水稲の発芽期における高温の発芽並びにその後の生育に及ぼす影響 第1報 催芽期の高温・ビニール畑苗床における発芽期の高温の影響について

抄録

In the present report, the authors examined the subsequent development of the rice seeds which were exposed to high temperature for some time. The results obtained are summarized as follows ; 1. The soaked rice seed which was left for 48 hours at the neibourhood of 37.5°C showed almost similar growth as that left for 48 hours at about 32.0°C. The former also showed somewhat better growth (0.4 sheets more in total number of main culm leaves) and equal heading date as compared to non-treated plot. 2. The sowed rice seed which was left for several days at high temperature (at about 35-45°C, about 6 hours per a day) in vinyl-tunnel-nursery, showed normal germination percentage when cultivated thereafter under normal condltions, however showed bad growth and development, decrease of the total number of main culm leaves, decrease of the number of tillers from low and middle node order, increase of delayed tillers from high node order and the accompanying delay of the heading date. 3. At germination stage, sate and critical maximum temperature should be determined more accurately, considering the time interval at that temperature.