Журнал сельскохозяйственных наук и пищевых исследований
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Distribution of Sweet Potato Viruses and Vectors in Homabay County, and under Climate Change Scenarios in Kenya

Quinter Akinyi Oginga*, Chemeda Fininsa, Simon Onywere, Bramwel Wanjala, Gladys Mosomtai, Alok Kumar

Sustainable agricultural productivity and food security are critical concerns in the face of climate change. Sweet potato (Ipomoea batatas) is among climate smart crops that can strengthen farming resilience and enhance food and nutrition security in Sub-Saharan Africa. However, farmers have not been able to achieve optimum productivity partly due to diseases caused by sweet potato viruses. This study sought to identify experiences and practices of sweet potato growers; assess prevalence of sweet potato viruses (i.e. Sweet Potato Chlorotic Stunt Virus (SPCSV), Sweet Potato Feathery Mottle Virus (SPFMV) and vectors; and model their future distribution under climate change scenarios of RCPs 4.5 and 8.5. Survey was conducted and virus testing done using RT-PCR. A total of 294 presence data of sweet potato viruses (SPCSV, SPFMV and begomovirus) and 65 presence data of vectors (whitefly and aphid) collected from field surveys and the Kenya Agricultural and Livestock Research Organization (KALRO) database were used as dependent variables. Bioclimatic data retrieved from AfriClim and soil data from ISRIC database were used to model the spread of sweet potato vectors and viruses using the MaxEnt model. Occurrence of virus disease and vectors was 51% and 31.6% respectively and the models’ most significant variables were moisture (moisture index moist quarter) and temperature (number of dry months and length of longest dry season). The results showed that on one hand, geographical extent of areas at risk of sweet potato virus disease will increase for Kenya under future climate change scenarios from a current 36,736.09 km² to about 63,179.76 km² by 2085 under RCP 8.5. On the other hand, virus disease risk incidence will decrease for Homabay County in future climate scenarios from a current 2,804.92 km² to 2,625.05 by 2085 under RCP 4.5. Increase in temperature and moisture variables will enhance niche suitability for sweet potato viruses and vectors. Therefore, the situation calls for climate smart practices such as better crop timing, better cultivar choice and management, integrated pest management and sustainable cropping systems to enhance sustainable production of sweet potato crop.