開花期前後における高温乾燥条件が作物の稔実に及ぼす影響

The effects of high temperature and low humidity during flowering on the ripening of crop plants were studied. The treatments of the plots were as follows: 30℃/30%， 35℃/30%， 40℃/30%， 45℃/30% in 1979， and 38℃/25%，38℃/40%， 43℃/25%， 43℃/40% in 1980. The treatments were carried out by placing the potted plants in growth chambers for 20 or 40 hours. Grain sorghum，sunflower，okra，cotton，mung bean and Jew's mallow were used as the test plants. Ripening was considerably influenced by changing the temperature， with the percentage of ripening decreasing gradually as the temperature was raised above 35℃，and reaching almost 0% at 45℃. On the other hand，there was no marked influence on ripening from changing the humidity level，although there was a slight tendency for the percentage of ripening in high humidity conditions to be lower than in low humidity conditions. The resistance of the various plants to the impediment in ripening due to these environmental factors was found to be in the following order: Jew's mallow>okra，cotton，sunflower>grain sorghum，mung bean.