Economic analysis of navel orange cv. ‘Lane late’ grown on two different drought-tolerant rootstocks under deficit irrigation in South-eastern Spain

During a three-year period, we evaluated the profitability of a deficit-irrigation (DI) treatment in mature ‘Lane late’ navel orange (Citrus sinensis (L.) Osb.) trees grafted on two different drought-tolerant rootstocks, ‘Cleopatra’ mandarin (Citrus reshni Hort. ex Tanaka) and ‘Carrizo’ citrange (C. sinensis (L.) Osb. × Poncirus trifoliata L. Raf.). The irrigation strategies for each rootstock were a control treatment, irrigated at 100% crop evapotranspiration (ETc) during the entire season, and a DI, irrigated at 100% ETc except during phase I (fruit set) and phase III (fruit maturation) of fruit growth, when complete irrigation cut-off was applied. The main difference found was between rootstocks, orchards of ‘Carrizo’ being 39% more profitable than those of ‘Cleopatra’ due to the greater yield and fruit size and higher price (0.02 € kg⁻¹) for trees on ‘Carrizo’. The application of the DI treatment increased the profit for ‘Carrizo’ since the decrease in pruning costs was greater than the reduction of incomes. The profit of ‘Cleopatra’ under DI decreased due to yield reduction. The variable and fixed operating costs during the growth cycle were decreased by the DI treatment, with a reduction of fertiliser (40%), water applied (30%) and electricity consumed (30%) compared with the control. In addition, in ‘Carrizo’, DI decreased the pruning (16%), machinery (11%) and phytosanitary products (9%) costs as a result of the reduction of the canopy growth. From these results, we conclude that, with similar crop management, orchards of ‘Lane late’ navel orange on ‘Carrizo’ rootstock were more profitable than those on ‘Cleopatra’ under deficit-irrigation conditions.