Development of Irrigation Program using Leaf Water Potential in Royal Table Grape Variety in the Mediterranean Region

This research was conducted over two consecutive years 2009-2010 in the cukurova conditions of turkey on royal table grape variety in order to determine the optimal timing of irrigation for high quality yield using mid-day leaf water potential values. in the study, six different treatments based on irrigation treatments; full irrigation (fi), soil water deficit in the 80 cm within the seven-day intervals was replenished to the field capacity; deficit irrigations, di_50; di_75; and partial root-zone drying prd_50 which received, respectively 50, 75 and a control treatment (non irrigated). .irrigation interval of 7-day used for all irrigated treatments experimental design is randomized blocks with three replications. in general, irrigation treatments had significant effect on yield at 1% level. the differences can be attributed to varying weather and soil water conditions occurred in the experimental years. highest yield was obtained from the full irrigation as 28.6 t ha^-1, and the lowest yield was obtained non-irrigated control treatment 12.5 t ha^-1. leaf water potential (lwp) were measured throughout the growing season with a pressure chamber. highest yields of royal table variety can be obtained when irrigated at lwp value ψ = -1.17 mpa. the results revealed that lwp can be used for irrigation scheduling of grapes.