Harvest dates are earlier this year in Michigan, following the warm summer. Randy Beaudry of Michigan State University Extension in the Department of Horticulture says with warmer temperatures in the early part of harvest season, growers must monitor the temperature of fruit going into controlled atmosphere (CA) storage.
“Gala and other fruit harvested in the early days of fall are now going in warm, so extra attention needs to be paid to temperature monitoring. In terms of temperature prior to CA storage, we usually like to see the temperatures of the warmest fruit at about 45°F to 50°F, but lower temperatures are better to be sure. Temperature control is your No. 1 friend when it comes to preserving apple fruit quality.”
Beaudry says another reason growers should monitor fruit temperatures is that fruit going into storage with higher temperatures respire much faster than cooler fruit.
This leads “to a rapid build-up of COthe storage environment. In a room with a closed (not sealed) door, CO2 levels can reach 5% overnight! For CO2-sensitive varieties (e.g., ‘Honeycrisp,’ ‘Empire,’ ‘Jonathan,’ ‘McIntosh’), this can be disastrous,” he writes.
For Beaudry’s recommendations for cooling and treatment, visit the Michigan State University Extension website.