作物と雑草との競争についての実験的研究 : 第3報 作物と雑草との相関及び回帰係数並びに作物と雑草との競争のはじまるときの雑草量について

抄録

1) In continuation of the earlier work, the present paper deals with the correlation and regression coefficients between crops and weed products, and the amount of weeds when competition starts. 2) Owing to the interspecific competition between crops and weeds, the presence of weeds in high density depresses the crop yields, the correlation and regression coeffecinets being significant (table 1). 3) It is suggested that there exists a linear relationship between the logarithm of the ratio of the average crop weight to the average weight of weeds and the logarithm of the regression coefficient related to crops and weeds products (fig. 1). 4) There is observed a curveilineal relationship between crop yields and weed products in logalithmic scale, and a start point of the curve when easily obtained, may prove useful in determining the time of onset of competition by weeds (fig. 2).