Estimation of Water Requirement and Water Productivity of Sesame Crop (Sesamum indicum L.) in Dryland Areas of Sennar State, Sudan
Keywords:Reference evapotranspiration (ETO), crop factor (Kc), semi-arid, semi-humid, water productivity, sesame
Sesame is one of the main oil crops grown under dryland areas in Sennar state, Sudan. However, rainfall is quite irregular within the season and between the seasons. Understanding the effect of rainfall variability on water requirement and yield of sesame is essential to help in selecting optimum management practices for crop production. The objective of this study was to determine the water requirement and water productivity of sesame crop grown under two agro-ecological zones and three farming systems. An experiment was conducted in two agro-ecological zones in Sennar State (semi-arid zone and semi-humid zone) during seasons 2014/2015 and 2015/2016.The tested cropping systems were conventional farming (CF), conservation agriculture (CA) and water harvesting techniques (WH). The collected data included weather data and sesame yield data. The results showed that the average values of reference evapotranspiration (ETO) during the two seasons ranged from 3.29 to 4.4 mm/day in semi-arid site and from 3.75 to 3.95 mm/day in semi-humid site. Regardless of agro-ecological site and season, the average values of crop factor (Kc) during the initial, development, mid-season and late-season stages were 0.30, 0.75, 0.98 and 0.51, respectively. The average values of water requirement for sesame during initial, development, mid-season and late-season stages were 24.1, 87.8, 132.1 and 36.3 mm; and 20.1, 78.2, 114.5 and 37.9 mm, in semi-arid and semi-humid sites, respectively. The average water requirement was 2802 and 2516 m3/ha in semi-arid and semi-humid sites, respectively. The overall average values of water productivity for sesame crop in semi-arid site was 0.18 kg/m3 and it was 0.29 kg/m3 in semi-humid site. Water harvesting and conservation agriculture systems gave higher performance compared with the conventional farming system for sesame production in dryland areas of Sennar state.