Colletotrichum acutatum, a post-harvest pathogen on apple in Norway
J. Børve, R.T. Djønne and A. Stensvand.
Journal of Plant Pathology Volume 90 (2, Supplement) August 2008, Book of Abstract, 9th International Congress of Plant Pathology, August 24-29, 2008 Torino,Italy,. 507 pages.
2008
บทคัดย่อ
Colletotrichum acutatum, a post-harvest pathogen on apple in Norway
Bitter rot on apple, caused byColletotrichum actutatum, develops symptoms during summer in warm, humid apple-growing regions of southeasternUSA,BrazilandNew Zealand. InNorway, the disease is severe on the main late ripening cultivar ‘Aroma’, but symptoms normally develop after some time in cold store. Summer epidemics on apple have never been observed inNorway, and only occasionally have symptoms developed at harvest. In a series of experiments with organically grown ‘Aroma’ apples picked over five weeks, 6, 14, 35, 33, and 35% (mean of three experiments (in different years) of the apples developed bitter rot if harvested 2 or 1 wk prior to normal harvest time, at normal harvest, or 1 or 2 wk after normal harvest time, respectively. Foliar applications of calcium during summer reduced bitter rot in cold store. In conventionally grown apples, dithianon either applied once 3 wk prior to harvest or 6 times earlier in the season (against apple scab,Venturia inaequalis), reduced the incidence of bitter rot after storage from about 50 to 25%. Various alternative means to reduce bitter rot in organic and conventional apple orchards (including harvest time and applications of calcium salts) and fungicide programmes are currently being developed inNorway.