engleski

Spur pruning of cv. Istrian Malvasia

Istrian Malvasia (Vitis vinifera L.) is an Istrian autochthonous white grapevine variety and the most widespread variety in the region of Istria, Croatia. Traditionally it has been head trained with one or two canes left during winter pruning, usually without renewal spurs. Different spur pruning techniques on cordon trained vines, grafted on two different rootstocks (Kober 5BB and 420A) were evaluated in this trial, in order to establish the performance of Istrian Malvasia under spur pruning. The trial was performed in 2006 and 2007 in a vineyard near Poreč, Istra, Croatia. Four different pruning techniques were used in this trial: one spur with two buds on each arm (8-1-2), two spurs with one bud on each arm (8-2-1), two spurs with two buds on each arm (8-2-2) and four spurs with one bud on each arm (8-4-1). All vines had eight arms, leading to 16 buds per vine left during winter pruning for pruning techniques (8-1-2) and (8-2-1), and 32 buds per vine for pruning techniques (8-2-2) and (8-4-1). Yield per vine, yield per hectare, number of clusters per vine and average cluster weight were measured as quantitative parameters and total soluble solids, titratable acidity and pH were measured as qualitative parameters. All pruning techniques produced satisfactory yields, ranged between 11.00 and 14.73 tons per hectare. Higher number of buds per vine led to higher yields, but the differences were not as high as expected. Vines with 32 buds left during winter pruning had the average yield per hectare only 2.21 tons (or 18%) higher than vines with 16 buds. Obtained results indicate that Istrian Malvasia is suitable for cordon trained spur pruning and this training system can be effectively used in order to produce satisfactory yields of good quality Istrian Malvasia grapes.

Istrian Malvasia; pruning; bud; yield; quality

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