Estimation of Potential Evapotranspiration at Botanga Irrigation Scheme in the Northern Region of Ghana
Climatic parameters such as temperature, rainfall, wind speed, relative humidity and sunshine hours were used to assess reference evapotranspiration and potential crop evapotranspiration of selected crops. The Penmann Monteith method for calculation of Reference Evapotranspiration, which has been incorporated in CROPWAT software, was used. Test crops included rice, tomato and pepper, which were part of the major crops cultivated in the Botanga irrigation scheme. Research findings indicated that temperature (r = 0.653) played a crucial role in assessing reference evapotranspiration and potential evapotranspiration. Temperature was lowest during the months from July to September due to lower solar radiation and higher rainfall. The potential crop evapotranspiration of rice, tomato and pepper were 697, 533 and 427 mm/season respectively. Rice growers will require more water for irrigation to ensure higher production due to its high evapotranspiration rate.