The Beneficial Effects of Biofertilizers for `Red Roomy' Grapevines (Vitis vinifera L.): 2. The Effect of Berry Set, Yield, and Quality of Berries

The positive influence of fertilizing `Red Roomy' grapevines with four biofertilizers (active dry yeast, phosphorene, rhizobacterium, and nitrobein) on berry set and productivity was investigated during 1995 and 1996. The improvement occurred in berry set and yield, as well as physical and chemical properties in vines treated with the four biofertilizers in the following ascending order: active dry yeast, nitrobein, rhizobacterium, and phosphorene. Highly significant differences in characters were observed between treated and untreated vines. The best results with regard to yield and quality of berries was obtained in `Red Roomy' vines biofertilized with phosphorene or rhizobacterium.