Updated: May 22, 2023
Russet on Apples: Current Understanding and Management
Russet on apples is a disorder of the skin that results in discoloration and changes to the ex-pected smooth texture of the skin of apples. Russet appears as a spectrum from mild brown weblike pat-terns to severe rough changes on the surface of ap-ples and many variations in between (Fig. 1). Rus-seting is only skin deep and thus will not affect the flesh of the fruit. It can occur due to naturally-occurring weather conditions, particularly humid and wet weather.
Updated: April 12, 2023
Managing Apple Growing Conditions to Prevent Fruit Cracking
Fruit cracking is a phenomenon that strongly limits fruit quality and yields, decreasing fruit marketability and grower profitability. Fruit cracking starts with microcracks in the skin. The skin acts as a protective layer covering the flesh, and consists of a cuticle made of cutin and wax.
Updated: November 2, 2022
Spots on Honeycrisp Apples: What are They and How to Differentiate Them?
Spots on Honeycrisp Apples: What are They and How to Differentiate Them? Authors: Zarah Ahmed, Candidate for B.S. in Physiology and Neurobiology, and Macarena Farcuh, Ph.D., Assistant Professor, and Extension Specialist, University of Maryland, College Park
Updated: October 12, 2022
From the Orchard to Cold Storage: A Closer Look at the Development of Nine Physiological Disorders in Apples (FS-2022-0640)
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. Authors: Carlos Corte, Candidate for B.S. in Biochemistry, and Macarena Farcuh, Ph.D., Assistant Professor and Extension Specialist; Title: From the Orchard to Cold Storage: A Closer Look at the Development of Nine Physiological Disorders in Apples (FS-2022-0640)
Updated: October 5, 2022
All About Apple Rootstocks (FS-2022-0638)
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. Authors: Sinead Claffey and Macarena Farcuh, Ph.D.; Title: All About Apple Rootstocks (FS-2022-0638)
Updated: September 20, 2022
Vegetable and Fruit News-September 2022
Vegetable and Fruit News, Volume 13, Issue 6 (September 2022). Topics in this issue are: Spots on Honeycrisp Apples, Early Insect Scouting, Bacterial Canker of Tomato, Stinkbug Damage on Tomato, Precautions for Grower during a Boil Water Advisory, Fungicide Resistance in Botrytis, Sweet Potato Harvest Curing & Storage, and upcoming events and grants.