The Late Spring Frost Hardiness of Some Apple Varieties at Various Stages of Flower Buds

Abstract

Abstract:In this study, survival rates of pistils of seven apple (Malus x domestica Borkh.) varieties at various stages from tight cluster to full bloom on trees were determined after frost that occurred on the morning at 3:00-8:00 of April 17, 2004 when the temperature dropped to -4 to -6 o C in the orchard. The survival rates of pistils of varieties ranged between 36.7 and 96.5% at tight cluster, 6.2 and 86.0 % at first pink and, 0.2 and 52.0 % at full pink stages after frost injury. 'Starkspur Golden Delicious' (18.0 %), 'Granny Smith' (33.0 %) and 'Canada Reinette' (36.7 %) were the least damaged apple varieties at various flower buds stages from tight cluster to first bloom on trees after frost. C'e düştüğü dondan sonra 7 elma (Malus x domestica Borkh.) çeşidinin açılmamış tomurcuk safhasından çiçek safhasına kadar farklı gelişme safhalarındaki çiçek tomurcuklarında dişi organların canlılık oranları belirlenmiştir. Dondan sonra dişi organlardaki canlılık oranları, açılmamış tomurcuklarda % 36.7 ve 96.5, pembe ucun göründüğü tomurcuklarda % 6.2 ve 86. 0, pembe tomurcuklarda ise % 0.2 ve 52.0 arasında değişmiştir. Açılmamış tomurcuk safhasından çiçek safhasına kadar farklı gelişme safhalarındaki çiçek tomurcuklarında 'Starkspur Golden Delicious' (% 18.0), 'Granny Smith' (% 33.0) ve 'Canada Reinette' (% 36.7) dondan sora en az zarar gören çeşitler olmuştur.Anahtar Kelimeler: Elma, Malus x domestica borkh., ilkbahar geç donları

Dormant carbohydrate reserves enhance pecan tree spring freeze tolerance: controlled environment observations

“…This study demonstrated branches at stage III early bloom, were the most severely damaged by all low temperatures compared to stage II and stage I samples. Freeze/frost injury is highly dependent on the phenological growth stage of the bud/flower ( Aygun and San, 2005 ; Hosseinpour et al., 2018 ). In pecans, freeze induced minimal harm to dormant or enlarged buds, but caused significant damage to buds during the leaf expansion ( Grauke and Pratt, 1992 ; Sparks, 1992 ; Farokhzad et al., 2018 ).…”

“…Low temperature tolerance varies among buds/flowers of different cultivars and species ( Hosseinpour et al., 2018 ). For example, the severity of springtime low temperature damage varies among genotypes/cultivars in almonds, apples, and sour cherry ( Aygun and San, 2005 ; Szpadzik et al., 2009 ; Imani et al., 2012 ).…”