Kentucky apple growers are faced with numerous plant disease issues throughout growing seasons. These diseases limit grower profits by reducing yield and increasing input costs.
Diseases of Greatest Concern to Growers
While diseases of concern may vary from orchard to orchard, a survey of growers found that the bacterial disease, fire blight, was of greatest concern for growers in terms of amount of yield loss and management difficulty. Table 1 details the results of the grower survey.
Critical Times of Chemical Applications to Manage Diseases
In commercial orchards disease management includes applications of fungicides and/or bactericides. Chemical applications can be costly and add to production costs. Thus, chemical applications timed only during infection periods and critical times can result in fewer applications per season. Table 2 presents the infection periods and critical times for chemical application in commercial orchards.
- A Profile of Commercial Apple Production in Kentucky 2017 (Link)
- Backyard Apple Disease & Pest Management Using Cultural Practices (with Low Spray, No Spray, & Organic Options) (PPFS-FR-T-21)
- Effectiveness of Fungicides for Management of Apple Diseases (PPFS-FR-T-15)
- Fruit, Orchard, and Vineyard Sanitation (PPFS-GEN-05)
- IPM Scouting Guide for Common Problems of Apple (ID-219)
- Midwest Fruit Pest Management Guide (ID-232)
- Scouting Guide for Problems of Apple Mobile Website (Apple Scout)
- Simplified Backyard Apple Spray Guides (PPFS-FR-T-18)
By Kim Leonberger, Plant Pathology Extension Associate and Nicole Gauthier, Plant Pathology Extension Specialist