Abstract
The present study was designed to examine the influence of water temperature upon the growth of rice plant due to continuous watering at tillering period in the paddy field (fig. 1). The temperature condition of irrigation water was showed in fig. 2. Experimental results were summarized as follows. As the water temperature ascended, the number of tillers and spikelets per hill decreased (fig. 4∼5). The total number of grains and the weight of grains per hill showed the greatest value in the plots subjected to 25∼26°C in mean water temperature and less than 30°C in maximum water temperature, and they decreased with the higher and the lower temperature than this (fig. 5). At the period of spikelet differentiation, the amount of nitrogen per hill showed also the similar tendency as above mentioned (fig. 6).
