Apple pests and diseases in Japan
In this paper, the main pests and diseases of apple in Japan are described, with their appropriate control methods.
Carposina niponensis (EPPO A1 quarantine pest) is a significant pest on apple, peach and pear. It has one or two generations per year depending on the local populations. Organophosphates and synthetic pyrethroids are effective against the eggs. Regular sprays are required from June to August because of the extended period of egg laying and hatching. Important mite pests are Panonychus ulmi and Tetranychus urticae. The apple leaf miner (Lithocolletis ringoniella) is occasionally a pest, high infestations can cause leaf deformation and photosynthesis reduction. It has three to five generations per year, and the application of nicotine sulphate or synthetic pyrethroids at the peak of adult emergence is generally sufficient. Among tortricid pests, the summer fruit tortrix (Adoxophyes fasciata) is the most serious, because in addition to fruit damage it has developed resistance to various insecticides. The insect has three to five generations per year. The larvae feed superficially on the fruit skin and early season feeding can cause deep scars on mature fruit, and deformation. Chemical treatment is generally required against overwintering larvae, soon after budburst. In summer, pheromone traps are used to determine the timing of treatments. Some organophosphates and most pyrethroids are still effective against this pest. The apple tortrix (Archips fuscocupreana) is a univoltine leafroller which damage flower clusters and small fruits. Organophosphates and insect growth regulators can be applied around blooming period, depending on the type of product.
In Japan, up to 68 diseases and disorders have been recorded in apple orchards. Among these, Monilinia laxa f. sp. mali, Alternaria mali (EU Annex II/A1) and Venturia inaequalis are the most serious diseases which require specific and regular control measures. Against Alternaria mali, applications of protectant fungicides after the petal fall are necessary. Many fungicides, e.g. mancozeb, ziram, thiram, oxine-copper, iminoctadine acetate, polyoxine etc., are recommended.
Sources
Sekita, N.; Fujita, K.; Kawashima, K. (1994) The present situation in the control of apple insect pests and diseases in Japan.
Agrochemicals Japan, no. 65, 5-8.