Abstract
The coefficients of correlation between the yield of hemp and the weather factors (i. e. monthly mean temperature, monthly amount of rainfall, monthly total number of rainy days and monthly total hours of sunsh ne) have been calculated by the method reported in a previous number of this magazine, for each prefecture in Japan, in each month during the cultivating time. The correlation coefficients calculated are shown in tables 1, 2, 3 and 4.
The correlation coefficients are generally small; only, in the north-eastern provinces, air temperature is more closely correlated with the yield than any other weather factor, and that positively, while in the southern part the closest correlation is found between the yield and rainfall. The results of this investigation show that the warm, rainy weather in the cultivation time of hemp is favourable for it in Japan proper.
