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Viability and composition of "seed" potatoes as affected by climatic conditions and by various other factors

Wessels, P.H., Hartwell, B.L.
Agronomy journal 1927 v.19 no.9 pp. 761-780
Solanum tuberosum, crop yield, nitrogen content, climatic factors
Especially the later varieties of potatoes grown at the Rhode Island Station are about a fourth less valuable for seed than those grown in northern New England. They progressively deteriorate even in spite of tuber-unit selection. The inferiority of the homegrown seed exhibited itself largely by a considerable admixture of inferior plants presumably affected by one or more of the so-called degeneration diseases. Storage conditions are not important factors in connection with viability. When smaller and larger seed potatoes were compared on the usual basis of about ounce pieces, conditions which had materially reduced the growth previously without affecting healthfulness, regardless of any other effect, resulted in seed which produced larger yields per acre, provided cultural conditions were satisfactory. Too pronounced acid-soil conditions, a shortening of the growth period, and insufficiency of any one of the fertilizer nutrients are such growth-limiting factors which were observed. When all but two "eyes" were removed from both partly developed and fully developed potatoes, the smaller potatoes were frequently not more productive. In fact, the larger potatoes or pieces led to a larger number of stalks from the two compound eyes, and somewhat larger production. When the stalks from the larger pieces were reduced to the number which arose from the smaller pieces, the yield was about the same in both cases. Nevertheless, even when seed for comparison was matched so that both samples contained the same number of different sized potatoes cut the same, there sometimes occurred differences in viability due to fertilization. Attention is called particularly to the tendency towards increased viability accompanying a scarcity of potassium, and to the larger percentage of nitrogen and greater proportion of nonprotein nitrogen in such seed. These same tendencies were exhibited by the superior, northern-grown seed when their analysis was compared strictly with that of home-grown seed. In addition to the determination of nitrogenous constituents, carbohydrate variations were determined in potatoes harvested at different stages of growth and analyzed before and after winter storage. Sulfated potato ash is suggested as an unchanging basis for comparison of analyses of potatoes before and after storage.