Ten years study of the discharge of ascospores is described. As the discharge started each year before the first flushing leaves reached the susceptible stage, growers can determine the best date of the first spraying simply from the flushing stage of the host. Radio warnings based on the first date of ascospore discharge are superfluous.
AbstractLiterature on pathogens observed on lodgepole pine {Pinus contorta var. latijolia S. Wats.) grown in Einland is briefly reviewed. Heterobasidion annosum (Er.) Bref and Scleroderris lagerbergii Gremmen appear to cause the most serious damage. Lachnellula subtilissima (Cke.) Dennis Crumenulopsis sororia (Karst.) Groves and Sclerophoma pityophila (Gorda) v. Hohn. cause damage less frequently. The majority of over 300 stands have reached an age of 40-60 years and their health is described as satisfactory to good.