The Effects of Nitrogen Fertilization on Yield and Development in Alphonse Lavallée Grape (Vitis vinifera L.) Variety

This study was conducted in the Keçiborlu district of Isparta during the years 2021 and 2022 with the objective of ascertaining the effects of varying nitrogen (N) doses (0, 50, 100, 150, and 200 kg ha-1) on the morphological characteristics and yield of the Alphonse Lavallée grape variety. The study was designed as a randomized block design, with three replications. The following parameters were examined: shoot length, internode length, berry width, berry length, cluster width, cluster length, cluster weight, weight of 100 berries, and yield. The study revealed that N doses had a statistically significant impact on all the characteristics that were examined. The findings of the two-year research study demonstrated that the increase in N doses up to 100 and 150 kg ha-1 resulted in an increase in various agronomic characteristics. These include an increase in shoot length, internode length, berry width, berry length, cluster width, cluster length, cluster weight, 100-berry weight, and yield. At higher doses, the measured characteristics either remained constant or decreased. The maximum yield was achieved at a N dose of 100 kg ha-1 in both years. The findings of this study suggest that a N dose of 100 kg ha-1 is the optimal level, with higher doses showing no additional benefits.