Quite a lot of questions, it is recommended to take more pictures, personal people see, I think it is a bean bacterial epidemic + fungal epidemic, leaf yellow leaves leaf edge yellowing is bacterial epidemic (Figure 3 lower right bottom those yellow leaves). Secondly, after the branches are blackened with water stain marks, the available methomyl. Manganese-zinc, or Fenoxaprop. Manganese zinc, or flumorph, or allylmorph, or pyrimethamine. Allylmorpholine, or Fenpyroximate, or Flumioxazin. Fenpyroximate hydrochloride and other drugs. Bacterial epidemics, can be used thiabendazole copper, or mesosporin, or thiessence copper, or quinoline copper and other drugs spray control.

Suggested medication: Fosfluorfen. Manganese zinc + thiabendazole. Once in 5-7 days, 2 consecutive sprays.

Recommended medication: uflumizole.