Effect of haze weather on vegetables in solar greenhouse

? I. adverse effects

It is mainly due to lack of light and lower temperature, which is not conducive to the growth of vegetables. The second is the high humidity of the air and the increase in the incidence of vegetables. In addition to these two obvious hazards, there are more pollutants in the haze weather air. These pollutants fall on the leaves through agricultural activities such as ventilation, which will block the stomata and affect the photosynthesis and respiration of vegetable leaves, thus affecting the growth of crops.

? II. Management measures

1. Be prepared and prevent in advance. First, we should have the habit of listening to the weather forecast, do a good job of watering and fertilizing before the haze day, cultivate strong seedlings and seedlings, accumulate nutrients and improve plant resistance. Second, it is necessary to improve the level of hardware facilities, such as the use of anti-fog dripping film and the installation of supplementary lights.

2. Light management. During the day, the heat preservation quilt (grass) should be opened as far as possible to make the vegetables exposed to scattered light. If possible, artificial light supplement measures such as lighting and installation of plant supplementary lights can be taken to minimize the impact of haze weather on vegetables in facilities. After the temperature in the greenhouse rises, release the air properly, exchange the air and reduce the humidity in the greenhouse.

3. Fertilizer and water management. Fertilizer and water management. Haze weather as far as possible not to water, topdressing, so as not to lower the ground temperature and increase the humidity in the shed. If watering is really needed, it should be irrigated with small water and drained in time. In addition, vegetable farmers are advised to try not to fertilize and water less in December and January. Watering will lower the temperature and increase the humidity, which will lead to slow growth of vegetables and increase the occurrence of vegetable diseases. It is recommended to concentrate on watering once in late November and chase a big fertilizer.

4. Pest control. Haze weather is easy to induce the occurrence of fungal diseases such as Botrytis cinerea leaf mold blight and other bacterial diseases in protected vegetables. Active measures should be taken to give priority to prevention and the combination of prevention and control to control the occurrence of diseases and insect pests. Chemical prevention and control should give priority to smoke agents; if spray control is needed, sensitive agents should be selected, such as powdery mildew, sulfur preparation should be selected first, and the mixture of trimethoprim and methyl topiramate should be used to penetrate at one time, with the feeling of dripping from leaves. 80% can be cured at one time; downy mildew and blight are the first copper preparations. It is necessary to drain the moisture in time and reduce the humidity in the shed. In a foggy day, the air is humid, and the water in the leaves is not easy to transpirate, causing the roots not to absorb water. At this time, the fertilizer elements transported to the leaves through water can not be transported, which can easily lead to the lack of nutrients in the roots and leaves. There are symptoms of yellowing of leaves or yellowing on the edges of leaves. In this case, if only fertilizing in the soil is not very effective, although there is a lot of fertilizer in the soil, but the root system does not absorb it, foliar topdressing should be used to supplement the problem of nutrient deficiency on the ground. Foliar topdressing should pay attention to the reasonable proportion of nitrogen, phosphorus, potassium and trace elements, and it is suggested that brassin and potassium dihydrogen phosphate should be sprayed for high utilization.