2019 ASHS Annual Conference

As harvesting labor costs steadily rise, blueberry growers are increasingly using over-the-row (OTR) machines designed to pick berries for the processed market to harvest their crop for the fresh market. Postharvest evaluations have shown that harvesting blueberries with conventional OTR machines results in fruit with a shorter shelf-life, excessive internal damage and lower fruit firmness (g/mm) than hand-harvested blueberries. Much of the loss in fruit quality from OTR machines is from impact damage or fruit falling directly on the harvester’s hard surfaces, such as the plastic catch plates and conveyor belts. In 2018, OTR blueberry harvesters (Oxbo 7440 and 8040) with the Orbirotor® picking heads and modified fruit catching surfaces were used to harvest northern highbush blueberries in Oregon and Washington. The modifications included softer berry catch plates and soft intermediate fruit collecting surfaces over the conveyor belts. These changes to the catching surface alone resulted in fruit quality of machine-harvested ‘Duke’ and ‘Draper to be nearly like that of hand-harvested fruit in terms of firmness and bruising. Reducing the drop height in OTR machines with intermediate soft fruit catching surfaces and soft catch plates instead of letting detached blueberries drop directly onto hard plastic catch plates and conveyor belts improved fruit quality and pack-out percentage. The details of harvester modifications and trials and tribulations of field testing of blueberry harvesting systems will be discussed.