2016-Progress Report. Individual Plant Treatments of Prickly Pear

Transcription

1 2016-Progress Report Individual Plant Treatments of Prickly Pear Site Locations: Cooperators: Authors: Somervell and Lampasas Counties Bob Miller, David Parker, David Harris and Nate Newton James Jackson, Extension Program Specialist, Stephenville Zach Davis, County Extension Agent, Somervell County Heath Lusty, County Extension Agent, Lampasas County Marty Vahlenkamp, County Extension Agent, Hood County Summary Multiple sites were established in 2015 and 2016 to research the efficacy of Dow AgroSciences products that are labeled and some in experimental stage on prickly pear. The current standards for prickly pear control are Surmount and, both of these products deliver a high rate of mortality on prickly pear, however; can take up to three years while Surmount can take up to 2 years to reach a high level of control. This study looks at multiple combinations to determine if there is any acceleration in the rate of mortality by using one of the experimental tank mixes or products. All treatments were mixed with MSO at a rate of 1.0% v/v. Apparent percent yellowing and mortality evaluations will be conducted at 4, 8, 12 and 24 months after treatment. Evaluations will be made with comparisons to the current standards of and Surmount to determine what treatment delvers the highest level of mortality at the quickest rate. Objective Prickly pear may interfere with movement and handling of livestock, with forage utilization, cause serious livestock health problems, and compete with desirable forage plants. These plants are extremely tolerant of drought and harsh conditions and are protected from grazing animals, to some extent, by their spines. Prickly pear thrives in the central and western half of Texas, both in rural pastures and urban lots. They have the ability to grow and increase in abundance very rapidly. Once prickly pear populations become very dense, control options are much more expensive and logistically difficult. When this occurs, an aerial or ground broadcast treatment could be the most cost and time effective method of control for prickly pear.

2 The herbicide recommended by the Brush Busters program for prickly pear control is Surmount, which can take up to two 2 years to reach a high rate of mortality on the prickly pear. is also an effective herbicide on prickly pear; however, this treatment takes an extended period of time, as well to see any results. Aminopyralid is Dow AgroSciences newest active ingredient that has activity on many different species and has been noted to have a yellowing effect on prickly pear. Another active ingredient that has activity on prickly pear is fluroxypyr, the primary objective of this project is to determine if any of the combinations of the active ingredients applied result in a faster mortality of prickly pear. The second objective of this project is to look at the comparison of Grazon P+D to Grasslan L, Dow AgroSciences newest version of 2,4-D and Picloram and the final objective of this project is to collect more data on PastureGard HL as a control option for prickly pear for non-private applicators license holders. Should any of these options prove to be a viable option for prickly pear control, the data generated by this project will be recommended as an addition to AgriLife Extension s publication RLM-1466 for faster results or non-restricted methods of controlling prickly pear? Materials and Methods Two sites were established in spring of 2015 in Somervell and Lampasas Counties. Three sites were established in the spring of 2016 in Hood, Somervell and Lampasas Counties. Each of the 2015 sites received all 11 treatments and the Somervell site of 2016 received all 11 treatments with the Hood and Lampasas site not receiving the Grazon P+D and the Graslan L treatments. Hi-light spray indicator was added to each treatment to indicate the plants that were sprayed in each plot. Each plot had a buffer of untreated plants between it and the next plot and the total spray volume was 1.5 gallons per treatment for the 2015 sites and lons per treatments for the 2016 plots. Evaluations on the 2015 sites have been conducted at 4, 8, and 12 months after treatment and will reevaluated at 24 months after treatments the 2016 sites will be evaluated on the same schedule with the 4 month after treatment data included in this report. Environmental conditions on the day of application are provided in Table 1 and specific treatment details are listed in Table 2. Table 1. Environmental conditions on the day of application for prickly pear Individual plant treatment trials established in 2015 and Site Date Spray Time Wind Speed/ Direction Soil Temp. Air Temp. Soil Type/ Moisture RH 2015 Sites Somervell 5/29/15 9:00-1:00 7 mph NW Krum/Wet 80% Lampasas 6/9/15 9:00-12:00 Clam Lukenbach/Mod Sites Somervell 3/29/16 9:00-12:00 12 mph SE Bastrop/Mod 73 Hood 4/1/16 9:00-11:30 11 mph NNE Tarrant/Mod 39 Lampasas 5/26/16 8:30-12:30 11 mph SSE Lukenbach/Mod 87

3 Figure 1. Layout of individual plant treatments on prickly pear applied in Lampasas County in Figure 2. Layout of individual plant treatmenst on prickly pear applied in Hood County in 2016 Figure 3 & 4. Layout of plots sprayed in 2016 in Lampasas(left) and Somervell(right) Counties in 2016.

4 Table 2. Herbicides, rates, and application data for Individual Plant Treatment trials established in 2015 and MSO at 1.0% v/v was added to all treatments Treatment No. Herbicide IPT Rate Material/ plot TSV/ Plot # Plants Treated 2015 Sites Somervell 1 1.0% 56 ml 1.5 gal 12 2 Surmount 1.0% 56 ml 1.5 gal 15 3 Sendero 28 ml 10 ml 1.5 gal ml 7 ml 5 ml 1.5 gal ml 1.5 gal ml 1.5 gal 30 7 ml 7 GF % 68 ml 1.5 gal 26 8 GF % 45 ml 1.5 gal 31 9 PastureGard HL 1.0% 56 ml 1.5 gal Grazon P+D 2.0% 113 ml 1.5 gal Grasslan L 1.34% 76 ml 1.5 gal 40 Lampasas 1 1.0% 56 ml 1.5 gal 12 2 Surmount 1.0% 56 ml 1.5 gal 15 3 Sendero 4 28 ml 10 ml 28 ml 7 ml 5 ml 1.5 gal gal ml 1.5 gal ml 1.5 gal 30 7 ml 7 GF % 68 ml 1.5 gal 26 8 GF % 45 ml 1.5 gal 31 9 PastureGard HL 1.0% 56 ml 1.5 gal Grazon P+D 2.0% 113 ml 1.5 gal Grasslan L 1.34% 76 ml 1.5 gal Sites Somervell 1 1.0% 75 ml 28 2 Surmount 1.0% 75 ml ml 25 27

5 Table 2. Herbicides, rates, and application data for Individual Plant Treatment trials established in 2015 and MSO at 1.0% v/v was added to all treatments Treatment No. Herbicide IPT Rate Material/ plot TSV/ Plot # Plants Treated GF % 90 ml 34 8 GF % 60 ml 24 9 PastureGard HL 1.0% 75 ml Grazon P+D 2.0% 151 ml Grasslan L 1.34% ml Hood 1 1.0% 75 ml 2 Surmount 1.0% 75 ml ml GF % 90 ml 8 GF % 60 ml 9 PastureGard HL 1.0% 75 ml Lampasas 1 1.0% 75 ml 2 Surmount 1.0% 75 ml ml 7 GF % 90 ml 8 GF % 60 ml 9 PastureGard HL 1.0% 75 ml

6 Results and Discussion The evaluations were conducted at 4 month intervals on the 2015 sites and are currently being conducted at the same intervals on the 2016 plots. Table 3 lists the data that was collected at each of the evaluations for each site. On the 2016 sites only the 4 month after treatment evaluation was conducted at the time of the report, the 8 and 12 month data will be reported in the progress report for2017. Table 3. Evaluation data for plot evaluations on 2015 and 2016 individual plant treatments on prickly pear. Herbicide IPT Rate 4 MAT 8 MAT 12 MAT % Yellow % Desi. %Green % Yellow % Desi % Yellow % Desi Somervell 1.0% Surmount 1.0% GF % GF % PastureGard HL 1.0% Grazon P+D 2.0% Grasslan L 1.34% Lampasas 1.0% Surmount 1.0% GF % GF % PastureGard HL 1.0% Grazon P+D 2.0% Grasslan L 1.34% Sites Somervell

7 Herbicide IPT Rate 4 MAT 8 MAT 12 MAT % Yellow % Desi. %Green % Yellow % Desi % Yellow % Desi 1.0% Surmount 1.0% GF % GF % PastureGard HL 1.0% Grazon P+D 2.0% Grasslan L 1.34% Hood 1.0% Surmount 1.0% GF % GF % PastureGard HL 1.0% Lampasas 1.0% Surmount 1.0% GF % GF % PastureGard HL 1.0%

8 % M o r t a l i t y IPT Prickly Pear Plots Percent Mortality 1% Months After Treatment Surmount 1% GF % GF % Figure 5. All 2015 treatments graphed by months after treatment in Somervell and Lampasas Counties. % M o r t a l i t y IPT Prickly Pear Results % Surmount 1% GF % GF % Months After Treatment Figure 5. GF-2969 treatments compared to industry standards of and Surmount in Somervell and Lampasas Counties. Acknowledgements This project was supported by Dow AgroSciences, the cooperating landowners Lampasas, Hood and Somervell Counties. 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.