Due to insufficient light, melon seedlings have weak photosynthesis, malnutrition, slow growth, pale leaves, cotyledons falling off, and are prone to stiff seedlings and sudden drop disease, resulting in a large number of dead seedlings. Management measures: remove the straw cover in the morning, clean the dust on the film, pat off the small water droplets in the film, maintain good transparency, cover the straw cover at night to keep warm, and apply pesticides to prevent diseases if necessary.
2. It rains continuously
The humidity in the seedbed is high, the light is poor, the temperature is low, the photosynthesis is weakened, and the nutrient accumulation is less, but the respiratory consumption is not reduced, the melon seedlings are yellow and weak, and the disease is aggravated. Management measures: As long as it doesn't rain, the plastic film must be uncovered during the day to increase the scattered light. It is forbidden to uncover the plastic film for several days. Dry fine soil or plant ash with a thickness of 1 ~ 1.5 cm can be spread on the border, and watering and spraying should be stopped in the border. Properly ventilate on the leeward side at noon.
3. foggy days
Poor light, high air humidity, easy water accumulation in the leaves of melon seedlings, easy to be infected with anthracnose and damping-off disease. Therefore, in foggy days, it is necessary not only to seal the seedbed to prevent the fog from entering, but also to remove the cover in time and properly ventilate and transmit light after the fog completely dissipates.
4. Cloudy and sunny for a long time
The bed temperature rises sharply, and the seedlings lose too much water, which leads to physiological water imbalance, wilting, growth stagnation and even death. Management measures: let the seedlings gradually see the light, uncover in the morning, let the seedlings see more light at a lower temperature, so as to have a longer adaptation process to strong light. When the temperature rises to a certain degree, the seedbed can be lightly covered with grass or sprayed with warm water of 10℃ ~ 20℃ to supplement the water loss and relieve wilting. You can also ventilate as soon as possible before the storm comes to reduce the temperature of the seedbed.
5. Strong winds and cold currents
Uncover the thatch cover every day to allow the seedlings some time to see the light, but it needs to be uncovered at night and early, usually after 1 1 in the morning and before 2 pm. The specific time is not short, and the heat preservation measures should be strengthened according to the weather at night.
I hope it helps you. If in doubt, please consult China Agricultural Technician Information Network. I wish you a good harvest.