RT Journal Article SR Electronic T1 Goals And Hurdles For Shade Tree Programs JF Arboriculture & Urban Forestry (AUF) JO JOA FD International Society of Arboriculture SP 176 OP 180 DO 10.48044/jauf.1976.044 VO 2 IS 9 A1 John A. Weidhaas, Jr. YR 1976 UL http://auf.isa-arbor.com/content/2/9/176.abstract AB McIntosh, D.L (ed). 1975. Proceedings of the 1974 APDW workshop on crown rot of apple trees. Canadian Plant Disease Survey 55: 109-116.At a workshop sponsored by the Apple and Pear Disease Workers and held at Summerland, British Columbia, 16-17 August 1974, participants from the USA, UK, Poland, and Canada considered problems associated with collar rot of apple trees incited chiefly by Phytophthora cactorum. Topics included pathogens, symptomatology, methods of isolating P. cactorum, evaluation of resistance, pathogenic variation in P. cactorum, cultural practices and pre-disposition, control, ecological studies, and areas requiring further research.