Basing their work on the foundation provided by Stakman, plant pathologists and plant breeders of the Department and State agricultural experiment stations have successfully combined their knowledge to produce many new varieties of crop plants that resist several races of disease organisms. These include many promising new kinds of oats, wheat, and other cereal crops.

Cooperation and collaboration bulk large in the traditions of science in farming. There are hundreds of examples of what I mean, but I give one, that of breeding plants for resistance to insects, which has been a tougher job than breeding for control of diseases. The idea dates from 1782, when a variety of wheat sown by Isaac Underhill of New York and his neighbors was reported to yield well, while all other kinds sown nearby were ruined by the hessian fly.

C. W. Woodworth, of California, probably did the first actual research on breeding plants that are resistant to insects when he made a systematic study of the variations in fly resistance of wheat in 1890. J. W. McColloch and S. C. Salmon, of Kansas, reported similar observations in 1918, and many wheat breeders tried to develop varieties that had fly resistance.

Through the work of many State and Federal plant breeders, we now have several varieties of crop plants that are resistant to insects. Besides several varieties of wheat that resist the hessian fly, the Sequoia potato resists leafhoppers, several lines of hybrid corn resist attacks of chinch bugs, others resist the corn earworm; and some varieties of sorghum resist attacks of chinch bugs. Work in progress gives promise of developing resistance to aphids in alfalfa and cotton.

Patience and persistence are part of the research tradition, too. These qualities are exemplified by W. W. Garner and H. A. Allard, two of the most modest men it has been my good fortune to know.

The desire of farmers in southern Maryland to grow seed of a giant tobacco that appeared as a sport led Garner and Allard to make one of the most profound botanical discoveries of all time. They were investigating other problems of tobacco in Maryland at the time, so they set out to make the giant tobacco flower and produce seed. This was in 1906.

They worked on this problem off and on for several years, and this work led them to discover the fundamental law of nature that many plants can flower and produce seed only when the duration of light, that is, the length of day, is right for that particular plant. The discovery explained many things not previously understood about the flowering and fruiting of plants, and it has many practical applications in present-day agriculture.

Garner and Allard got their first hunch that they were on the trail of something big when the giant tobacco that would not flower outdoors in Maryland readily flowered and set seed when grown in tubs in a house that could be darkened in mid-afternoon. (It also flowered in Florida, but nematodes often killed the plants before they could mature seed. ) These investigators were also keenly interested in a report from Tennessee saying that successive plantings of soybeans throughout the summer months tended to blossom at the same time, for they themselves had made the same observation.

Over a period of several years—for this was a side line to their regular work—the scientists painstakingly eliminated every other factor they could think of that might explain the behavior of the tobacco and soybeans. They added several other plants to their list. They tricked chrysanthemums into blooming in midsummer by moving potted plants into a dark house in mid-afternoon. Then, finally, in 1920 they announced their discovery. In the meantime, they had found that some plants seemed to get along, all right with either a short or a long day. Others required a short day, and a third group required a long day.

Many practical gains to agriculture have resulted from this work. These are recounted in another article in this volume. Potatoes that would not produce seed for plant breeders now do so. Varieties of plants that bloom at different times can now be made to bloom to suit the convenience of the plant breeder. Failures with crops like onions may often be prevented by knowing their day-length requirements. Chrysanthemums can be brought into flower before or after their normal season—for football games, for instance.