Water Productivity as a Tool for Deficit Irrigation Strategy to Optimize Watering Requirements for the Production of Sunflower (Helianthus annuus L.) under Dry Land Conditions of the Northern State, Sudan

Abstract

A field experiment was carried out for two consecutive seasons (2015/16 and 2016/17) at  the sandy loam soil of New Hamdab Research station with a view to investigate the effect of deficit irrigation  induced at different growth stages of sunflower (Helianthus annuusL.) on yield and water productivity. Five irrigation treatments were conducted, I₁ (100% crop water requirement throughout the season was considered as control), I₂ and I₃ indicated 75% and 50% crop water requirements at crop vegetative growth stage, respectively, whereas I₄  and I₅   indicated 75%  and 50% crop water requirements at crop ripening stage, respectively. The results showed that there were no significant differences between the treatments in yield and yield components. On the other hand the deficit irrigation treatment I₃ (Imposing 50% crop water requirement at vegetative stage) resulted in higher water productivity with no reduction in yield, therefore, it becomes evident that in order to save irrigation water while keeping high productivity of sunflower under such desert conditions, deficit irrigation of 50% crop water requirements at the crop vegetative stage of the crop should be applied.