南昌高温逼熟发生规律及其对早稻产量的影响

Characteristics of High-Temperature Forced Maturity Disaster and It's Impacts on Early Rice in Nanchang Area

利用南昌市5个国家气象站1960-2012年逐年6月下旬-7月上旬的日平均气温、日最高气温统计资料,根据江西省地方标准《江西省双季稻气象灾害指标》,分析近53a当地早稻灌浆成熟期高温逼熟气象灾害的发生周期及时空分布特征,并就其对早稻产量及其构成因素的影响进行分析。结果表明:(1)南昌高温逼熟气象灾害平均2a一遇,且近53a来灾害有由轻度转为重度发生的趋势;(2)南昌地区高温逼熟灾害的出现有较强的空间分布规律,重度高温逼熟南部多、中部少、北部无;轻度高温逼熟中部多、南北少。(3)轻度高温逼熟年份中,温度越高水稻空壳率越低、结实率越高,有利于产量形成;重度高温逼熟年份中,温度越高空壳率越高、结实率越低,不利于产量形成。说明轻度高温逼熟对早稻产量基本无不利影响,而重度高温逼熟应积极防御。研究结果有利于合理安排早稻播期及双季水稻种植结构的调整。

With the average and maximum daily temperature data during late June and early July （ about 20 days every year） recorded by five national weather sub-stations in Nanchang in 1960 -2012, according to local standards the meteorological disaster indicators of double cropping in Jiangxi province, the change cycle and temporal-spatial distribution of weather disaster by the high-temperature and its impacts on early rice yield were analyzed. The results showed that, （ 1 ） the high-temperature forced maturity disaster happened every other year in Nanchang, and tended to happen more increasingly and seriously in recent years with the climate warming. （2） The distribution of high- temperature forced maturity disasters appeared with a little stronger spatial and regular pattern, the severest ones appeared in the south part, some appeared in the middle, but almost none in the north. While most of the mild disaster appeared in the middle, and few in north and south of Nanchang. （3） In years with mild heat-forced maturity disaster, the higher the temperature was, the lower the rate of undeveloped grains and the higher the seed rate were, caused high yields. While severe heat-forced maturity disasters caused higher rate of undeveloped grains and lower seed rate, reducing yields. Therefore in the practical rice production, mild heat almost didn＇ t affect the early rice yield, but severe heat affected the yield seriously. We should take active measures to defend severe heat. The study findings will be good for arranging the rice sowing and adjusting the cultivation structure on double rice growth.