Submitted to: HortScience
Publication Type: Review Article
Publication Acceptance Date: November 18, 2006
Publication Date: January 11, 2008
Citation: Smith, B.J. 2008. Epidemiology and pathology of strawberry anthracnose: a north american perspective. HortScience 43:69-73. Technical Abstract: Colletotrichum species incite serious diseases of many fruit and vegetable crops worldwide, and three species, C. acutatum, C. fragariae and C. gloeosporioides, are major pathogens of strawberry, (Fragaria 'ananassa). Strawberry anthracnose crown rot has been a destructive disease in strawberry nurseries and fruit production fields in the southeastern United States since the 1930s. The causal fungus, C. fragariae, may infect all aboveground plant parts; however the disease is most severe when the fungus infects the plant crown causing crown rot, wilt, and death. The presence of the anthracnose fruit rot pathogen, C. acutatum, originally reported in Queensland, Australia, was first reported on strawberry in the U.S. in 1986. Colletotrichum gloeosporioides was responsible for an epidemic of anthracnose crown rot in strawberry nurseries in Arkansas and North Carolina in the late 1970s. The increase in losses due to anthracnose fruit and crown rots in the U.S. since the 1980s may be related to the shift from matted row culture to the annual plasticulture production system, as well as a change in cultivars being grown. Anthracnose investigations in the U.S. have concentrated on its epidemiology and differences among the three causal Colletotrichum species in their cultural, morphological, and molecular characteristics; their infection processes; and pathogenicity. Survival of the pathogens in the field is dependent on soil temperature and moisture and decreases as temperatures and moisture increases. Strawberries grown in soils with high nitrogen levels are more susceptible to anthracnose than those grown in soils with lower nitrogen levels or those amended with calcium nitrate. Anthracnose is spread more rapidly in fields using overhead irrigation and plastic mulch than in field where drip irrigation and straw mulch are used. Fungicide efficacy has been determined in in vitro, greenhouse, and field studies; and pathogen resistance to some fungicides has been detected. Methods to rapidly and reliably identify infected nursery plants are being developed. The development of anthracnose resistant cultivars is a major objective of most strawberry breeding programs in the U.S. and is the primary focus of strawberry research at the United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Small Fruit Research Station, Poplarville, MS. Four anthracnose resistant-breeding lines and one cultivar have been released from this program.