Thinning of pome and stone fruits automatically may be nearing reality for producers as international research moves the procedures closer to commercial orchards.

“Feasible and cost effective thinning machines studied in recent years are being demonstrated,” said Belgium researcher Josse De Baerdemaeker.

Baerdemaeker spoke during the 12th International Conference on Precision Agriculture in Sacramento, Calif. in July.

Bud thinning is still mostly conducted through manual labor, comprising a large part of a grower’s costs, and machines still lack sufficient selectivity to take into account the specific fruit-bearing capacity of each tree, says Baerdemaeker of the Department of Biosystems at Katholieke University in Belgium.

“Current devices often damage shoots, leaves, and fruitlets which makes the trees more susceptible to diseases like fire blight and cankers,” he added.

But Baerdemaeker’s latest research is helping bring labor-free tree floral bud thinning nearer reality.

“We investigated a new non-contact way using pulses of compressed air in combination with a sensor capable of detecting floral bud distribution,” Baerdemaeker said.

“This way, the thinning efficiency can be improved by providing real-time information of floral bud distribution.”
His study focuses on early phonological stages (until bloom) of Conference variety pears, a cultivar with few chemical thinning alternatives.