Effect of green pruning on the fruitfulness of winter buds, quantity and quality of yield in Cabernet Franc cultivar

F. Emurlova1*, A. Ivanov1

1Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 7 June 2022; accepted for publication 31 August 2023)

Abstract. A study was conducted to investigate the effect of bunch normalization and defoliation on winter eye fertility, quantity and yield quality in Cabernet Franc. It was found that the application of green pruning resulted in an increase in mass per bunch and per 100 grains, but a decrease in yield per vine. The sugar content increased slightly in the green pruned variants. In the two-year period of the study, high temperatures and low rainfall during the growing season reduced the effect of bunch rationing and defoliation on grape yield and quality. There was no significant difference in grape quality between the treatments under high temperatures. After the hot and dry year of 2021, lower values of the actual fertility indicators – percentage of fruiting shoots and fertility coefficient – were observed in 2022.