Farmers reported that 245.9 million pounds (a.i.) of pesticides were applied to field corn in the major producing States during 1980. This consisted of 209.5 million pounds (a.i.) of herbicides and 36.4 million pounds (a.i.) of insecticides. Pesticide acre-treatments totaled 135.4 million and consisted of 73.8 million with single material herbicides, 25.7 million with herbicide mixes, and 35.9 million with insecticides. The primary herbicides were alachlor, atrazine, and 2,4-D. The major insecticides were carbofuran, fonofos, and terbufos. Herbicides were applied primarily to control cocklebur and foxtail infestations. Insecticides were mainly applied to control corn borer and corn rootworm larvae infestations. Coefficients of variation were computed for acres of field corn treated with specific pesticide materials.