P. NyamudezaDepartment of Research and Specialist Services
Chiredzi Research Station, Chiredzi, Zimbabwe
Trials were conducted on Vertisols in the semiarid region of Zimbabwe to investigate the influence of landform and plant population density on the yield of sorghum.
When rainwater was conserved and concentrated in 1-, 1.5- and 2.5-m wide furrows, sorghum grain yields increased by 25% in a dry year compared to the flat treatments. The highest yield was recorded from the 1.5-m wide furrows, which outyielded the widely practised 1-m row spacing on the flat by 34%. The 1.5-m row spacing on the flat outyielded the 1- and 2-m row spacings on the flat in the dry year. Yield of stover in the dry year showed no difference between furrow and flat, but the 1-m row spacing significantly outyielded the 1.5- and 2-m row spacing.
Population densities of 22 000, 44 000 and 88 000 plants ha tested in a wet year did not show any significant difference in yield. However, the trend was that in a wet year the yield decreased with increasing population, while in a dry year the trend was the reverse.
