account for another 16 percent. The remainder are distributed among other crops. The major users of fungicides are fruit crops at 60 percent, with vegetables second at 24 percent.
The crop use can be overstated as well. Of the 890 million acres of U.S. cropland, only 17 percent is treated with herbicides, 6 percent with insecticides, and 0.9 percent with fungicides. These figures include land used as pastures, and if this land is removed from the picture, the results are 34 percent treated with herbicides, 12 percent with insecticides, and 2 percent with fungicides, still not a vast proportion of the land. For any one crop, insecticide treatment may vary by geographic area, according to perceived need in different places. In the mountain region where large quantities of potatoes are grown, 65 percent of the potato acreage is treated with insecticides; in the Southeast where early potatoes are grown, 100 percent of the potato acreage is treated. The difference probably reflects the higher intensity of pest attack occurring in the warmer regions. Cotton insect pests are more of a problem in the Southeast than in other regions, and in such warmer climes 84 percent of cotton acreage is treated, while in other regions only 41 percent is so treated (Pimentel et al., 772-773).
The reason for all this use of pesticides is clearly the belief that not to do so would be to open up crops to damage and destruction by insect and other pests. Pests each year already reap a tremendous harvest of the food intended for human and animal consumption, but quantifying these losses on a worldwide basis is very difficult. A 1967 study, though out of date, showed that about one-third of the world's food was lost to pests, and that in the important rice crop the loss was at 46 percent. This 33 percent loss means that there is a potential to increase the world's food supply by 50 percent if these pests could be eliminated. The losses are high...