Studies on Water Economy in Crop Plants : III Water economy in some grass and legume plants with special reference to temperature

[摘要] The influences of night temperature on the water economy in some grass and legume plants were observed. The results of the experiment were as follows : 1) The cool night conditions of this experiment were favorable to the growth and yield of red clover, timothy and Italian ryegrass. Especially, red clover was susceptible to injury of a high temperature. On the other hand, ladino clover seemed to be adapted to the warm night conditions. 2) As the air temperature was going down in autumn, the cool night conditions became less favorable for the growth of all species tested. Above all, Italian ryegrass was susceptible to a low temperature. 3) The amount of water transpired through grass and legume plants was directly proportioned to the amout of water evaporated through Livingston's spherical atmometers. Namely, the march of transpiration from these plants followed the march of the evaporating power of the atmosphere, and especially that of air temperature and sunshine. 4) In general, the cooler night temperature yielded lower figures for the water requirements of red clover, timothy and Italian ryegrass than the warmer night temperature in summer. On the contrary, through ladino clover plant the water was spent efficiently under the warmer night temperature. 5) As the air temperature falled in autumn, the water utilization of all these plants became to be uneconomical. To the fall of autumn temperature red clover was the most tolerable and Italian ryegrass was the most susceptible of all except timothy.

[学科分类] 农业科学（综合）