Partial Rootzone Drying: Changing Alternation Frequency at Different Phenological Stages and Impact on Tomato Crop

摘要

The goal of the current work was to assess the effect of different alternation frequency applied at different phenological stages on physiological parameters of a Partial rootzone drying (PRD) irrigated tomato crop. Three treatments were applied. Besides the control irrigated at 100% of its water requirements, T3 and T4 are both treatments that received 50% of water requirements and that were irrigated by PRD strategy. Crop cycle was divided into three stages: S1 lasted from transplanting to 6thtruss flowering, S2: the period separating the 6thtruss flowering and the 2ndtruss harvest, S3: lasted for the remaining crop cycle period beginning at 2ndtruss harvest. While T4 was alternated every 10 days similarly, T3 was alternated every 14 days, 12 days and 10 days during S1, S2 and S3, respectively. T3 maximum daily shrinkage (MDS) was 70% higher than T4 showing that the later is more efficient than the former. As far as stomatal conductance (Cs) and leaf water potential (|·l), results show that both PRD treatments were affected b y stress without noticing any statistical differences in terms of those parameters. The control presented the highest Cs and |·l lev els d uring the whole crop cycle and the lowest water use efficiency (WUE).