In the battle against weeds it's wise to know your enemy. Among the wickedest fiends on the farm is Palmer amaranth, commonly called pigweed. This highly-adaptive weed is prevalent in fields throughout the state, and its appearance varies widely thanks to a broad genetic base.

“I call pigweed the most immoral of weeds,” said UA weed scientist Dick Oliver. “It'll breed with anything.”

Jason Bond, Ph.D. student at the University of Arkansas, has been studying variations in Palmer amaranth. Like most graduate students in Dale Bumpers College of Agricultural, Food and Life Sciences, Bond works with UA Division of Agriculture scientists in research programs for the Arkansas Agricultural Experiment Station. With support from the Soybean Promotion Board, Bond has been working three years in pigweed projects with Oliver.

“I've collected seed from all across the southern U.S., from New Mexico to South Carolina,” he said.

“I wanted to see how samples from different parts of the country grow. I also want to see if the different varieties respond differently to herbicides commonly used in Arkansas.”

Palmer amaranth is not native to Arkansas, Bond said. It came here from other areas of the country, and plants that originated in different areas may have variable susceptibility to or tolerance for various herbicides.

“The idea is to be able to know what herbicides are going to be the best choice for pigweed in specific areas,” he said.

Soybean producers will be relieved to know he found no variations in Palmer amaranth's susceptibility to Roundup and Reflex, two herbicides commonly used with soybeans. He did, however, find wide variation in how the weeds responded to Staple, commonly used in cotton.

“This is something we'll have to stay on top of,” Bond said. ““With its variability, Palmer amaranth may eventually become tolerant of today's herbicides. We'll need to be able to see that coming so something new can be developed to control it.”

Bond is nearing completion of his Ph.D. in agronomy. His graduate school research has already contributed to the body of science that gives producers the tools and information they need to farm successfully.

“When they graduate, our students are real experts in their fields,” Oliver said. “Their research projects accomplish useful research that benefits Arkansas producers now, and give the students a solid basis for a broad range of careers in agricultural research, education and industries.”

“The Soybean Promotion Board's support for graduate student research has been a real asset to us because they help us prepare young people who'll be carrying on the work we're doing today,” Oliver said. “They'll be the ones we rely on in the future to keep agriculture going.”


Fred Miller is science editor for the Arkansas Agricultural Experiment Station. e-mail: fmiller@uark.edu.