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 m 3 , 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 m 3 of water were consumed, giving a productivity of 0.95 kg m 3 . The water-use efficiency was affected by the different types of soil in the irrigation perimeter.

Sorghum has become ever more prominent on the global energy scene, with studies in the area becoming extremely important. Agricultural production in the semi-arid region of the Brazilian Northeast is intrinsically dependent on rainfall in the region. However, on both inter-and intra-annual scales, the rainfall regime is quite irregular. The aim of this study was to evaluate the productivity of sorghum grown under a rainfed regime, and the water-use efficiency of crops in the semi-arid region of the northeast of Brazil. The work was carried out in the city of Tabuleiro do Norte in the semi-arid region of the State of Ceará. Mean productivity of the sorghum was 919.42 kg•ha •kg −1 was seen in lot 02. It was found that the low productivity of sorghum in a rainfed regime shows that the lack of success in production systems in semi-arid regions is not due to the total amount of rainfall, but rather the spatial and temporal distribution of the rains, as well as the occurrence of hot, dry spells. Furthermore, it can be seen that the best ratio of grain production to water demand shows a strong correlation with the distribution of water throughout the cycle, and not only with the total volume.