Status of Root-Knot Nematode (<i>Meloidogyne</i> Species) and Fusarium Wilt (<i>Fusarium oxysporum</i>) Disease Complex on Tomato (<i>Solanum lycopersicum</i> L.) in the Central Rift Valley, Ethiopia

Abstract

Development of diseases in cultivated crops depends on the complex interrelationship among host, pathogen and prevailing environmental conditions. In nature, plants are rarely, if ever, subject to the influence of only one potential pathogen and this is especially true of soil-borne pathogens like fusarium wilt ( Fusarium oxysporum ). In the present study, the co-occurrence of root-knot nematode ( Meloidogyne species) and Fusarium oxysporum f.sp. lycopersici was surveyed in the main tomato growing areas of the central rift valley of Ethiopia. Mineral and organic samples were collected from 59 farmlands representing five districts and two commercial farms during the main cropping season of 2017. Cultural, morphological and virulence analysis of these pathogens revealed their co-existence. Out of 59 samples, 39% were found infected with the disease complex [ Meloilodogyne species.* Fusarium oxysporum f.sp. lycopesici (FOL)]. Off which, 16.9% and 6.8% resulted from concomitant infection of Meloidogyne incognita * FOL and Meloidogyne javanica * FOL, respectively. The percent prevalence of the disease complex ranged between 27.3% and 60%. The co-occurrence of these pathogens within a single host plant within the same ecological niche will indicate the probability of any type of interaction between each other. Therefore, subsequent research studies on their nature of interaction should be done in the future.