The 2021 Honeycrisp Playbook: Early Foliar Calcium
Dan Donahue, Tree Fruit Specialist
Eastern New York Commercial Horticulture
Early is where it's at: Individual Honeycrisp fruits analyzed for mineral content around the end of the cell division period of fruit development (+40 mm) have been found to be highly variable in mineral content, particularly calcium. Four years of research results in the Hudson Valley show that early season fruit calcium content can vary as much as 4.2X from a low Ca fruit to a high Ca fruit (figure 1). These finding suggest that our calcium troubles start early in the growing season and therefore should be addressed early as well. The calcium cation is not very mobile with plant tissue and doesn't move from cells with a surplus to cells in deficit. Calcium cations need to be available for cell walls and membranes locally, and when needed. Too far away and/or too late is of little help. Since calcium plays a role within the plant in hormonal signaling, the cations cannot remain "free" within cell cytoplasm or within the spaces between cells and cell walls. Free calcium cations that are not incorporated promptly into cell membranes, cell walls, and endoplasmic reticulum are quickly deactivated and made unavailable through sequestration within cell vacuoles.
Early Foliar Calcium (pdf; 226KB)

Upcoming Events
Ag Labor Road Show IX
December 1, 2025 : Save the Date! - Ag Labor Roadshow Webinar 1
In addition to the in-person Ag Labor Roadshow program in our region on December 9, two webinars are scheduled for December 1 and December 22. Each webinar will focus on different program content that is different from the in-person sessions. These webinars are an added benefit to program registration.
December 9, 2025 : Save the Date - Ag Labor Road Show In-Person Event (Greenwich, NY)
Greenwich, NY
The Roadshow delivers essential updates on labor law, regulations, and workforce best practices—tailored for farm owners, managers, and ag service providers. Sessions also focus on practical strategies to boost communication, strengthen retention, and build a positive workplace culture.
The in-person session for Eastern NY is December 9 - Elks Lodge, Greenwich, NY - full day in person session
Additional in-person sessions are:
December 10 - Hilton Garden Inn, Watertown, NY, December 17 - Cornell AgriTech, Geneva, NY, December 18 - Genesee Community College, Batavia, NY
December 22, 2025 : Save the Date! - Ag Labor Roadshow Webinar 2
In addition to the in-person Ag Labor Roadshow program in our region on December 9, two webinars are scheduled for December 1 and December 22. Each webinar will focus on different program content that is different from the in-person sessions. These webinars are an added benefit to program registration.
How to Obtain a Pesticide Applicator License
December 17, 2025
Thinking about becoming a certified pesticide applicator in New York, but aren't sure where to start? Join DEC representative Kenneth Klubek for a discussion on who needs to become a certified pesticide applicator, certification types, examination procedures, and recertification. Participants will have ample opportunity to ask questions during the program.
2026 Winter Cut Flower Webinar Series
January 6, 2026 : Session 1: Cut Flower Cost Calculator Updates and Woody Cuts
Session 1: Cut Flower Cost Calculator Updates and Woody Cuts
January 13, 2026 : Session 2: Perennials and Industry Trends
Session 2: Perennials and Industry Trends
January 20, 2026 : Session 3: Anaerobic Soil Disinfestation and Biochar
Session 3: Anaerobic Soil Disinfestation and Biochar
January 27, 2026 : Session 4: Beneficial Insects and Propagation Techniques
Session 4: Beneficial Insects and Propagation Techniques
February 3, 2026 : Session 5: Fungal and Insect Pests and Market Trends
Session 5: Fungal and Insect Pests and Market Trends
