This study assessed the determinants of weed management strategies on yield of cassava in Kogi State, Nigeria using the ordinary least square regression analysis. A multi-stage random sampling technique was used to select 450 cassava farmers in the state in 2009. The result showed that there was a significant difference in the yield of cassava between plots applied with herbicides and plots without herbicide application. The common herbicides used by the farmers were Primextra GoldÒ(Atrazine 370 g + S-metolachlor 290 g per litre), GalexÒ(Metobromuron 250 g + Metolachlor 250 g per litre), Cotoran multi® 500EC (Fluometuron 250 g + metolachlor 250 g per litre), Codal Gold® 412.5DC (250 g prometryn + 162.5 g per litre) and Fusilade Forte® 150 EC (150 g Fluazifop-p-butyl per litre) and Dual Gold® (960 g S-metolachlor per litre). Except Fusilade Forte® that was applied post-emergence to the weeds, the herbicides were mostly applied preemergence to both crops and weeds. Mean yield of cassava for plots applied with herbicides was 8,199 kg/ha and 6,999 kg/ha for plots with zero herbicide application. The study found a significant (p ≤ 0.05) negative relationship between age of farmer and cassava yield. Education, use of herbicides, hand weeding, slashing and intercrop with melon had a significant ( p ≤ 0.01) positive relationship with cassava yield. The coefficients for household size, farming experience and intercrop with okra (Abelmoschus esculentus L. Moench) were positively associated with cassava yield at 10.0% level of probability. Implicit in these results is that weed management strategies should be aimed at the use of herbicides, subsequent hand weeding or slashing, as well as intercrop with crop such as okra and melon (Colocynthis citrullus L.). Also to encourage experienced farmers to remain in production, there should be policy advocacy on free education and intensification of extension education to farmers.
Key words: Weed management, cassava yield, ordinary least square regression.