Vegetative Growth Control of Six Grapevine Cultivars by Spray Application of (2-Chloroethyl)Phosphonic Acid (Ethephon)

Ethephon (2-chloroethyl) phosphonic acid arrested vegetative growth when applied to the upper third of growing grapevine (Vitis vinifera) shoots of six cultivars. Ethephon sprays (420 to 720 mg/L) were most effective when applied on freshly topped shoots. Ethephon treatments after fruit-set reduced vegetative growth considerably without inhibiting fruit growth and maturation, which was in many cases slightly enhanced. The effectiveness of ethephon on growth inhibition was dependent on the vigor of the vines. Ethephon sprays on topped shoots were suggested for reducing density in vigorous vineyards and allowing the development of a larger number of growing points with controlled growth increasing the fruiting capacity of the vines.