Numerous methods of calculating ET₀ and ETP offer a great practical possibility for their application, but in order to improve their efficiency it is necessary to check them in particular regions. The experimental study of Virginia type tobacco in irrigation conditions was carried out in the area of village Brzi Brod (Niš). The established potential evapotranspiration of Virginia type tobacco ranged from 498.1-512.7 mm, depending on annual weather conditions.

The field trial of Virginia type tobacco (Hevesi-9) was set in irrigation conditions, in the vicinity of Brzi Brod village, Nišava River's valley, on the alluvium soil type. Water consumption for evapotranspiration, at the irrigated variant and the control one, was calculated for each month and the whole vegetation period, by making the balance between water consumption from the soil layer to 2m under the ground, total precipitation amount in the vegetation and water added by irrigation.