Evaluation of Blackberry Cultivars Adapted to the Southeastern United States for Rosette and Post-Harvest Fruit Diseases

Authors: Smith, Barbara; Miller Butler, Melinda

Submitted to: International Journal of Fruit Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/25/2015
Publication Date: 6/24/2015
Citation: 2015 Smith, B.J., Miller Butler, M.A. 2015. Evaluation of Blackberry Cultivars Adapted to the Southeastern United States for Rosette and Post-Harvest Fruit Diseases. Eleventh International Rubus Ribes Symposium Program, p. 29.

Interpretive Summary:

Technical Abstract: Rosette (caused by the fungus Cercosporella rubi) is considered a limiting factor of blackberry production in the southern U. S. Fruit rots annually cause extensive losses to blackberry farmers. The development of cultivars with increased resistance to rosette, fruit rot and other diseases should result in reduced use of fungicides and greater profits for growers. The susceptibility of blackberry cultivars to diseases was evaluated in a series of trials conducted in south Mississippi. In each trial 5 to 9 cultivars adapted to the southeastern U. S. were evaluated for foliar, cane, and post-harvest fruit diseases. Fruit quality data were also collected. Rosette severity was assessed in the spring, fruit diseases were scored 3 and 5 days after harvest, and foliar and cane diseases were assessed during the summer. Thorny cultivars, including ‘Kiowa’, ‘Shawnee’, and ‘Chickasaw’, had significantly more rosettes per plant than thornless cultivars, including ‘Sweetie Pie’, ‘Navaho’, and ‘Apache’. Gray mold caused by Botrytis cinerea was the most common post-harvest disease, and ripe rot caused by Colletotrichum spp. occurred less frequently. ‘Navaho’, ‘Ouachita’, and ‘Chickasaw’ had fewer berries with post-harvest disease symptoms than the other cultivars. ‘Shawnee’ and ‘Arapaho’ had the highest Botrytis scores.