Occurrence of Fusarium Oxysporum and Ralstonia (Pseudomonas ) Solanacearum on Root-Surface of Tomato (Lycopersicon Esculentum Mill)

Abstract

The microflora associated with the root-surface of five tomato cultivars commonly cultivated in Edo State Nigeria, was investigated by inoculating serially washed 5 mm tomato root segments on potato dextrose agar (PDA) incubated at room temperature (28-30oC). Fusarium oxysporum and Ralstonia (pseudomonas) solanacearum together with Botryodiplodia theobromae, Trichoderma koningii and Aspergillus niger were frequently isolated from virtually all the five tomato cultivers . F. oxysporum and R. solanacearum which were by far the most frequent in occurrence in all the variety of tomato, appeared early on the root and persisted strongly throughout the sampling period with peak frequency of occurrence in the 6 to 8 week and 8 to 10 week old plants, respectively. The population build-up of the two microorganisms on the root system was found to have played an important role in relation to the pattern of occurrence of pathological wilting among tomato plants in the field.

(Af. J. of Science and Technology: 2002 3(1): 18-21)