Studies on the Growing Process of Potato Plant : VII The ecological studies on the determination of planting space of potato

[摘要] 1) In order to obtain some fundamental informations for determination of planting space of potato, the responses for theee elements, planting space, amounts of fertilizer and number of stem per tuber were investigated by using two varieties on the cultivated volcanic ash soils. 2) As the stem length was shortened by decreasing planting space, no lodging was observed. 3) In the case of dense planting or of numerization of stem number per tuber, number of stolons and number of tubers became numerous and percentage of tuber bearing stolons and mean weight of one tuber were decreased. But, the reverse relationships were obtained in the case of corse planting or of diminution of stem number. 4) The nitrogen content of leaves of main stem at the maximum top weight period was lowered and the phosphorus content was slightly heightened by the reduction of planting space in Irish Cobbler. But these tendencies were not observed for Norin No. 1. 5) The distribution rate to underground part of dry matter was increased in case of the low amount of each element in the leaves at the early growing stage. High minus correlation between nitrogen content and distribution rate was observed throughout the growing season and very high minus correlation between potassium content and distribution rate was observed at the flowering stage. But such correlation value for phosphorus at the flowering stage was low. 6) The ut'most top dry weight and tuber yields per unit area accompanied with the decrease of plant spacing were estimated by the A. J. Reestman's method. In the case of the most dense planting, the top dry weight approached to the limit, but the tuber yields were observed to be increased even when the planting space was enormously dense and the amount of fertilizer was higher. 7) The ideal planting space was thought to be obtained by using 7, 100 hills per 10 ares.

[学科分类] 农业科学（综合）