The probability of cold weather in winter is more than 70%. There is a large difference between the north and the south. The degree of cold weather in the north is more obvious, and the later winter will be more cold than the previous winter.

Low temperature injury:

The plant damage caused by low temperature is collectively referred to as cold injury, including cold injury and freezing injury. Cold injury refers to the cold injury above freezing point (zero degree Celsius). The adaptation of plants to it is called cold resistance. Cold damage generally occurs in early spring and late autumn. Cold damage during plant germination will delay germination, reduce germination rate and induce disease; The main chilling injury at seedling stage was chlorosis and wilting of leaves. Frost damage refers to the cold damage below the freezing point, and the adaptation of plants to it is called frost resistance. Frost damage often occurs with frost damage, causing crop yield reduction or even crop failure.

Antifreeze mechanism of plant growth regulator:

Plant growth regulators play an important role in improving the cold resistance of plants and improving the cold resistance stability of microtubules, and are one of the promoters of cold resistance gene expression. For example, there are many studies on chlormequat, ABA (abscisic acid), paclobutrazol, uniconazole, brassinolide, prochloraz, etc. Their action mechanism is mainly shown in:

(1) Reduce electrolyte permeability and increase cell membrane permeability

(2) Increase the accumulation of soluble sugar

(3) Enhance the enzyme activity of POD and SOD in vivo

(4) Increase the accumulation of proline

(5) Reduce the content of malondialdehyde

(6) Induction of cold resistance gene expression and cold signal transduction

Regulators that can improve the cold resistance of crops:

(1) Chlormequat

(2) Abscisic acid

Endogenous abscisic acid (ABA) is the "stress inducer" of plants, known as "stress hormone". In the process of plant growth and development, its main function is to induce plants to produce resistance to adverse growth environment.

(3) Paclobutrazol and uniconazole

Paclobutrazol is also a widely used regulator, which can improve the stress resistance of many crops. The principle of action of uniconazole is similar to that of paclobutrazol, which can stabilize the structure of cell membrane, increase the content of proline and sugar, improve the plant resistance and make the plant cold resistant.

(4) Brassinolide (BR)

Brassinolide can improve the resistance of plants to high temperature, low temperature, drought, high salt and pathogenic bacteria.

(5) DA-6

DA-6, a broad-spectrum plant growth regulator, can regulate and promote plant growth, increase the content of chlorophyll, protein and nucleic acid in the plant, increase the light and speed, increase the activity of peroxidase and nitrate reductase, improve the metabolism of carbon and nitrogen in the plant, enhance the absorption of water and fertilizer by the plant, and adjust the balance of water in the plant, thus improving the drought and cold resistance of the plant.

In the face of fierce low temperature injury, with the coat of plant growth regulator, crops can survive the winter safely.

Part of the content of the article comes from the network. The above contents are for reference only. Please consult with agricultural experts in combination with local planting habits to plant reasonably.