Tree Fruit Newsletter — June 21, 2023

Fruit thinners have finally taken effect. Where we applied chemical thinners in late May and early June, fruit became easy to remove around June 15. Additional fruit have since dropped.

Apple shoot with brown wilted leaves due to Fireblight infection
Fireblight infection of an apple shoot; photo by Renae Moran

If your Honeycrisp blocks have good fruit set, repeat bloom enhancement sprays should begin soon if this is part of your protocol for reducing the degree of biennial bearing. Three NAA products (PoMaxa®, Fruitone®, Refine®) or ethephon at a low dose applied every two weeks in summer will encourage the tree to form a few more additional flower clusters for next year. In orchard blocks with a light crop load, this practice is not recommended since it is expected that there will be too much bloom next spring. The New England Guide has more info

on repeat bloom enhancement: Return Bloom Enhancement | New England Tree Fruit Management Guide (

Growers have continued to report frost rings and pumpkin-shaped apples in orchards that had freeze damage. If you have crop insurance, this loss may be covered. Contact your insurance agent if you have any questions.

Fireblight has occurred in one orchard that had a history of the disease. A quick walk or drive through orchard blocks should be enough to find out if your trees have been infected. For those of you who find any, pruning them out now will reduce spread of the disease. To ensure that you get most or all of the infective bacteria, prune back about 12 inches into healthy branch sections. Here is a link to an article on some recent research on pruning out fireblight: Good to Know: Take a bite out of blight – Good Fruit Grower


Save the Date

July 19, 2023

9:00 a.m. to 4:00 p.m.

The Maine State Pomological Society along with Ricker Hill Orchards will be hosting the annual Summer Tour at the Vista of Maine in Greene ( This year the Society celebrates its 150th anniversary. One pesticide applicator recertification credit will be offered for attending the morning and afternoon sessions.

To RSVP, call Renae Moran at 207-713-7083 (or email at by July 12. Cost to attend the summer tour will be $30, but the Society will cover the registration for grower members in good standing, two from each membership. You may view the Summer Tour Agenda on the Upcoming Events page.


Renae Moran
University of Maine Cooperative Extension
(207) 933-2100

Where brand names or company names are used, it is for the reader’s information. No endorsement is implied nor is any discrimination intended against products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these producers assume all associated risks.

In complying with the letter and spirit of applicable laws and pursuing its own goals of diversity, the University of Maine System does not discriminate on the grounds of race, color, religion, sex, sexual orientation, transgender status, gender, gender identity or expression, ethnicity, national origin, citizenship status, familial status, ancestry, age, disability physical or mental, genetic information, or veterans or military status in employment, education, and all other programs and activities. The University provides reasonable accommodations to qualified individuals with disabilities upon request. The following person has been designated to handle inquiries regarding non-discrimination policies: Director of Equal Opportunity, 5703 Alumni Hall, University of Maine, Orono, ME 04469-5754, 207.581.1226, TTY 711 (Maine Relay System).