Glyphosate-based herbicides on weeds management and maize performance under conservation agriculture practices in eastern Kenya

A three-season research study was conducted at Embu Agricultural Research Station farm to determine the effect of glyphosate-based herbicides on weeds management and maize (Zea mays L.) performance under zero-tillage conservation agriculture practice. Glyphosate herbicide sprays were prepared from Roundup Turbo product at the rate of 2.5 L ha<SUP align="right"><SMALL>−1</SMALL></SUP> and Roundup Weathermax at 1.5, 2.5 and 3.0 L ha<SUP align="right"><SMALL>−1</SMALL></SUP> rates. Significant (p ≤ 0.05) differences in weeds management were observed under the tested rate of Roundup Turbo compared to un-weeded control plots. The average grain yield from conventionally tilled plots was 3.6 t ha<SUP align="right"><SMALL>−1</SMALL></SUP>. This did not differ significantly from those of herbicide-managed plots. Low-grain yield (0.1 t ha<SUP align="right"><SMALL>−1</SMALL></SUP>) was observed from un-weeded plots compared to those from zero-tilled plots that had also exhibited significantly (p ≤ 0.05) higher net-benefits. The study concluded that the application of herbicides improves weeds control and maize performance.