July 20, 2023

Cherry harvest continues throughout the county and Spotted Wing Drosophila has been caught in all traps.

GDD50 is approximately on par with the 20-year average.

Date 7/19 2019 2020 2021 2022 2023 20-year avg.
Base 50 956.5 1084 1151 1010 1100.5 1110


Hand thinning should be complete. While thinning now will help reduce late-season disease pressure, earlier thinning has greater impacts on fruit size and quality.


Codling Moth continues to be caught in many orchards.

Wooly Apple Aphids, San Jose Scale, European Red Mites, and Tarnished Plant Bugs were found this week in multiple orchards.

The first Apple Maggot in the county was caught this week. For more information on managing Apple Maggot, see this article from Christelle Guédot.


Apple scab pressure will increase with recent rain events and protectants should be applied before rain events. Primary spore dispersal has ended in the county and sprays can now be spaced out 10-14 days if scab pressure is low in your orchard. Monitor apple scab models at your nearest enviroweather station to time your fungicide applications.

Fireblight has been found on- and off-station and needs to be pruned out quickly to minimize the spread of the disease. See the most up-to-date pruning recommendations in this article by Leslie Holland.  Powdery mildew pressure continues to be high throughout the county and should be scouted for in your orchard. Check your fungicide label to be sure it is being controlled if present.


Harvest continues throughout the county and many pick-your-own operations are open. Fruit quality looks good despite a light crop.


Spotted Wing Drosophila was caught in all regions of the county and all fruit has entered ‘high risk’ status. It is critical to maintain protective sprays through harvest, monitoring PHIs, and rotating modes of action as much as possible to minimize resistance development.

The ‘Special Local Need Label’ for Mustang Maxx allowing a 3-day Pre-Harvest Interval in cherries remains in effect until December 31, 2023.


Cherry leaf spot pressure is increasing with the recent rains. Powdery mildew is also present in many orchards and regular sprays are needed to reduce pressure and protect clean growth. Protection should still be applied before rain events, particularly in orchards with existing lesions. Maintaining the orchard canopy for as long as possible is critical to the overwintering hardiness of trees and fruiting buds.


Grapes on the station are approaching berry touch. Applying a fungicide now can help protect the rachis and the fruit cluster from various diseases. You can see more information on choosing proper fungicides for these stages here.