Determining Bud Necrosis Rate and Distribution in Grapevine Cultivars Growing in Vineyards of Fars Province

This study was carried out to determine the distribution of bud necrosis in the vineyards of Fars Province, in a factorial experiment as completely randomized design (CRD). In fall and winter (during dormancy period) 30 canes of each cultivar with different diameters were harvested and the bud necrosis percentage was calculated on the basis of cutting sections (1 to 5, 6 to 10 and 11 to 15 nodes). Results indicated that percentage of the primary bud necrosis was different in 1-5 nodes depending on the cultivar and the region. ‘Siyah-e-Shiraz’ cultivar indicated the highest bud necrosis percentage (30.2%) in Saadat-Shahr region and the lowest percentage in Shiraz region (2.66%). The lowest percentage of bud necrosis was observed in ‘Askari’ and ‘Siyah-e-Shiraz’ cultivars (3.33%) in Doshman-Ziyari region and the highest percentage (20.66%) was in ‘Lorkosh’ cultivar. Also in most cultivars, a positive correlation was observed between vigor (according to cane diameter) and incidence of bud necrosis, although this correlation was negative with cane length.