Apple Maturity for Optimum Harvest Dates
Online newsletter
Fruit Pulse (Apple Maturity Assessments for the Mid-Atlantic)
Routine measurements of fruit starch levels, ground color and other maturity indices allow growers to make improved decisions about optimum harvest dates for long-term storage.
Learn more on routine measurements of fruit starch levels
Publications
From the Orchard to Cold Storage: A Closer Look at the Development of Nine Physiological Disorders in Apples (FS-2022-0640)
Carlos Corte, Candidate for B.S. in Biochemistry, and Macarena Farcuh, Ph.D., Assistant Professor and Extension Specialist
Physiological disorders are abnormalities within the different apple fruit tissues that lead to a loss of quality, marketability, and profitability, and therefore an increase in fruit loss and waste. Physiological disorders are not caused by pathogens or mechanical damage but can be a result of several factors, such as: genotype/genetic background (cultivar/strain), maturity at harvest time, orchard/preharvest factors, seasonal variations, and postharvest storage conditions. Different cultivars are more prone to developing certain disorders than others, e.g., Honeycrisp fruits are highly prone to bitter pit development. In the case of maturity at harvest, it is known that fruit that is harvested too early are more prone to developing bitter pit, while fruits that are harvested too late (overripe) are prone to developing chilling injury. Besides, late-ripening cultivars are more susceptible to disorders such as watercore. Preharvest factors such as tree fruit mineral nutrition, rootstock selection, or crop load, have all been shown to play a key role in the development of physiological disorders, as bitter pit has been shown to be exacerbated in Honeycrisp fruit with low calcium levels and larger sizes. Additionally, environmental variations such as high temperatures, increased precipitation or excessive sunlight exposure can all trigger physiological disorder development. Finally, postharvest storage conditions, e.g., humidity levels, temperature, gas concentrations, which are key in maintaining fruit quality during storage, can also increase susceptibility to physiological disorders. In this fact sheet we will take a closer look at nine physiological disorders that can develop in apples during postharvest storage, but can be triggered by the different factors described above. We will briefly discuss their symptoms, why and when do they develop, and how can they be prevented.
How Can Growers Determine Apple Fruit Maturity and Optimal Harvest Dates? (FS-1180)
Independent of the target market of your apples, estimating optimum harvest dates is critical not only for scheduling labor, but also to ensure a high-quality product. Author: Macarena Farcuh
Important Apple Cultivars in the Mid-Atlantic Region (EB-2023-0684)
Md Shipon Miah and Macarena Farcuh
Choosing the right apple cultivar is crucial when establishing an apple orchard; being well-informed and carefully selecting cultivars that align with your specific requirements and thrive in your environmental conditions are essential for your orchard's success.
Apple Red Skin Coloration: A Grower's Checklist (FS-2025-0753)
Matthew Trause, James Schupp, Ph.D., and Macarena Farcuh, Ph. D.
Red skin coloration is highly associated with apple fruit marketability and profitability. It is determined by the content and composition of anthocyanins. A multifaceted approach—considering environmental factors, site of establishment, cultivars, rootstocks, mineral nutrition, crop load, and fruit maturity —are key to meeting the required apple red skin coloration standards.
Controlling Bitter Pit in Apples: Best Practices for Growers (FS-2023-0701)
Talia Tracton and Macarena Farcuh
Bitter pit is a physiological disorder in apples that negatively impacts its marketability. It is linked to a calcium imbalance in fruit cells. A multifaceted approach—monitoring and balancing factors like plant nutrition, vigor, and chilling injury susceptibility—is key to avoiding the disorder.
Videos
Apple Maturity Assessments
Video Length: 5:54 | Date: September 19, 2023
Description: In this video, two graduate students at the #FarcuhLab, at @agnrmaryland demonstrate how to determine apple harvest maturity and optimal harvest dates by using different maturity indices, including changes in fruit background and surface color, fruit firmness, starch contents, and soluble solids contents. This is important as an individual maturity index cannot explain the true maturity status of an apple. These indices should be monitored at least 4 weeks before the anticipated commercial harvest. Happy harvesting!
The FarcuhLab has started a YouTube channel for you to subscribe and follow! Go to https://www.youtube.com/@FarcuhFruitLab
Organic Apple Production - A Beginner's Guide
Apples: Organic Production Guide
Publication by Tammy Hinman and Guy Ames, NCAT IP020 (published 2011), provides information on organic apple production from recent research and producer experience. Produced by the NCAT Sustainable Agriculture Project.
Apple Cultivars for the Retail Market
Video on apple cultivars that have characteristics suited for direct market retail operations. These include favorites customers are already familiar with, and some less familiar ones that have interesting flavors and appearances that will help you differentiate yourself at the market. This list contains apples that ripen throughout the harvest season, and while they may not all store well, their excellent flavor make them ideal for the farmers market or roadside stand. Published by Penn State Extension.
All About Apple Rootstocks (FS-2022-0638)
Sinead Claffey and Macarena Farcuh, Ph.D.
Rootstocks are a key element in the establishment of any commercial apple orchard. Apple trees are not grown on their own roots, but propagated on rootstocks that can impart important characteristics to the tree, improving the economics and profitability of growing apples. The number of rootstocks available commercially has been steadily increasing. As there is a not a one-size-fits-all rootstock, it is of vital importance to be informed, and select the rootstock that satisfies your needs and performs best under your soil and environmental conditions.
Bark Grafting Apple Trees
This video discusses how to bark graft a block of trees to quickly convert a portion of orchard. This project is supported in part by the Agriculture and Food Research Initiative of the National Institute of Food and Agriculture, Grant # 2015-70017-22852.
By Penn State Extension, Produced by Mike Basedow, James Schupp, Robert Crassweller, and Tara Baugher
Bench Grafting Apple Trees
This video discusses how to bench graft different varieties onto the rootstock of your choice. This project is supported in part by the Agriculture and Food Research Initiative of the National Institute of Food and Agriculture, Grant # 2015-70017-22852.
By Penn State Extension, Produced by Mike Basedow, Robert Crassweller, James Schupp, and Tara Baugher.
Fruit Production
Tree Fruit Production Guide
Web pages on Production & Harvesting, Cultivars & Rootstocks, Soil Fertility & Management, Pest & Diseases, Weed Management, Organic Production, Sustainable Agriculture, Personal Safety, and Business Management from Penn State Extension.
Learn More
Great Apples - MSU Extension
Information from Michigan State University Extension's fruit expertise team.
Insect IPM in Apples
Part of a series highlighting the latest breakthroughs in bio-rational pest control, this fact sheet looks at the use of kaolin clay as an integrated pest management strategy.
Orchard IPM
In this short video, you will learn some basic orchard scouting principles for a common disease – apple scab – and also mite pests and beneficials. From Penn State Extension.
Controlling Bitter Pit in Apples: Best Practices for Growers (FS-2023-0701)
By Talia Tracton and Macarena Farcuh
Bitter pit is a physiological disorder in apples that negatively impacts its marketability. It is linked to a calcium imbalance in fruit cells. A multifaceted approach—monitoring and balancing factors like plant nutrition, vigor, and chilling injury susceptibility—is key to avoiding the disorder.
Apple Orchard System Blueprint
A video discussion on how components relate to the management steps for pre-plant planting and tree care during the first season, second season, and early bearing years.
Developed by Penn State Extension, Produced by Tara Baugher, Senior Extension Educator, James Schupp, Professor of Pomology, Robert Crassweller, Professor of Tree Fruit, and Mike Basedow, Extension Assistant.
Educational Articles
- Fireblight Updates – 2024
Dr. Chris S. Walsh | Published Vegetable and Fruit News, Vol. 15, Issue 4 - Keeping CO₂ at bay: avoiding CO₂ injury in apples
Emily Johnson, M.S. Student in Plant Sciences and Macarena Farcuh, Ph.D. Assistant Professor and Extension Specialist University of Maryland, College Park | Published Vegetable and Fruit News, Vol. 15, Issue 7 - Preventing Senescent Scald: Key Strategies for Apple Growers
Jamie Flynn, B.S. Student in Biology, and Macarena Farcuh, Ph.D. Assistant Professor and Extension Specialist, University of Maryland, College Park | Vegetable and Fruit News, Vol. 16, Issue 2 - Climate Change in the Apple Orchard: Sunburn and Blight
Dr. Chris S. Walsh & Kathy Hunt | Published Vegetable and Fruit News, Vol. 15, Issue 7