Look at the pictures, Figure 1 and Figure 2, they should be normal cowpea seedlings when there is no rain. Picture 3, Picture 4, Picture 5. The leaves are yellowing and the ground is relatively wet. Depending on the situation, there has been heavy rain in your area recently, or there has been continuous rain. The reason why the leaves are yellow is because the ground is too wet and the root system is not good. Remember to drain water in time (you can’t see the accumulated water in the following pictures), use chlorine, chloramphenicol, or fludioxon, chlorine, etc.) + better rooting agent + ethosalin (halve the dosage) or zhongsheng Root irrigation with mycocin. Once every 6-7 days, root irrigation twice continuously. The leaves should be sprayed with amino acid foliar fertilizer or humic acid foliar fertilizer + micro-fertilizer + fungicides such as chlorothalonil or Daisenlian + Zhongshengmycin or thiadiazole. (While supplementing nutrients on the leaves, pay attention to preventing diseases, which are prone to occur after rain)