Canonical correlation analysis applied to regulated deficit irrigation in ‘Tommy Atkins’ mango trees

Abstract

The objective was to identify the effect of regulated deficit irrigation on physiological, yield and root descriptors of ‘Tommy Atkins’ mango tree grown in a semi-arid region of Brazil. The work was carried out during two production cycles on an 11-year-old mango orchard. The design was randomized blocks with five treatments and six replications. Irrigation treatments were based on the trees’ development stage: T1, irrigation supplying 100% of the crop evapotranspiration (ETc) in three production stages: fruit set stage (SI), fruit expansion stage (SII), and physiological maturation stage of the fruits (SIII); T2, 50% ETc in SI and 100% ETc in SII and SIII; T3, 100% ETc in SI and SIII and 50% ETc in SII; T4, 100% ETc in SI and SII, and 50% ETc in SIII; and T5, without irrigation in all three stages. Physiological data were measured once per stage. After harvesting the second cycle, roots were collected, following a completely randomized design, with five treatments and three replications, to determine the total root length density. Total or partial water deficit in ‘Tommy Atkins’ mango trees was identified by decreasing transpiration (E) and photosynthesis (A) and increasing leaf temperature (Tleaf). The total root length density is similar in all irrigation strategies up to 1 m horizontal distance and 0.10 m depth. Water deficit applied in the physiological maturation stage improves yield and water use efficiency.