果树的低温伤害及其防御果树的低温伤害，是指冬、春或秋季低温对树体造成的危害，主要有冻害和霜冻。一、冻害冻害是指在休眠期，因遭受０℃以下严寒，使细胞和组织发生冰冻而受伤或死亡，进而造成树体的一部分或全株死亡的现象。冻害在我国水果主产区均有发生，而在北方... Low temperature injury of fruit trees and their low temperature damage to the fruit trees refers to the harm caused by low temperature in winter, spring or autumn to the trees, mainly including frost damage and frost damage. First, frost damage frost damage refers to the dormant period, due to the cold below 0 ℃, frozen cells and tissues and injury or death, resulting in the death of a part of the tree or whole plant phenomenon. Frost damage occurred in the main fruit producing areas in China, while in the north ...