Damage by early autumn freeze varies with pecan cultivar

摘要

Pecan [Carya illinoinensis (Wangenh.) C. Koch.] trees were injured by freezing temperatures in Oct. 2000, occurring about 4 weeks before the average first freeze and 6 weeks before the normal killing freeze (less than or equal to -2 degreesC). Nonbearing and bearing cultivars were rated for injury at four sites the following May. Nonbearing cultivars with little or no damage included 'Caddo', 'Clark II', 'Giles', 'Kanza', and 'Peruque'. Those that had substantial damage included 'Maramec','Pawnee', 'Oconee', 'Shawnee', and 'OK642'. Bearing cultivars with little or no injury included 'Stuart', 'GraKing', 'Pawnee', 'Tejas', and 'Wichita'. The most severely damaged bearing cultivars were 'Gratex', 'Shoshoni', and 'Squirrel's Delight'.