Current status of bacterial wilt (Ralstonia solanacearum) disease in major seed potato (Solanum tuberosum L.) growing areas of Ethiopia

Abstract

On-site assessment and detection of plant diseases is a prerequisite to inspect the health status of seed potatoes and to make cost-effective disease management decisions. The present study was conducted in 60 major seed potato producing cooperatives of Ethiopia to assess the extent of potato bacterial wilt disease and to generate information on current status of R. solanacearum. The field assessment and inspection survey was conducted during 2015/16 for 3 seasons in 140 potato fields covering 123.30 hectares of seed potato. Symptomatic plants were confirmed for R. solanacearum by Agri Strip kit, potassium hydroxide (KOH) test and vascular flow (VF) techniques. The results of the study indicated that out of 140 seed potato fields assessed, 26 (equivalent to 18.57%) or some 33.3% of seed cooperatives were infested by bacterial wilt. The highest disease incidence (82.5%) was recorded in Jeldu district followed by Wonchi district (60%) where most of seed potato is being distributed to the country. Based on the results of three disease confirmation tools (Agri Strip, KOH and VF) implemented, 34.75 (28.18%) hectares of the fields showed positive results. Disease prevalence ranged from 0 to 100%. In some districts like Cheha, Doyo-gena and Shashamane, the disease prevalence was 100%, whereas 50% disease prevalence was recorded in Arsi-Negelle and Kofole districts. This study describes the current infestation level of bacterial wilt in major seed producing cooperatives of Ethiopia and potato production is highly threatened by Ralstonia solanacearum in most of the areas addressed by this survey.

Potato bacterial wilt in Ethiopia: history, current status, and future perspectives

“…Since then, it was reported from different parts of southern, west, southwest, northern, and central highlands of the country ( Table 1 ; Fig. 1 ) with more emphasis in central high lands where major seed potato is being distributed to the country ( Gorfu, Woldegiorgis & Kassa, 2013 ; Abdurahman et al, 2017 ; Sharma et al, 2018 , Tessema et al, 2020 ; 2022 ). The disease transmission was slow and not a plague too many potato farms at a time, so that no one gave due attention to the pathogen and by now it becomes a serious production threat for the farming community ( Gorfu, Woldegiorgis & Kassa, 2013 ; Sharma et al, 2018 ; Tafesse et al, 2021 ).…”

“…The disease incidence in some parts of Ethiopia from 1985 to 1987 report was 0.8% to 21% in Tsedey farm, Zewai and 1.5% to 24% in Bako areas. In recent years, the disease prevalence raised to above 90% in most potato growing areas of Ethiopia ( Abdurahman et al, 2017 ; Tessema et al, 2020 ). Furthermore, the disease was important only in warmer areas of the country, but the occurrence of bacterial wilt in the highlands like Tsedey farm laid a base to consider and gained attention even at higher altitude potato domain areas would have probability to be infected with the pathogen ( Kassa & Hiskias, 1994 ) and recent studies confirmed that Ethiopian highlands with an altitude of above 3000 m.a.s.l.…”

“…In the current scenario, bacterial wilt has a worldwide distribution, found in almost all continents and threatening the agricultural community of the globe ( EPPO, 2020 ; Gorfu, Woldegiorgis & Kassa, 2013 ). Likewise, bacterial wilt distributed to many African countries and became one of serious potato production constraints in Burundi, Cameroon, Egypt, Ethiopia, Kenya, Madagascar, Nigeria, Rwanda and Uganda, to mention some ( Kabeil et al, 2008 ; CTA, 2014 ; Elnaggar et al, 2018 ; Abdurahman et al, 2019 ; Tessema et al, 2020 ). Major seed potato exporting countries like Canada, Netherlands, France and United Kingdom ( van Loon Kees, 2007 ) as well as seed potato importing countries of Africa like Algeria, Egypt, Morocco and Tunisia are highly influenced by potato bacterial wilt.…”

“…Though potato bacterial wilt is a soil-borne disease, the spread and prevalence as well as disease outbreak could be aggravated by many biotic and abiotic factors such as poor agricultural practices, unlimited animal and human movement to farming fields, lack of knowledge on appropriate field sanitation procedures, planting pathogen infected seed year after year, weak seed quarantine rules, soil acidity, and environmental variations ( Gorfu, Woldegiorgis & Kassa, 2013 ; Tafesse et al, 2021 ; Tessema et al, 2020 ; 2022 ). It was evidenced that environmental temperature also has direct effect on the success of pathogen invasion to varying host species ( Wei et al, 2015 ).…”

Microbial Contaminants and Their Control Methods: A Review with Reference to Potato Tissue Culture

“…Root and tuber crops, being propagated vegetatively, are inherently more susceptible to maintenance, increase, as well as dissemination of both systemic and non-systemic diseases than that of sexually reproduced crops which come from true seeds (Bryan, 1983;Tessema et al, 2020). The systemic diseases, like viruses, viroid, bacteria, and mycoplasma pathogens are the most devastating in terms of yield loss for the root and tuber crops (Bryan, 1983).…”