Effect of regulated deficit irrigation and partial rootzone drying on the quality of mango fruits (Mangifera indica L., cv. ‘Chok Anan’)

Mango is a crop of major economic importance in Thailand, produced during the dry season when irrigation is necessary to ensure stable yields of high quality. As local water resources are increasingly scarce, more efficient water usage in agriculture is important. Deficit irrigation has frequently been shown to increase water use efficiency of many agricultural crops. In this study, regulated deficit irrigation (RDI) and partial rootzone drying (PRD) were evaluated for their effect on yield and quality of ‘Chok Anan’ mango fruits over two seasons (2004 and 2005). A control group of trees was irrigated with 268.7 mm (2004) and 231.2 mm (2005), whereas RDI and PRD received only 137.5 and 131.2 mm in 2004 and 150.0 mm and 125.0 mm in 2005, respectively. One group of trees was not irrigated. On-tree development, harvest and post-harvest analyses were conducted. Results showed that yields were reduced in deficit irrigation treatments as compared to the fully irrigated control. However, development and post-harvest quality of fruits grown under deficit irrigation were not adversely influenced. Under PRD in particular, fruit size was increased and fruits had a higher fraction of edible parts as compared to all other treatments. In conclusion, in areas where water is a limiting factor for production PRD may be the key for a sustainable increase in mango production.