V. LALITHA AND K. A. RAVEESHA
Abstract
Antagonistic potentiality of Trichoderma koningii was tested against ten important seed borne fungal pathogens of paddy under in vitro. Hyphae of T. koningii colonized the mycelium of Bipolaris oryzne, Drechslera halodes, Tricoconis padwickii, Drechslera tetramera and Fusarium oxysporum. There was hyphal development and physical coiling between the hyphae of the mycoparasite and test fungi. The production of penetration structure was also evident. In dual culture method, class-2 type of antagonism was observed against all test fungi except Fusarium oxysporum and Fusarium solani. Cell free culture filtrate of T.koningii totally inhibited the pathogens and the results were comparable with that of synthetic pesticides at recommended doses. Significant inhibition in spore germination of test pathogens, were also observed. The mechanism of antagonism was found to be Mycoparasitism and Antibiosis.