以热量指数表示北疆棉区棉花延迟型冷害指标的研究

应用乌兰乌苏农业气象试验站棉花试验的生育期、产量及旬气温资料,计算出棉花不同播期和不同生长阶段的热量指数,研究分析不同播期棉花产量、霜前花率与棉花不同生长阶段的热量指数之间的关系发现:1)随播种期推后,棉花生长前期热量指数明显增加,而棉花生长后期的热量指数则呈现出明显的下降趋势。2)现蕾—开花阶段的热量满足状况很好,热量指数稳定。3)分期播种的单产与棉花生长后期的热量指数具有很好的线性关系,霜前花率也与棉花生长后期的热量指数关系密切,生长后期的热量指数变化对棉花品质的影响较产量更加敏感。4)以减产幅度为标准,在棉花开花期以前热量充足的情况下,后期生长热量指数低于64为一般延迟型冷害年指标,低于61.8为严重延迟型冷害年指标。5)以霜前花率为标准,在棉花开花期以前热量充足的情况下,后期生长热量指数低于 70.9 会出现一般冷害年,低于63.2,会出现严重冷害年。

Characterization of Growth-delayed Cotton Cool Damage by Heat Index in the Northern Xinjiang

According to data of cotton growth, output and temperature during five stages from Wulanwusu Agro-meteorological Experiment Station in xinjiang in 2003, heat indexes of every growth stages in different sowing times were calculated and analyzed. The results showed that: 1) With prolongation of sowing times heat in the cotton previous growth period rise. By contrast, heat index was also obviously increased. However, in the later period it began decrease. 2) If heat in bud and bloom periods were efficient, heat index would be stable. 3) There was linear correlation between output in different sowing times and heat index in the later growth period. Heat index in the later growth period was closely related to rate of cotton harvested before frost and more influenced on the quality of cotton than output. 4) Due to output reduction heat index in the later below 64 was usually defined as delay cool damage year and below 61.8 more serious year under the sufficient heat condition before blooming. 5) In terms of rate of cotton harvested before frost, heat index in later growth period below (70.9) was regarded as cool damage year and below 63.2 more severe under the sufficient heat condition before blooming in the northern Xinjiang.