Global Advanced Research Journal of Agricultural Science (GARJAS) ISSN: 2315-5094
May 2017 Vol. 6(5): pp. 119-127
Copyright © 2017 Global Advanced Research Journals

Full Length Research Paper

Biocontrol Management of Rhizoctonia solani and Meloidogyne javanica infecting Watermelon Plants Using Pseudomonas spp.

Asmaa A. Mokbel^1&2* and Asmaa A. Alharbi²

¹Plant Pathology Department, Faculty of Agriculture, Alexandria University, Egypt 

²Biology Department, Faculty of Science, Jazan University, Kingdom of Saudi Arabia

Email: d.mokbel76@gmail.com

Accepted 20 May, 2017

Abstract

A survey study was conducted, during watermelon growing seasons 2014 & 2015, to identify root-rot fungi and the root-knot nematodes infecting watermelon plants cultivated in Abu-Arish governorate fields, Jazan province, southwest Saudi Arabia. Soil and root samples revealed the presence of three root-knot nematode species, e.g. Meloidogyne arenaria, M. incognita and M. javanica was the most prevalent species in all collected samples followed by M. incognita and M. arenaria. Also, three root-rot fungi, e.g. Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani were isolated from watermelon root samples and the most prevalent fungus was R. solani. The mixed infection with both pathogens; M. javanica and R. solni was common in most of the surveyed fields. In vitro tests using the bioagents, Pseudomonas aeruginosa, P. chlororaphis, P. fluorescens showed significant inhibitions in growth of R. solani, egg-hatch and juvenile mortality % of M. javanica. Under greenhouse conditions, watermelon plants inoculated with R. solani alone showed a root-rot infection of 39.6 % increased up to 69.5% with the presence of M. javanica (mixed inoculation). Under a field condition, during the two growing seasons 2014 & 2015, application of the three Pseudomonas species resulted in suppressive effects on R. solani and M. javanica infecting watermelon plants, reduced percent of fungal root-rot infection, nematode population and improved plant growth parameters compared to  the check treatment.

Keywords: Root-knot nematode, survey, soil borne pathogens, biological control, antagonistic organisms, frequency of occurrence, Citrullus lanatus.