Irrigation productivity and water-use efficiency in papaya crop under semi-arid conditions

Papaya (Carica papaya L.) has a great economic importance in tropical and subtropical countries, Brazil being one of the largest producers of papaya  in the world. This crop requires a considerable amount of water during its cycle, making proper irrigation management essential for optimal water use. Improving water-use efficiency can increase levels of agricultural production as well as the efficient use of water resources in semi-arid regions.The aim of this work was to evaluate productivity and water-use efficiency of irrigation inpapaya. The research was carried out in the Curupatiirrigation Perimeter, located in the semi-arid region of Brazil. The volume of water applied to the crop was quantified by calculating the number of operating hours of the pump unit supplying the irrigated lot, determining the flow rate of the emitters used in the irrigation system, and evaluating the soil moisture profile.The total volume of water applied was 2,663,296.20 m3, for a yield that ranged from 80 to 106 t ha-1. For water-use efficiency, it was found that for each kilogram of papaya produced, 1,042 m3 of water were consumed, giving a productivity of 0.95 kg m3. The water-use efficiency was affected by the different types of soil in the irrigation perimeter. Key words: Water-use efficiency, irrigation management, irrigated agriculture, production, Carica papaya L.