Evaluation of herbicide mixtures and manual weed control method in maize (Zea maysL.) production in the Southern Guinea agro-ecology of Nigeria

Field trials were conducted in 2015 and 2016 cropping seasons to evaluate some herbicide mixtures and manual weed control method in the production of maize in the southern Guinea savanna of Nigeria. The experiment consisted of 10 treatments as follows: Metolachlor + atrazine at 1.0 + 2.0 kg a.i./ha, metolachlor + atrazine at 2.0 + 2.5 kg a.i./ha, metolachlor + atrazine at 3.0 + 3.0 kg a.i./ha, pendimethlin + atrazine at 1.0 + 2.0 kg a.i./ha, pendimethlin + atrazine at 2.0 + 2.5 kg a.i./ha, pendimethlin + atrazine at 3.0 + 3.0 kg a.i./ha, metolachlor + atrazine at 1.0 + 2.0 kg a.i./ha plus one supplementary hoe weeding (SHW) at 6 weeks after sowing (WAS) and pendimethlin + atrazine at 1.0 + 2.0 kg a.i./ha plus one SHW at 6 WAS, hand weeding at 3 and 6 WAS and a weedy check. These treatments were laid out in randomized complete block design with three replicates. Results showed that metolachlor + atrazine and pendimethalin + atrazine at 1.0 + 2.0 kg a.i./ha plus one SHW at 6 WAS significantly reduced weed infestation and gave higher maize grain yield and economic returns. These methods are therefore recommended to farmers as alternative to two hand weeding at 3 and 6 WAS.