In autumn, the weather changes frequently, and the management of vegetable greenhouses should be changed in time

After the autumn vegetables are planted, the temperature difference between morning, middle and evening is large, and the weather changes a lot. This requires vegetable farmers to adjust the environment in the shed in time according to the weather changes.

Even cloudy weather: heavy protection against low light

Even on cloudy days, do not cover the sunshade net again to ensure the light intensity required for crop growth, and avoid weak light that makes photosynthetic products less synthesized, resulting in weak plant growth, small fruit or no fruit set. At the same time, do a good job of humidity control.

First of all, pay attention to enhancing the lighting in the shed under continuous cloudy weather.

The seedlings that have not been colonized are very concentrated and occupy a limited area, so artificial light supplementation is necessary and feasible. If the light is severely insufficient, a spotlight shade can be used in combination. It is suggested that vegetable farmers should choose the time when the light in the shed is the strongest before and after noon during the day when the light is supplemented even on cloudy days. The seedlings that have been planted have a large distribution area and the effect of artificial light supplementation is poor. By removing the cooling agent on the surface of the shed film, wiping the shed film in time, and hanging the reflective film, the light transmission conditions in the shed can be improved.

Secondly, proper temperature control, especially night temperature, minimizes the consumption of photosynthetic products. High temperature at night and strong respiration will consume more photosynthetic products, resulting in high jointing, yellow leaves and leggy growth of seedlings. Therefore, do not blindly keep warm in management, especially for some new sheds with good thermal insulation, the night temperature is 10℃-13℃, and the daytime temperature is about 25℃.

Even cloudy days turn sunny again: prevent wilting

Plants often wilt after continuous cloudy days. The direct reason is that the loss of water is greater than the absorption, resulting in plant water shortage, wilting and curling of plant leaves, and in severe cases, large areas of leaves wither and die. After a sunny day, the temperature rises rapidly, especially when the high temperature exceeds 35 °C, the air humidity in the shed decreases rapidly, so that the delicate growth points cannot withstand the high temperature, and the water evaporates in a short time, causing rotten heads.

One is to reduce the light intensity, and it will clear up after continuous cloudy and rainy days. It is recommended to lay a sunshade net or sprinkle mud, ink, etc. on the shed film to reduce the light intensity as much as possible, so that the plants have a slow adaptation process, and the evaporation will gradually increase.

The second is to spray water in the shed to increase the air humidity, thereby reducing the evaporation of water from the leaves. For wilted leaves, it is recommended to spray foliar fertilizer in time to promote the recovery of leaves as soon as possible.

Rainy weather: heavy protection against high humidity

First of all, it is necessary to prevent rainwater from flooding the shed. Vegetable farmers should develop the habit of watching the weather forecast. Before heavy rain comes, they should close the air vents to prevent rainwater from pouring into the shed. If the protection is not appropriate, after the shed is irrigated with rainwater, the accumulated water in the shed should be quickly drained, and the soil should be ploughed in time when the soil is dry or wet to loosen the soil and increase its air permeability to prevent the occurrence of root retting or root diseases. After cultivating, it is best to irrigate and apply a root mulch fertilizer once to promote the growth of vegetable roots.

Secondly, the humidity in the shed is high, pay attention to disease prevention. In the rainy season, the humidity in the shed is high, and the high temperature and high humidity environment is easy to induce diseases. In addition, close the air vents before the heavy rain, and do not operate it too early. The front vents can be kept open as long as the water does not enter. After the heavy rain, all the vents should be opened immediately to reduce the temperature in the shed and make the The shed temperature is consistent with the outside temperature, which is an effective measure to reduce nutrient consumption.

In addition, proper fruit thinning and reducing dipping of flowers and fruits can also reduce nutrient consumption, which is conducive to balanced nutrient distribution. Before the arrival of rainy weather, it is recommended to use root-raising fertilizer to irrigate the roots to improve root activity, increase nutrient absorption, and improve plant resistance. After the rain, foliar fertilizer is sprayed on the foliage to supplement nutrients directly through the leaves and delay the senescence and yellowing of the leaves.