Studies on the good and bad harvest of cotton in Yamanashi Prefecture : I. The relation between yields and some weater factors

Abstract

For the purpose mainly of yield-forcasting of cotton, the authors made experimental reserches in 1939 to 1951, at Cotton Branch, Yamanashi Agricultural Experiment Station. In general, correlations of yield to monthly or accumulated monthly mean temperature and to quantity of sun shine were positive, while that to the precipitation was negative. The absolute values of the coefficient, however, being almost similar, and higher in earlier periods of growth, especially in the period of June to July, of July to August (exclusive of sun shine), and of July, while in later periods especially in August and August to September, they were lower. It may be almost possible to forcast the yield by measuring the following factors, namely the quantity of sun shine in May, May to June, gnd June to July ; precipitation in May to June, and June to July ; and mean temperature in June to July ; because regression coefficients of yield on these factors were altogether significant.