大豆在田间易受虫害和早霜的影响，有时虫蛀率高达50％。而这些虫蛀粒、冻伤粒及机械破损粒的呼吸强度要比完整粒大得多，极易吸潮，引起大量霉变。在高温下，大豆蛋白质很容易老化变质，以致影响种子生活力。贮藏较久、经过高温季节的大豆，就可能出现两子叶靠脐部位变红。大 Soybeans in the field are susceptible to pests and early frosts, sometimes up to 50% moth-eaten. However, the insecticidal particles, frozen particles and mechanical damage particles respiration intensity is much larger than the complete grain, easy to absorb moisture, causing a large number of mildew. At high temperatures, soy protein is very easily aged and deteriorated, affecting seed viability. Stored for a long time, after the hot season of soybeans, there may be two cotyledons by the umbilical red. Big