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ARS Home » Southeast Area » Poplarville, Mississippi » Southern Horticultural Research Unit » Research » Publications at this Location » Publication #318310
Title: Evaluation of Blackberry Cultivars Adapted to the Southeastern United States for Susceptibility to Post-Harvest Fruit Diseases

Author
item Smith, Barbara
item Miller Butler, Melinda

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2015
Publication Date: 5/30/2016
Citation: Smith, B.J. and Miller-Butler, M. Evaluation of blackberry cultivars adapted to the southeastern United States for susceptibility to postharvest fruit diseases. Acta Hortic. 1133, 461-467. DOI: 10.17660/ActaHortic.2016.1133.70. http://dx.doi.org/10.17660/ActaHortic.2016.1133.70. 2016.

Interpretive Summary: Fruit rots cause extensive losses to blackberry farmers each year. These losses could be greatly reduced by the development of cultivars with increased resistance to pre- and post-harvest fruit rot. This research evaluated blackberry cultivars adapted to the southeastern United States for resistance to post-harvest fruit diseases and identified the pathogens causing these losses. Berry quality data were also collected to determine if there was a correlation between fruit rot disease severity and these quality parameters. Cultivars were also evaluated for their susceptibility to rosette. Disease and quality evaluation data from these five trials showed that berries from the cultivars ‘Ouachita’ and ‘Navaho’ consistently had the least post-harvest diseases, were the firmest, and had the highest soluble solid concentration. ‘Chickasaw’ and ‘Kiowa’ berries were the largest in all trials. Cultivars in these trials that were most resistant to post-harvest berry diseases also received high scores for quality parameters. The thorny cultivars in these trials were more susceptible to rosette disease than the thornless cultivars. This study identified cultivars with good post-harvest disease resistance and the results can be used by growers and extension agents selecting cultivars to plant and by plant breeders selecting parental lines for their breeding programs.

Technical Abstract: Pre- and post-harvest fruit rots, rosette, and other diseases are limiting factors of blackberry production in the southern USA. The development of cultivars with increased resistance to these diseases should result in reduced use of fungicides and greater profits for growers. Five to nine blackberry cultivars adapted to the southeastern USA were evaluated for susceptibility to post-harvest fruit diseases and quality in five trials. Fully ripe, blemish-free berries were incubated in the laboratory for four or five days and scored for Botrytis fruit rot, ripe rot, and other fruit diseases on a visual scale of 0 = no disease symptoms to 3 = severe symptoms. Botrytis fruit rot (gray mold) caused by Botrytis cinerea was the most common post-harvest disease identified in these trials while ripe rot caused by Colletotrichum spp. was also important. Across all the studies, ‘Navaho’, ‘Ouachita’, and ‘Chickasaw’ had the fewest berries with post-harvest disease symptoms, while ‘Shawnee’ and ‘Arapaho’ had the highest Botrytis scores. Cultivars with the lowest levels of post-harvest fruit diseases received good quality evaluations. Rosette disease occurred on the plants at one location, and disease severity was assessed on the cultivars in that trial. The erect, thorny cultivars, ‘Chickasaw’ ‘Shawnee’, and ‘Kiowa’, had significantly more rosettes per plant than the thornless cultivars, ‘Sweetie Pie’, ‘Navaho’, and ‘Apache’.