As production of Honeycrisp increases, the apple industry will need to know how best to store the variety, Dr. Dana Faubion, former Washington State University Extension educator, points out.
Speaking at a fruit quality meeting in Yakima, Washington, last summer, Faubion said there are three postharvest problems associated with Honeycrisp: bitter pit, soft scald, and internal browning. To minimize those problems, the fruit should be harvested at the correct maturity and pickers should be trained to pick it based on the ground color, which changes from green to creamy yellow. The variety needs to be harvested at least three times, he said.
Faubion is now employed by AgroFresh, the company that sells SmartFresh (1-methylcyclopropene). During the meeting, he reported on tests he has done with various storage regimes. He found that applications of ReTain (aminoethoxyvinylglycine) before harvest had no impact in terms of reducing the ethylene production of the fruit in storage. SmartFresh treatments resulted in low acid levels in the fruit. Soluble solids levels were lower when the fruit was stored at 33°F than at 38°F.
He found that a delay in cooling—holding the fruit at 50°F for a week before putting it into storage—reduced soft scald and internal breakdown. The cooling should be done in a place with good air circulation, and Faubion said a breezeway might be better than a storage room.
Decay was unaffected by the delay, but was worse in the 38°F storage temperature than in 33°F. Bitter pit was increased by the delay in cooling. However, Faubion said he felt confident that as Honeycrisp plantings mature, bitter pit would be less of a problem. Faubion concluded from his trials that a good storage regime for Honeycrisp might involve holding the fruit for a week at 50°F with as much fresh air as possible, and then storing at a temperature of 33°F to maintain the acidity.
He did not see a need for MCP treatment or controlled atmosphere storage if the fruit would not be stored for more than four months.