Managing McIntosh harvest is not for the faint of heart. The fruit is prone to drop but doesn’t get good color until the end of the season when nights get cold; growers often walk a fine line waiting to pick to maximize color but before a sudden drop.
That’s why Canadian growers are eager to try out Harvista, the pre-harvest formulation of ethylene-blocking 1-MCP from postharvest chemical manufacturer AgroFresh.
Although it’s been commercially available in the U.S. for several years, it was just registered in Canada for use on apples in time to manage this year’s harvest.
It has a different mode of action than other stop-drop products already on the market. Growers in the U.S. have used it for several years to manage harvest labor and improve fruit quality for some varieties.
“It’s really just a fabulous product for McIntosh specifically,” said Jennifer DeEll, a postharvest researcher for the Ontario Ministry of Agriculture, Food and Rural Affairs.
That’s because McIntosh fruit produce 10 to 20 times more ethylene than most apple varieties, which accelerates ripening and drop.
“It’s always a battle to get the red color. Being able to hold the fruit on the tree that much longer, they can get better red color, better grades, and reduce fruit loss to drop,” DeEll said.
Citing her own experiments with the product, she said Harvista gave trees about twice as much drop control as other products tested.
Cornell experiments have also found that Harvista delays drop in McIntosh about 20 days after predicted harvest, longer than its competitors.