Utjecaj djelomične defolijacije na kemijski sastav mošta i rodnost traminca mirisavog (Vitis vinifera L.) | Effect of partial defoliation on chemical composition of must and fecundity of Traminac mirisavi (Vitis vinifera L.)

Croatian. Poznato je da agrotehnički i ampelotehnički zahvati mogu značajno utjecati na rodnost, te kvalitativni sastav grožđa, mošta i vina. U cilju istraživanja utjecaja djelomične defolijacije na Traminac, tijekom tri godine praćen je sadržaj šećera, ukupne kiselosti, pH vrijednost, sadržaj vinske, jabučne i limunske kiseline u moštu te prosječna masa grozda kao i prosječan prinos po trsu. Djelomična defolijacija u vidu uklanjanja nula (ND), četiri (D1) i osam (D2) listova obavljena je ručno u trenutku šare grožđa. Uzorci su uzimani više puta tijekom perioda dozrijevanja grožđa do trenutka tehnološke zrelosti te u trenutku tehnološke zrelosti (berbe). Uočen je značajno niži sadržaj vinske kiseline u moštu kod varijanata defolijacije u sve tri godine istraživanja. Zamjetan je i utjecaj defolijacije na povećanje sadržaja šećera te na sniženje razine ukupne kiselosti i pH vrijednosti, ali samo u pojedinim godinama istraživanja. Djelomična defolijacija nije utjecala na promatrane parametre rodnosti.

English. It is known that agro technical and ampelotechnical measures can significantly affect fecundity, as well as qualitative content of grapes, must and wine. For the purpose of research of effect of partial defoliation on Traminac, a content of sugar, total acidity, pH value, content of wine, malic and citric acid in must, and average weight of grapes, as well as average crops per grape-vine have been observed during the period of three years. Partial defoliation in the form of removing zero (ND), four (D1) and eight (D2) leaves has been performed by hand at the moment of grape- flourish. Samples have been taken several times during the period of grape ripening until the time of technological ripeness, and in the time of technological ripeness (grape harvest). Significantly lower content of wine acid in must has been noticed with the variants of defoliation during all three years of research. The effect of defoliation on increasing the content of sugar and lowering the level of entire acidity and pH value has also been noticed, but only during certain years of research. Partial defoliation hasn’t affected the observed parameters of fecundity.