The Effect of Mechanical Harvesting on Yield, Quality of Fruit and Bush Damage of Highbush Blueberry1

Abstract

On 15 occasions, either Wolcott, Jersey, Morrow or Murphy cultivars of highbush blueberry (Vaccinium corymbosum L.) were harvested by commercial hand-pickers and over-the-row mechanical harvesters in eastern NC during 1970 and 1971. Compared with hand-harvesting, machine-harvesting reduced yield of marketable ripe fruit 19 to 44%. Compared with commercially hand-harvested fruit, machine-harvested fruit was 10 to 30% softer in compression tests; and when held for 7 days at 21°C, the fruit developed 11 to 41% more decay. Machine-harvested fruits sorted on a commercial cleaner were softened still more and developed 5 to 10% more decay than fruit mechanically harvested but not sorted. Fifty times as many canes were damaged by mechanical harvesting as by hand-harvesting.

Quality of ‘Tifblue’ Rabbiteye Blueberries and Efficiency of Machine Harvesting at Different Times of Day

“…Total cullage after mechanical harvest averaged 31%. This is similar to values reported by Mainland et al (7) for highbush blueberries. Our data do not include ripe, overripe, or green fruit lost on the ground from mechanical harvest.…”

“…Our data do not include ripe, overripe, or green fruit lost on the ground from mechanical harvest. For mechanically harvested fruit, ground losses ranged from 8 % on young, well-pruned plants (1) to 29% on mature plants (7). For commercially hand-harvested fruit, ground loss ranged from 2 % to 8 % (1, 7).…”

“…This would result in more cullage of unripe fruit in the first harvest date, but less overripe fruit at later harvest dates. Green fruit removal is one of the major causes of cullage by machine harvesting (7). Adjustment of shaker bar vibration frequency to accommodate turgor potential changes within a day may be necessary.…”

Rabbiteye Blueberry Storage Life and Fruit Quality in Controlled Atmospheres and Air Storage

“…Earlier reports (1,3,20,22) have shown that mechanical harvest reduces fruit firmness and storage life when blueberries are stored in air. In this study, quality, as indicated by marketable fruit, firm fruit, and sensory ratings of either hand-or machine-harvested rabbiteye blueberries stored in atmospheres containing 15% or 20% C 02 and 5% 0 2 were substantially better than quality of blueberries stored in air.…”

“…Blueberries were less firm and exhibited more postharvest decay when harvested by machine than when harvested by hand (1,3,20,22). The stem scar has been identified as the primary Received for publication 22 June 1987.…”