Pecan Bud Damage Caused by Freezing Temperatures During Spring 2009 was Affected by Cultivar

Abstract

Freezing temperatures on 7 April 2009 damaged developing pecan [ Carya illinoinensis(Wangenh.) C. Koch.] buds throughout most of Oklahoma. Bud injury was evaluated on several cultivars at an orchard in northeastern Oklahoma. Bud death varied among cultivars with the greatest rate of death in ‘Pawnee’, ‘OK642’, and ‘Mohawk’. The cultivars with the best bud survival were ‘Giles’, ‘Kanza’ and ‘Mount’. Within cultivars bud survival was closely related to the bud development stage. However, comparisons at the same bud development stage indicated that certain cultivars possessed greater cold tolerance. Thus cultivars avoiding damage had a later budbreak and/or developing tissue had greater freeze tolerance. Budbreak was delayed on branches that were vegetative the previous season compared to those that bore fruit, resulting in less bud injury on vegetative branches in some cultivars.