Biological control of Hordeum spontanum by fermentation broth of Aspergillus westerdijkiae UTMC 5040

Hordeum spontanum is one of the most important crop weeds, especially for wheat. The aim of this study was screening of phytopathogenic fungi for biocontrol of H. spontanum. Firstly, 150 fungal isolates were obtained from different soil sources of Iran. The isolates were subjected under primary and secondary screening on the sunflower and H. spontanum leaves. In these steps, 200 µl of centrifuged fermentation broth of cultivated fungi in PDB medium was sprayed on the leaves of sunflower and H. spontanum. Also, the ability of selected isolates to induce disease and necrosis on H. spontanum leaves in pot, preventing seed germination and root growth repression were studied. Finally, the host range of selected isolate was investigated. The results of primary and secondary screening showed that Aspergillus westerdijkiae UTMC 5040 produced the highest lesion halo on H. spontanum leaves. In pot test, treatment with 1.5 ml of fermentation broth produced huge necrosis on mature H. spontanum plant after 3 weeks. H. spontanum seed germination decreased from 90 to 25% and root emersion decreased from 60 to 35 mm 10 days after treatment by the fermentation broth. Host range study revealed that among 25 different plant strains, A. westerdijkiae UTMC 5040 caused disease onH. spontanum, Eremopyrum bonaepartis and Convolvulus arvensis leaves.Discussion and This study was the first report of biological control ofH. spontanum with fermentation broth of A.westerdijkiae UTMC 5040. The obtained results can be useful to finding a new fungal bio-herbicide.