2019 ASHS Annual Conference

Modified over the row (OTR) mechanical harvesters (Oxbo 7440 and 8040) were used to harvest early to late season blueberries (‘Duke’, ‘Draper’, and ‘Aurora’) for the fresh market in the Pacific Northwest in 2017 and 2018. Fruit were sorted on packing lines and stored up to four weeks in commercial coolers. Fruit firmness, internal bruising damage (IBD), Brix, and acidity of machine-harvested fruit were compared to handpicked fruit. No difference in fruit acidity was observed between machine and hand harvested fruit after packing. Although the firmness of machine-harvested fruit was generally acceptable for fresh market, fruit firmness decreased more in cold storage than handpicked fruits. The correlations between fruit firmness and IBD of various cultivars after packing and during storage failed to show consistency. Such inconsistencies in packed fruit appeared to be caused by the location of IBD, while firmness measurements by FirmTech were always taken at the fruit equator. Near-infrared hyperspectral imaging (HSI) can locate IBD. FirmTech measurements at 0, 90⁰ and 180⁰ from the IBD location produced different firmness readings on the same berry depending on the size of IBD. HSI also found many fruits with moderate to extensive IBD in fresh packed clamshells. The data suggest that HSI has great potential to better sort blueberries for fresh market by eliminating fruits with moderate to severe IBD.