The use of a freezing technique to determine the bud hardiness of twenty grape genotypes (Vitis sp.).

摘要

Pencil-thick canes from 20 grape cultivars (Vitis sp.) were harvested in October and November 2000 from Frelighsburg, Quebec, Canada. These cultivars had previously been classified as hardy (A), semi-hardy (B) or tender (C). Single-bud cane sections were placed in a refrigeration unit and subjected to sequential freezing temperatures (-7, -15, -22 and -30 degrees C) and held for 24 h at each temperature before being removed for evaluation. October samples had almost 100% bud kill from all cultivars at -22 degrees and colder. There was a marked separation among the 3 cultivar groups at -15 degrees C, with 46, 68 and 94% mortality for A, B and C, respectively. By the November sampling, most of the hardy cultivars (A) were relatively little affected at -22 degrees C, whereas groups B and C suffered 25 and 83% mortality, respectively. In spite of this, considerable hardiness had been gained with the extra month exposed to the natural elements.