Abstract :
The aim of this study is to develop a bio-control method against Zymoseptoria tritici blotch (STB) which is a leaf disease causedby the fungus Zymoseptoria tritici in wheat. This disease in one the main diseases of wheat in Morocco. 120 isolates of bacteriaand 70 isolates of Trichoderma spp. of various ecological and geographical origins, were tested in vitro for their antagonisticpotential towards two strains of Zymoseptoria tritici, namely G1-1 which was isolated from soft wheat (Triticum aestivum L.) andA5-1 which was isolated from durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.). Compared to the controls, all theantagonists selected after the in vitro tests (9 bacterial strains and 18 Trichoderma spp. isolates) showed a very high antagonismpotential, generating zones of inhibition of the radial growth of Zymoseptoria tritici, which ranged from 34 to 84 % for the bacterialstrains and from 40 to 70 % for the Trichoderma spp., after 96 hours of confrontation. To confirm the performance of theselected isolates in vitro, an in vivo assay on inoculated potted plants by the pathogen was conducted using two sensitive wheatvarieties to septoria disease; ‘Aguilal’ (soft wheat variety) and ‘Karim’ (durum wheat variety). Spraying of selected antagonistssuspensions onto leaf surfaces of wheat plants proved to be effective and significantly reduced the severity of the septoria diseaseup to 91 % in the preventive treatments. For curative treatments, the intensity of disease was more important. The symptoms werereduced from 7 to 72 % in the case of bacterial treatments and from 19 to 81 % for Trichoderma spp. strains.
NaturalLanguageKeyword :
Zymoseptoria tritici , Trichoderma spp. , Bacteria , biological control , wheat
