RT Journal Article SR Electronic T1 Effect of Girdling on Leaf Gas Exchange, Water Status, and Non-structural Carbohydrates of Field-grown Vitis vinifera L. (cv. Flame Seedless) JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 49 OP 54 DO 10.5344/ajev.2000.51.1.49 VO 51 IS 1 A1 Larry E. Williams A1 William A. Retzlaff A1 Weigang Yang A1 Peter J. Biscay A1 Nona Ebisuda YR 2000 UL http://www.ajevonline.org/content/51/1/49.abstract AB Flame Seedless grapevines were girdled at fruit set to determine the effect of this practice on leaf net CO2 assimilation rate (A), carbohydrate partitioning, and water potential. The treatments consisted of vines that were trunk girdled, cordon girdled (one of a vine's cordons were girdled), the non-girdled cordon from vines of the previous treatment, and a non-girdled control vine. Girdling reduced midday A and stomatal conductance (gs) by approximately 50% for a period of four weeks after treatment imposition when compared to vines or cordons that were not girdled. Midday leaf water potential values were more negative for the two control treatments than those of the two girdled treatments during the same time period. Diurnal measurements of leaf non-structural carbohydrates did not differ among treatments. Both girdling treatments increased berry size compared to the controls. The data indicate that the reduction in gs due to girdling resulted in less leaf transpiration and, therefore, a more favorable vine water status (as measured by leaf water potential) for those vines. In addition the reduction in A after girdling was probably due to a reduction in gs and not to an accumulation of carbohydrates in the leaf.