Performace dos aspectos agronômicos e econômicos do meloeiro sob diferentes manejos de irrigação

Abstract

Irrigation management is essential for the rational use of water, especially in arid and semi-arid environments. Moreover, irrigation management often aims solely at maximizing yield, neglecting economic aspects. This research aimed to evaluate the agronomic and economic performance of the melon production system under different irrigation management practices. The experiment was conducted in the Baixo Acaraú Irrigation Project – CE, using fertigation through drip irrigation. The experimental design was randomized blocks with five treatments and four replications, consisting of five irrigation management strategies. Managements M1, M2, M3, and M4 used the Ômega irrigation management system with different input parameters: M1: daily evaporation from a Class "A" pan with a tank coefficient (kt) of 1.0; M2: daily evaporation from a Class "A" pan with kt = 0.75; M3: daily evaporation from a Class "A" pan with kt adjusted by relative humidity, average wind speed, and tank border; M4: reference evapotranspiration (ETo) estimated by Hargreaves and Samani; and M5 followed the farmer's traditional irrigation method, adjusting water depth according to the crop’s phenological stages. Total water depth, agronomic and production characteristics of the melon crop, and economic analysis of each system were evaluated. Significant differences were observed in water depths applied among the different management strategies, but there were no significant differences in agronomic and yield characteristics. Results, through irrigation water productivity, indicate the importance of farmers adopting technical irrigation practices for rational water use and increased profitability, compared to empirical methods. Treatment M4 led to greater dry mass and leaf area at 41 and 59 DAE. The different irrigation strategies did not influence the relative growth rate of the melon. Water-related factors—such as irrigation management, pumping energy, and water cost—accounted for less than 2% of total production costs, showing low impact on the final cost, despite water use differences exceeding 100%. In the financed scenario, social reproduction could be achieved with just 0.2 ha, one-fifth of the area required without financing, highlighting the importance of rural credit as a driver of agricultural activity.