Abstract
1) This is a result of mathematicai discussion for growth curve of potato plant in 1946 and 1947. 2) The growth curves of the p1ant height and the body weight are represented in Expression logy/(A-y)=k(x-x1) (Robertson's automono-molecular curve) and Exprcssion y=b-ax2. The former represent the growth process which is from sprouting to the most growth stage, the later the withering process. 3) The increase curve of the average weight per one plant is represented more moderate in ret linear Expression than in Robertson's Expression.4) Tuber swelling is commenced at stage of changing point of (dy)/(dx) in Robertson's Expression. 5) There is a difference of time, about 20 days, between the most growth stage and the last stage of tuber swelling.
