Studies on the Improvement of Potato Culture by Using Seed Tubers of Suitable Age : II. Relation between age and productivity of seed tubers in the fall culture

Abstract

The object of this experiment is to determine the suitable physiological age of potato seed tubers for fall culture in relation to certain varieties. The results obtained may be summarized as follows: 1) From the standpoint of the total yield (above 23 gr. in weight per tuber) per 10 are, four commercial varieties used in this study were grouped into typed of early spring-grown seed tubers and of spring-grown seed tubers ; in the former about 3 months of age and in the latter 2.5 months of age are suitable for fall culture. 2) Wheeler which has a long rest period, belongs to a type of early spring-grown seed tubers, Norin No. 1 which is late in maturing in spite of ifs a short rest period, is also a type of early spring-grown seed tubers. 3) Ojiro Arid Unzen are of type of spring-grown seed tubers. These varieties have a short rest period and early maturity. 4) From the results of these experiments it is noted that the spring-grown seed tubers of Ojiro and Unzen and the early spring-grown seed tubers of Wheeler and Norin No. 1 become of use for fall culture of potato.