Effect of some Bioagents on Root-Rot Disease Incidence on Bean Plants

Abd El-Moneim, Maisa; Gad El-Mola, Manal; Gaafer, Samy

doi:10.21608/ejp.2012.103179

Effect of some Bioagents on Root-Rot Disease Incidence on Bean Plants

Document Type : Original Article

Authors

¹ Central Lab. of Organic Agric., Agric. Res. Centre, Giza, Egypt

² Modified Climate Res. Dept., Central Lab. Agric. Climate, Agric. Res. Centre, Giza, Egypt

³ Protected Cultivation Dept., Hort. Res. Inst.., Agric. Res. Centre, Giza, Egypt

10.21608/ejp.2012.103179

Abstract

Root-rot of beans is one of the most dangerous diseases which reduce the number of plant stands and consequently the seed yield. Different methods are used to control the disease however, the biological method is the most safe and economic one. In this research work the effect of four bioagents, i.e. Trichoderma harzianum, T. hamatum, Bacillus subtilis and Pseudomonas fluorescens were in vitro tested against Fusarium solani, Rhizoctonia solani, Sclerotium rolfsii and Sclerotinia sclerotiorum. All bioagents significantly reduced the mycelial growth of the causal organisms. T. hamatum gave more significant results in reducing the linear growth of the tested pathogenic fungi. These beneficial microorganisms in addition to a mixture of T. harzianum + T. hamatum were also used as seed treatment to study their effect (s) on bean seedling root-rot disease and their effect on nutrition status of plants under commercial green house condition, in seasons, 2008/09 and 2009/10. B. subtilis gave more significant effect as single bioagent against root-rot disease and only 2% disease incidence was recorded compared to 54% in the control treatment. Reinoculation using one of these bioagents as soil treatment after 5 days from sowing treated seeds with same bioagent led to more significant increase in plant protection. Percentage of survived plants in these treatments ranged from 96-100% compared with the control treatment where the recorded percentage of survived plants ranged from only 46-48% in the two seasons. Positive correlation was observed between the tested doses (5, 10 and 20 gm/kg seed) of bioagent and their efficacy against root-rot disease. Bean plants treated with different bioagents showed higher percentages in contents of N, P and K due to the effect of the different bioagents on roots, compared to plants in control treatment. Treated plants also showed vigour growth and more yield when compared to the control plants.

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