Effect of Irrigation Management Methods on Growth, Grain Yield and Water Productivity of Three Lowland Rice (Oryza sativa L.) Varieties

It has been predicted that Ghana will face water shortage by the year 2025 due to increased demand of water resources from all sectors of the economy. Rice production will be negatively affected since rice consumes the highest amount of water in the agricultural sector. To develop a strategy to reduce water use for rice production while maintaining or increasing rice yield, a pot experiment was carried out in the screen house at Soil and Irrigation Research Centre - Kpong during 2016 and 2017 cropping seasons to determine the effect of irrigation management methods on growth, yield and water productivity of three rice varieties. A three by five (3 x 5) factorial experiment was laid out in a randomized complete block design and replicated six (6) times. The levels of the variety were: Agra (VA), Ex Baika (VB) and a hybrid (VH). Irrigation management methods included: continuous submergence (I1), alternate wet and dry soil condition (AWD) from transplanting to panicle initiation (PI) then submergence to harvest (I2), AWD from transplanting to booting then submergence to harvest (I3), AWD from transplanting to flowering then submergence to harvest (I4), and continuous AWD (I5). Results from the experiment revealed that, I3 saved 21.7% and 20.4% of water used when compared with I1 in 2016 and 2017, respectively however, these treatments produced similar growth and yield in both seasons. I3VH recorded 21.2% and 20.8% of water saved in 2016 and 2017, respectively however, it produced similar grain yield with I2VH and I1VH treatments in both seasons.