GHANA: View of Effects of spacing and water control on growth and yield performance of irrigated rice in Guinea savannah Agro-ecological zone
This aim of the study, conducted at Golinga irrigation scheme in Ghana, was to investigate how water supply and plant density, components of the System of Rice Intensification (SRI), can improve rice yield and reduce water use. Water control and planting distance interaction significantly influenced plant height where intermittent flooding promoted taller plants in narrow and wider planting distance (20 x 20 cm and 40 x 40 cm). Days to 50% flowering lengthened with increasing planting distance. Tiller and reproductive tiller number per plant increased with increasing planting distance. Intermittent flooding and increased spacing induced better root development. Panicle number per unit area, paddy grain yield and straw weight performed best under 25 x 25 cm planting distance. Paddy yield of 5.2 ton/ha at a planting distance of 25 x 25 cm was above the national average and within the potential yield of the variety. Intermittent and continuous flooding gave a similar performance. Increasing plant spacing helps to improve individual hill performance.
In conclusion, the study shows that wider spacing improves individual hill performance but if the plant density is low the higher individual hill performance cannot compensate for the reduced plant density. Intermittent flooding of rice does not put the crop in a disadvantageous position as it elicited similar response as continuous condition. Farmers are recommended to increase planting distance of rice to between 20 x 20 cm and 25 x 25 cm and apply water intermittently.