This book is a research work in the field of Crop Protection. The book gives a description of the occurrence of cowpea mild mottle virus (CPMMV) and other viruses (Cowpea aphid-borne mosaic virus [CABMV] and Cucumber mosaic virus [CMV]) that infect cowpea (Vigna unguiculata, L) in western Kenya. It also describes the results of varietal screening test for resistance against CPMMV and biological characteristics of the CPMMV isolates from western Kenya. The study was done through survey and laboratory detection of the viruses by DAS-ELISA. The work was funded by McKnight foundation and National Commission for Science, Technology and Innovation (NACOSTI - Kenya).