Survey on the occurrence of apple diseases in Korea from 1992 to 2000

Abstract

In the survey from 1992 to 2000, twenty-eight parasitic diseases were observed in major apple producing areas in Korea. The predominant apple diseases were white rot (Botryosphaeria dothidea), Marssonina blotch (Mar-ssonina mali), Valsa canker (Valsa ceratosperma), Alter-naria leaf spot (Altemaria mali), and bitter rot (Collecto-trichum gloeosporioides and C. acutatum). Apple scab that reappeared in 1990 after disappearance for 15 years was disappeared again since 1997. A viroid disease (caused by apple scar skin viroid) was newly found in this survey. The five diseases, fire blight (Erwinia amylovora), black rot (Botryosphaeria obtusa), scab (Cladosporium carpophilum), Monochaetia twig blight (Monochaetia sp.), and brown leaf spot (Hender-sonia mali), which had once described in 1928 but no further reports on their occurrence, were not found in this survey. However, blossom blight (Monilinia mali), brown rot (Monilinia fructigena), and pink rot (Tricho-thecium roseum), which did not occur on apple after mid 1970s, were found in this survey. © The Korean Society of Plant Pathology.