Page:Popular Science Monthly Volume 80.djvu/585

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581
THE IMPROVEMENT OF PLANTS

to consider their value as forage crops for animal food, and here a much greater latitude for selection is possible. A very large number of our native plants should be tested and the most promising improved for forage purposes.

In the development of leguminous crops we have a valuable field of research. Of the many hundreds of legumes, we now cultivate only about a dozen species, such as beans, peas, clover, alfalfa, crimson clover, cowpeas, soy beans and the like, representing a natural adaptation to as many localities. None of the species ordinarily cultivated in the northern United States are natives of this great section. Yet an examination of the botanies shows that some 150 different species of legumes are natives of this section. Would it not seem absurd to assume that our present cultivated species represent the best types for this section, when the most promising of those that the great Master Breeder gave us have not been thoroughly improved and tested? Among the wild native species of Desmodium, Vicia, Lespedeza and other legumes, we have a number of promising sorts. We have tested many of these species in comparison with our ordinary cultivated crops and discarded them, but our tests have been of the wild, unimproved, against the improved types. We might as reasonably put gloves on a wild pygmy of Africa and test him on the mat with a trained modern athlete.

Doubtless the mere mentioning of the improvement of native plants suggests to the minds of each one of you some wild plant that you have observed and thought to possess valuable qualities. If our sources of nitrogen supply are to be exhausted soon, we must cultivate more leguminous crops that can gather their own nitrogen and improve the soil in this respect while furnishing crops. We should have leguminous tuber crops to take the place of potatoes, beets and turnips. Nature has given us such wild legumes as the groundnut (Apios tuberosa) and the Pomme de Prairie (Psoralea esculenta), which already have edible tubers and which could doubtless be developed into very valuable cultivated plants by a few years of breeding.

Dr. J. Russell Smith,[1] of the University of Pennsylvania, has emphasized the importance of breeding tree crops, and here we have an inexhaustible field of experimentation. We should breed chestnuts, walnuts, hickories, oaks, beeches, hazelnuts, and the like, in order to improve them for the use of man and for growth as stock food. Many hundreds of thousands of acres of rough, hilly land unadapted for cultivation would be suited for the growth of such crops.

The possibilities of breeding tree crops are well illustrated by the excessive increase in vigor, rapidity of growth and size of fruit obtained by Burbank in a hybrid between the English walnut (Juglans

  1. Smith, J. Russell, "The Breeding and Use of Tree Crops," American Breeders' Association, Vol. I., p. 86.