Crop evapotranspiration was calculated using the water balance method by monitoring the change in soil water content over a period of time (Allen et al., 2011). There was no precipitation in
the greenhouse and no surface runoff from the plots since all furrows were blocked. Contribution from groundwater table was also negligible since the water table was below 25 m. Non-weighting,
percolation type lysimeters (1 mm thick steel) of 1.0 m long and 1.2 m wide were installed 0.6 m beneath the bottom of the furrow (Fig. 2) to collect drainage water. However, no drainage was
observed from the lysimeters in each of the plots. Thus ETc (mm)can be estimated by: