On the occasion of the Spring Festival, the weather continues to be fine and the temperature rises rapidly, which is very conducive to the growth of melons. But a week later, as the strong cold air moves south, the temperature plummets and is accompanied by 4-5 days of rain, snow and ice. To this end, we remind the majority of melon farmers to take countermeasures in advance.
1. Reasonable ventilation to promote the health of melon seedlings.
In early spring, the weather fluctuates and the drop is very large, so it is necessary to pay attention to the weather changes at all times, and maintain a more suitable temperature condition in the shed by adjusting the ventilation volume of the greenhouse and the time of closing the shed in the afternoon. Whether it is a seedling shed or a production shed, when the temperature is high on a sunny day, it is ventilated in the morning, and the temperature in the shed is closed at 25 o'clock in the afternoon. When the temperature is low even when it rains, the greenhouse is generally not ventilated, but if the humidity in the shed is high, it can be ventilated for a short time around noon. In the shed covered by multiple layers, the second film or small greenhouse film in the shed is generally opened and closed from 10 a.m. to 3 p.m., and the greenhouse is kept warm at night. The temperature of the space where the seedlings are located should be controlled at 20 to 30 degrees as much as possible to promote the healthy growth of melon seedlings. If the greenhouse temperature is too high, the growth rate of melon seedlings is too fast, the internodes are slender, the leaf color is light and thin, and the stress resistance is weakened.
When the outside temperature is low, the greenhouse vent should be small, and the leeward side should be ventilated, otherwise it may cause cold injury or wind damage.
Improper ventilation causes the leaves to lose their green spots.
2. Replenish water and fertilize in a timely manner, and do a good job in pest control.
Because the spring melon sowing period is relatively long, the current greenhouse melon several growth and development stages coexist, the earliest planted melon into the vine extension stage, part of the slow seedling stage, most of the still in the seedling stage. According to different growth and development stages, different production management measures need to be taken.
Seedling stage: pay attention to the insulation and water control of the seedbed, the relative humidity of the seedling substrate is about 70%, try to reduce the air humidity in the seedling shed, and use the fill light to increase the light when it is rainy to promote the health of the melon seedlings. Replenish water seedlings 1-2 days before the onset of low temperature and rain, and avoid replenishing water on rainy days.
LED fill light.
Planting period: The water of the live trees when planting in spring is determined according to the soil moisture in the shed. Some water-soluble fertilizers containing beneficial microorganisms such as humic acid, amino acids and algins can be added to the planting water to promote the rapid rooting of melon seedlings and early revival.
Thermal insulation measures should be fully considered before planting, and it is recommended to cover multi-layer arch sheds in the greenhouse. At the end of planting, build a shed film, seal and compact all around, and generally do not need to remove the film for ventilation within 35 degrees of shed temperature, so as to facilitate heat preservation, moisturizing, and promote live trees. However, when the temperature in the greenhouse exceeds 35 degrees, proper ventilation is necessary.
During the planting period of live trees, it is necessary to avoid low temperature and rainy weather, and the seedlings of unlive trees have poor resistance and are prone to diseases such as rooting and blight. If the seedling age is suitable, be sure to plant it in good weather; If it is too late to plant, take squatting seedlings (temperature and water control), and then plant after rainy days.
Vine extension stage: The greenhouse melon in the vine extension stage should not only promote the growth of trees, but also ensure steady growth. Generally, the daytime temperature is controlled at about 25, and the nighttime temperature is controlled at more than 15. In terms of water and fertilizer, the principle of proper control is adopted, and a small amount of water is generally not topdressed, and a small amount of water is replenished in a timely manner. If the growth is too vigorous, it will affect fruit set. Broad-spectrum fungicides and foliar fertilizers can be sprayed before the arrival of low temperature and rainy rain to improve the disease resistance and stress resistance of plants.