Dec. 25, 2008 - Controlling and preventing brushy weed invasions in Northeast Texas was the topic at the recent Agriculture Technology Conference at Texas A&M University-Commerce. Dr John Boyd, Extension weed scientist from the University of Arkansas Division of Agriculture explained the modern methods of identifying and eliminating several species of brushy weeds within the region.
"When spraying herbicides to control or prevent weed invasions, the applicator must first identify the weed and determine which stage the weed is in," said Boyd. "Once the weed is identified the chemical to use to kill the weed can be determined. There are several chemicals on the market today. All safety precautions and warnings should be thoroughly read before applying."
Weed control may range from spraying flower beds or fence rows, to aerial spraying from crop-dusters.
"Controlling weeds in flowerbeds, along treelines and fence rows may be done by backpack style or pump sprayers," said Boyd. "If long distances are to be covered, either spraying treelines or fence rows, spray rigs on the back of All-terrain vehicles (ATV) may work best. Herbicides sprayed over large areas of land may either be done by large spray rigs pulled behind tractors, or even sprayed from the air by crop-dusters. Smaller spray rigs may be more efficient, but when controlling weeds, they can be very time consuming. Larger areas of land may need herbicides applied by larger equipment, but can be very costly."
In addition to the manner of application, the equipment used can also vary.
"There are also several different tips that may affect the coverage when applying herbicides," he said. "Brass tips are generally more expensive, but may last longer than plastic tips. Depending on the chemical being applied, a TX1 tip with very small holes may be used to receive a narrow very fine mist spray. For a larger and heavier stream spray, applicators may use a TX8 tip which has very large holes. Filters may also be used in tips to prevent them from clogging. Filters are available in different mesh screens, which may also affect the flow of the spray."
Stump treatment may also be crucial when controlling and eliminating brushy weeds.
"As landowners clean fence rows and treelines, they most often forget about treating the stumps from trees and brushy weeds," said Boyd. "If the stumps are not treated, they will re-sprout. Some landowners find themselves cutting the same weeds each year because they did not treat the stumps. For best results, stumps should be treated within three to four hours.
"To properly treat the stump of a tree to prevent it from re-sprouting, the cambian, or growing part of the tree which is the outer most edge, should be sprayed."
Boyd also suggest, the hack and squirt method to control larger brushy weeds.
"The hack and squirt method is done by chopping a small wedge out of the tree and then injecting a herbicide into the cut" said Boyd. "The cut needs to be at an angle in which the chemical will not drain out."
There are several weeds species that may take different chemicals and procedures to eliminate.
"Throughout the region, there are certain weeds that need to be sprayed during certain periods of the year, or after the weed has reached certain foliar growth," said Boyd. "Wild roses should be sprayed when they have plenty of foliar growth. Spraying wild roses after they have been mowed will not control the weed.
"As horse nettle becomes established, it is more difficult to control. Treatment should be applied in the early growth stage of horse nettle to properly control the weed. The ripened fruit from horse nettle can be toxic to livestock, therefore pastures containing livestock should be properly treated for horse nettle."
Pasture brush herbicides for numerous weeds common throughout the region can be found at www.uaex.edu/Other_Areas/publications/PDF/MP44/T2_Forage.pdf .
For maximum coverage, surfactant may need to be added to herbicide mixture.
"Many brushy weeds contain a waxy coating over the leaves causing herbicides to bead up and run-off the leaves of the plant," said Boyd. "To properly control these weeds, surfactant may need to be added to reduce surface tension and allow for maximum coverage."
For more information about controlling brushy weeds contact a Texas AgriLife Extension agent.