An Agro-Economic Performance of Maize under Different Weeding Regimes: A Case Study of Siam Weed (Chromolaena

Field experiments were carried out in 2009 and 2010 to evaluate the effects of Siam weed competition on the agro-economic performance of maize in South Western Nigeria. Two groups of treatments were applied. Firstly, plots were kept weed-free for timed periods only before allowing uncontrolled weed growth subsequently and second, weed growth was allowed for same periods before being continuously controlled afterwards. Average of yields over the two-year period was used for the measurement of output while the values of input and output were obtained from market surveys and through consumer panels approach. Partial farm budgeting analysis was employed. Results showed the first 8 weeks of maize field life (WAE) to be most critical for Siam weed control being as effective as keeping the plot weed-free throughout the crops field life. Delaying weeding for 6 weeks or more is as detrimental to yield as if plot is un-weeded for the entire growing period. The agro-economic indicators of performance employed-Yield, Net Returns and Benefit- Cost ratios were positive for the practice of keeping the maize plots Siam weed-free for the first 8 WAE. It gave a yield of 4.50 tonnes per hectare, net return ₦94,496.80 ($629.98) and highest Benefit/cost ratio of 1.9:1. In terms of the over-all economic contribution, an 8 WAE weeding programme timed at 4 weeks interval is recommended for maize farmers in South Western Nigeria