Analysis of the Growth in Forage Crops : 4. Effect of temperatur on organ formation in Ladino clover with special reference to non-photosynthetic organ formation.

In this paper, the effects of temperatures on the growth of petiole, stolon and root, which are non-photosynthetic-organs of Ladino clover and the correlations among organs were analyzed with the materials used in previous study that were carried out under both conditions of controlled environment and field. The results obtained are as follows. 1) The growth of petioles were better at lower temperatures (15-20°C) than at higher temperatures (25-30°C). This temperature response of petiole was about the same as that of leaflet. There were high positive correlations between the length and thickness of petiole, and also between length and thickness of petiole and length of leaflet. 2) The growth of stolons decreased as temperature rose in accordance with the reduction of weight per stolon and of branching numbers per plant. In this case, the weight reduction of stolon was caused by the shortening of each internode, as well as by the thinning of it. 3) There were high positive correlations between length or thickness of internode and petiole length, and these factors of internode and leaflet length respectively. These results suggest that the elongation of internode is accompanied with the horizontal magnification of space where to leaflets expand their area, and the thickening of internode is accompanied with the suitable growth of vessels and storage tissues to growth of leaflet. 4) The growth of roots decreased as temperatures rose. The facts that there were high positive correlation between numbers or weight of stolon per plant and root weight per plant, show that the growth of root is closely related to that of stolon.