EFFECTS OF SHADING ON THE INTERNODE ELONGATION OF LATE MATURING SOYBEAN

The present experiment was conducted in order to obtain detailed data on the internode elongation in soybean plants (Glycine max Merr.) of a late maturing cultivar in Kyushu area, under shading condition at various growth stages. The shading treatment during the period from floral differentiation to the beginning of flowering stage was the most effective, followed by the period from the beginning of flowering to the end of vegetative growth stage. For each internode length, the promotion by shading treatment was limited to the elongating internodes on the upper positions. The shading treatment during the period from the floral differentiation to the beginning of flowering stage slightly increased the number of nodes on the main stem. From the results it appears the optimal shading treatments at optimal stages can control the plant height and plant type by increasing the length of internodes and the number of nodes on the stem.