Declining yields of maize as a result of Striga infestation has necessitated a new technology
known as Imazapyr-resistant maize (IRM) to contain the problem. As a result, research and
development initiatives with substantial participation of the private sector to transfer this new
technology to farmers have been made in western Kenya. This study therefore assesses the
adoption of IRM variety and efficiency levels of farmers in western Kenya. A multi-stage
sampling technique was used to select a total of 600 households from Nyanza and Western
provinces for this study. Tobit model and stochastic production frontier analysis were the
analytical methods. Results show that age, education, maize production gap, risk, contact with
extension agents, lack of seeds, membership in social group, effective pathway for IRM
dissemination and compatibility of the technology are the variables that were found to be
significant (P<0.05) in shaping the decisions of households on whether to adopt or not. The
study reveals that the mean technical efficiency of maize production of sampled farmers is
70% indicating some inefficiencies of maize production in western Kenya. Also, adoption of
IRM significantly increased frontier maize output (P<0.01); household size decreased
inefficiency along with farm size. It was recommended that efforts to increase adoption of
IRM for enhanced farm efficiency should focus on farmers’ education, farming experience
and access to information and farm basic inputs.