Tomato (Solanum lycopersicum) is the third most important vegetable crop after potato (Solanum tuberosum) and onion (Allium cepa). Its production heavily involves the use of synthetic pesticides with detrimental impact on humans, insect pollinators, water sources, soil fertility and environment. This study uses different mulch types to mitigate this problem. Mulching is an agricultural technique that protects the roots of plants from heat and cold by use of inorganic and organic mulch types to

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... over the soil surface around plants. Tomato production in Kakamega County is below 2%. Weeds are ranked high among the yield reducing factors. This study consists of four mulch treatments of white polyethylene (0.18mm thick), maize stalks (18.0cm thick), grass clippings (18.0cm thick), guava leaves (18.0cm thick) and no mulch as control with three popularly grown tomato varieties. The mulch treatments were arranged as factorial in a completely randomized block design replicated three times in the experimental plots, at Masinde Muliro University of Science and Technology (0°17 1 N, 34°45 1 E). Tomato variety sub-treatments were completely randomized in the plots to minimize non-experimental bias during sampling weeds incidence. The field project was conducted during the short rains and long rains season of 2016-2017. Data obtained was subjected to analysis of variance (ANOVA) using SAS software, version 9.3 (SAS Institute lnc.) at p<0.05 confidence level. Least Significance Difference (LSD) was used to separate the means. Mean weed density was significantly highest in control plots (94.51%) and least in mulched plots (11.41%). The tomato plant growth parameters (leaf length, leaf width, stem height and stem width) were significantly higher in mulched than control plots. Mulches provide clean field sanitation, inhibits weed seed germination, promotes plant growth with high crop yields and reduces synthetic pesticides and herbicides application.