Effect of Harvesting Time on Berry Losses During Mechanical Harvesting of Wild Blueberries

Abstract

More than 90% of the total wild blueberry crop area in Canada is mechanically harvested. Only fields in rough terrain are still hand raked. Prior to this study, there were no identified protocols related to fruit maturity and time of harvest that could be used to minimize fruit losses and/or improve berry quality during harvesting. In this study, wild blueberry fields were selected in the Atlantic Provinces to examine the impact of different harvest times on the berry picking efficiency of a wild blueberry harvester. The results revealed that fruit losses of 17%, 21% and 23% were observed in early, middle and late season harvesting, respectively. The results also showed that higher ground speed in concomitance with higher header rpm resulted in substantially increased fruit losses in each harvesting season. These losses became more significant in late season due to the presence of over-ripened berries. Results of physico-chemical composition of wild blueberries suggested that total soluble solids and anthocyanin contents increased gradually from early to late season and the highest increase in total soluble solids were observed in middle season, while most pigment accumulation in blueberries took place in early and middle season. A significant decrease in acidity and an increase in TSS:TA were noticed in middle and late season harvesting. The maximum gain in moisture content, expansion in diameter and increase in weight were observed in middle season harvesting, while reduction in moisture, shrinkage of berries and loss of weight occurred in late season. This information would help the wild blueberry producers to develop a timely harvest plan and adjust machine parameters appropriately to reduce fruit loss during mechanical harvesting.