江淮地区气温变化对一季中稻产量和产量构成的影响

在气候变暖背景下,最高和最低气温不同的变化特征会对水稻产量和产量构成产生明显影响。根据江淮地区代表性站点近50年来一季中稻产量形成阶段最高和最低气温的统计分析表明,1991年以来,最低气温升温速率大于最高气温,日较差减小,极端高温事件强度、频率有所增强。利用安徽省农科院2000~2004年中稻分期播种试验水稻产量和产量构成数据与产量形成阶段的最高与最低气温不同步长滑动平均值进行动态相关统计分析。结果表明,气温对水稻产量构成和产量在始穗前和始穗后各有一个负影响时段,其影响程度始穗前大于始穗后;对结实率影响最大,其次是千粒重,再次是产量;最低气温的影响大于最高气温。随着滑动步长的增加,最高气温负影响程度的增大主要体现在抽穗前,最低气温则贯穿于整个产量形成过程中。

Impacts of maximum or minimum temperature on yield and yield components of single-season Indica rice in Yangtze-Huaihe area

Under the background of climate warming, characteristics of maximum and minimum temperature variation may markedly affect yield and yield components of rice. Maximum or minimum temperatures in the stage of yield formation during recent 50 years in the Yangtze-Huaihe area were analyzed. The result showed that the temperature-rising rate of minimum temperature has been higher than that of maximum temperature, with a decreasing diurnal temperature range (DTR), and an increasing intensity and frequency of extremely hot weather since 1991. The dynamic analysis of daily maximum or minimum temperature in different step-lengths with rice yield and yield components were made, using experimental data of Anhui Academy of Agricultural Sciences during 2000~2004. The result indicates that there are two negative effect stages of temperature on rice and rice yield before tasseling and after tasseling. And the temperature effect is most obvious on seed-setting rate, secondly on 1000-grain weight and thirdly on yield. The effect of minimum temperature on rice is greater than that of maximum temperature. With the increase of moving step-length in temperature, the increase of negative effect on maximum temperature occurs before tasseling, while the negative impacts of minimum temperature appear throughout yield formation process.