水稻由于低温所引起的生理性障碍称为冷害，分为以下两种类型：１．延迟型冷害水稻在营养生长期遭受低温的危害，造成生育期显著延迟而导致减产的现象叫延迟型冷害。其情形有二：一种是水稻的营养生长期因低温而延迟，造成发育不良，最后使出穗延迟，结果穗小、粒少、秕粒多， The physiological barriers caused by low temperature in rice are called chilling injury, which are divided into the following two types: 1. Delayed cold-damaging rice in the vegetative growth period suffered cold damage, resulting in a significant delay in growth period led to the phenomenon of reduced production called delayed chilling injury. There are two situations: one is delayed vegetative growth of rice due to low temperature, resulting in dysplasia, and finally make the ear delay, the results of small spikes, fewer grains, grains and more,