new herbicide is available that shows promising results for pricklypear control and possibly cholla control. This project evaluates the use of Tordon 22K, Surmount and Reclaim herbicides with aerial applications at two spray droplet sizes. Plot evaluations will be made within one year posttreatment and again at one and two years posttreatment. Evaluations will be made on both pricklypear and cholla cactus. MATERIALS AND METHODS On November 12, 2005 a study was initiated to evaluate herbicides and droplet size effects on control of cholla cactus. A site was selected on the Morgan Ranch in Howard County that contained dense stands of mature cholla and pricklypear. Six treatments were established with Tordon 22K, Surmount or Reclaim herbicides (Table 1) using two separate spray nozzles with different droplet sizes on 10 acre plots. Rivet (MSO/Silicone NIS) was added to each spray volume at a rate of 19.2oz/ac. Page 15

19 Treatments were applied by North Star Helicopters (Figure 1). The spray was delivered through 45 ft. flow-through booms equipped with either CP-03 poly aerial nozzles delivering a mediumfine droplet size ( µ) or.028 Accuflo nozzles delivering a coarse droplet size (1000µ). Spray pressure was 40psi. Plots were documented with GPS guidance technology with ESRI shape files downloaded to a laptop computer for future identification of the plot and calculation of acreage sprayed. Initial evaluations within one year of treatment were made by estimating percent yellowing and percent desiccation of cactus plants. Evaluations of percent apparent mortality are made by counting sub-samples of live and dead plants. A line through the plot is selected and 100 plants counted as either live or dead. Three transects lines are made within each plot and an average mortality calculated for each. Percent mortality estimates are made at one and two years posttreatment. Table 1. Aerial treatments applied to cholla and pricklypear cactus on the Morgan Ranch in Howard County on November 12, Plot no. Herbicide and Formulation Rate (prod./ac) Material/plot Adjuvant/Acre Plot Size Nozzle 1 Tordon 32 oz. 320 oz oz. Rivet 8.4 Accuflo 2 Surmount 64 oz. 640 oz oz. Rivet 9.9 Accuflo 3 Tordon+Reclaim oz oz oz. Rivet 10.0 Accuflo 4 Tordon 32 oz. 320 oz oz. Rivet 8.0 CP 5 Surmount 64 oz. 640 oz oz. Rivet 8.1 CP 6 Tordon+Reclaim oz oz oz. Rivet 9.6 CP Figure 1. Layout and location of cholla and pricklypear cactus plots applied on the Morgan Ranch in 2005 Page 16

20 RESULTS AND DISCUSSION Percent apparent mortality of Cholla cactus was estimated six months and two years posttreatment. Results from final two year post-treatment evaluations are presented in Table 2 and Figure 2. Mortality ranged from a low of 20% to a high of 80%. Only two plots had lower than expected mortality (Tordon and Tordon+Reclaim), both were with CP nozzles. Averaged across nozzle type, Accuflo nozzles showed a higher mortality rating than CP nozzles, although the difference can be mainly attributed to the Tordon+Reclaim plot with the CP nozzles. Surmount showed the highest mortality among herbicides and it appeared to be very similar when comparing nozzle types. Tordon 22K provided the next highest average mortality, but did much better with the Accuflo nozzle. Using a lower rate of Tordon tank mixed with Reclaim provided the lowest average mortality. Table 2. Percent apparent mortality of Cholla cactus two years after treatment at the Morgan Ranch in Howard County. Plot Herbicide and Transect Number no. Formulation Rate (prod./ac) Nozzle Average 1 Tordon 32 oz. Accuflo 71% 70% 69% 70% 2 Surmount 64 oz. Accuflo 65% 75% 70% 70% 3 Tordon+Reclaim oz Accuflo 72% 73% 65% 70% 4 Tordon 32 oz. CP 50% 50% 50% 50% 5 Surmount 64 oz. CP 70% 77% 93% 80% 6 Tordon+Reclaim oz CP 15% 20% 25% 20% Page 17

21 Figure 2. Two year post-treatment evaluations of percent mortality on Cholla cactus at the Morgan Ranch in Howard County. Lower graphs 2 and 3 pool data by nozzle type and herbicide. Standard deviation is represented by vertical bars. Plot numbers for upper graph correspond to Table 1. ACKNOWLEDGMENTS This project was supported by Howard County, Dow AgroSciences, North Star Helicopters and the Morgan Ranch. The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied. Page 18

22 2007 Aerial Application trials on Mesquite SUMMARY Charles R. Hart, Extension Range Specialist, Stephenville Robert K. Pritz, County Extension Agent, Callahan County Aerial applications of several Dow AgroSciences herbicides for Mesquite control were applied to a site in Callahan County in August Final evaluations are being made two years posttreatment. OBJECTIVES Mesquite is the most common noxious plant invading Texas Rangelands. Densities can reach such proportions as to severely limit desirable forage growth by competing for nutrients, water and sunlight. This project was established to investigate the efficacy of different herbicides and rates as aerial treatments for mesquite control. MATERIALS AND METHODS Plots were established on August 9, 2007 on the Williams Ranch in Callahan County (Figure 1). The plots were set up to evaluate Reclaim and Remedy Ultra mixes and test other herbicides as well. Herbicides and rates are presented in Table 1. Each treatment had 0.50 % NIS added to the herbicide mix. Plots were treated aerially by North Star Helicopters with a swath width of 45 feet. Applications were made with a CP nozzle set at the smallest orifice and highest deflection to deliver a fine to medium fine droplet. Each plot measured ten acres and was replicated twice. When treated, mesquite plants were in the post-bean stage of growth. Evaluations will be made one and two years post-treatment by counting live and dead plants in each plot. Table 1. Herbicide, rates and application data for Mesquite control on two sites in Callahan County applied in August Treatment No. Herbicide Rate (pr/acre) Total Spray Volume Williams Ranch Reclaim + Remedy Ultra oz oz 7.5 gpa 2 DAS oz 7.5 gpa Reclaim + Remedy Ultra oz oz 3 DAS oz 7.5 gpa 4 Reclaim + DAS oz oz 7.5 gpa 5 Remedy Ultra + DAS oz oz 7.5 gpa 6 Reclaim oz 7.5 gpa Page 19

23 Figure 2. Plot location and layout of Aerial herbicide treatments applied for Mesquite control in Callahan County on the Williams Ranch. RESULTS AND DISCUSSION Preliminary control data will not be available until ACKNOWLEDGMENTS This project was supported by Callahan County and Dow AgroScience The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by AgriLIFE Extension is implied. Page 20

24 Control of Mesquite-Pricklypear Complex with Aerial Application of Herbicides, SUMMARY Charles R. Hart, Extension Range Specialist, Stephenville Rocky Vinson, County Extension Agent Ag, Shackelford County Tommy Yeater, County Extension Agent Ag, Howard County Chase McPhaul, County Extension Agent Ag, Crockett County Robert Pritz, County Extension Agent Ag, Callahan County Will Hatler, Extension Assistant - Stephenville 2007 Aerial application of Reclaim, Remedy, and Tordon 22K herbicides were applied at varying total spray volumes to dense stands of mesquite with an understory of pricklypear. Surmount herbicide was also compared to Tordon 22k for pricklypear control. Plots were established during the summer of 2003 in Shackelford County, summer of 2004 in Howard County, summer of 2005 in Crockett, Callahan, and Shackelford Counties, summer of 2006 in Shackelford County and summer of 2007 in Callahan County. Final evaluations are made two years post treatment. OBJECTIVES Two of Texas most invasive and difficult to control species often occupies the same environment. Control of pricklypear in this complex has been difficult due to physical obstruction of chemical applications by mesquite foliage. Fixed-wing applications of Tordon 22K plus Remedy plus Reclaim have had moderate success, with pricklypear control likely lower due to Picloram interception by mesquite foliage. Leaf interception leads to higher Picloram photodegradation and less available for control of pricklypear. Most landowners have resorted to treating mesquite first, then a separate application on pricklypear after mesquite defoliation, or treating pricklypear in late fall after mesquite leaf drop. This project was designed to look at application techniques for treating both mesquite and pricklypear with the same aerial application. MATERIALS AND METHODS Historically, helicopters have been used almost exclusively for herbicide applications in the forestry industry. The technology includes precision application with high total spray volume and large droplet size. Recently, helicopters have been used to apply Arsenal for control of saltcedar. This Page 21

25 application technology has allowed for greater plant coverage through increased canopy penetration by the high total spray volume and larger droplets. We test the use of this technology on the mesquite-pricklypear complex to allow for spray droplet penetration through the mesquite canopy resulting in increased coverage and greater control of pricklypear and mesquite with a single application. Applications were made on the Moon ranch in Shackelford County on August 6, 2003 with a rotary wing aircraft. Accuflo nozzles with a.016 orifice were used to deliver varying rates of total spray volume. This nozzle delivers and extremely large droplet size ranging from microns in size. Treatments applied in 2003 included a 16 oz/ac. rate of Crop Oil Concentrate (COC) with the herbicide in a water carrier. Applications were again made on the Morgan Ranch in Howard County on August 4, Treatments in 2004 varied in that a combination nozzle system was utilized to broaden the droplet spectrum. The spray boom was equipped with alternating Accuflo.028 and CP Nozzles. Orifices were used with each during pre-treatment tests to ensure a ratio was obtained for the two nozzles. For example, if the TSV was 10gpa, 5 gpa would be through the Accuflo nozzles and 5 gpa would be through the CP nozzles. Treatments applied in 2004 included a 32 oz/ac. rate of MSO with the herbicide in a water carrier. Similar plots were established in 2005 on August 8 in Shackelford County, August 3 in Crockett County, and August 7 in Callahan County. The same combination nozzle configuration was again used in Treatments applied in 2005 also contained a comparison between methylated seed oil, non-ionic surfactant and diesel as adjuvants. During 2006 treatments were applied on July 17 on the Davis Ranch in Shackelford County and included varying combinations of Reclaim, Remedy, Tordon and Surmount. During 2007, three replicated treatments were made on the Shaw Ranch property in Callahan County on August 8. These treatments evaluated CP and Accuflo nozzles individually compared to the combination setup during an early August application window. Both Tordon 22K and Surmount herbicides were evaluated for pricklypear control. The standard commercial rates of Reclaim and Remedy herbicides were simultaneously applied for mesquite control. Herbicide rates and total spray volumes are summarized in Table 1. The helicopter was equipped with a GPS system for precise calculation of acres and areas sprayed. Figures 1-7 show the layouts of the various treatments at each site. Plot sizes were 10 acres for all plots except the 2003 Surmount tests. Evaluations will be made at one and two years post treatment to determine percent mortality of pricklypear and mesquite. Evaluations are made by three observers walking through each plot counting 100 plants as live or dead. Initial pricklypear mortality is estimated as percent desiccation. Final mortality evaluations are made two years post-treatment. Page 22

26 Table 1. Herbicide combinations, rates, and total spray volumes applied on mesquitepricklypear complex in 2003 through Herbicide Rates Total Spray Vol. Plot Size 2003 (a.i./acre) (gallons) (acres) Tor+Rec+Rem+COC lbs Tor+Rec+Rem+COC lbs Tor+Rec+Rem+COC lbs Sur+Rec+Rem+COC lbs. 4.1 Sur+Rec+COC lbs Tor+Rec+Rem+MSO lbs Tor+Rec+Rem+MSO lbs Tor+Rec+Rem+MSO lbs Sur+Rec+Rem+MSO lbs Tor+Rec+Rem+MSO lbs Sur+Rec+Rem+MSO lbs Tor+Rec+Rem+MSO lbs Sur+Rec+Rem+MSO lbs Sur+Rec+Rem+NIS lbs Sur+Rec+Rem+Diesel lbs Tor+Rec+MSO lbs Sur+Rec+MSO lbs Sur+Rec+NIS lbs Sur+Rec+Diesel lbs Tor+Rec+Rem+NIS lbs Sur+Rec+Rem+NIS lbs Tor+Rec+NIS lbs Sur+Rec+NIS lbs Sur+Rec+Rem+NIS lbs Sur+Rec+NIS lbs Sur+Rec+Rem+MSO lbs. 20 w/cp 10 Sur+Rec+Rem+MSO lbs. 20 w/cp+accuflo 10 Sur+Rec+Rem+MSO lbs. 20 w/accuflo 10 Sur=Surmount, Tor=Tordon 22K, Rec=Reclaim, Rem=Remedy herbicides. MSO=Methylated Seed Oil, NIS=Non-ionic Surfactant, COC=Crop oil concentrate. Emulsifier was used with Diesel treatments. Page 23

27 Figure 1. Layout of aerial plots on the Moon Ranch in Shackelford County applied on August 6, Page 24

28 Figure 2. Layout of aerial plots on the Morgan Ranch in Howard County applied on August 4, Page 25

29 Figure 3. Layout of aerial plots on the Chandler Ranch in Crockett County applied on August 3, Page 26

30 Figure 4. Layout of aerial plots on the Finley Ranch in Callahan County applied on August 7, Page 27

31 Figure 5. Layout of aerial plots on the Mathews Ranch in Shackelford County applied on August 8, Page 28

32 Figure 6. Layout of aerial plots on the Davis Ranch in Shackelford County applied on July 17, Page 29

33 Figure 7. Layout of aerial plots on the Shaw Ranch in Callahan County applied on August 8, Page 30

34 RESULTS AND DISCUSSION Shackelford County 2003 Site Final results from treatments applied on the Moon Ranch in Shackelford County are presented in Table 2. With the larger droplet size, mesquite mortality was not acceptable. Pricklypear mortality was good, averaging % mortality with Tordon 22K across all spray volumes. Surmount provided slightly lower mortality compared to Tordon 22K when compared at similar spray volumes. Results of this research indicate 1) the rate of Surmount should be increased to 4 pints/acre, and 2) large droplets do a good job penetrating through the mesquite canopy and controlling pricklypear, but no mesquite mortality was realized. Table 2. Final results (2 years after treatment) of treatments applied to mesquite and pricklypear on the Moon Ranch in Shackelford County in Applications made by helicopter with.016 Accuflo nozzles. Herbicide Combinations Rates TSV Pricklypear Mesquite (gal.) (% Apparent Mortality) Tordon 22K+Reclaim+Remedy lbs Tordon 22K+Reclaim+Remedy lbs Tordon 22K+Reclaim+Remedy lbs Surmount+Reclaim+Remedy 3 pts lbs Surmount+Reclaim 3 pts+0.25 lbs Sur=Surmount, Tor=Tordon 22K, Rec=Reclaim, Rem=Remedy herbicides. Howard County 2004 Site Final results from treatments applied in 2004 are presented in Table 3 and Figure 8. Initial results indicate that Surmount provided faster desiccation on pricklypear cactus compared to Tordon 22K at similar spray volumes. Percent desiccation of pricklypear increased with increases in total spray volumes. The lower spray volume (10gpa) appears to provide lower mortality of mesquite compared to 20, 30 or 40 gpa. Table 3. Final results (2 years after treatment) of treatments applied to mesquite, pricklypear and redberry juniper in Herbicides Rates TSV Pricklypear Mesquite Juniper (gal.) (% Desiccation) (% Mortality) (% Mortality) 1.Tor+Rec+Rem lbs Tor+Rec+Rem lbs Tor+Rec+Rem lbs Sur+Rec+Rem 3 pts lbs Tor+Rec+Rem lbs Sur+Rec+Rem 3 pts lbs Sur=Surmount, Tor=Tordon 22K, Rec=Reclaim, Rem=Remedy herbicides. Page 31

35 % Mesquite Mortality 100.0% 90.0% 80.0% 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% Treatment No. 100% % Pricklypear Desiccation 80% 60% 40% 20% 0% Treatment No. Figure 8. Percent mesquite mortality and percent pricklypear desiccation two years after aerial treatments applied on the Morgan Ranch in Howard County during Page 32

36 Callahan, Shackelford and Crockett Counties 2005 Two year results from treatments applied in 2005 are summarized in Table 4 and presented by site in Figure 9. There were site differences evident among the three sites with the Shackelford County (Mathews) site resulting in significantly lower mesquite and pricklypear mortality. We attribute this to lower soil temperatures (<75F) at the time of spraying due to high moisture conditions following heavy rains. Initial results one year after treatment indicated that Surmount provided faster desiccation on pricklypear cactus compared to Tordon 22K at similar spray volumes. However, no differences were evident following two year evaluations (Figure 10). Percent desiccation of pricklypear increased with increases in total spray volumes. The lower spray volume (10gpa) appears to provide lower mortality of mesquite compared to 20, 30 or 40 gpa. Results did show a slight decrease in both mesquite and pricklypear control when Remedy was not included in the mix. Additional evaluations were made comparing Methylated Seed Oil (MSO), Non-Ionic surfactant (NIS) and Diesel:Water emulsion in the mix. Results show no differences among adjuvant for mesquite or pricklypear control two years after treatment. Table 4. Final results (2 years after treatment) of treatments applied to mesquite and pricklypear averaged across three sites in Herbicides Rates TSV Pricklypear Mesquite (gal.) (% Mortality) (% Mortality) Tor+Rec+Rem+MSO lbs ± ±6.8 Sur+Rec+Rem+MSO lbs ± ±9.9 Sur+Rec+Rem+NIS lbs ± ±3.1 Sur+Rec+Rem+Dies lbs ± ±15.9 Tor+Rec+MSO lbs ± ±18.6 Sur+Rec+MSO lbs ± ±17.4 Sur+Rec+NIS lbs ± ±13.2 Sur+Rec+Dies lbs ± ±13.2 Sur=Surmount, Tor=Tordon 22K, Rec=Reclaim, Rem=Remedy herbicides. Figure 9. Apparent mesquite and pricklypear mortality by site two years after treatments in Page 33

37 Figure 10. Apparent mesquite and pricklypear mortality with and without Remedy in the mix and with Tordon compared to Surmount two years after treatments in Page 34

38 Shackelford County site 2006 Preliminary results for this site are presented in Table 5. Initial results are somewhat lower than expected. Pricklypear appears to on-track with all plots estimated at about 75% yellowing. Mesquite mortality is, however, lower than expected. Plots will be re-evaluated two years posttreatment. Table 5. Preliminary results (1 year after treatment) of treatments applied to mesquite and pricklypear on the Davis Ranch in Shackelford County in Herbicides Rates TSV Pricklypear Mesquite (gal.) (% Desiccation) (% Mortality) Tor+Rec+Rem+NIS lbs Sur+Rec+Rem+NIS lbs Tor+Rec+NIS lbs Sur+Rec+NIS lbs Sur+Rec+Rem+NIS lbs Sur+Rec+NIS lbs Sur=Surmount, Tor=Tordon 22K, Rec=Reclaim, Rem=Remedy herbicides. Callahan County Site 2007 Table 6 shows treatments applied in No results are available yet. Table 6. Treatments applied to mesquite and pricklypear on the Shaw Ranch in Callahan County in Herbicides Rates Nozzle TSV Pricklypear Mesquite (gal.) (% Desiccation) (% Mortality) Sur+Rec+Rem+MSO lbs. CP 20 Sur+Rec+Rem+MSO lbs. CP+Accuflo 20 Sur+Rec+Rem+MSO lbs. Accuflo 20 Sur=Surmount, Rec=Reclaim, Rem=Remedy herbicides. ACKNOWLEDGMENTS This project was supported by Dow AgroSciences, North Star Helicopters, Shackelford County, Callahan County, Crockett County, Howard County, and cooperating ranches. The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied. Page 35

39 2007 High volume aerial applications on Redberry Juniper Charles R. Hart, Extension Range Specialist, Fort Stockton Tommy Yeater, County Extension Agent Ag, Howard County Marty Vahlenkamp, County Extension Agent Ag, Hood County SUMMARY A study was initiated to evaluate the potential of high volume aerial applications for redberry juniper control. Currently, no aerial treatments are recommended through Texas AgriLife Extension. Plots were established during 2004, 2005, 2006 and 2007 in Howard and Hood Counties. Preliminary results are presented. OBJECTIVES Redberry Juniper is a common evergreen tree found in abundance in many eco-regions of Texas. Control methods for this plant are limited due mainly to the fact that it vigorously resprouts from buds located just beneath the soil surface on the crown of the plant. For this reason, tree cutting techniques tend to be less beneficial to plant control as compared to Ashe Juniper trees. The most common method of redberry juniper control is currently mechanical removal using a dozer. This method is very expensive costing as much as $100-$150 per acre and more. Juniper is an aggressive invader of rangelands. When left unchecked, juniper can form a complete canopy coverage reducing desired forage production. Once juniper gets to this stage control options are limited. However, smaller junipers can be controlled easier and cheaper. It is for this reason that the Brush Busters approach to individual plant treatments has become increasingly viewed as a favorable alternative. The premise of the program is to control the smaller juniper plants before they become a large problem. There are two Brush Buster individual plant treatment methods for chemical control of redberry juniper. The first is a soil spot spray method using Velpar L. The second is a foliar applied leaf spray method using Tordon 22K. Excellent results with both Brush Buster treatments have been obtained. However, treatments with Tordon 22K applied aerially have failed. This is extremely important for areas where density and plant size has gone beyond the realm of treating individual plants. We know that Page 36

40 Tordon 22K has activity on redberry juniper; the problem appears to be a coverage and concentration issue when applied from the air. Simply stated, we have not been successful in getting enough herbicide into the plant when applied aerially. This research is looking at the use of helicopter, droplet size, high total spray volume and spray adjuvants to increase spray coverage and ultimately herbicide absorption into the leaf of juniper, thereby increasing mortality from aerial applications. The project is intended to be a multiple year project, with only three years of applications completed. Additional trials will be based on results from previous trials, building on the successes and failures of previous results. MATERIALS AND METHODS On August 3, 2004 an initial study was instigated. A site was selected on the Morgan Ranch in Howard County that contained dense stands of mature redberry juniper. Eight treatments were established with Tordon 22K and Overdrive herbicides (Table 1) using varying total spray volumes (10-40 gpa) on 10 acre plots. Rivet (MSO/Silicone NIS) was added to each spray volume at a rate of 16oz/ac. Treatments were applied by North Star Helicopters. The spray was delivered through 45 ft. flow-through booms equipped with CP-03 poly aerial nozzles delivering a medium-fine droplet size ( µ) at 40psi. Plots were documented with GPS guidance technology with ESRI shape files downloaded to a laptop computer for future identification of the plot and calculation of acreage sprayed. A second set of plots were established on the Morgan Ranch in Howard County on November 13, Six treatments were established (Table 1) using Tordon 22K, Overdrive, Escort, and Krenite herbicides with MSO/silicone surfactant (Rivet), Crop Oil Concentrate (Superb HC) or NIS/crop oil concentrate (Topfilm). Treatments were again applied by North Star Helicopters using a combination nozzle system with Accuflo.028 nozzles (#6 orifice) and CP-03 nozzles (middle orifice, high deflector). This combination nozzle system provided a wider range of droplet size from µ in size. Plots were again documented with GPS guidance technology with ESRI shape files downloaded to a laptop computer for future identification of the plot and calculation of acreage sprayed. A third set of plots were established on the Diamond A Ranch in Hood County on November 14, Eleven treatments were established (Table 1) using Tordon 22K, Overdrive, Escort, and Krenite herbicides with Topfilm surfactant. Additionally, two treatments used Load Out adjuvant to increase spray absorption. Treatments were again applied by North Star Helicopters using a combination nozzle system with Accuflo.028 nozzles (#5 orifice) and CP-03 nozzles (middle orifice, high deflector). This combination nozzle system provided a wider range of droplet size from µ in size. Plots were again documented with GPS guidance technology with Page 37

41 ESRI shape files downloaded to a laptop computer for future identification of the plot and calculation of acreage sprayed. A fourth set of plots were established on the McKay Ranch in Hood County on April 18, Eight treatments were established (Table 1) using Tordon 22K, Escort, and Krenite herbicides with Synurgize surfactant. Treatments were applied by North Star Helicopters using.028 Accuflo nozzles and CP nozzles (small orifice, high deflection), #6 orifice in both, and 25 psi boom pressure. All 2007 plots were documented the same as previous years with GPS guidance technology. Initial 60 day leaf brownout evaluations are made by visual estimations. Evaluations of percent apparent mortality are made by counting sub-samples of live and dead plants. A line through the plot is selected and 100 plants counted as either live or dead. Three transects lines are made within each plot and an average mortality calculated for each. Final Percent mortality estimates are made at two year post-treatment. Table 1. Herbicide treatments and rates applied to redberry juniper during 2004, 2005, 2006 and 2007 in Howard and Hood Counties. Acres Rate Total Spray Plot No. Herbicide T reated (product/acre) Volume/Acre Applications made August 3, Tordon 22K + Overdrive oz. 10 gal. 2 Tordon 22K + Overdrive oz. 10 gal. 3 Tordon 22K + Overdrive oz. 20 gal. 4 Tordon 22K + Overdrive oz. 20 gal. 5 Tordon 22K + Overdrive oz. 30 gal. 6 Tordon 22K + Overdrive oz. 30 gal. 7 Tordon 22K + Overdrive oz. 40 gal. 8 Tordon 22K + Overdrive oz. 40 gal. Applications made November 13, Tordon+Rivet oz. 20 gal. 4 Tordon+Overdrive+Rivet oz. 20 gal. 5 Tordon+Superb HC oz. 20 gal. 7 Tordon+Overdrive+Superb HC oz. 20 gal. 8 Krenite+Escort+Tordon+Topfilm oz. 20 gal. 10 Krenite+Topfilm oz. 20 gal. Page 38

42 Table 1. Herbicide treatments and rates applied to redberry juniper during 2004, 2005, 2006 and 2007 in Howard and Hood Counties. Acres Rate Total Spray Plot No. Herbicide Treated (product/acre) Volume/Acre Applications made November 14, Tordon 22K 10 32oz. 15 gal. 2 Tordon 22K + Escort oz. 15 gal. 3 Tordon 22K + Overdrive oz. 15 gal. 4 Escort + Overdrive oz. 15 gal. 5 Escort 10 2 oz. 15 gal. 6 Escort 10 4 oz. 15 gal. 7 Tordon 22K + Escort oz. 15 gal. 8 Tordon+OD+Escort oz. 15 gal. 9 Krenite+Escort+Tordon oz. 15 gal. 10 Tordon+Escort+LO oz. 15 gal. 11 Tordon+LO oz. 15 gal. Applications made April 18, Tordon 22K lbs 15 gal. 2 Tordon 22K lbs 15 gal. 3 Tordon 22K lbs 15 gal. 4 Tordon 22K+Escort lbs+1.2 oz. 15 gal. 5 Tordon 22K+Escort lbs+2.4 oz. 15 gal. 6 Escort oz. 15 gal. 7 Escort oz. 15 gal. 8 Krenite+Escort+Tordon 22K lbs+1.2 oz.+0.5 lbs 15 gal. Figure 1. Location and layout of redberry juniper plots on the Morgan ranch in Howard County in Page 39

43 Figure 2. Location and layout of redberry juniper plots on the Morgan ranch in Howard County in Figure 3. Location and layout of redberry juniper plots on the Diamond A Ranch in Hood County in Page 40

44 Figure 4. Location and layout of redberry juniper plots on the McKay ranch in Hood County in RESULTS AND DISCUSSION To date, two year evaluations have been made on plots established in 2004 and 2005, one year evaluations on 2006 plots and six month evaluations on 2007 plots. At 60 days after treatment, no treatment has provided greater than 50% leaf brownout, while most were below 40%. One year post-treatment canopy reduction estimates are low with the exception of 82% estimated on the 2005 Krenite + Escort + Tordon 22K plot (Figure 1). After one year evaluations on 2005 plots, no difference is detected between different adjuvant types (Figure 2), but after two year evaluations Superb HC and Topfilm out perform Rivet (Figure 4). Two year evaluations on plots established in 2004 showed no mortality effect, regardless of treatment or total spray volume. For the 2005 plots, two year evaluations show little morality effect (Figure 3). In 2006 plots, only three treatments showed any canopy reduction and only two of those treatments showed mortality at one year evaluations (Figure 5). The 2007 plots showed little mortality at six month evaluations (Figure 6). Page 41

45 Table 2. Percent apparent mortality of redberry juniper after herbicide treatments in in Howard and Hood Counties. Plot No. Herbicide + Rate TSV/Acre 2004 Plots, Morgan Ranch % Brown 60 DAT 1 % Canopy Reduction 1 YAT % App. Mortality 2 YAT 1 Tordon 22K (2pts) + Overdrive (4oz) 10 gal Tordon 22K (2pts) + Overdrive (8oz) 10 gal Tordon 22K (2pts) + Overdrive (4oz) 20 gal Tordon 22K (2pts) + Overdrive (8oz) 20 gal Tordon 22K (2pts) + Overdrive (4oz) 30 gal Tordon 22K (2pts) + Overdrive (8oz) 30 gal Tordon 22K (2pts) + Overdrive (4oz) 40 gal Tordon 22K (2pts) + Overdrive (8oz) 40 gal Plots, Morgan Ranch 1 Tordon 22K (2pts) +Rivet 20 gal. NA Tordon 22K (2pts)+Overdrive (8oz) +Rivet 20 gal. NA Tordon 22K (2pts) +Superb HC 20 gal. NA Tordon 22K (2pts)+Overdrive (8oz) +SuperbHC 20 gal. NA Krenite (6qts)+Escort(2oz)+Tordon 22K(2pts) +Topfilm 20 gal. NA Krenite (6qts) +Topfilm 20 gal. NA Plots, Diamond A Ranch 1 Tordon 22K(2pts) 10 gal Tordon 22K(2pts) + Escort(2oz) 10 gal Tordon 22K(2pts) + Overdrive(8oz) 10 gal Escort(2oz) + Overdrive (8oz) 10 gal Escort(2oz) 10 gal Escort(4oz) 10 gal Tordon 22K(2pts) + Escort(4oz) 10 gal Tordon 22K(2pts) +Overdrive(8oz) +Escort(2oz) 10 gal Krenite(6qts) +Escort(2oz)+Tordon 22K(2pts) 10 gal Tordon 22K(2pts) +Escort(2oz)+LoadOut 10 gal Tordon 22K(2pts)+LoadOut 10 gal Plots, McKay Ranch 1 Tordon 22K (0.5 lbs) + Synurgize (9.6 oz) 15 gal. 0 2 Tordon 22K (0.75 lbs) + Synurgize (9.6 oz) 15 gal. 2 3 Tordon 22K (1.0 lbs) 15 gal Tordon 22K (0.5 lbs) + Escort (1.2 oz) + Synurgize (9.6 oz) 15 gal. 3 5 Tordon 22K (0.5 lbs) + Escort (2.4 oz) + Synurgize (9.6 oz) 15 gal. 1 6 Escort (1.2 oz) + Synurgize (9.6 oz) 15 gal. 0 7 Escort (2.4 oz) + Synurgize (9.6 oz) 15 gal. 0 8 Krenite (6.0 lbs) + Escort (1.2 oz) + Tordon 22K (0.5 lbs) + Synurgize (9.6 oz) 15 gal. 5 DAT= Days after treatment, YAT= Years after treatment, 60 DAT rating is % of leaves brown. Page 42

46 Juniper Live Canopy Reduction One Year After Treatment Morgan Ranch 100.0% 80.0% % Canopy Reduction 60.0% 40.0% 20.0% 0.0% -20.0% Treatment No. Figure 1. Canopy reduction one year after treatment on aerial juniper plots at the Morgan Ranch applied in Juniper Live Canopy Reduction 60% 40% 20% 0% Rivet Superb HC Topfilm Figure 2. Comparison of adjuvants used on aerial juniper plots at the Morgan Ranch in Page 43

47 Juniper Mortality Two Years After Treatment Morgan Ranch 12.0% 10.0% 8.0% % Mortality 6.0% 4.0% 2.0% 0.0% Treatment No. Figure 3. Percent mortality two years after treatment on aerial juniper plots at the Morgan Ranch applied in Juniper Mortality Two Years after Treatment 20% 15% 10% 5% 0% Rivet Superb HC Topfilm Figure 4. Comparison of adjuvants used on aerial juniper plots at the Morgan Ranch in 2005 Page 44

48 Figure 5. Mortality one year after treatment on aerial juniper plots at the Diamond A Ranch applied in Figure 6. Mortality six months after treatment on aerial juniper plots at the McKay Ranch applied in ACKNOWLEDGMENTS This project was supported by BASF, DuPont, North Star Helicopters, cooperating landowners, and Howard and Hood Counties. The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by AgriLIFE Extension is implied. Page 45

49 2007 Individual Plant Foliar Sprays on Blackberry Charles R. Hart, Extension Range Specialist, Stephenville Nicholas B. Hoffman, County Extension Agent, Freestone County SUMMARY Demonstration plots were established to evaluate four herbicides, Remedy Ultra, Pasturegard, Surmount, and PD2, for Blackberry control. Surmount was applied twice using two different rates. Individual plant foliar spray applications were established in the summer of 2007 on one site in Freestone County. Preliminary evaluations have been made, but final evaluations will not be available until two years post-treatment. OBJECTIVES Blackberry is a thicket-forming, prickly and invasive shrub that can be a significant problem on Texas rangelands. The purpose of this project is to evaluate and determine the efficacy of five herbicide treatments and best control method for Blackberry. MATERIALS AND METHODS Individual plant leaf spray applications were established on July 11, 2007 in Freestone County. The test plots were located on the F.E. Hill Co. property. Each treatment had a total spray volume of one gallon with 1% v/v MSO added to the herbicide mix. Herbicides and rates are presented in Table 1. Plots were treated using backpack sprayers with an individual plant leaf spray treatment. Each sprayer was equipped with an X20 nozzle. When sprayed, plants were at a post-bloom stage of growth. All plots were variable in size. Treatments were evaluated for percent brown-out at 60 days after treatment and for percent mortality, estimated visually, at 120 days after treatment. Additional mortality estimates will be made at one and two years post-treatment. Table 1. Herbicide, rates and application data for blackberry control in Freestone County applied in July Treatment No. Herbicide Rate Material/plot F. E. Hill Co. 1 Remedy Ultra 1.00% v/v 38.4 ml 2 Pasturegard 2.00% v/v 76.8 ml 3 Surmount 2.00% v/v 76.8 ml 4 Surmount 1.00% v/v 38.4 ml 5 PD2 2.00% v/v 76.8 ml Page 46

50 RESULTS AND DISCUSSION Visual percent brown-out estimates were made sixty days post-treatment on August 18, Also, percent mortality evaluations were made 120 days after treatment on November 6, All percent brown-out results were similar, except PD2 was somewhat lower. Later, percent mortality evaluations were made and some differences were seen. The lower rate of Surmount had the highest mortality while PD2 still showed the lowest (Figure 1). Results for all the evaluations are shown in Table 2. Table 2. Preliminary results for percent brown and percent mortality of blackberry 60 and 120 days after herbicide treatment. Plot No. Herbicide Rate % Brown % Mortality F. E. Hill Co. 60 DAT, 8/26/ DAT, 11/6/07 1 Remedy Ultra 1.00% v/v 100% 85% 2 Pasturegard 2.00% v/v 100% 85% 3 Surmount 2.00% v/v 100% 90% 4 Surmount 1.00% v/v 100% 100% 5 PD2 2.00% v/v 90% 50% Figure 1. Percent mortality estimates 120 days post-treatment on IPT greenbriar plots. ACKNOWLEDGMENTS This project was supported by Freestone County The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by AgriLIFE Extension is implied. Page 47

51 2007 Individual Plant Foliar Sprays on Greenbriar Charles R. Hart, Extension Range Specialist, Stephenville Nicholas B. Hoffman, County Extension Agent, Freestone County Marty J. Vahlenkamp, County Extension Agent, Hood County SUMMARY Greenbriar control trials were established in 2007 to evaluate several different herbicides and rates. Individual plant leaf spray applications were established at two sites in Freestone and Hood Counties. Some preliminary evaluations have been made, but final evaluations will be available two years post-treatment. OBJECTIVES Greenbriar is a tough, woody, invasive plant and a significant problem in areas of central to East Texas. Several herbicides alone and mixes are evaluated in this project to determine the best control for Greenbriar. MATERIALS AND METHODS Individual plant leaf spray applications were established on June 18, 2007 in Freestone County and July 3, 2007 in Hood County. The site in Freestone County was located on the Maysel property and the site in Hood County was located on the Rockin H property. Each site included the same herbicides and rates. The Maysel site sprays had a total spray volume of 4 gallons, while the Rockin H property sprays had a 2 gallon total spray volume. Also, each treatment had 0.25 % v/v Topfilm surfactant added to the herbicide mix. Herbicides and rates for both sites are presented in Table 1. Plots were treated using backpack sprayers with an individual plant leaf spray treatment. Sprayers used on the Maysel site used a x26 nozzle and on the Rockin H a x28 nozzle was used. Each plot was variable in size. Treatments were evaluated for percent brown-out at days after treatment and for percent mortality, estimated visually, at days after treatment. Additional mortality estimates will be made at one and two years post-treatment. Page 48

52 Table 1. Herbicide, rates and application data for Greenbriar control on two sites in Freestone and Hood Counties applied in June and July Treatment No. Herbicide Rate (pr/acre) Material/plot Maysel Property 1 Remedy 2.00% v/v ml 2 Remedy + Cimarron Plus 2.00% v/v 1 g/gal ml 4.0 g 3 Remedy + Cimarron Plus 2.00% v/v 2 g/gal ml 8.0 g 4 Forefront 2.00% v/v ml 5 PD2 2.00% v/v ml 6 Surmount 1.00% v/v ml 7 Vista 1.00% v/v ml Rockin H Property 1 Remedy 2.00% v/v ml 2 Remedy + Cimarron Plus 2.00% v/v 1 g/gal ml 2.0 g 3 Remedy + Cimarron Plus 2.00% v/v 2 g/gal ml 4.0 g 4 Forefront 2.00% v/v ml 5 PD2 2.00% v/v ml 6 Surmount 1.00% v/v 76.8 ml 7 Vista 1.00% v/v 76.8 ml RESULTS AND DISCUSSION Visual percent brown estimates were made sixty days post-treatment, August 13, 2007, on the Maysel site and forty days post-treatment, August 16, 2007, on the Rockin H site. Also, percent mortality evaluations were made 150 days after treatment, November 6, 2007, on the Maysel site and 120 days after treatment, November 7, 2007, on the Rockin H site. The first evaluations were made for percent brown-out on each site. The two sites were generally similar, but when a difference was seen, the Maysel site showed greater percentage brown-out (Figure 1). Later, percent mortality evaluations were made and the Rockin H site had greater average mortality than the Maysel site (Figure 2). Results for all the evaluations are shown in Table 2. Table 2. Preliminary results for percent brown and percent mortality of greenbriar after herbicide treatment. Plot No. Herbicide Rate % Brown % Mortality Maysel site 60 DAT, 8/13/ DAT, 11/6/07 1 Remedy 2.00% v/v 100% 90% 2 Remedy % v/v 100% 75% Cimarron Plus 1 g/gal 3 Remedy % v/v 100% 40% Cimarron Plus 2 g/gal 4 Forefront 2.00% v/v 90% 60% 5 PD2 2.00% v/v 95% 10% 6 Surmount 1.00% v/v 100% 10% 7 Vista 1.00% v/v 60% 10% Page 49

53 Table 2. Preliminary results for percent brown and percent mortality of greenbriar after herbicide treatment. Plot No. Herbicide Rate % Brown % Mortality Rockin H site 40 DAT, 8/16/ DAT, 11/7/07 1 Remedy 2.00% v/v 99% 90% 2 Remedy + Cimarron Plus 2.00% v/v 1 g/gal 99% 90% 3 Remedy + Cimarron Plus 2.00% v/v 2 g/gal 99% 90% 4 Forefront 2.00% v/v 30% 90% 5 PD2 2.00% v/v 70% 50% 6 Surmount 1.00% v/v 90% 30% 7 Vista 1.00% v/v 15% 30% Figure 1. Percent brown estimates 60 and 40 days after treatment on IPT greenbriar plots. Page 50

54 Figure 2. Percent mortality estimates 150 and 120 days after treatment on IPT greenbriar plots. ACKNOWLEDGMENTS This project was supported by Freestone and Hood Counties The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by AgriLIFE Extension is implied. Page 51