How to prevent sunburn and navel rot from growing sweet peppers in summer?

How to prevent sunburn and navel rot from growing sweet peppers in summer? Please introduce the method that sweet pepper in greenhouse often has rotten fruit, which is mainly caused by sunburn and navel rot. Sunburn is mainly due to direct sunlight on the fruit surface or the appearance of dew on the greenhouse film in the morning, and the sun shines on it to produce heat, resulting in pericarp cell burns. Umbilical rot is mainly due to the decrease of calcium mobility in soil caused by high temperature and drought and the decrease of calcium absorption ability of roots, which leads to a physiological deficiency caused by temporary calcium deficiency in fruit. In the early stage of sunburn, the disease shows dark brown, gradually brown, and finally white, the cortex becomes thinner, the tissue is necrotic, it is easy to be infected by fungi after drying, black mold is saprophytic; navel rot, the disease shows dark green watery spots at the beginning, and then expands, shrinks and depresses, often blackening or rotting as a result of parasitic other bacteria. Sunburn generally occurs in the sunny side of the fruit, while navel rot occurs in the navel of the fruit. When preventing sunburn, first of all, sunshade nets should be set up on the shed, and the reflective curtain and plastic film should be removed as soon as possible to reduce the reflection of light. Secondly, we should frequently pour small water to reduce the temperature in the shed. In addition, there should be reasonable close planting to hide the stems and leaves from each other and avoid direct sunlight on the fruit. And timely supplement of trace elements such as calcium, magnesium, boron, zinc, manganese, iron and molybdenum to improve plant resistance. In the prevention and control of navel rot, it is necessary to prevent excessive drought in the greenhouse, often irrigate small water, and promote the root system to absorb calcium in the soil normally. And in the fruit setting and fruit expansion period, foliar supplement of calcium can effectively alleviate the disease. Click to get more sweet pepper planting techniques click to get more vegetable planting techniques