Assessing the Impact of Combined Tillage and Herbicide Weed Management Combinations on Growth and Yield of Rice (Oryza sativa l.) in the Guinea Savannah Agroecological Zone of Ghana

Abstract

Rice production in resource-constrained environments with poor inherent soil nutrition also adversely affected by weeds depends on tillage and herbicide weed management systems that provide high yields and preserve soil, and biodiversity. The research was conducted in the Guinea savannah agroecology of Ghana, during the 2022 cropping seasons at two locations (Botanga and Golinga) to evaluate the impact of tillage and herbicide weed management systems on the sustainable production of lowland rice variety AGRA rice by resource-poor farmers. The experiment was a 3 x 3 factorial laid out in a split-plot design with three replications. The factors consisted of a tillage system at three levels (no-tillage, conventional tillage, and minimum tillage) laid out as main plots and herbicide weed management (pendimethalin 400 g a.i. /ha applied as pre-emergence, bispyribac sodium 25 g a.i/ha applied as post-emergence, and pendimethalin 400 g a.i /ha + bispyribac sodium 25 g a.i/ha applied as pre and post-emergence) laid on the subplot. All parameters measured had a significant two-way interaction effect on tillage and herbicide weed management systems (P < 0.05). The grain yield of rice was significantly influenced by minimum tillage systems with pre + post-emergence herbicides giving the highest yield of 8,642 kg/ha at Golinga whilst recorded the highest grain yield of 8,016 kg/ha with the same treatment combinations. This interaction also gave the highest benefit/cost ratio of 4.6. Weed density and biomass were recorded highest in pendimethalin entries but decreased under bispyribac sodium and further declined with pendimethalin + bispyribac sodium application.