IRRIGATION STRATEGIES WITH WATER DEFICIT IN ‘TOMMY ATKINS’ MANGO TREE

ABSTRACT With the limited availability of water in semi-arid regions, it is necessary that irrigation is accurate and there is high water use efficiency. This study aimed to evaluate the regulated deficit irrigation (RDI) and partial rootzone drying (PRD) in yield, water use efficiency and gas exchange of ‘Tommy Atkins’ mango tree in semi-arid conditions. The experimental design was a randomized block with seven treatments for RDI under micro sprinkler and five treatments for the PRD under drip. Treatments were applied in phases PI - early blooming to early fruit expansion, PII - early expansion to early physiologic ripening and in phase III - physiologic ripening of fruits, with application of the RDI of 100, 75 and 50 % of ETc in different combinations of phases and application of PRD 100, 80, 60 and 40 % of ETc in three phases with the partial rootzone druing at 15 days. Photosynthesis, carboxylation efficiency and quantum efficiency of photosynthesis are lower in PRD 40% ETc at 8 a.m. compared to full irrigation and PRD 80 % of ETc. Phases of expansion and fruit ripening are more appropriate for application of RDI with 50 % and 75% of ETc without loss to the crop yield of ‘Tommy Atkins’ mango tree and greater water use efficiency. The strategy of partial rootzone drying, PRD, every 15 days with 40 % of ETc, provides greater WUE