Excerpts from the report Summary: Over half of all U.S. farmers use weed, insect, or disease control chemicals on their crops. In 1966, about 37 percent of the farmers growing crops used herbicides, 29 percent used insecticides, 4 percent used fungicides, and 8 percent used other pesticides (including defoliants, desiccants, growth regulators, miticides, and rodenticides). The proportion of crop acreage treated with pesticide chemicals is increasing. This is especially true for herbicides. For example, corn acreage treated with herbicides increased from 11 percent in 1952 to 57 percent in 1966. Cotton acreage on which herbicides were applied went up from 7 percent in 1958 to 52 percent in 1966. Considering all crops, about 27 percent of the total cropland (not including pasture and rangeland) was treated with weed control chemicals in 1966. They were applied on over half of the corn, cotton, rice, peanuts, and potato acreage.