Scientific management of vegetables in greenhouse how to deal with bad weather

Greenhouse vegetables

Now, it is the critical period for the growth of vegetables in the greenhouse. however, the low temperature, coupled with the frequent haze and snowfall, has a great impact on the production of vegetables in the greenhouse.

Haze and snow weather continue to make greenhouse vegetables obviously lack of light and temperature, low temperature, high humidity microclimate environment can easily lead to greenhouse vegetables grow slowly, or stop growing, or even die seedlings. In order to ensure the high yield and income of greenhouse vegetables, all kinds of growers should manage scientifically and take active measures to deal with it. Pay attention to the cold protection and heat preservation of the greenhouse, timely cover the grass, heat preservation quilt and cold protection film to reduce the heat loss in the greenhouse; in case of haze weather, we should pay attention to increasing temperature and replenishing light, and conditional greenhouses should be installed as soon as possible, such as heating lights, supplementary lights, hot fans and other facilities to increase temperature, increase light, and promote plant growth. In case of snowy weather, the snow on the greenhouse film should be removed in time. The snow on both sides of the greenhouse should also be removed in time to prevent melting from absorbing a large amount of heat and reducing the temperature in the greenhouse, and damage to the greenhouse film should be avoided when removing snow. In addition, it is necessary to control watering and rational fertilization to prevent and control diseases and insect pests. In low temperature and sunny weather, try not to irrigate or irrigate less, and dehumidify in time by spraying plant ash and other measures. When applying fertilizer, it is necessary to control the amount of nitrogen fertilizer and increase the application of phosphorus and potassium fertilizer.

Due to the low temperature in winter and slow growth of vegetables in greenhouse, vegetables in greenhouse can be fertilized properly to promote the growth of vegetables. A small amount of fertilizer should be applied frequently, and fertilizer should be dissolved in advance and combined with irrigation. Secondly, the ventilation time in the greenhouse is less in winter, the temperature difference and humidity in the greenhouse are large, and diseases and pests such as vegetable downy mildew, gray mildew, white planthopper and other diseases and pests are easy to spread. It is suggested that farmers spray insecticides once a week and spray at noon on a sunny day to prevent the occurrence of diseases and insect pests and reduce pests. In addition, when the light is strong at noon on a sunny day, the curtain should be properly opened and ventilated to reduce the temperature and humidity in the shed and eliminate the harmful gases in the shed.

It is particularly noteworthy that during this period, Botrytis cinerea is a high incidence disease of cucumber and other vegetables in greenhouse, and vegetable farmers should control it in time. The disease mainly harms young melons and leaves, and the pathogen is re-infected by airflow and agricultural operations. The suitable temperature for Botrytis cinerea is 20 ℃-23 ℃, humidity is more than 90%, low temperature, high humidity and weak light are conducive to the disease. Flood irrigation and continuous cloudy days or haze and foggy days are all important factors to induce Botrytis cinerea. The ultraviolet ozone germicidal light source can be installed, and its function is to use the ultraviolet light emitted by the light source to produce low concentration ozone, at the same time, it can purify and sterilize the environment, which is suitable for the prevention and elimination of air-borne diseases in greenhouse and reduce diseases. Its advantages are as follows: first, it is safe, efficient and low cost. Ozone can achieve multiple uses, control a variety of diseases and pests at the same time, and the cost of control is low. Compared with spraying pesticides, it is more safe, convenient and reliable, and at the same time greatly reduces the use of pesticides, thus reducing the cost of medicine. Second, it is pollution-free. Ozone is unstable in dry air and can be quickly decomposed and reduced to oxygen, so there is no pollution and no residue in the plant and fruit. The third is to improve quality and increase production. Through the experiment, after installing the ultraviolet ozone germicidal light source, the cucumber has good coloring, good taste and higher yield. Attention should be paid to the reasonable determination of the amount and time of release, the amount and time of ozone release should be appropriately adjusted according to different crops and their growth periods, and the application should be as uniform as possible, and the nozzle should not be directly facing the vegetables. it should be more than 0.8 meters away from the vegetable plant. Ventilation should be timely after the release time arrives, and the general ventilation time should not be less than 30 minutes. During this period, people and animals should be strictly prevented from entering, so as not to cause poisoning or other adverse reactions. When ozone is applied, the indoor temperature should be kept in the range of 10 ℃-30 ℃, and the control effect will be better under the condition of high air humidity.