Curvularia flower blight

The disease is characterized by small dark brown spots on the flowers, and similar symptoms of the flowers can also be caused by Botrytis cinerea.

(Botrytis cinerea) and Sclerotinia sclerotiorum (Sclerotina fucheliana). The treatment is to spray with zinc, thiram or manganese, and never spray the flower with carbendan, as it can harm the flower. (Liu Zhongjian)