FEATURES AND THE SEASONAL VARIATIONS IN EMERGENCE OF TWO SIDE-ROT SYMPTOMS ON 'HORT16A' KIWIFRUIT
Two disease symptoms, sooty mould and dimples usually solitary on the side of fruit, have been observed on Actinidia chinensis Hort16A kiwifruit in Japan and Korea since 2009. Anetiological study showed that each symptom is caused by different pathogens. The sooty mould caused by Pseudocercospora actinidiae and dimple caused by P. hangzhouensis. The distinction of two types of symptoms was revealed. Sooty mould: Distinct and blackish brown spots with sooty mould were observed on lower leaf surface. On the side of fruit, a large concavity (2-5 cm) is developed. The flesh of the fruit under the lesion is turned into spongy, light brown. Blackish brown conidial masses are often observed. These symptoms are observed mainly in maturation period on tree. Fruit softening and rotting are mainly started after the harvesting. Dimple lesion: Spots on upper leaf surface are distinct, brown with dark brown border, irregular to angular. Small concavity (1-2 cm) is developed on the fruit. The flesh of the fruits under the lesion is turned into corky and brownish. Symptoms are observed mainly through the period of maturation on tree and that of storage or ripening after harvest. On the other hand, fruit softening and rotting mainly start with ripening. From the results of exposure-tests in Japan, it is suggested that pathogens mainly infect to fruits from end of May to June. In addition, conidia of P. actinidiae and P. hangzhouensis were trapped on May, June, and August in orchards in Korea. These seasons are synchronized with rainy season in both places. And also, these results are related to the emergence pattern of these diseases in the field.
Yano, T., Nakashima, C., Nakahama, M., Kimura , K., Tsuneoka, H., Shimizu, S., Donovan , R., Kwon, J., Yoshimaru , M., Ochi, M. and Manning, M. 2015. FEATURES AND THE SEASONAL VARIATIONS IN EMERGENCE OF TWO SIDE-ROT SYMPTOMS ON 'HORT16A' KIWIFRUIT. Acta Hort. (ISHS) 1096:389-396
kiwifruit, 'Hort16A', side-rot, Pseudocercospora actinidiae, Pseudocercospora hangzhouensis