Jane Muthoni^1,2 , Jackson Kabira² , Hussein Shimelis¹ , Rob Melis¹

1. African Centre for Crop Improvement, University of KwaZulu-Natal, College of Agriculture, Engineering and Science, School of Agricultural, Earth and Environmental Sciences, Private Bag X01, Scottsxille 3209, Pietermaritzburg, South Africa
2. Kenya Agricultural Research Institute (KARI), National Potato Research Centre, Tigoni, Kenya
Author    Correspondence author
International Journal of Horticulture, 2014, Vol. 4, No. 3   doi: 10.5376/ijh.2014.04.0003
Received: 03 Jan., 2014    Accepted: 13 Jan., 2014    Published: 15 Jan., 2014

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Muthoni et al., 2014, Spread of Bacterial Wilt Disease of Potatoes in Kenya: Who is to Blame? International Journal of Horticulture, 2014, Vol.4, No.3 10-15 (doi: 10.5376/ijh.2014.04.0003)

Bacterial wilt (caused by Ralstonia solanacearum) has spread to all potato growing areas in Kenya, affecting over 70% of potato farms and causing yield losses of between 50 to 100%; it is followed by late blight affecting 67% and viral diseases (12%). The disease was first reported in Kenya in 1945 around the Embu area from where it spread to other parts of the country. The disease is believed to have been introduced with tuber seeds imported from Europe. In potatoes, the bacteria is tuber borne and is primarily disseminated through infected seed tubers. It is further spread through infected run-off water or soil adhering to tools and shoes.  Infected seed tubers from bacterial wilt infested areas have mainly contributed to the spread of the disease to many potato producing areas in Kenya; this is mainly a consequence of the informal potato seed system prevalent in the country. Because the country produces less than 1.1 % of her national certified seed requirement, most farmers are forced to plant seeds from informal sources such as farm-saved (self supply), local markets or neighbours. The certified seeds are also highly priced thereby discouraging most small scale farmers from using them. Although most farmers have been trained on production of clean seed from basic or certified seeds on their farms, such seeds (known as Quality Declared Seeds) are not recognised by the Kenyan law and their trade is illegal. With no option, potato growers continue using planting material from informal sources. With informal sources, seed quality cannot be assured. The situation is worsened by the uncontrolled and/or illegal cross border trade. In addition to the prevalence of informal seed systems, farmers are unaware and/ or are unable to apply affective measures for the control of bacterial wilt.   From the foregoing, it is unlikely that bacterial wilt of potatoes will ever be tamed in Kenya. Unless all stakeholders tackle the problem collectively, the blame game will continue. 

Bacterial wilt; Kenya; Potatoes