Petrolina and Juazeiro, formerly remote towns facing each other across the São Francisco river, deep in the dry backlands of north-eastern Brazil, have tripled their combined population in the past 30 years to about 600,000.

The reason is fruit, grown for the domestic and international markets on irrigated farms that were previously large, dusty landholdings. Since grapes and mangoes began to be produced and packed here, Petrolina has sprouted high-rise office blocks and boasts an airport.