MUMMY BERRY DISEASE BLIGHT RESISTANCE IN HIGHBUSH BLUEBERRY CULTIVARS

Fifty-five highbush blueberry (Vaccinium corymbosum I,.) cultivars and selections were evaluated over 2 years for their resistance to the shoot blighting phase of mummy berry disease [Monilinia vaccinii-corymbosi (Reade) Honey]. Blight incidence in 1993 ranged from 1% to 78% and differences among cultivars were significant. In 1994, infection levels were lower and ranged from 0% to 43%, again with significant differences among the entries, Several cultivars exhibited mummy berry blight resistance in both years. Ranking most resistant to less resistant were 'Jersey', 'Elliott', 'Bluejay', 'Duke', 'Stanley', 'Barrow', 'Meader', and 'Angola'. Among the cultivars consistently blight-susceptible. were 'Bluehaven', 'Bluegold', 'Northblue', 'Croatan', 'Northsky', 'Sierra', 'Harrison', 'Coville', and 'Murphy'. The consistent resistant reaction of certain cultivars indicates that they may be suitable as parents for introducing resistance into a breeding program. The evaluation methodology developed in these tests should be useful in screening germplasm for new sources of resistance and evaluating segregating progeny from crosses.