Influence of partial defoliation on the chemical composition of grapes of the 'Graševina' variety in conditions wine growing region Slavonski Brod

Defolijacija je jedan od zahvata zelene rezidbe u kojem se vrši prorjeđivanje ili potpuno uklanjanje lisne mase u zoni grožđa. Ako se djelomična defolijacija provodi u fenofazi cvatnje vinove loze smatra se ranom dok se defolijacija u fenofazi šare smatra kasnom defolijacijom. Međutim, vrijeme provođenja zahvata defolijacije se još uvijek aktivno istražuje. U ovome radu je bio cilj istražiti utjecaj djelomične defolijacije provedene u tri različite varijante (jedna varijanta predstavlja bazalnu defolijaciju u fenofazi zametanja boba, druga bazalnu početkom šare, te treća defolijaciju iznad zone grozda također početkom šare) na kemijski sastav grožđa sorte 'Graševina' u podregiji Slavonija. Defolijacija u vrijeme zametanja boba imala je najveći sadržaj šećera dok je defolijacija u fenofazi šare iznad zone grožđa imala najviše mase grozda, peteljkovine i boba, koncentraciju kiselina te smanjeni sadržaj šećera.Defoliation is one of the green pruning performations of thinning or complete removal of leaf mass in the grape zone. If partial defoliation is carried out in the grapevine flowering phase, it is considered as an early defoliation, while defoliation in the pattern phase is considered to be a late defoliation. However, the timing of defoliation is still being actively researched. The aim of this study was to investigate the influence of partial defoliation performed in three different variants (one variant represents basal defoliation in grape berries germination phenophase, another basal defoliation at the beginning of the pattern, and the third defoliation above the cluster zone also at the beginning of the pattern) on the chemical composition of Graševina variety in Slavonia. Defoliation at the time of grape berries germination had the highest sugar content, while defoliation in the phenophase of the pattern above the grape zone had the highest mass and acid concentration, while sugar content was reduced