RT Journal Article SR Electronic T1 Green Survival: Taking The Story To America JF Arboriculture & Urban Forestry (AUF) JO JOA FD International Society of Arboriculture SP 89 OP 92 DO 10.48044/jauf.1978.021 VO 4 IS 4 A1 Lederer, Robert F. YR 1978 UL http://auf.isa-arbor.com/content/4/4/89.abstract AB Thompson, S.V. et al. 1977. Pesticide applications can be reduced by forecasting the occurrence of fireblight bacteria. California Agriculture 31 (10): 12-14.Fireblight, caused by the bacterium Erwinia amylovora, is an erratic and devastating disease. Blight “strikes” have been continuously and carefully pruned from diseased trees since fireblight first arrived in California. Chemical spray treatments, first used to control the disease in the 1940’s, have been relied upon heavily, especially in the critical flowering period. Until recently, it has been common practice to spray or dust trees with copper or antibiotic materials at 5-day intervals throughout the flowering period. It became apparent that spray applications were frequently unnecessary. Lack of data on the occurrence of the bacteria prohibited the development of a usable forecasting system. In the late 1960’s we began developing a selective, differential growth medium for the isolation of fireblight bacteria. This medium has been a key element in the development of a monitoring program that allowed us to correlate the occurrence of fireblight bacteria with weather.