THE INFLUENCE OF MYCORRIZAL FUNGI INOCULATION ON THE GRAŠEVINA (Vitis vinifera L.) GRAPEVINE CULTIVAR’S PLANT NUTRIENT SUPPLY

The aim of the study was to determine the effect of a live mycorrhizal vaccine on the dynamics of grapevine’s plant nutrient supply. The experiment was performed on the Graševina variety (Vitis vinifera L.), grafted on an SO4 rootstock in the conditions of the Kutjevo Vineyards. The training system was Guyot, with a 10‐bud load. In the root system’s immediate vicinity, 20 ml of mycorrhizal suspension containing approximately 2,000 propagation units of a live mycorrhizal mycelium were inoculated. From the viticultural aspect, the research was conducted in two climatically very different years. The first research year (2014) was characterized by an abundant precipitation and less sunny days, resulting in a later technological grape maturity, amounting to 34 days when compared to the year 2015, which was extraordinarily warm and arid during the grape ripening period. In both research years, in the conditions of the soil’s low supply with the organic matter, phosphorus, and potassium, a mycorrhizal symbiosis influenced the higher content of phosphorus and potassium in the Graševina’s dry leaf matter. In a year experiencing more precipitation and less heat, a higher nitrogen content was found in the vine leaves manifesting a mycorrhizal symbiosis. In the dry and warm conditions, the calcium content was increased during the entire period of grape ripening, and a justifiably higher content of zinc, manganese, and iron was found in the period immediately preceding a technological grape ripeness. A positive influence of mycorrhiza on the yield, sugar content, and total acidity was not determined.