Traditional Culture Encyclopedia - Weather inquiry - How to prevent seedlings from being killed by heat in high temperature weather?

How to prevent seedlings from being killed by heat in high temperature weather?

Planting mother-in-law of appropriate age is the basis of stable and high yield of rice. In order to ensure rice seedlings and seedlings, it is necessary to do a good job in rice seedling management. There are many kinds of early rice transplanting in the middle and lower reaches of the Yangtze River, and there are differences in transplanting age or transplanting growth period. According to the growth of local transplanting and stump planting, strengthen the classified management of seedlings and make them go underground. South China is prone to "late spring cold" weather, so it is necessary to adjust the temperature with water in time and spray fungicides to keep the field temperature to prevent seedlings from dying. Therefore, in order to cultivate strong seedlings, we must do the following "quartet"!

When seeds are damaged by low temperature during transplanting, it will not only reduce the germination rate, but also inhibit the growth of seedlings. Seedling rot will occur in field, and various diseases and Fusarium wilt will occur in dry transplanting. In severe cases, a large number of dead seedlings, especially those with poor root development and long seedlings, suffer more, and often have problems such as weak seedlings, small seedlings, lack of seedlings and rotten seedlings.

After rice seedlings are damaged by low temperature, measures such as film mulching, irrigation and seedling raising should be taken in time, and water should be changed to protect the seedlings when the temperature gets warmer to prevent the seedlings from rotting due to low temperature rooting and excessive temperature change. After the temperature is normal, timely drainage and ventilation can improve the root activity of seedlings.

On sunny and cloudy days, the lowest temperature in the film rises greatly, and the temperature in the film tends to rise above 35 at noon and afternoon, which is easy to cause seedbeds. Pay attention to the weather forecast and be alert to the lowest high temperature flower seedlings.

Usually, on sunny days when the maximum temperature is above 15 during the day, both sides are ventilated around 8 ~ 9 am.

The proportion of mechanical transplanting of early rice in our province is high, and the requirements of mechanical transplanting for seedlings are higher. When raising seedlings, the temperature is too high and there is too much water, so it is necessary to prevent the seedlings from growing.

After sowing, the greenhouse or the lowest temperature is kept at 30-32, and the humidity is controlled at 90%-95%. After germination, the temperature is reduced to 28-30℃. Leaf age 1. 1-2. 1, the optimum temperature is about 25, and the maximum temperature adjustment is no more than 28. The leaf age is 2. 1-3. 1, and the suitable temperature is 22-25.

When transplanting rice seedlings in plastic greenhouse, water them in time as needed, keep them half wet, not turn white, and the seedlings are not dead.

Before ventilation, inject "horse racing water" at both ends of the seedlings, and gout or periosteum is exposed in the middle part. First pour the mother board into shallow water, and then uncover the film to prevent the leaves from wilting or the seedlings from wilting. After 30 minutes of irrigation and ventilation, it enters the half bone marrow. Digging ditches in rainy days. Long-term aquifer irrigation will lead to the decline of root activity and even avoid rotten seedlings. Three days before transplanting, drain water on sunny days, cook seedlings on cloudy days, and plug in the machine to continuously grow seedlings.

The sowing amount of 9-inch rice seedlings is120-150g/dry grain, which is equivalent to 300-380kg/mu. The planting density is 5-6 times that of traditional wet transplanting, and the transplanting age should not be too long.

The standard seedling suitable for inserting into early rice machinery is about 3.5 leaves, and the seedling height 12- 14 cm, 1 leaf sheath length is less than 3 cm. The occipital distance between basal leaves should not exceed 1 cm. If the leaf age is above 3.5 leaves, if it is not transplanted in time, the leaves will elongate, the seedlings will increase, the plants will be crowded, the individual growth difference will increase, and the seedling quality will decrease obviously. Planting qualified machines and transplanting early rice seedlings require high temperature and water management. At the same time, seedlings are often encountered in production, which has reached the age of transplanting leaves, but there are also cases where they cannot be transplanted in time because of low temperature and rainy weather. Proper temperature management at seedling stage and early suppression of excessive growth of seedlings can reduce the adverse effects of delayed transplanting.