Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2005
Publication Date: 10/1/2006
Citation: Marshall, D.A., Spiers, J.M., Smith, B.J. 2006. Spring freeze damage to rabbiteye blueberry buds and berries. Acta Horticulturae. (ISHS) 715:101-104
Interpretive Summary: Susceptibility to spring freeze damage in rabbiteye blueberries depends on the stage of development of the bud or berry, but there are also cultivar differences. Flower buds were more resistant to freeze damage than young berries over the 11 cultivars rated and the stage of maturity of the bud or bloom was dependent on cultivar bloom time. Within maturity stages, the amount of resistance is dependent on the cultivar. This study indicates the need for regional testing since all of the freeze resistant cultivars except 'Austin' were released from North Carolina (the northern production range limit), and with the exception of 'Montgomery' the more susceptible cultivars were released from Georgia (the major southern area of production).
Technical Abstract: A spring freeze on March 31, 2003 with a low temperature of -1.9ºC provided an opportunity to evaluate freeze tolerance of 11 rabbiteye (Vaccinium ashei) blueberry cultivars over a range of bloom maturity. On April 4, three flower buds at bloom maturity stages of 4, 5, and 6 along with 3 small fruit ( < 4 mm) and 3 large fruit (> 5 mm - all still green) were tagged and labeled with stage of bloom and number of individual flowers present or number of fruit present. On April 25, flower bud, flowers, and fruit were rated for survival and viable flowers and fruit were counted. Rate of survival was calculated from the number of potential fruit present (flower buds and green fruit) and the number of fruit alive after freeze. Over all cultivars, flower buds, regardless of stage, had a higher survival rate than did fruit. There were differences between cultivars. 'Austin', 'Centurion', and 'Yadkin' had a greater freeze damage susceptibility to smaller fruit compared to larger fruit. The large fruit of 'Yadkin' and 'Centurion' had equal damage resistance as flower buds. Overall, 'Powderblue', 'Ira', 'Centurion' had the greatest freeze damage resistance while 'Climax', 'Montgomery', 'Tifblue', and 'Premier' were more susceptible to spring freeze damage