落花生の莢実の発育および収量におよぼす気温の影響

抄録

The authors examined the effect of air temperature on pod development after peg penetration and the influence of air temperature on the yield of peanut plants after the first flowering. The experiments were carried out in pot and field, using a variety of peanut plants, Chiba-handachi (large seed, semi-erect type). The results obtained were as follows. 1. Pod development of peanut plants was suppressed according to the retardation of the time of peg penetration into the soil, regardless of the difference in sowing time. 2. The effect of air temperature on the pod development was very remarkable at the stage of pod enlargement from 21 to 40 days after peg penetrating. 3. When the effective heat summation accumulated by a daily mean temperature over 15°C in the pod stage was higher than 450°C, the pod development was affected chiefly by inner factors of plant, while when this value was lower than 450°C, the pod development was influenced mainly by air temperature. 4. The shoot weight of peanut plants usually increased rapidly and reached its maximal value at about 60 or 70 days after the first flowering time. While the starting time of increase in pod weight was a little later that of the shoot weight, namely at about 30 days and reached its maximal weight at about 90 or 100 days after the first flowering time. 5. The influence of air temperature on the yield of peanut plants was striking beween 31 and 60 days after the first flowering time.