Some 100 acres of soybeans at the state-funded agriculture experiment station at Keiser in Mississippi County have been ruined by the herbicide dicamba.

The afflicted field will be disced up and replanted, said Chuck Wilson, director of the Northeast Research and Extension Center, which is operated by the University of Arkansas System Division of Agriculture. “We’re going to have to start over,” Wilson said Monday.

A problem common to farmers last year, crop damage from herbicides, has returned with 41 complaints filed already this year with the state Plant Board.

The Keiser farm consists of 750 acres, where UA scientists research all aspects of farming, including the effectiveness — and potential pitfalls — of herbicides and pesticides on soybeans, cotton, rice, corn, sorghum and other crops.

Wilson said the damage was discovered Friday and that officials are uncertain of its source.

In a statement Monday, Gov. Asa Hutchinson said he was aware of the complaints and will have Wes Ward, secretary of the state Department of Agriculture, and Terry Walker, Plant Board director, “personally view the areas addressed in those complaints and report back with any findings and recommendations.”

Dicamba is a broad-leaf weed killer long used on farms, around homes and on golf courses but now is being used heavily, and sometimes illegally, in combating pigweed, which has grown resistant to other herbicides, including Roundup, because of overuse by farmers.

Soybeans are especially vulnerable to dicamba — unless the beans are a dicamba-tolerant, genetically modified variety released last year by Monsanto. The company also released dicamba-tolerant cotton in 2015. Millions of acres of those crops have been planted across the mid-South.

The state Plant Board, a division of the state Agriculture Department, has received 41 formal complaints through Monday but has fielded dozens of complaints by telephone that haven’t become official investigations.