晚霜冻又称“倒春寒”，是我国长江中下游地区春季气温回升过程遇到北方强冷空气南下，或夜间辐射冷却，突然出现大幅度降温引起霜冻的现象。“倒春寒”会对已萌发茶芽和新梢造成严重冻伤。防御“倒春寒”的农枝措施有多种，如霜前覆盖，采摘受害叶等。但对于每一种防御措施的 Late frost, also known as “late spring cold”, is the mid-lower reaches of the Yangtze River in China during the spring temperature rise encountered strong cold air north of the North, or radiation cooling at night, a sudden significant cooling caused by the phenomenon of frost. “In late spring” will have a serious frostbite on buds and shoots that have germinated. There are many kinds of measures to prevent “late spring cold” agricultural sticks, such as frost before covering, pick victim leaves. But for every defensive measure