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United States Department of Agriculture

Agricultural Research Service

Title: Fruit Firmness and Holding Abilty in Highbush Blueberry-Implications for Mechanical Harvesting

Author
item Ehlenfeldt, Mark

Submitted to: Small Fruit Reviews
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 16, 2001
Publication Date: N/A

Interpretive Summary: Fruit firmness plays a critical role in the ability of blueberry cultivars to be machine harvested. Cultivars with firmer fruit and superior holding ability will machine harvest better and retain quality better during subsequent handling and shipping. A survey of fruit firmness in a large group of highbush cultivars and southern highbush cultivars with varying percentages of wild species ancestry found an approximately 2.4-fold difference between the softest and the firmest selections. Many of the firmest selections were newer cultivars with some V. darrowi ancestry. Cultivars also differ in their ability to retain quality once ripeness has been achieved. In preliminary studies, Legacy appeared best at retaining firmness, but several other cultivars retain good quality by merit of having very high initial firmness values. The ability to retain quality presents growers with more harvest options, in that, it might allow greater percentages of ripe fruit to accumulate before harvesting, thereby minimizing harvest expenses. Initial studies, indicate that there are trade-offs between harvest frequency and yield. Experiments that delayed harvest until the total fruit load was 75 to 80% ripe decreased yield on average from about 65 to 70%. This information will be of value to researchers, growers, and extension personnel interested in machine harvesting and fruit firmness.

Technical Abstract: Fruit firmness plays a critical role in the ability of blueberry cultivars to be machine harvested. We recently completed a survey of initial fruit firmness in a large group of highbush cultivars and southern highbush cultivars with varying percentages of V. corymbosum L., V. angustifolium Ait., V. ashei Reade, V. darrowi Camp ancestry. The cultivars exhibited an approximately 2.4-fold difference between the softest and the firmest selections. Many of the firmest selections were newer cultivars with some V. darrowi ancestry. Cultivars also differ in their ability to retain quality once ripeness has been achieved. In preliminary studies,Legacy appeared best at retaining firmness, but several other cultivars retain good quality by merit of having very high initial firmness values. The ability to retain quality presents growers with more harvest options, in that, it might allow greater percentages of ripe fruit to accumulate before harvesting, thereby minimizing harvest expenses. Initial studies, however, indicate that there are trade-offs between harvest frequency and yield. Experiments that delayed harvest until the total fruit load was 75 to 80% ripe decreased yield on average from about 65 to 70%.

Last Modified: 8/1/2014
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