Recently, the temperature in our city has been somewhat abnormal. At normal temperature of 20-30 degrees Celsius, sudden cold air southwards, resulting in severe damage to rice seedlings in some townships in our city. In response to this situation, I proposed the following technical points for the management of rice seedlings in my hometown:

First, temperature management

Before the emergence of the insulation work, but not the higher the better. Before emergence, if the temperature in the bed exceeds 36°C in the morning, it should be ventilated to cool or shade to prevent it from burning at a high temperature. Before and after emergence, the temperature should be controlled at 30°C-32°C. 1 leaf 1 heart temperature control at 25 °C -30 °C. When the temperature outside the bed reaches 15°C or above, the seedlings shall be ventilated. At night, seed beds should be well covered to prevent damage from cold waves and frost. In case of frost, irrigation can be done in the trenches when conditions permit, and the water will be discharged after sunny days. The temperature of the bed in the 2 leaf 1 heart period should be maintained at 20°C-25°C. The size, number, position and direction of the vent should be adjusted according to the seedling condition and the weather, wind force and wind direction. The time for ventilation and hardening should be determined to control the temperature in the bed. Before the film is uncovered, it must be ventilated in 3-5 days. During the rainy days, it is not necessary to close the vents at night, and the cover is gradually opened until it is not covered at night.

Second, Putian management

1, water management

Before planting soaked bottom water, no water until the emergence. Appropriate amount of water should be added after emergence. When the seedlings are flushed and all of their heads are fresh, water should be poured according to the moisture of the seedbed, but water must not be poured. After the seedlings grow properly with water, the principle of replenishing water is to make up the water on the surface of the bed soil. Pay water can be poured, you can also ditch water irrigation or irrigation horse water, timely drainage after irrigation. The replenishment must be avoided before 10 o'clock in the morning or after 3 o'clock in the afternoon if it is to avoid high temperature.

2. Burning seedlings The burning of seedlings refers to a phenomenon that damages the growth of seedlings due to excessive fertilization, and often the entire bed or piece of seedlings does not appear or is not uniform. The roots of the seedlings that are damaged by the fertilizer are short, black, and not rooted. When they are severely emerged, they stop growing after the needle stage or the 2-leaf stage, and turn yellow from the first leaf. At this point, as long as free from frost damage as early as possible to remove the film, remove the film, repeated watering during the day, late cover film.

3, Roasted young sprouts refers to the phenomenon of seedling stems and leaves yellow due to excessive temperature. Therefore, you should immediately remove the tiled plastic film immediately after emergence. If the phenomenon of roasted seedlings occurs, do not easily destroy the seedlings, because the temperature of the soil is lower than the temperature in the shed. Sometimes the stems and leaves of rice seedlings are roasted, but the growth point can continue to grow. Every 50m of ammonium sulphate and rooting agent is chased by m2, and under 30°C to ensure proper humidity, rice seedlings can be promoted. Until rice grows 2 leaves, it enters normal management.

4. In the early stage of frozen rice, rice seedlings rely on the protection of plastic film and soil, and freezing temperature will not occur if the external temperature reaches -4°C. However, the bigger the seedlings after emergence, the more sensitive to temperature and the heavier the degree of frost damage. After the cold injury occurs, the rice leaves turn into a water-drenched thick green color that turns yellow and white after the sun has dried. During the nursery period, if the temperature is below 0°C, watering the previous day can effectively reduce the occurrence of frost damage. The more the seedbed becomes dry, the heavier the damage occurs. In the event of serious freezing injury (there is no green leaf above the ground), follow the application of 50g/m2 ammonium sulfate and the rooting agent. Under 30°C, ensure the proper humidity as much as possible, promote new leaves of rice seedlings, and grow 2 leaves of rice seedlings. After entering normal management. When some leaves are subjected to freezing damage, the growth of rice seedlings is generally not affected.

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