黑龙江省地处高纬度,是我国水稻栽培的北部边缘,属寒冷稻区。热量条件较差,积温的年际变化又大,偏差在±300℃之间,属不稳定类型。因此,每遇低温冷害年,常受其害,致使水稻单产不高,总产不稳。据在汤源稻区的调查分析,冷害年份约占30％,相对产量下降20—50％,其它寒冷地区因低温危害延迟成熟或障碍结实而引起的减产也是相当普遍的。我们于一九七七年至一九七八年进行分 Heilongjiang Province is located in the high latitudes, is the northern edge of rice cultivation in China, is a cold rice area. Thermal conditions are poor, interannual changes in accumulated temperature, deviation of ± 300 ℃, is an unstable type. Therefore, whenever chilling injury occurs, it is often harmed, resulting in low yield of rice and unstable output. According to the investigation and analysis of the Tangyuan rice planting area, about 30% of the chilling injury years and 20-50% of the relative decline in output are also common in other cold regions due to delayed maturation of low-temperature endangerment or strong obstacles. We divided in from 1974 to 1978