A naturally occurring fungus may prove useful in the weed control fight against Palmer amaranth, an aggressive southern weed that can grow at the rate of 2 inches a day and out-compete corn, cotton, soybean and other crops for resources, potentially reducing their yields.
Weed Control Important to Avoid Glyphosate Resistance
To make matters worse, some biotypes of the weed have become resistant to weed control using glyphosate herbicides. As a possible alternative, USDA scientists are exploring ways to formulate Myrothecium verrucaria, a fungus which attacks Palmer amaranth’s leaf and stem tissues, causing wilt, necrotic lesions, loss of chlorophyll and other disease symptoms that can kill young plants and weaken older ones. Studies at the Jamie Whitten Delta States Research Center operated by USDA’s Agricultural Research Service in Stoneville, indicate Myrothecium can wreak similar havoc on biotypes of Palmer amaranth that resist glyphosate and other herbicides such as triazines. Learn more about this possible weed control in the February 2014 issue of Acres U.S.A.