The effect of foliar application at different doses of salicylic acid on yield and quality characteristics of spil karasi and ece grape varieties (vitis vinifera L.)

Salicylic acid maintains its importance as a plant growth regulator that plays an important role in plant growth and development and also supports plant defense mechanisms against stress conditions. This study aimed to determine the effects of salicylic acid applied at different doses (0, 50, 100, 200 and 400 mg L-1) on yield, quality and some ecophysical properties in Spil Karası and Ece table grape varieties (Vitis vinifera L.). Salicylic acid was applied twice from the leaves, the beginning of veraison (June 15) and during veraison (June 22). The applications did not cause significant difference in traits other than cluster width in Spil Karası. In Ece grape variety, in 100 mg L-1 and 200 mg L-1 applications, it was concluded that grape yield (9210 and 9088 g vine-1, respectively), cluster weight (383.8 g and 378.7 g, respectively) and cluster length and size increased. It was determined that the effects of the applications on berry properties were not significant in both varieties. In the study, berry removal force was significant in Ece grape variety and the highest value was measured in the control (650.3 g) application. In terms of must properties, the highest total soluble solids value (15.87%) in Ece grape variety was obtained from 50 mg L-1 and 400 mg L-1 applications, while no significant difference was found in Spil Karası in this respect. The highest maturity index values were calculated at 50 mg L-1 (33.89) in Spil Karası and 50 and 100 mg L-1 (30.98 and 31.34, respectively) in Ece variety. Statistical differences in ecophysical properties were observed in Ece variety in terms of leaf relative water content, the highest value was measured in 100 mg L-1, control and 200 mg L-1 applications (86.66%, 87.49% and 88.91%, respectively). As a result, the findings obtained showed that there is a potential to contribute to developing new strategies for more effective use of salicylic acid in viticulture. In this context, it was concluded that studies on the subject should be continued in line with the goals of sustainable agriculture and quality grape production. Keywords: Grapevine, biostimulant, ecophysiology, salicylic acid, stress