The investigation and occurrence of guava disease in central part of Taiwan
'Jen-Ju Bar', 'Sai-Ji Bar', and 'Shui-Jing Bar' are main cultivars which are planted in central part of Taiwan. The plants are sensitive to nematodes (Meloidogyne incognita, Pratylenchus spp.), damping-off (Myxosporium psidii), and twig blight disease (Colletotrichum gloeosporioides, Phytophthora sp., Pestalotiopsis sp., Fusarium semitectum, Curvularia sp., Drechslera sp.). Whereas in fruits, anthracnose (Colletotrichum Gloeosporioides), black spot phyllosticta rot (Phyllosticta psidiicola) and guava canker disease (Pestalotia psidii) are main diseases. Investigation on the infection rate of both plants and fruits was done at orchards in Ershui, Xitou, and Yuanlin Township in Changhua County. Farmers did not spray pesticide whole year. The result showed damping-off disease in 'Sai-Ji Bar' at Xitou had the highest infection rate, 43.8%. The most severe nematode infection was found in 'Jen-Ju Bar' at Yuanlin where the highest infection rate of 68.8% was found in August. Twig blight disease in 'Jen-Ju Bar' at Xitou had the highest infection of 56.3% in January. In fruits, the anthracnose appearances were about 17% in Yuanlin in September; black spot phyllosticta rot was about 7.5% in July and September in Ershui; and guava canker disease was about 17% during September. To conclude, 'Jen-Ju Bar' and 'Shui-Jing Bar' are sensitive to nematodes and twig blight disease, whereas 'Sai-Ji Bar' is sensitive to damping-off disease. In fruit, antrachnose disease occurs from June to August and October to February; black spot phyllosticta rot occurs from July to September; and guava canker disease occurs from July to November.
Yeh, Shih-Tsai and Shiesh, Ching Chang 2017. The investigation and occurrence of guava disease in central part of Taiwan. Acta Hort. (ISHS) 1166:115-124
guava (Psidium guajava L.), diseases, central Taiwan