Late Season Rescue Thinning with Ethephon
Ethrel for Rescue Thinning in Eastern New York - Dan Donahue
Our colleagues in Massachusetts and New Jersey have conducted extensive research over the years on the use of Ethephon as a "rescue thinner" when fruits reach the 20-25 mm stage. I've posted a fact sheet and a power point presentation on the ENYCHP website that offers excellent guidance on the use of this material as a thinner. With this seasons bumper fruit set, coupled with weak thinner performance, ethephon should be considered as an option, but please follow the links below and study the information provided before acting. Ethephon can be a strong thinner, very sensitive to temperatures in the several days following application, capable of defruiting the tree in some circumstances. Thank you to Win and Wes for giving ENYCHP permission to post this information.
Rescue Thinning with Ethephon PowerPoint/pdf Talk (pdf; 4398KB)
- Author: Win Cowgill presented at the Connecticut Pomological Society
Fact sheet- F-129R UMASS-Rutgers- Late Season Rescue Thinning with Ethephon (pdf; 682KB)
- Authors: Wesley Autio, Win Cowgill

Upcoming Events
2026 Champlain Valley Summer Orchard Field Tour
July 15, 2026 : 2026 Champlain Valley Summer Orchard Field Tour
Keeseville, NY
Join the ENYCHP and Cornell scientists on July 15 for our annual Champlain Valley Summer Orchard Meeting! This year we will be meeting at Hart Apple Farm to learn about the varieties they are growing in one of their newer plantings, hear updates from faculty and extension agents on their current research projects, and view a few of Mike's local thinning projects firsthand.
DEC credits in categories 22, 1A, and 10 will be available. Refreshments will be provided.
Free to attend, however we do ask that you register ahead so we know how many people to expect. Rain date is July 16.
2026 Hudson Valley Berry Field Day
July 15, 2026 : 2026 Hudson Valley Berry Field Day
Kinderhook, NY
Join specialists Heather Kase, Scott Cosseboom, Nathaniel Westrick, and Anna Wallis for updates and a review of berry phenology and pest management. Presentations will be given on berry horticultural and pest management considerations for strawberries, blueberries, brambles, and minor fruit crops. Light refreshment & snacks will be provided. Registration is encouraged but there is no fee for attendance. 1.00 DEC credit will be available in categories 10, 1a, and 22
