What if a large number of pumpkin leaves turn yellow?

A large number of pumpkin leaves turn yellow, which generally have physiological damage and infectious damage. If there is no disease spot in the yellowed leaves, it is mostly due to too much water content in the soil, insufficient light and too little oxygen content in the soil, resulting in asphyxiation and death of cucumber roots, a sudden drop in the ability of roots to absorb nutrients, and an increase in plant ethylene content. the chlorophyll in the leaves can be yellowed by rapid water energy. But in general, the yellowing of the above leaves is relatively uniform (except for the existing disease spots), and the solution is to spray 0.02PPM brassinolide and foliar fertilizer to improve the stress resistance of the plant, and quickly supplement the urgently needed nutrients with foliar fertilizer. Foliar fertilizer can be selected, such as humic acid Kangbao, algin Waldebao, Lujin, Nongfukang and so on. In addition, if the leaf wilts from the bottom to the top, the mesophyll tissue between the leaf margin and veins turns yellow, and then gradually expands to the whole leaf. The stem of a cut plant can be selected. if the vessel is brown, the plant will be infected with Verticillium wilt. At the initial stage of the disease, 70% Fu ·methyl sulfur wettable powder 600 times solution or 50% carbendazim wettable powder 500 times solution can be used to spray stems, leaves and roots, 250 ml per plant, once every 5 days, for 2 times in a row.