Biological control of root rot caused by Pythium aphanidermatumand growth promotion in hydroponic cucumber with microorganisms from mangrove

Abstract: The prospection of biological control agents in similar environments to the microbeapplication improves the chances of microorganisms establishment added to the environment.The low survival of these beneficial microorganisms added to hydroponic environment is aproblem for the growth promotion and root rot biological control success in hydroponic crops.Because of the environmental similarity between hydroponic systems and mangrove ecosystems,the aim of this work was to evaluate the ability of mangrove microbes to control root rot causedby Pythium aphanidermatum and to improve plant growth in hydroponic cucumbers. Among the28 strains evaluated for disease control in small-hydroponic system using cucumber seedlings,Gordonia rubripertincta SO-3B-2 alone or in combination with Pseudomonas stutzeri (MB-P3A-49, MB-P3-C68 and SO-3L-3), and Bacillus cereus AVIC-3-6 increased the seedlings survivaland were subsequently evaluated in hydroponic cucumbers in a greenhouse. Bacillus cereusAVIC-3-6 protected the plants from stunting caused by the pathogen and Gordoniarubripertincta SO-3B-2 and Pseudomonas stutzeri MB-P3A-49 increased the plant growth. Weconcluded that microorganisms from mangroves are useful as biocontrol agents and forimproving plant growth in hydroponic crops.