Field quantification of the water productivity of a peach orchard within an arid climate zone.

Irrigation management is the key to improving water productivity in fruit orchards growing under marginal conditions in dry areas where the water for irrigation is significantly decreasing. The aim of this work was to determine the yield response to variable water supply of an early maturing peach orchard and to assess the water productivity in an environment where the water is extremely scarce. Field experiments were carried out on peach trees for a private farm in south of Tunisia for two relevant period (2010/2011 and 2013/2015), in an area with sandy soil, hot summer and mild winter conditions.  Old trees were irrigated with different irrigation strategies 100%, 60%, 50%, 40% and 20% of the estimated ETc. In the first experimental period, Flordasar peach trees were subjected to DI40, DI60 and DI20 and gave a variable yields ranged between 23-30 Kg tree^-1. The highest WP values were obtained for DI60 et DI40, respectively 4.26 and 3.63 kg m^-3. However, experimental work in peach trees under DI50 with two irrigation strategies, average water productivity varied between 2.21-2.24 and 2.81-3.14 kg m^-3 respectively when yields was increased from 25.5 to 34.1 Kg tree^-1. The yield reductions under low to severe water defcits accompanied by gains in WP may be justifable in the light of anticipated water restriction.