杂交水稻生产季节性强,特别是抽穗开花期,对温度反应非常敏感.温度过高过低都不利于授粉结实。据观察,杂交水稻抽穗开花期的适宜温度是28—30℃.如每日平均温度低于23℃时,空壳率就显著增加,达到30%以上。这个临界温度,比常规品种高2—3℃。如每日平均温度在30℃以上,最高温度超过35℃时,空壳率亦显著增加,可达40％以上。这个临界温度,比常规品种低2—3℃.故合理安排杂交水稻的抪种期,让抽穗开花避过高温或低温的影响,是降低空 Hybrid rice production is seasonal, especially during flowering and flowering, which is very sensitive to temperature, and it is not conducive to pollination if the temperature is too low. It is observed that the suitable temperature for heading and flowering of hybrid rice is 28-30 ° C. If the daily average temperature is lower than 23 ° C, the shell percentage increases significantly, reaching more than 30%. This critical temperature, 2-3 ℃ higher than conventional varieties. If the average daily temperature above 30 ℃, the maximum temperature exceeds 35 ℃, the shell rate also increased significantly, up to 40%. This critical temperature, 2-3 ℃ lower than the conventional varieties. Therefore, reasonable arrangements for the hybrid rice seedling stage, so that flowering heading to avoid the impact of high or low temperature, is to reduce the empty