Evapotranspiration, crop coefficient and water use efficiency of coriander grown in tropical environment

Evapotranspiração, coeficiente de colheita e eficiência de uso de água do coentro cultivado em ambiente tropical

ABSTRACT

The water scarcity is expected to intensify in the future and irrigation becomes an essential component of crop production, especially in arid and semiarid regions, where the available water resources are limited. Four field experiments were carried out at tropical environment in Brazil in 2013 and 2014, in order to evaluate the effect of planting date on crop evapotranspiration (ET_c), crop coefficient (K_c), growth parameters and water use efficiency (WUE) of coriander (Coriandrum sativum) plants. The planting dates occurred during winter, spring, summer and autumn growing seasons. ET_c was obtained through the soil water balance method and the reference evapotranspiration (ET_o) through the Penman-Monteith method, using data collected from an automatic weather station located close to the experimental area. The results of the research showed that the mean values of coriander ET_c and K_c were 139.8 mm and 0.87, respectively. Coriander water demand is higher in the summer growing season and lower in the winter; however, its yield is higher in the autumn and lower in the winter. Coriander has higher yield and development of its growth variables in the autumn growing season. The results also indicated that the interannual climate variations had significant effects on most growth variables, as yield, ET_c and K_c of coriander grown in tropical environment.

Keywords:
Coriandrum sativum; soil water balance; irrigation; Penman-Monteith approach