Plant Resistance to Insects Attacking Corn and Grain Sorghum

Abstract

North Carolina and Tennessee ranked as the number one and two states in the Southeast in 1986 in corn (Zea mays L.) production with 1.6 and 0.9 million acres and value of the crop at 167.0 and 94.0 million dollars, respectively. Arkansas and Louisiana were the top two sorghum [Sorghum bicolor (L.) Moench] producers in 1986 with 675 and 370 thousand acres and the value of the crop at 56.0 and 35.2 million dollars, respectively. There are three major efforts to develop plant resistance in corn to insects in the southeast: USDA's Insect Biology and Population Management Research Laboratory at Tifton, GA; USDA's Crop Science Research Laboratory at Mississippi State, MS; and the program of Dekalb/Pfizer Genetics at Union City, TN. Only the Tifton, GA, program has resistance of sorghum as one of its goals. Mass rearing [except for Contarinia sorghicola (Coq.)], infestation technology, and evaluation systems for identification of resistant germplasms have been perfected for several growth stages of both crops. A total of 12, 10, 9 (corn), and 54 (grain sorghum) resistant cultivars have been released and registered from the southeastern United States over the last 15 years for public use with resistance to corn earworm, fall armyworm, southwestern corn borer, and the sorghum midge, respectively. Some releases of corn germplasm possess resistance to as many as six leaf-feeding insect species.