VIEW ARTICLE

Disease Control and Pest Management

Phenology and Control of Endocronartium harknessii in Pennsylvania. W. Merrill, Professor, Department of Plant Pathology, The Pennsylvania State University, University Park 16802; B. R. Kistler, Research Assistant, Department of Plant Pathology, The Pennsylvania State University, University Park 16802. Phytopathology 66:1246-1248. Accepted for publication 10 April 1976. Copyright © 1976 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-66-1246.

Sporulation of Endocronartium harknessii is synchronized with host development (Scots pine, Pinus sylvestris). The peridermioid teliospores are disseminated from the beginning of needle emergence from the fasicle sheath until the needles have reached about 75% of maximum length. A single application of maneb (3.6 g/liter = 3 lb per 100 gallons of water) at the beginning of spore release prevented infection of Scots pine Christmas trees. Three systemic fungicides tested gave negative results.