|Authors: ||A. Salgado, J.R. Clark|
|Keywords: ||Rubus, postharvest disorders, marketability, shelf-life, breeding|
Postharvest quality and shelf-life of blackberries are critical traits for successful commercialization of new blackberry cultivars intended for long-distance shipping.
The University of Arkansas blackberry breeding program, begun in 1964, has released several cultivars with the aim to provide high-quality fruit to the fresh-market, shipping industry.
Since 2008, this program has intensively evaluated postharvest potential of 30-40 genotypes each season, including both standard cultivars and advanced selections.
Some of these breeding selection genotypes have been released, such as 'Natchez', 'Osage', and 'Prime-Ark® 45', following positive postharvest performance in annual evaluations.
The postharvest evaluation protocol used has included measurements or ratings of overall marketability, in addition to weight loss, decay, leakiness, color reversion, firmness, and glossiness after one week of storage at ~5°C. Since the use of the protocol became routine in the breeding program, some genotypes have shown potential postharvest storage potential beyond the 7-d storage time utilized.
This resulted in the initiation of postharvest evaluations being extended to 14 d during the 2013 and 2014 seasons for the most promising genotypes.
In 2013, nine genotypes were evaluated for two weeks and 14 in 2014. In both seasons all evaluated selections showed, after two weeks of storage, more than 50% marketability.
In 2013 only two selections had weight loss above 5%, and in 2014 all genotypes maintained weight loss under 5%. In both seasons, half of the genotypes had more than 30% of their fruits rated in category 1 of firmness scale (measured subjectively on scale from 1 to 5, 1=very firm). Color reversion, after two weeks of storage, ranged from 8.7 to 74.0% in 2013 and from 16.0 to 88.9% in 2014. In both seasons, leakiness was the variable that increased the greatest after 14 d of cold storage compared to 7 d of storage.
These findings are encouraging in that some selections are showing an increased postharvest storage potential for an extended period.
These will be evaluated more fully as parents or as potential cultivars for extended storage potential.
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