库尔勒香梨历年冬季低温评价及严重冻害成因分析

Evaluation of Low Temperature in Winter Over Years and Analysis on the Reasons of Korla Fragrant Pear Freezing Injury

通过评价1958-2008年库尔勒香梨越冬期间及早春低温资料,分析了历年冻害发生情况及冻害成因。结果表明:1958-2008年,气温异常偏低年份有9年,香梨发生了6次严重冻害,其中5次严重冻害发生在越冬期间,早春冻害1次(2005),剩余3年气温在临界线附近,没有造成严重冻害;1958-1986年极端最低气温变化趋势基本正常,之后有升高趋势;2007-2008年冬季气温异常偏低,导致了大面积冻害;香梨冻害发生临界温度大致为-20℃;香梨冻害与极端低温、低温持续日数、降温幅度、降雪厚度及持续时间、立地条件及管理水平等因素有关。

The occurrence of freezing injury and its cause of Korla Fragrant Pear over years in Korla area of Xinjiang was investigated by the data observed in 1958--2008. The results showed that there were 9 anomaly cold years in 51 years, severe freezing injury occurred during 6 years in which 5 years were in overwintering period, 1 year was in early spring period （2005）, and in the remaining 3 years air temperature were a bit lower than critical temperature, hence, there was no severe freezing injury occurred. The variation trend of annual extreme low air temperature was normal from 1958 to 1986 and after that it was increased; the critical low air temperature for freezing injury were --20 C for Fragrant Pear; freezing injury was related to the duration of low air temperature, the temperature decrease range, snow thickness and continued time, standing environment and the management level.