VIEW ARTICLE

Factors Affecting Apothecium Development of Monilinia vaccinii-corymbosi from Mummied Highbush Blueberry Fruit. R. D. Milholland, Associate Professor of Plant Pathology, North Carolina State University, Raleigh 27607; Phytopathology 64:296-300. Accepted for publication 12 July 1973. DOI: 10.1094/Phyto-64-296.

Mature apothecia of Monilinia vaccinii-corymbosi develop from overwintering mummies in highbush blueberry plantings by March 5 in southeastern, North Carolina. In the presence of adequate soil moisture, the majority of apothecia develop by 20 March. The mean temp for this date 1972 and 1973 was 15 C. Soil moisture is the most important factor in germination and apothecium development. A soil moisture level of 42% by weight is adequate for germination and apothecial development; 18% is inadequate. A temp of 16 C is optimum for germination and development of apothecia; whereas 5 C was sufficient to stimulate germination. Light is also a necessary stimulus for apothecium development. A greater percentage of the mummies placed on the soil surface produced apothecia than those buried beneath the soil surface. Development of apothecia is completely inhibited in mummies buried at least 2.5 cm below the soil surface.