is considered safe biological agent and their potential as biocontrol agent is considered to be high (Kim et al., 2004 Etesami and Alikhani, 2017). The use of bacteria like Pseudomonas sp., Bacillus sp., and various other bacteria has been investigated because of their properties to produce antifungal metabolites and protect plants from fungal infection (Gupta and Kaushal, 2017). It is likely that most cases of naturally occurring biological control result from mixtures of antagonists for example, mixture of antagonists are considered to account for protection in disease- suppressive soils (Lemanceau and Alabouvette, 1991).īiological control offers an important alternative to synthetic chemicals. Most approaches for biocontrol of plant diseases have used single biocontrol agents as antagonists to a single pathogen (Siddiqui et al., 2000). Interest in biological control of plant pathogens has increased considerably over the past years, partly as a response to public concern about the use of hazardous chemical pesticides (Raaijmahers et al., 2002). It was found that bacteria that produced more compounds associated to phytopathogen biocontrol and/or plant growth had a higher efficacy for biocontrol (Mota et al., 2017).īiological control, a bioeffector method with other living organisms to control pests (insects, mites, weeds, and plant diseases) (Flint et al., 1998), has been considered as effective approaches. The use of biological control measure is one of the best strategies available to combat the pests and diseases in an ecofriendly manner and much experimental work is being carried out all over world to assess its commercial acceptability and applicability. Rhizo-bacteria that exert beneficial effects on plant development are referred to as plant growth-promoting rhizo-bacteria (PGPR) (Kloepper and Schroth, 1978) because their application is often associated with stimulation of plant growth. Bacteria are estimated to occupy between 7% and 15% of the total root surface area (Gray and Smith, 2005). Various species of rhizospheric bacteria like Pseudomonas, Azospirillum, Azotobacter, Klebsiella, Enterobacter, Arthrobacter, Bacillus and Serratia and endophytic bacteria like Pseudomonas, Bacillus, Xanthomonas and Erwinia have been reported to be associated with soil crops. The rhizosphere of plant is a zone of intense microbial activity, and some bacteria from this zone, termed rhizobacteria, exhibit active root colonization in the presence of the existing native microfolora. Soil bacteria, particularly rhizospheric ones with antagonistic properties, reveal biological control effectiveness to some plant diseases, and are the most likely for development of biological control agents (BCAs) (Essghaier et al., 2009). A number of investigators’ have documented antagonism of fungi, actinomycetes and true bacteria to root rot pathogens (Ortiz-Castro et al., 2009). Antagonism between soil microorganisms is a common phenomenon. Rhizobacteria play an important role in plant defense and could be promising sources of biocontrol agents. Antagonism in Rhizobacteria: Application for Biocontrol of Soil-borne Plant Pathogens. phaseolina and Fusarium induced diseases on legume and seed spice crops in arid soils.Cite this article: Iqbal, M.N., Ashraf, A., 2017. versicolor as soil applications gives improved control of M. Significant increases in disease control were not recorded after single or repeated delivery of A. versicolor in the soil, which was greater than in the non-amended soil. versicolor in neem compost amended plots resulted in maximum populations of fungi, bacteria and A. During both years, the treatment combination of A. versicolor + farmyard manure amended plots. versicolor was amended with neem compost compared to the non-amended soil (5.7-10.5%). In both winter seasons, the lowest incidence of wilt (1.0-5.2%) on cumin was recorded when A. versicolor with farmyard manure supported the maximum populations of total fungi and actinomycetes. Root colonization by the combined biocontrol agent treatments was better than the individual biocontrol agent treatments. versicolor + farmyard manure resulted in maximum nodulation this was not significantly different to B. firmus coated seeds had better nodulation than any of the individual A. The lowest level of plant mortality (3-4%) due to charcoal rot of cowpea was recorded when bacterium coated seeds were sown in radish compost amended soil compared to the non-amended soil (13.8-20.5%), but this was not significantly better than some other treatments. Field experiments were conducted for 2 years to determine the effectiveness of combined use of two biocontrol agents, Bacillus firmus and Aspergillus versicolor for control of Macrophomina phaseolina induced charcoal rot of cowpea and Fusarium oxysporum f.