The effect of foliar fertilizing on ecological optimization of the application of fungicides on the productivity and phenolic complex composition of grapes

¹ Chechen State University Grozny, Russian Federation
² All-Russian National Research Institute of Viticulture and Winemaking “Magarach”, 298600, 31 Kirov St., Yalta, Russian Federation

Abstract

One of the ways to reduce the pesticidal burden in mature ampelocenoses is the use of foliar bio-preparations of multifunctional action. We studied the influence of growth bioregulators “Albit” and “Mival-Agro” at reduced by 25–50% fungicidal load on productivity and phenolic complex composition (using the HPLC method) of Vitis vinifera “Asma” (Crimean autochthonous table cultivar), “Cabernet Sauvignon” and table grapes of complex genetic structure “Moldova”, grown in the mountain-valley seaside region of Crimea. It was established that bio-regulators increase the harvest of grapes, especially in the first and third years of treatment, depending on the preparation and grape cultivar, by 27–64% and 24–29%, respectively, as compared to control; the bunch weight increased by 134 ± 41%. The first two years of treatment enhance sugar accumulation in berries by 0.7–2.6 Brix. “Albit” preparation proved to be more effective as compared to “Mival-Agro”. The use of “Albit” on “Moldova” and “Cabernet Sauvignon” grapes increased components content in the berries by 19%–88% relative to control, depending on the cultivar and year of treatment, of which: anthocyanins – by 23–83%, stilbenes – by 24–138%. Regardless of treatment, the anthocyanin complex consisted by 75–87% of malvidin monoglucosides in “Cabernet Sauvignon” and “Asma”; 22–56% of malvidin monoglucosides and 21–62% of malvidin diglucoside in “Moldova”. The studied preparations had no significant impact on the quality of wines from “Cabernet Sauvignon”, however, they improved the quality of table grapes and their preservation capacity during storage.