一、中下部蕾铃严重脱落原因的分析当前棉花生产上导致棉株中下部蕾铃严重脱落的原因,除虫害造成的脱落外,其生理脱落主要有三个方面:第一,不良气候的影响。主要是阴雨天气。由此带来三个不利因素。一是雨水直接破坏开放花朵的花粉,影响受精作用进行而脱落。二是光强降弱。据气象资料,我国黄河流域、长江流域两大主产棉区的自然光强,一般盛夏的上午可达10万勒克司以上,多云天气只有2.5～3万勒克司,阴天仅有1—2万勒克司。加上棉花的消光系数比较大,每通过一层叶片,光强约要降弱到相当 First, the middle and lower part of the reasons for the serious fall off of bolls The current cotton production led to the lower part of the cotton boll fall off the cause of the serious, pest control shedding, its physiological shedding mainly in three aspects: First, the impact of adverse weather. Mainly cloudy weather. This brings about three unfavorable factors. First, the direct destruction of the rain pollen flowers open, affecting the role of fertilization and fall off. Second, the light intensity weakened. According to the meteorological data, the natural light intensities of the two major cotton producing areas in the Yellow River and Yangtze River valleys in China are generally above 100,000 lux in the midsummer, with only 2.5 to 30,000 lux in cloudy weather and only 1-2 Wan Lok Division. Coupled with the cotton extinction coefficient is relatively large, each pass a layer of leaves, the light intensity to be reduced to about the same