Different Approaches of Bio-control Agents for Controlling Root Rot Incidence of Some Vegetables under Greenhouse Conditions

Abstract

Different approaches of some antagonistic fungal, bacterial and yeast agents applied as seed treatment or soil drench was evaluated against various soil-borne pathogens causing vegetables root rot disease under greenhouse conditions. The tested pathogenic fungi were <i>Alternaria solani Fusarium solani, F. oxysporum, Rhizoctonia solani, Sclerotium rolfsii, Macrophomina phaseolina </i>and<i> Pythium </i>sp<i>.</i>, meanwhile the tested bio-agents were <i>Trichoderma</i> <i>harzianum</i>, <i>T</i>. <i>Viride </i>and<i>Bacillus subtilis, Pseudomonas flourescens </i>and <i>Sacchromyces serivisae</i>. Significant reduction in the disease incidence was observed in bio-agent treatments in comparison with untreated control. Root rot incidence, at pre-emergence stage, significant effect was observed in bio-agent treatments as seed soaking comparing with soil drench treatment. The treated seeds showed a protective effect for seeds germination against the invasion by soil-borne pathogenic fungi.Meanwhile,soil drenched with different bio-agents showed more efficacy for reducing root rot incidence at post-emergence growth stage of tested vegetables, Cucumber, Cantaloupe, Tomato and Pepper. The obtained results revealed that the antagonist <i>T. harzianum</i> showed significant superior effect to reduce diseases incidence followed by <i>B. subtilis</i>. Also, the antagonists <i>T. viride</i> and <i>P. fluorescence</i> occupied significantly the second degree for reducing root rot incidence. The treatment with <i>S. serevisiae</i> had the lowest effect on disease incidence, although it significantly lesser than check control treatment.The present study demonstrates that application of bio-agentsas seed treatment and soil drench may be useful for controlling root rot disease in field.