The effects of leaf removal, cluster thinning and topping applications on yield and quality of Alphonse lavallée grape cultivar

This research was carried to determine to effects of applications of leaf removal, cluster thinning and topping in Alphonse Lavalèe cultivar. Leaf removal applications were carried out before flowering with taking leaves and side shoots under first flower, and in fruit set with taking leaves and side shoots under top cluster. Cluster thinning in ¼ rate was applied in before flowering and fruit set. Topping was applied at 20 cm and 40 cm above the last wire. The applications did not affect fresh grape yield and cluster number. Fresh grape yield and cluster number ranged between 21,5 and 27,5 kg/asma with 29,0 and 35,1 number/vine respectively. Topping did not affect cluster weight, while thinning increased cluster weight from 680g to 755g in vines removed leaves at before flowering. In addition, leaf removal at fruit set increased cluster weight when compared with that of leaf removal at before flowering. The applications did not affect on cluster width and length, cluster tightness, berry width and length. Berry weight increased from 9,35g to 9,59 g with thinning. The applications did not affect on L,a,b hue degree. Thinning increased croma value from 5,35 to 5,52 in vines removed leaves at fruit set. Topping at 40 cm compared with that of 20 cm at fruit set increased berry firmness. Topping at 40 cm compared with that of 20 cm increased total soluble solids from 14,3 to 15,5. The applications did not affect % acidity, ripeness index, antioxidant contents. Vines removed leaves at fruit set had more total phenol contents (91,6 mg GAE/100 g) than that of vines removed leaves at before flowering. Key Words: Leaf removal, cluster thinning, topping, grape, Vitis vinifera L, yield and quality.