$300,000 Grant Targets Cold Storage Problems for Honeycrisp Apples

Honeycrisp apples are among the most highly profitable varieties for U.S. growers, with wholesale prices nearly triple that of others. But the cold temperatures needed to maintain freshness on the journey from harvest to a grocer’s display can injure the sensitive fruits, turning that crisp, snappy texture to brown mush.

Macarena Farcuh, assistant professor of plant sciences and extension specialist at the University of Maryland, is investigating new methods to help farmers overcome cold-sensitivity issues that can ruin up to 50% of a Honeycrisp crop during transportation and storage.

Farcuh received $300,000 from National Institute of Food and Agriculture’s Critical Agricultural Research and Extension program to study how the plant hormone ethylene affects ripening characteristics and cold sensitivity of Honeycrisp apples. Although harmless to humans, the gas ethylene is key to ripening in some fruit. Avocados and bananas emit ethylene after they’re picked, which is why putting them in a paper bag helps them to ripen, as the ethylene accumulates.

Farcuh will spray apple trees with different treatments that change the way the plants regulate ethylene to determine whether they can reduce the apples’ susceptibility to chilling damage, and delay ripening after harvest to allow for longer storage times.

Currently, farmers limit cold injuries in Honeycrisps by cooling harvested apples to an intermediate temperature before fully chilling them. This “pre-conditioning,” however, can cause “bitter pit,” in which brown pits form on the outside of the apple and reduce their desirability in the marketplace.

If Farcuh’s treatments resolve the cold injury quandary, farmers will be able to start using it right away, because part of the grant money will go toward University of Maryland Extension work to convey the team’s findings to farmers.