Effects of Some Cultural Conditions on the Development in Later Growth Stage of Rice Plant in the Ill-drained Paddy Field

Effect of Field Drainage on Root Lodging Tolerance in Direct-Sown Rice in Flooded Paddy Field

“…Several researchers (Miyasaka, 1970;Kawata and Soejima, 1977) pointed out that field drainage stimulated the root growth in rice plant when compared with the root in continuously submerged fields. However, in our experiment, the difference in root dry weight among different irrigation management schemes was significant only in the 1997 experiment, and the relationship between root dry weight and drainage treatment remained unclear.…”

“…In relation to the above point, Miyasaka (1970) reported that field drainage induced root extension into deeper soil layers. Kawata and Soejima (1977) also observed that the density of formation of thick secondary roots was higher in the fields that had been subjected to midsummer drainage than in constantly submerged fields.…”

“…Seko (1962) reported that midsummer drainage improved culm morphology and increased stem breaking resistance. Miyasaka (1970) also pointed out that the effect of field drainage on lodging tolerance is related to the amount of nitrogen absorbed during the elongation of No. 3 internode (counted from the uppermost).…”