Pest, pathogen, and weed control for increased food production.

If the ideal of assured "Food for All" is to be attained, it will be necessary to do a better job of preventing the debilitation or destruction of crop plants by noxious weeds, voracious animals, and devastating plant diseases. For these destructive agents continually tend to nullify the constructive efforts to increase food production. Food production per unit area of land has been increased greatly in advanced countries during the past half century by producing continually better varieties of food plants and by devising better methods of soil cultivation and fertilization. Unfortunately, however, bad weather, pests, and pathogens too often prevent the better-bred and better-fed varieties from realizing their full productive potential. The destructive effects of these inanimate and animate enemies of crop plants must be prevented or reduced by more widespread and effective use of materials and methods now available and by devising better ones for the future. Education and research are man's most potent allies in this continuous fight against the destructive agents that continually menace his food supplies and often deplete them dangerously; ignorance and apathy are his most powerful enemies. Although phenomenal progress has been made in fighting pests and pathogens, the fight against them is far from won. Even in a relatively advanced country like the United States, weeds, insect pests, and plant diseases reduce the potential annual crop production by more than 20 per cent, and the losses in many of the less-advanced countries are considerably higher. In the United States we are still using the equivalent of 75 million acres of crop land to feed weeds, insects, and plant pathogens instead of human beings. Countries that produce a surplus may be able to afford such losses yet a while, but fooddeficient countries cannot. The situation often is aggravated by the tendency of many insects and plant pathogens to become devastatingly destructive periodically. Outbreaks of insect pests and the epidemic development of plant diseases often destroy huge quantities of man's basic food crops. In two successive years, 1953 and 1954, stem rust epidemics destroyed one fourth of the bread wheat and three fourths of the durum wheat in the principal spring wheat area of the United States. Losses of this magnitude are catastrophic in countries that are always hungry and often on the verge of famine, as is illustrated by the death of upward of a million people in India, about a decade earlier, because Helminthosporium blight destroyed much of the rice crop in large areas of production. The control of the living enemies of crop plants often makes the difference between food and famine. The control of pests and pathogens of the principal cereal food grains-wheat, rice, maize, sorghums, and millets-would add 200 million tons annually to the billion tons now produced. Assuming an average of about 45 lb to a bushel, there would be about an additional 2.7 bushels, or 120 lb, a year for each of the world's 3.3 billion people, enough to furnish each person 2000 calories for about 100 days. These data are based on an estimated 20 per cent annual loss, which is conservative in view of the fact that calculated average losses are somewhat higher in the United States. Although plant protection specialists sometimes are accused of overesti-