Pear rust: orange-yellow round spots are formed on the front of leaves, and small spots as big as orange needles are densely produced, that is, sex spore apparatus. When wet, there is light yellow mucus overflowing, that is, sexual spores, and small particles turn black in the later stage. The tissue on the back of the leaf corresponding to the diseased spot thickens and grows gray-yellow hairs, that is, rust spore apparatus. Yellow-brown powder, namely rust spores, is released after the hair is broken. Fruits, fruit stems, new shoots and petioles were damaged, and the lesions were similar to those on leaves in the early stage, and hairs were produced on the surface of the same lesions in the later stage.

Spot disease: at the initial stage of the disease, there are nearly round brown water-soaked spots on the surface of leaves, and then they expand to oval to amorphous, grayish brown to grayish white, surrounded by water-soaked light green halo, with the spot size of15-20 mm. In severe cases, the spots converge and make the leaves dry locally. In the late stage, the middle part of the lesion is tissue-like, pale yellow or grayish white, and it is easy to break, which mostly occurs in the middle and lower leaves in the late stage of growth. When wet, there are small black spots on the spot surface, and the spot surface is often prone to rupture or perforation. In the hot and rainy season, the lesion quickly expands into a large plastic spot, and then withers and falls off.