Intervarietal variations in the responses to fertilizer in rice. : (Phylogenetic differentiation of the cultivated rice plant. IV.)

Abstract

1. The aim of the present study is to gain information on variation patterns in fertilizer resporises of rice varieties belonging to different phybgenetic groups. Fertilizer experiments were carried out in 1947 and 1948 using several Formosan native varieties (Continental group) and Horai ones (Temperate Insular group ; selected from Japanese varieties), and in 1949 using a number of varieties from various Asian countries. 2. A certain combination of the three elements of fertilizer was applied to the standard plot, and no-fertilizer plot, standard plot, doubled plot and etc. were compared. Further, the effect of the number of plants per hill was obseved in 1948. Anaiyses of variance showed that the interaction of varieties and fertlizer was significant in most yieldcomposing characters. Intervarieal variations of fertilizer responses were then investigated in regard to various characters. In 1949, Iinear or curvilinear regressions of characters on the amount of fertilizer were calculated in each variety and the percentages of regression coefficients (or differential coefficients in curvilinear regression) to the average measurement were used for expressing fertilizer responses.