Response of the grapevine cv. Merlot to five times of cleft grafting

Abstract

A study was carried out to compare five times of cleft grafting on Berlandieri x Riparia SO4 rootstock. Delaying grafting from July 10 to August 19, 1979, there was a linear increase in percentage of final success and a linear decrease in sprout growth duration. No differences were observed in relation to sprout length and girth, and number of leaves per vine. The results suggest, considering the occurence of frost damage, a superior success by delaying the grafting operation until near the begining of growth season. However, influences on sprout growth and vigour were not observed.