Yield and water use efficiency in 'Tommy Atkins' and 'Palmer' mango trees under localized irrigation with water deficit

Abstract

The increasing water demand of crops in response to climate change; the prospect of expanded irrigated areas; the population growth; and competition with multiple uses of water affect the availability of water resources for agriculture. Thus, measures are required that involve the adoption of irrigation-management strategies able to increase water savings without compromising crop yield, especially in semi-arid conditions, where water resources are limited, and in large-scale commercial cultivation such as in 'Tommy Atkins' and 'Palmer' mango, the second most widely grown irrigated fruit crop. The objective of this study was to examine the influence of irrigation systems (drip and micro-sprinkler) and deficit-irrigation strategies on the yield and water use efficiency (WUE) of 'Tommy Atkins' and 'Palmer' mango trees. The study was developed through two experiments conducted in the Irrigated Perimeter of Ceraíma, located in municipality of Guanambi - BA, Brazil. Two trials were carried out in a completely randomized design. For the 'Tommy Atkins' cultivar, 12 strategies were tested, involving regulated deficit irrigation (RDI) by micro-sprinkler irrigation and partial rootzone drying (PRD) by drip, in three production cycles. For ‘Palmer’ mango, 10 irrigation strategies were evaluated under the same previously described conditions, in only one production cycle. The reduction in water application in RDI was 25 and 50% of the crop evapotranspiration (ETc); and, in PRD, 20, 40 and 60% ETc. ‘Tommy Atkins’ mango achieved higher yields under micro-sprinkler irrigation with full irrigation and in the strategies involving the application of 50 and 75% ETc in stages II and III. These two strategies also provided greater WUE, along with PRD40. Water use efficiency was lower in the third evaluation cycle when compared with the first. ‘Palmer’ mango showed higher yields and WUE under drip irrigation, with the best yields achieved with full irrigation and in the strategies of PRD100, 80%, 60% and RDI with 50% ETc in stage III. The best WUE was obtained in PRD with 60 and 40% ETc.