Evapotranspiration and crop coefficients of corn in monoculture and intercropped with jack bean¹

Evapotranspiração e coeficientes da cultura do milho Caatingueiro em monocultivo e consorciado com feijão-de-porco

ABSTRACT

This study was carried out to determine the evapotranspiration (ETc) and crop coefficients (Kc) for four stages of “Caatingueiro” corn under the climate condition of Seropédica, RJ, Brazil, using weighing lysimeters. The field trial occurred in 2015, from March 18 to June 25, in two areas cultivated with “Caatingueiro’ corn intercropped with jack bean and in monoculture. The reference evapotranspiration (ETo) was estimated by the FAO-56 Penman-Monteith model and the Kc values were determined by the ratio between ETc and ETo. The Kc values obtained for the intercropping and monoculture systems, were respectively: 0.78 (I); 1.01 (II); 1.10 (III) and 1.01 (IV), and 0.62 (I); 0.92 (II); 1.27 (III) and 0.81 (IV), and they were different from the values presented by FAO.

Key words:
water requirement; weighing lysimeter; irrigation; organic cultivation