Pigweed poses stubborn problem for row crops

By Peter Kent

PigweedMike Marshall is as pigheaded about weed control as pigweed is prolific. Pigweed (Palmer amaranth) can produce up to 650,000 seeds per plant, making it a devastating weed in row crops, says Marshall, Extension weed specialist at the Edisto Research and Education Center in Blackville. The weed can grow two inches a day up to seven feet or more, crowding out crops, and is so tough that it can damage harvesting equipment.

Over the past 15 years, pigweed has adapted so herbicide is not as effective as it once was. The situation could lead to higher food prices because of lower crop yields and rising farm costs.

Marshall and other Clemson scientists are coming up with ways to control pigweed. Some are high-tech, such as satellite-guided precision weed-killer treatments, and some are low-tech – pulling the weeds by hand.

“We have to use the herbicides we have wisely and keep chipping away at the whole landscape of weed resistance in cotton, soybeans, corn, wheat and other crops in South Carolina to manage the problem until we get new tools,” says Marshall.

For information: Mike Marshall, 803-284-3343 x 228, marsha3@clemson.edu