New Grant Awarded by the Monsanto Fund to work on potato viruses and their aphid vectors in Kenya

Potato (Solanum tuberosum L.) is the second most important food crop in Kenya after maize. Potatoes play an important role in food security as they are traded locally and have high nutritional value. Consumption per capita is approximately 89kg per year and rising. There are 5 million potato producers and the potato industry was worth approx. 10 billion KSh (£100 million) in 2007. However, average yields are less than 10 t/ha.

Virus diseases are the major cause of degeneration of seed potato stocks because in potatoes (and other vegetatively propagated crops) once a plant is infected by a virus it cannot be ‘cured’.  Infected plants produce virus infected tubers and infected progeny plants.  Aphids transmit viruses from infected plants to clean stocks during the growing season thus very quickly infection builds up in the crop unless aphids can be controlled.

The biggest limitation on potato production in Kenya is lack of supply of disease-free certified seed tubers. Less than 1% of growers have access to certified seed. There are bottlenecks in multiplication of sufficient disease-free tubers to supply the demand, as a result growers use home saved seed or that obtained from local markets which is often diseased.  In a recent visit to the Mount Kenya potato producing regions of Buuri and Meru we saw newly emerging crops displaying symptoms of PLRV in >60% of plants as well as a high proportion of plants with mosaic symptoms.  Potato varieties with traits such as high levels of virus disease resistance, drought tolerance and good processing qualities are required.

During the project we will survey virus incidence in potato crops in the major potato growing regions.  We will also conduct aphid monitoring to identify regions with low aphid pressure that might be suited to seed tuber multiplication to increase seed production. We are also interested to examine potato virus variation with particular focus on potato virus Y. Another aspect of the proposal is training and demonstrating the benefits of growing crops from ‘clean’ seed. We will work with commercial growers, government agencies and researchers to help support seed tuber production and distribution to increase yields and to increase farmers’ incomes in a self-sustaining manner.

The project is funded for 24 months and involves a collaboration between SCRI and three organisations in Kenya. Lead partner at SCRI is Dr Lesley Torrance, Virologist and leader of Plant Pathology Programme. The lead Kenyan partner is Dr Hassan Were (virologist), Department of Biological Sciences, Masinde Muliro University of Science and Technology, Kakamega. Other partners are Dr Florence Olubayo (entomologist) University of Nairobi and Dr Jackson Kabira (potato breeder) Director and Head of Potato Programme, National Potato Research Centre, KARI Tigoni.

Photograph of some of the partners on a farm in Buuri district.