Proc. 27th Meeting of Soc. Prom. Agr. Sci. p. 75 (1906)

Improving Wild Potatoes by Selection
Dr. W. J. Beal
Mich. Agr. College

It must have been thirty years since Dr. Asa Gray of Harvard sent me some tubers of Solanum tuberosum, with the statement that they were recently collected in Mexico where they grew wild. In other words they were the parent form of our cultivated potatoes. They were all small, nearly spherical and just about an inch in diameter, weighing less than half an ounce. Ever since that time I have grown them in the Botanic Garden placing some in the cellar over winter. No extra care was taken in this cultivation; no increase in the size of the tubers was noticeable, till perhaps fifteen years ago, since which time I have each year selected a few of the largest tubers for planting. This year has been one of extremes in Michigan, not very favorable to the growth of potatoes. The largest tuber weighed six ounces, fully twelve times the weight of the original size. The tops of these plants were large and healthy till we had a hard freeze about the middle of October, much surpassing in vigor any of the hundred or more cultivated sorts in the horticultural department of the college. They always bear berries. A few years ago some of the tubers were boiled, but the quality was not good. Having increased the size of the tubers by selection, it occurs to me to send some tubers to some good potato region in the north part of the state, to see if the quality will not improve.

For about fifteen years, I have grown Solanum Jamesii in the garden. This species grows wild in Arizona and is too small to be promising for food. The tubers received were dark in color, and warty. With no attempt at selection, some of them became less warty and much lighter in color, increasing in size fully three times, some of them even becoming pink in color like the old mercer.