Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 9, 2002
Publication Date: March 1, 2003
Citation: PETERSON, D.L., TAKEDA, F. FEASIBILITY OF MECHANICALLY HARVESTING FRESH MARKET QUALITY EASTERN THORNLESS BLACKBERRY. APPLIED ENGINEERING IN AGRICULTURE. 2003. 19(1):25-30 Interpretive Summary: High harvest labor requirements and costs prevent expansion of fresh market quality blackberry production. An experimental mechanical harvesting system was developed and tested on an eastern thornless blackberry. Harvested fruit quality was disappointing. Plant and fruit characteristics were identified that should be considered by plant breeders to develop new cultivars that are compatible with mechanical harvesting.
Technical Abstract: A harvesting system was developed to determine the feasibility of mechanically harvesting fresh market quality eastern thornless blackberries. An over-the-row harvester utilized a direct-drive spiked-drum shaker for selective fruit removal and an energy-absorbing catching conveyor to collect the berries. The catching conveyor transferred the fruit to an inspection conveyor where five people graded the berries. A rotatable trellis training system was used to position the fruiting canes in a harvestable position. Blackberries were harvested on 2-day intervals. The packout of fresh market quality fruit ranged from 39 to 56% of harvested berries in the best treatment. However, only about 40% of the fresh market quality berries were being removed by the shaker. Hand sorters were unable to keep up with machine capacity. Factors to improve feasibility of machine harvesting were identified as; uniform fruiting canopy, cultivars that have significant differences in detachment force between mature firm berries and immature berries, and cultivars that retain higher fruit firmness in mature berries. Keywords. Mechanical harvester, Blackberry, Bramble, Trellis, Quality.