Evaluating the effects of manual hoeing and selective herbicides on maize (Zea mays L.) productivity and profitability

The objective of this study was to evaluate maize production and the economic profitability of weed management techniques. Field trials were conducted at the Kasapa farm during the 2021/22 growing seasons using a split-plot design with three repetitions. The main factor was the herbicides applied in pre-emergence alone (2L ha(-1): acetochlor, bentazon, imazethapyr and 60 g ha(-1) chlorimuron-ethyl), then mixed (1L ha(-1): acetochlor plus bentazon plus imazethapyr plus 30g ha(-1)chlorimuron-ethyl), manual hoeing (3-5WAS) including the non-weeding. The secondary factor: maize varieties (GV672A, GV673A, GV664A and Sam4vita). The highest maize dry grain yield (7.66 t ha(-1)) was associated with imazethapyr, while those of acetochlor and chlorimuron-ethyl (6.86 and 6.92 t ha(-1)) compared to manual hoeing (7.62 t ha(-1), respectively) were low, but much higher than no weeding (1.21 t ha(-1)). The yields of varieties GV672A and GV664A were higher (6.87 and 6.77 t ha(-1)), compared to Sam4vita (5.64 t ha(-1)). The total dry weight of weeds was negatively correlated with all crop parameters, with its maximum value (127.56 g m(-2)) characterizing non-weeding, and the minimum for manual hoeing (18.83 g m(-2)). The Ratio Cost Value showed that all treatments were profitable: imazethapyr > bentazon > chlorimuron-ethyl > combination > acetochlor > manual hoeing. However, imazethapyr was economically more profitable and could replace manual hoeing when the field to be weeded increases and labor is scarce.