VIEW ARTICLE

Disease Control and Pest Management

Interaction of Eradicant and Protectant Treatments Upon the Epidemiology and Control of Mummy Berry Disease of Highbush Blueberry. D. C. Ramsdell, Associate Professor, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824; J. W. Nelson(2), and R. L. Myers(3). (2)Director of Research, Michigan Blueberry Growers Association, Grand Junction 49056; (3)Laboratory Technician, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824. Phytopathology 66:350-354. Accepted for publication 1 September 1975. DOI: 10.1094/Phyto-66-350.

Eradicant ground sprays of dinoseb (DNBP) were applied to emerging apothecia of Monilinia vaccinii-corymbosi, the incitant of mummy berry disease of highbush blueberry, in a commercial field. Protectant fungicide sprays were also applied to bushes in dinoseb-treated and untreated blocks during prebloom and bloom periods. Apothecial density was reduced an average of 85.3% by the dinoseb treatment within 4 days after treatment. Numbers of ascospores trapped from air in the dinoseb-treated block were reduced 59.3% compared to the untreated block during the period of susceptibility to primary infection. The simple interest infection rate “QR” was 0.003 and 0.009 per unit per day, respectively, in dinoseb-treated and untreated blocks during this period. Primary infection (shoot blight) was reduced 57% as a result of the dinoseb treatment alone. Additional protectant fungicide sprays did not give a further significant reduction of primary infection. Numbers of conidia trapped from air in the dinoseb-treated block were reduced 34% compared to the untreated block. Secondary infection (mummy berries) at harvest was not significantly reduced by the dinoseb treatment. Additional protectant fungicide sprays significantly reduced the mean number of mummy berries at harvest up to 80.2%.