Effectiveness of Surmount on Black Brush and Mixed Brush Donnie Montemayor County Extension Agent-Ag Bee County

Result Demonstration: Summary Five different herbicide treatments were evaluated on the AD Walker Ranch in Western Bee County near the Mineral Community. Evaluation in October of 2005 indicated that the best treatment for the efficacy of Surmount on Black Brush was 6 pt./ ac. Prior to the treatment in the fall of 2004, the black brush and mixed species had been shredded. At the time of the treatment there was numerous multi-stemmed plants, making foliar spraying the only logical approach in chemical brush suppression.

Problem Beef cattle producers continue to deal with re-infestation of brush plants in improved pastures that have been previously cleared. Many pastures in the Bee County area use shredding as a form of brush control. The shredding only makes it more of a challenge due to maintenance of equipment, fuel and labor costs.

Objective To evaluate the effectiveness of 3 different Surmount rates and two other different herbicide formulation treatments for the control of Black Brush and mixed brush plants.

Typical Bee County Native Pasture

Blackbrush Acacia

Huisache

Honey Mesquite

Materials and Methods 5 herbicide treatments were applied to re-growth black brush on October 15 th, 2004 with soil conditions considered to be wet. 2 replications were used. Plot size was.4 ac. The temperature was 73 degrees, with 50% relative humidity. Wind direction was from the north west. The soil in the treated area was a sandy loam soil. Equipment used to apply the herbicide treatments included a tractor /boom sprayer.

Mixing of Formulations

Spraying of Plots

Materials and Methods cont. 20 gal/ac. of water was used as the carrier, and a.25% agricultural surfactant was used with no die added. Treatments: 1. pt/ac. 2. pt/ac. 3. pt/ac. 4. Tordon pt/ac. + 1pt./ac 5. Cimarron rate 1oz.+ 2pt./ac.)

Surmount™ herbicide Active Ingredient: picloram + fluroxypyr

Tordon® 22K herbicide Active Ingredient: picloram

DuPont™ Cimarron® Max herbicide Active Ingredients By Weight Metsulfuron Methyl* Methyl 2-[[[[(4-methoxy-6-methyl -1,3,5-triazin-2yl)amino]carbonyl] amino]sulfonyl]benzoate % Dimethylamine salt of dicamba (3,6-dichloro-o-anisic acid)** % Dimethylamine salt of 2,4-dichlorophenoxyacetic acid*** % Inert Ingredients % TOTAL 100.0%

Results PlotNo. Plants 100% Kill 100% top w/sprouts 50% kill <50 % kill No kill

Cost of Application PlotTreatmentCost/ac. pt./ac$22.50/ac. pt./ac$30/ac. 6 pt./ac.$45/ac. 4Tordon 2 pt./ac + $25.50/ac. 5Cimarron Rate 3 $25.00/ac.

Conclusion The best results in this particular test were seen with the 3 rd treatment using 6 pts. of Surmount. Moreover, black brush and other south Texas brush that have been in a management system that includes shredding, have developed a large root making complete kill almost impossible after one application. Thus, additional treatments are required, which increases the cost of the chemical treatment. Due to the lack of data on Surmount, more demonstrations are needed.

Acknowledgements Appreciation is expressed to Mr. A.D. Walker for providing the pasture in conducting the test. Also appreciation is expressed to Mr. Rudy Alaniz, and Mike Hiller for installing the treatments and to Dr. Wayne Hanselka for his support in organizing the demonstration and development of the plot plan.

References uvalde.tamu.edu