Chrispo Makheti Mutebi - Kenya Agricultural and Livestock Research Organization, P.O. Box ۱۴۹۰-۴۰۱۰۰, Kisumu Kenya
Vincent Moranga - Kenya Accreditation Service, P.O. Box ۴۷۴۰۰-۰۰۱۰۰, GPO, Nairobi, Kenya

The present study was done to determine the effect of different soil fertilities on cowpea mosaic virus disease incidence. The fertilities  were; ۵۰ kg/ha Diammonium phosphate (۱۸.۴۶.۰), ۵۰ kg/ha Mavuno (۱۰.۲۶.۱۰) that is a mineral fertilizer that has been extensively utilized in western Kenya, ۳ tons/ha farmyard manure (FYM), FYM/Mavuno combination with half rate of the latter at ۲۵ kg/ha, FYM/DAP combination with half rate of the latter at ۲۵ kg/ha and unfertilized control, all applied at planting time. Certified cowpea seed of Kenkunde variety was planted using the different fertilizers in a randomized complete block design (RCBD). Percent cowpea mosaic disease incidence (DI) data was collected and analyzed through one-way ANOVA. The results of cowpea mosaic DI shown as a descriptive statistics collected from the six fertilizer treatments indicated that FYM/DAP combination had the smallest mean for DI (M = ۱۲.۵۵), while DAP alone had the highest DI mean (M = ۳۳.۹۷). Associations among groups in the ANOVA table showed that the fertilizer effects were  significant (p < .۰۰۵). Fisher’s LSD post-hoc tests at ۵% level of confidence was used to evaluate the nature of the differences in mean DI. It was observed that ۹۲% of the variance in DI was accounted for the type of fertilizer treatment applied. In conclusion, application of DAP combined with FYM at ۲۵ kg/ha and ۱.۵ tons/ha can be helpful in lowering the cowpea mosaic virus infection in the region where this study was carried out, though these could be used with knowledge of soil reaction.Abbreviations: ANOVA, Analysis of variance; DAP, Diammonium phosphate; DI, Disease incidence; FYM, Farmyard manure; LSD, Least significant difference; KALRO, Kenya Agricultural and Livestock Research Organization; NRF, National Research Fund; RCBD, Randomized complete block design; SPSS, Statistical package for social sciences

Cowpea mosaic virus, DAP, Disease incidence, Farmyard manure, Soil fertility