EFFECTS OF FERTILIZATION AND IRRIGATION ON THE ELEMENTS OFYIELD OF THE WINE GRAPE VARIETY VRANAC

This work presents the three-year results of the effects of mineraland different types of organic fertilizers on the elements of the yield (the relativecoefficient of fertility, the absolute coefficient of fertility, cluster weight and theyield of grapes per area unit) of the Vranac variety of grape. The research wascarried out in Podgorica vineyard, at the location Lješkopolje. Eight differentvariants of nutrition were applied: (1) control (without fertilization); (2) NPK(8:16:24) - 500 kg/ha; (3) cow manure - 20 t/ha; (4) poultry manure - 10 t/ha; (5)peat - 10 t/ha; (6) cow manure + poultry manure - 10 + 5 t/ha; (7) cow manure +peat - 10 + 5 t/ha; (8) poultry manure + peat - 5 + 5 t/ha. All the variants ofnutrition were tested under irrigated and non-irrigated conditions. The resultsshowed that the relative coefficient of fertility in all the tested variants of nutritionhad high values. Regarding the number of inflorescences per productive shoot in athree-year average, a particularly good variant was the cow manure and the variantwith the combination of poultry manure and peat. The application of mineral anddifferent types of organic fertilizers had a positive effect on the average clusterweight. The variant with the combination of poultry manure and peat gave thehighest average cluster weight in the three-year average. All the tested variants ofnutrition in the three-year average had a higher yield than the variant withoutfertilization. The variant with cow manure had the highest yield of grapes.Irrigation had a positive effect on all the tested indicators of the yield.