2019 Apple Pest GuideDOWNLOAD FILE
April 7, 2020
This table is meant to serve as a season-long guide for when various life stages of key pests are expected and the best time to target management strategies based on an AVERAGE year. The dates, growth stages and pest development were all correlated with the Peach Ridge weather station near Sparta, Michigan maintained by MSU Enviroweather. Degree day calculations were determined using the Baskerville-Emin method based on averages of 2009-2018. Your actual situation during any given year may be different. The blue areas indicate principle monitoring periods, the yellow areas indicate possible control periods, and the red areas indicate critical control periods.
Acknowledgements: Much of the information provided in this table was originally developed by Philip Schwallier, District Horticulture Educator, MSU Extension, with assistance from James Johnson, formerly of MSU Department of Entomology. Peter McGhee, Larry Gut, John Wise, and David Epstein, MSU Department of Entomology, and Philip Schwallier, MSUE revised the table and printed it in poster form in 2006.
The 2018 revision was made by Julianna Wilson, Tree Fruit Integrator, MSU Entomology and Amy Irish-Brown, Tree Fruit IPM Educator, MSU Extension. Laura Vandenberg provided technical assistance. This revision adds black stem borer , brown marmorated stink bug , apple scab , fire blight , and powdery mildew.