We have an interesting example of tree crop productivity in Hawaii, where the agaroba was introduced from Peru in the last century. It has now spread until it covers considerable area with forests, and information from the Hawaiian Experiment Station is to the effect that it is now the mainstay of the dairy industry of the island. The annual crop of four tons of big beans to the acre can be and is ground into a highly nutritious meal food selling at $25 a ton, an agriculture which, for ease of operation and richness of return, puts Illinois to shame, for, in addition to the $100 worth of animal food, there is a ton of wood per acre every year.
The tree crop agriculture seems to hold the possibility of letting the worst third of our soil (Class 1 as mentioned above) become as productive as the best land (Class 3), while (Class 2) the hill land can probably be doubled in productivity. This is a goal well worthy of much endeavor on the part of the plant breeder.
Tree crops offer equal possibilities for the arid land. The grains with their period of crisis are an uncertain dependence on land of such uncertain rainfall as exists in the United States west of the 100th meridian. This is attested by the fact that some of this land has been settled three times and abandoned twice to the wreckage of hundreds of thousands of private fortunes. Yet the tree with its far-reaching roots and ability to store energy can survive in much of this area where grains are so very uncertain. The mesquite, yet a tree weed over much of this area, has one species which produces a nutritious seed that has been used for bread stuff by unknown generations of Indians. The screw bean, a legume, with a nutritious seed, grows from El Paso to the Imperial Valley; while the broad leafed honey locust, with a seed closely akin to that of the carob, or St. John's Bread, will also grow over wide areas in the arid southwest. Five varieties of the small but productive wild almond have been found by a Government botanist growing upon the shores of Pyramid Lake; while Frank Myer, Plant Explorer of the Department, brings back from Turkestan accounts of wild almonds producing good fruit on mountain slopes with a rainfall of 8 inches a year. These productive plants, several of them legumes, adjusted by nature to this region, with allied species in other continents, seem to hold before the plant breeder the possibilities of hundreds of thousands of square miles of Western orchard ranges of high productivity, rather than the present would-be grass-ranges of low and declining productivity.
I believe that the development of a tree crop agriculture offers one of the greatest possibilities in constructive conservation of natural resources. Individuals cannot be depended upon to do it. The work is too slow. A man might by decades of work create species that would be, if fully utilized, worth a hundred million dollars a year to a state like Pennsylvania; yet he would be unable to realize personal gain from the results, provided he had secured them. Institutions must do it. It is like the Geological Survey and the Census Bureau and Agricultural Experiment Stations, which depend upon appropriations. The appropriations depend upon the realization of the importance of the work. There are interesting examples of similar work already in operation, of which the following might be mentioned: The Agricultural Experiment Station of Arizona has started a twenty-four-year series of experiments in breeding the date palm. In North Dakota, where the blizzards kill nearly all the ordinary fruits, an experimenter has done much work in the breeding of hardy strains of apple, cherry and other trees.
Then followed a display of lantern slides showing scenes from Spain, Portugal, Balaeric Islands, Sicily, Corsica, Italy, Algeria, Tunis, France and southern and central United States. This collection of pictures revealed a surprising amount of tree crop agriculture already worked out but needing wider application.
The meeting adjourned without discussion of either lecture at 10 P.M.