Int. J. Agr. Ext. 02(03) 2014. 211-218 211 Available Online at ESci Journals International Journal of Agricultural Extension ISSN: 2311-6110 (Online), 2311-8547 (Print) http://www.escijournals.net/IJAE IMPACT OF MAIZE LETHAL NECROSIS DISEASE ON MAIZE YIELD: A CASE OF KISII, KENYA *Samson M. Makone, Dickson Menge, Evans Basweti Kisii University, Faculty of Agriculture and Natural Resources management, Department of Agricultural Education and Extension, Kisii, Kenya. A B S T R A C T The study aimed at determining the level of Maize Lethal Necrosis Disease and its effect on maize yield in Kisii County and come up with a document showing the prevalence and distribution of the disease across the nine Sub-counties in the region. A simple random sampling technique was used to obtain a sample of 172 respondents from a target household population of 10,000 maize farmers. A structured questionnaire was used to collect data that was subjected to Microsoft Excel and Statistical Package for Social Sciences (SPSS) software (Version 20) for analysis. The findings indicated that the mean age of the respondents was 41.5 years and the average proportion of land allocated for maize production was 1.25 acres. Majority of the respondent had secondary education as their highest level of education. The findings further showed that, Masaba South was the most affected Sub-County by Maize Lethal Necrosis Disease at 74.8%, followed by Bobasi at 74% while Kitutu Chache South was the least affected at 31.2%. The correlation between maize yields and Maize Lethal Necrosis Disease revealed a negative weak relationship of r= - 0.277 at a p value of 0.000. It is recommended that farmers should avoid growing maize in consecutive seasons, movement of affected crop debris or materials from one region to another should be stopped to minimize the incidence rates; diversify crops planted and practice crop rotation with non-cereal crops, formulation of extension policy and implement them in all counties to ensure that farmers get necessary information on how to mitigate Maize Lethal Necrosis Disease hence improved maize yield. Keywords: Maize yield, maize lethal necrosis disease, maize shortage. INTRODUCTION: Maize is the main staple food for more than 1.2 billion people in Latin America and Sub-Saharan Africa (Iken & Amusa, 2004). The crop is ranked the third most important cereal plant after wheat and rice (Khalili et al., 2013). The majority of producers in Africa are small scale farmers who grow maize for human consumption although it has increasingly been utilized for livestock feed (Onasanya et al., 2009). Maize grain has greater nutritional value since they are rich in carbohydrates, vitamins, essential minerals and contain 9% protein. In addition, the grains are also rich in dietary fiber and calories which are a good source of energy (Mghenyi, 2006). Maize lethal necrosis is a serious disease of maize from its first appearance in Kenya (Wangai et al., 2012). The disease has now gained the momentum in spreading to many countries of East African where maize crop is grown simply because of insufficient knowledge on how to manage the disease. It has therefore raised a major concern in Eastern Africa communities because of the effect associated (CIMMYT, 2013). The disease is naturally known to affect varieties of maize resulting in chlorotic mottling of the leaves, severe stunting and necrosis which as a result hinders the physiological processes of the plant such as photosynthesis, chlorophyll formation as well as denaturing enzymes necessary for the crop to produce, this further leads to low maize yields or plant death (Wangai et al., 2012). Maize Lethal Necrosis disease is caused by double infection with Maize chlorotic mottle virus (MCMV) and any of the cereal viruses in Potyviridae group; Sugarcane mosaic virus (SCMV), Maize dwarf mosaic virus (MDMV) or Wheat streak mosaic virus (WSMV). In Kenya and __________________________________________________________________ * Corresponding Author: Email: manozy08@gmail.com © 2014 ESci Journals Publishing. All rights reserved.