RESPONSES OF ROOT SYSTEM OF RICE TO WATER AND NUTRIENTS
Ling Qihong Zhang Guoping et al. (Dept. of Agron., Jiangsu Agric. Coll.)
In 1985—1986, the responses of the root system of rice to water stress and the culture solution in high or low concentration at different leaf—age—period, and the relationships between the dry weight of roots and the yield were studied with soil culture in pot and water culture. The results were as follows. 1.The uppermost 3 nodal-root (UR) requires adequate water and the high level of nutrients during UR—primordium—differetiating-period, adequqte water and the low level of nutrients during the middle—late—period of UR—cmergencing, a little water and the high level of nutrients during the middle-late-pcriod of UR-branching. 2.The responses of low—nodal—root (LR) to nutrients is obtuse during the middle—late—period of LR—branching, but to water is sensitive during the middle—period of LR-branching, and is obtuse to water during the late-period of LR-branching. 3.The dry weight of UR is significantly correlated with the yield positively. The relationships between the dry weight of LR and the yield varies with cultivated conditions.