Water requirement and single and dual crop coefficients of sesame cultivated in the coastal tablelands of Brazil

Abstract

Sesame irrigation is essential in drought‐prone regions. However, information about the water needs of sesame is scarce. Therefore, the objective of this study was to determine crop evapotranspiration (ETc) and the sesame crop coefficient (Kc) during the rainy (S1) and dry (S2) seasons in the coastal tablelands of Alagoas, Brazil. The BRS Seda cultivar was grown in Rio Largo, Alagoas, Brazil, between 2021 and 2022. A system with 25 drainage lysimeters was installed to estimate the daily and cumulative ETc and the Kc for the entire crop cycle. The ETc was partitioned into transpiration (T) and evaporation (E), and the basal crop coefficients (Kcb) and soil evaporation coefficients (Ke) were subsequently estimated. The daily and cumulative ETc were 3.04 mm day−1 and 450.4 mm cycle−1, respectively, in S1 and 3.52 mm day−1 and 440.1 mm cycle−1, respectively, in S2. Regardless of the season, T was the main water flux (74%–80% of the ETc). The mean values of Kc were similar for S1 (0.79) and S2 (0.75), and Kcb and Ke followed the same trend as T and E, respectively. The accumulated ETc and Kc of sesame cultivated in the coastal tablelands of Alagoas, Northeast Brazil, are similar for the rainy and dry seasons.