长江下游地区水稻阴雨害的发生规律及其防御技术

Regularity of Insufficient Illumination Calamities to Rice Crop in the Lower Reaches of the Yangtze River and Countermeasures

本文分析了我国长江下游稻区水稻分蘖期与开花灌浆期阴雨害出现的机率，分别为１０年３～４遇和２～４年１遇。阐明了分蘖期阴雨害通过减少同化物的积累与植株营养器官间光合产物分配不协调，致使植株分蘖数减少，穗数不足而减产。灌浆期阴雨害则使穗子里积累的光合产物与由茎鞘转移的同化物明显不足；碳水化合物的有效性降低，蛋白质合成能力被削弱，导致植株体内氮含量显著增加，造成颖花不育率增高，千粒重下降，产量降低。并指出因地制宜地进行合理的品种布局与茬口安排，对受害稻株采用各种调节技术以及选用耐阴害的高产品种，是克服水稻阴雨害的重要途径。

Insufficient illumination calamities(IIC)occur occasionally at various development stages of rice in the lower reaches of the Yangtze River.IIC at the tillering phase,occurring 3-4 times per decade,caused yield decrement by diminishing tiller and panicle numbers through reduciug the accumulation of assimilation products and disordering their distribution among vegetative organs.IIC during the filling period,once in 2-4 years,decreased the accumulation of photosynthetic products in panicles and the assimilation products translocated from stems and sheaths to panicles,declined the ratio of soluble carbohydrate to nitrogen in the plants,and then resulted in higher spikelet sterility,lower 1000-grain weight and less yield. The authors suggested some important ways to reduce the impact of insufficient illumination on rice,including appropriate varietal arrangement and seasonal disposition,applying chemical regulators to impaired plants, and selectiug high-yielding rice varieties with strong endurance to insufficient illumination.