Study of the Effect of Spacing on Sorghum Growth and Yield in Yobe State

Plant spacing determines crop population density and directly influences canopy architecture, resource competition, and ultimately grain yield, and its optimisation for sorghum production in the Sahel savanna of North East Nigeria requires site-specific experimental evidence. This study investigated the effect of three inter-row spacings (60 cm, 75 cm, and 90 cm) at a constant intra-row spacing of 20 cm on the growth and yield of sorghum (Sorghum bicolor L. Moench) in Damaturu, Yobe State, North East Nigeria. A randomised complete block design with three replications was used during the 2023 rainy season using SAMSORG 17 variety. Plant height, leaf area index, stem circumference, and tiller number were measured during the growing season, and panicle weight, grain number per panicle, 1000-grain weight, and grain yield were measured at harvest. Results showed that the 60 cm spacing produced the highest grain yield at 2.91 tonnes per hectare, while 90 cm spacing produced the lowest at 2.14 tonnes per hectare, though the difference between 60 cm and 75 cm was not statistically significant. Higher plant density at 60 cm spacing was associated with increased competition for light but did not suppress yield below the wider spacing threshold under the prevailing conditions. The study concludes that a spacing of 60 to 75 cm inter-row is optimal for sorghum in the Yobe State Sudan savanna and recommends further evaluation under variable rainfall conditions to confirm robustness of the recommendation.

Keywords: sorghum, plant spacing, grain yield, Sahel savanna, Yobe State