Optimizing irrigation and fertilization at various growth stages to improve mango yield, fruit quality and water-fertilizer use efficiency in xerothermic regions.

Mango (Mangifera indica L.) is one of the widely grown fruit crops and brings remarkable economic benefit in the xerothermic regions of southwest China. However, mango yield and quality can not be guaranteed due to the severe seasonal drought, low precipitation and extensive management of water and fertilizer. To investigate the effects of irrigation amount and fertilizer regime on mango yield, fruit quality, water use efficiency (WUE) and partial fertilizer productivity (PFP), an orthogonal experiment [L 9 (3)4] was conducted on mango under drip fertigation during 2018–2019. The four factors were irrigation amount (IA) and fertilization rate at the flowering (F Ⅰ), fruit expansion (F Ⅱ) and fruit ripening (F Ⅲ) growth stages. There were three irrigation amounts, i.e., full irrigation (FI: 100%ET c), mild deficit irrigation (DI M : 75%ET c) and severe deficit irrigation (DI S : 50%ET c), and three fertilization rates, i.e., 75 (F 75), 50 (F 50) and 25 (F 25) kg ha−1 using a compound water-soluble fertilizer (N:P 2 O 5 :K 2 O=20%:20%:20%). The results showed the order of factors influencing fruit yield and WUE in terms of their importance was IA, F Ⅱ , F Ⅰ and F Ⅲ , that influencing water, vitamin C and carotenoid contents in fruit was IA, F Ⅲ , F Ⅱ and F Ⅰ , and that influencing soluble solids and total sugar contents was IA, F Ⅲ , F Ⅰ and F Ⅱ. The WUE of DI M F Ⅰ50 F Ⅱ75 F Ⅲ25 was highest. FIF Ⅰ25 F Ⅱ75 F Ⅲ50 achieved the highest fruit yield, PFP and contents of soluble solid, vitamin C and carotenoid. DI M F Ⅰ25 F Ⅱ50 F Ⅲ75 had the highest total sugar content and the lowest titratable acid content. Based on the comprehensive scoring method, DI M F Ⅰ50 F Ⅱ75 F Ⅲ25 achieved the optimum score in terms of fruit yield and water–fertilizer use efficiency, while FIF Ⅰ25 F Ⅱ75 F Ⅲ50 was optimum for fruit quality. Further, the TOPSIS method indicated DI M F Ⅰ50 F Ⅱ75 F Ⅲ25 had the optimal comprehensive benefit. To obtain high yield, quality and water–fertilizer use efficiency, the recommended water and fertilizer scheduling was irrigation with 75% ET c and fertilization with 50, 75 and 25 kg ha−1 at the flowering, fruit expansion and fruit ripening stages, respectively. The research results provided a scientific reference for identified optimum combination irrigation and fertilizer in the xerothermic environment of southwest China. • Fruit yield, WUE, PFP and quality were more sensitive to irrigation than staged fertilization. • Increasing fertilizer allocation at fruit expansion stage, FI elevated fruit yield and PFP, while DI M increased WUE. • Improving fertilizer allocation at the later growth, FI increased SS, VC and CC, while DI M increased TS. • Optimal strategy of irrigation and split fertilization for mango was revealed. [ABSTRACT FROM AUTHOR]