2019 ASHS Annual Conference

Increasing labor costs and low worker availability challenge farms that grow highbush blueberry for the fresh market. Mechanizing harvest operations while maintaining fruit quality and harvest efficiency would greatly benefit the fresh market blueberry industry by reducing growers’ reliance on hand labor for harvesting. Over-the-row (OTR) harvesters are routinely used to harvest fruit for the processing market. However, current commercial OTR harvesters are not routinely used to harvest fresh market blueberry due to increased internal bruise damage of harvested fruit. In this study, a modified Oxbo 8040 OTR harvester with soft-catching surfaces designed to reduce bruising was studied in Oregon and Washington in 2018. Early-to-late season ‘Duke’, ‘Draper’, and ‘Liberty’ were harvested with the modified Oxbo 8040 and compared to standard OTR harvesters and hand harvest. Pack out, fruit firmness, internal bruise damage, and postharvest quality were evaluated. The modified Oxbo 8040 had fruit quality and pack out equal or comparable to hand harvested fruit and better than standard OTR harvested fruit. Higher fruit quality was generally maintained for 2-3 weeks with hand harvested fruit but not for machine harvested fruit. Pack out also varied by cultivar, with pack out being greater for ‘Duke’ and ‘Draper’ compared to ‘Liberty’. Ground speed and head speed of the harvester also impacted pack out and was cultivar dependent. Overall, harvest efficiency is improved using OTR harvesters and the soft-catching surfaces in the modified Oxbo 8040 reduced bruising and improved fruit quality compared to standard OTR harvesters. Pack out and fruit quality were cultivar and plant size dependent, indicating optimizing machine harvesting parameters for fresh market fruit will have to include these factors by the harvester operator.