Determination of Mineral Matter Changes in Leaves Taken at Different Times in Some Table Grape Varieties

The mineral composition of grapevines is of great importance for the healthy development of the plant and the production of high-quality fruit. Moreover, it is known that the mineral content enhances the vine's resistance to diseases and its tolerance to cold stress. In this study, the mineral content of the leaves of six different grape cultivars (Isabella (Vitis labrusca L.), Barış, Italia, Tekirdağ Çekirdeksizi, Trakya İlkeren, and Yalova İncisi (Vitis vinifera L.) was examined over a two-year period, with samples collected on June 15, July 15, and August 15. In this context, changes in the levels of nitrogen, potassium, phosphorus, calcium, magnesium, iron, zinc, manganese, copper, and sodium in leaf samples collected at different times were evaluated. The results revealed that the amounts of the examined macro- and micronutrients varied significantly depending on both the genotypes and the sampling dates. The findings of this study contribute to more effective nutrient management in viticulture, thereby supporting increased productivity and improved fruit quality.