Affected by the cold air from the south recently, the "cold spring cold" has struck strongly. It is expected that starting from the 16th, the country will usher in a large-scale cooling weather one after another, and the maximum temperature drop can reach more than 20 ℃. The cooling has a wide range and a large impact, and the harm to agricultural production has to be prevented.

　1. What is a cold spring
The "cold in spring" refers to the weather phenomenon that in the process of normal temperature rise in early spring, the continuous cold air intrusion in the later period suddenly caused the temperature to drop suddenly, and the weather phenomenon of continuous low temperature and rain. The "cold spring" usually occurs from the beginning of March to the end of April. At this time, because the climate in spring is still in the process of drastic changes, although the temperature rises quickly, it is easily affected by the cold air from the south, causing the weather phenomenon of warm and cold in spring.
"Cold in the Spring" is a very serious forestry and agro-meteorological disaster. In agricultural meteorology, we usually judge the weather phenomenon that the daily average temperature in spring is lower than 12 ℃ and the maintenance period is more than 3 days as "cold in spring". For agricultural production, the occurrence of "cold spring" means that the coefficient of risk to crops increases sharply.

The damage of rice seedlings by the cold spring

Second, the harm of the cold spring
The occurrence of "falling spring cold" mainly harms the new young shoots and young leaves of plants, young fruit of flowers, etc., and even damages the root system of plants in severe cases, reducing crop yield or harvest, and even causing plant death. Therefore, it is of great significance for agricultural production to correctly understand and prevent the harm of "falling spring cold".
For the field planting areas, when the "cold spring" occurs, rice, peanuts, corn and other crops are in the critical period of sowing and raising seedlings. The sudden low temperature and rainy weather can easily cause the seedlings to fail to germinate normally. In severe cases, it can even cause rotten seedlings and direct death.
For vegetable planting areas, vegetables in early spring are mainly planted in facilities and protected areas. Due to the large and fast cooling caused by "cold spring", it is difficult for vegetable seedlings to adapt, and the longer the duration, the more serious the harm.
For the fruit tree cultivation area, it is in the budding and flowering stage of deciduous fruit trees such as peach, plum and apricot. It directly affects the fruit setting rate of fruit trees, resulting in reduced production and no harvest.

　　Harmful symptoms of apple blooming period

3. Measures to prevent the harm of cold spring
1. Preferred varieties:
Seeds are the basis of agricultural production, and improved seeds make the greatest contribution to all the factors of high agricultural yield. For crop varieties sown in early spring, the varieties with strong cold resistance should be preferably cultivated, or the adaptability of the plants themselves to low temperature should be enhanced through low temperature seedling refining.
2. Physical measures:
Before the "cold in spring" comes, we should use irrigation for heat preservation, fumigation to increase temperature, and mulching to prevent freezing to reduce the cold damage caused by "cold in spring". Frozen.
3. Chemical measures:
(1) Spray antifreeze: External application of S-decoction induces the expression of plant stress resistance genes and activates stress resistance in plants The immune system can improve the resistance of crops themselves to adversity stress. It is recommended to use Ziqi to spray the whole plant before the low temperature comes, and use it together with Baohua Baoguo. While supplementing nutrients, it can also increase the concentration in the cytoplasm, enhance the cold resistance of crops, and prevent and alleviate the "cold in spring". ” impact on crops.
(2) Apply anti-stress fertilizers: After harvesting and before the arrival of "cold spring", strengthen fertilizer and water management, supplement the nutrients needed by crops, promote root growth, and strengthen crops. It is recommended to use Miaogenwang together with vegetable area Laobiao to improve the soil environment, provide the nutrients needed by crops, enhance the activity and vitality of root growth, promote root growth and improve resistance, effectively strengthen crops, and achieve prevention and Reduce the impact of "cold spring" on crops.

Top spray combination

Combination

　　Reminder:
After the "falling spring cold" ends, the temperature rises and stabilizes, the affected tissues should be removed in time, the corresponding cold damage remediation work should be done, and fertilizer and water should be supplemented to provide sufficient nutrition for the germination and growth of new tissues.
Due to the differences in the occurrence time and intensity of "falling spring cold" in different places, as well as different plant varieties, climatic conditions, cultivation and management methods, tree vigor, etc., the plans introduced above are for reference only.