A Comparison of the Effects of Cycocel and Tipping on Fruit Set in Vitis Vinifera L

Abstract

Rooted cuttings of V. vinifet'a cv. Cabernet Sauvignon were grown in nutrient culture solutions. When Cycocel [(2-chloroethyl)trimethylammonium chlorideJ was added to the nutrient solutions, plants retained 40% of their berries. Plants from which the shoot tip was removed at anthesis, either with or without Cycocel treat-ment, showed similar fruit set. Control plants retained only 20% of their berries. Percentage fruit set was inversely related to the rate of shoot elongation during the week following anthcsis. The results suggest that treatment with Cycocel and tipping increase fruit set by reducing competition between the developing leaves and ovaries for available metabolites.