The season that is most harmful to crops

Frost is the most harmful season for crops.

Frost is a common agricultural meteorological disaster, which occurs in winter and spring, and is mostly caused by the cold wave heading south and the temperature dropping sharply below zero degrees Celsius in a short time. Still affected by the cold wave, the weather changed from cloudy to sunny that night, which was caused by strong radiation cooling on the ground. This is what people often say "adding insult to injury". When the temperature is lower than the ground, the water vapor condenses into white crystals on the surface of the object. Less water vapor and no frost are called black frost.

First frost and the first frost solar terms are not the same thing, but three different concepts. "Frost" refers to white ice crystals formed by condensation of water vapor on the ground in cold weather; "Frost" refers to a common agricultural meteorological disaster phenomenon; The "first frost" solar term refers to the season that reflects the sudden drop of temperature.

Introduction of frost types:

1, spring frost is also called late frost, that is, the frost that occurs after spring sowing crops are in seedling stage, fruit trees are in flowering stage and overwintering crops turn green. With the increase of temperature, the frequency and intensity of late frost gradually decrease, but the later it appears.

2. Autumn frost, also known as early frost, occurs when the autumn harvest crops are immature and the vegetables in the open field are not harvested. As the season goes on, the frequency and intensity of autumn frost increase gradually.

3. Advection frost: frost caused by the invasion of strong cold air in the north, which is common in early spring and late autumn in the north of the Yangtze River and in winter in South China and Southwest China. Northerners call it "wind frost" and meteorology "advection frost".