Both pepper umbilical rot and sunburn are physiological diseases that are prone to high temperature and drought. The difference lies in their different pathogenesis. Usually, sunburn is that peppers are exposed to direct sunlight and the epidermal cells are burned and necrotic, dry and white, or pigmentation is formed. The cortex turns black to form tiger-skin pepper; while umbilical rot is a high temperature and drought caused by high water evaporation of leaves, insufficient water absorption by the root system, resulting in water loss of the fruit, insufficient calcium for young and new growth points, and overall necrosis and blackening of the flesh.

 The control methods of umbilical rot and sunburn are basically the same, and shading treatment can be carried out under conditions of high temperature and drought. The most direct way is to spray seaweed extract on the leaves of peppers to improve the stress resistance of plants and fruits and increase the thickness of epidermal cells. At the same time, strengthen the management of water and fertilizer, and use chitosan fertilizer for flushing to ensure that the root system can normally absorb the nutrients required by the plant under high temperature and drought conditions, and improve the drought resistance of the plant itself.