|Authors: ||A.F. Brighenti, R. Cipriani, L.I. Malinovski, G. Vanderlinde, R. Allebrandt, N.P. Feldberg, A.L. Silva|
|Keywords: ||yield, bud load, Vitis vinifera L., Guyot, Vara Sobreposta|
Among the various cultural operations in grapes, pruning has the maximum influence on the ultimate yield and quality of a cultivar.
The degree of berry quality depends on the precision of the pruning operation.
The pruning requirement of different cultivars differs as per their growth behaviour.
The objective of this study was to determine the effect of two pruning methods in the ecophysiology of the Italian cultivars 'Verdicchio', 'Nebbiolo' and 'Rebo'. The experiment was conducted in Água Doce, Santa Catarina State, Brazil, at Villaggio Grando winery (26°43'92”S, 51°30'72”W, altitude 1,350 m). The pruning methods used were Guyot and Vara Sobreposta.
Guyot is a cane-pruned method with spurs.
The cane buds grow into shoots that produce the yield in the following season and the spur buds produce shoots that can be used as canes the following year.
With the Vara Sobreposta method, the plants are pruned in spur cordon, and the spurs are left two to four canes with four to six buds, where each cane is overlapped on the spurs.
The variables analysed were production indices, grapes chemical quality and leaves gas exchange.
The results showed that all cultivars pruned in Vara Sobreposta have a higher number of buds after pruning, sprouted buds and cluster number.
Vara Sobreposta also increases the yield of 'Verdicchio' and 'Nebbiolo', and increases anthocyanins and polyphenols contents of 'Rebo'. Guyot increases total soluble solids contents in 'Rebo' and polyphenols in 'Nebbiolo'. Only 'Verdicchio' was influenced by pruning in titratable acidity contents.
The pH was not influenced by the pruning method adopted.
By increasing photosynthetic photon flux density, 'Verdicchio' increases CO2 assimilation when pruned in Vara Sobreposta.
All cultivars have a tendency to absorb more CO2 into individual leaves when pruned with the Vara Sobreposta method.
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