In the spring vegetable greenhouse planting, farmers need to strictly guard against these "three evils".

    Vegetables are an essential food for people every day and an important food for people to maintain a balanced diet. It is also the main channel for farmers across the country to create profits and increase income. How can farmers increase their income?

    It is precisely based on the regional differences in temperature in my country that in order to meet the vegetable needs of the people across the country, greenhouses have also emerged as the times require. 2022 will usher in the new year, and my country has also entered the spring. Most of the vegetables in my country can start to be planted. In greenhouse vegetable production, due to the change of the field microclimate, good pest and disease control is the key to achieving high yields.

    1. Freezing damage

   The temperature in the north is still severe in spring, accompanied by ice and snow disasters, which have damaged greenhouses and other facilities to varying degrees. Under the conditions of low temperature, high humidity, and little sunlight in the shed, vegetables are not only susceptible to freezing damage, but also stunted in growth, thin and weak, and easily infected with pests and diseases. The main preventive measures are:

    1. Clear the snow: Clear the snow in the greenhouse in time after the snow to prevent the greenhouse from collapsing.

    2. Moderate ventilation: Due to long-term closed management, the shed has low temperature, high humidity, and little light. After snow or after continuous cloudy days turn to sunny, the shed should be properly shaded or gradually uncovered to prevent the plants from "flashing seedlings" due to sudden water loss. ".

    3. Watering control: Controlling watering or ground mulching can reduce the air humidity in the shed, maintain and increase the ground temperature, and improve the light transmission conditions of the shed film.

     2. Fatty

    Greenhouse vegetable fertilizer damage can be roughly divided into three types. The first is that the amount of fertilizer is too large or too close to the plants, and the crops are burned by high-concentration fertilizers; the second is that the excessive application of a certain nutrient element leads to the lack of other elements. To take appropriate measures according to the cause of the fertilizer damage:

    1. Scientific fertilization: To prevent excessive fertilization at one time, the base fertilizer should be covered with soil or fully mixed with the soil; for top dressing, it is recommended to apply deep soil cover, and water should be irrigated in time after application, and the fertilizer should not be spread on the ground.

    2. Timely ventilation: Especially after fertilization in early spring, the poisoning of harmful gases is easy to occur. Once it occurs, the ventilation conditions should be improved in time to discharge harmful gases.

    3. Inhibit the production of nitrite gas: Prevent soil acidification and apply an appropriate amount of nitrification inhibitors to inhibit the production of nitrite gas.

     3. Pests and diseases

     In spring, vegetable greenhouses are prone to various diseases due to low temperature, low sunlight and high humidity. Comprehensive prevention and control are carried out through the following measures:

    1. Strengthen field management: control watering, and moderate ventilation at noon on sunny days to reduce humidity in the shed, improve light and strengthen carbon dioxide supply; implement formula fertilization.

    2. Improve planting conditions: In greenhouses with high surface humidity, high ridge and narrow furrows and three furrows can be used for supporting cultivation; in intensively managed greenhouses, dark plastic films can be used to cover the ground in the greenhouse as a whole.

   3. Do a good job of monitoring and forecasting pests and diseases, and carry out chemical control in a timely manner: Tomato diseases mainly include gray mold and late blight. There are many types of pesticides for the control of vegetable diseases and insect pests in greenhouses, and generally high-efficiency, low-toxicity and low-residue pesticides are used.

Therefore, the management work of farmers to control the "three pests" plays a pivotal role in increasing income, and the current is a critical period for the prevention and control of diseases and insect pests. space.