THE EFFECT OF DIFFERENT ZINC LEVELS ON THE GROWTH OF GRAPEVINES

The effect of different zinc levels on the vegetative growth, photo sy nthetic activity, and Zn content of water-cultured Muscat d'Alexandrie , grafted onto 110 Richter and 140 Ruggeri, was investigated under gre enhouse conditions. Typical Zn deficiency symptoms, such as small leav es and disturbed apical dominance occurred at low Zn concentrations. A n increase in Zn concentration resulted in slight increases in fresh a nd dry mass. With rootstock 140 Ruggeri average leaf area and internod e length seemed to increase with an increase in Zn concentration. The photosynthetic activity generally increased with an increase in Zn con centration.