The objective of the work was to assess the effects of partial rootzone drying (PRD) strategy‘s alternation frequency on some agronomic responses of a tomato crop cultivated in greenhouse and on a sandy substrate. Three treatments were applied: a control and two PRD treatments. The control (T0) received 100% of water requirements while T3 and T4 were irrigated at 50% of water requirements. Those two treatments were alternated at 20% and 40% of dry side water storage depletion, respectively. The control registered the highest yield but the lowest water use efficiency while T4 produced 15% more than T3. Compared to the control, PRD treatment leaf area was decreased and T4 had 27% higher leaf area than T3. Biomass production reached its higher levels for T3 and root biomass accumulation is greater than stem, leaf and fruits. Total soluble solid concentration and acidity of T3 fruits was 25% as higher as T4 and the control.
