A new biological control agent offers a natural alternative to chemicals now used to combat sicklepod and coffee senna, two major weeds in southern crops such as soybeans, cotton and peanuts.

Scientists with USDA’s Agricultural Research Service say two applications of a mixture of corn oil, water and spores of the fungus Colletotrichum gloeosporioides killed 95 percent of newly emerged sicklepod in soybeans. Three years of field tests showed overall weed populations were reduced 90 percent. Plant pathologist C. Douglas Boyette led the tests at ARS’ Southern Weed Science Laboratory, Stoneville, Miss.

The fungus offers a definite improvement for soybean farmers: The active ingredient in the chemicals used to combat sicklepod and coffee senna also kills soybean plants.

The ARS researchers will test the spores this summer against sicklepod in cotton. ARS has patented the fungus--known as Strain NRRL 21046--and is seeking industry cooperators to commercially develop the fungus as a biological alternative to chemical herbicides. (Patent No. 5,529,773)

Scientific contact: C. Douglas Boyette, ARS Southern Weed Science Laboratory, Stoneville, Miss., phone (601) 686- 5217; fax 686-5265, [email protected].