Effect of Herbicides on Forage Dry Matter Yield and Plant Density in the Old Arable Lands in Communal Area of the Eastern Cape Province, South Africa

With the world’s population growing at an alarming rate, there is an urgent need to improve food security. This study aimed to assess forage dry matter yield and plant density under different herbicide treatments at Kubedlana arable lands. The study was carried out using eight treatments consisting of seven herbicide treatments and a control. Seed mixtures of seven legume species were broadcasted in 24 plots of 3 m × 5 m size. Herbicide treatments including Bendioxide (BEN), Glyphosate (GLY), Haloxyfop-R methyl (HAL), Haloxyfop-R methyl and Bendioxide (HBE), Paraquat (PAR), Bendioxide (BRR), and Paraquat (PRR) were applied individually in three plots. Dry matter production and plant densities were determined in five randomly distributed 0.25 m2 quadrats per plot. The results revealed that GLY had a significantly (p < 0.05) higher effect on the DM yield compared with other treatments. Both BRR and HBE significantly (p < 0.05) decreased the DM yield. GLY and HBE significantly reduced (p < 0.05) the grass density in 2017 and BRR significantly affected (p < 0.05) the legume density in May 2017 and May 2018, respectively. These results indicate that the application of GlY and HAL resulted in the reduction of grass density. Furthermore, none of the applied chemicals negatively influenced the legume density.