BIOLOGICAL-CONTROL OF FUSARIUM FOOT ROT IN WHEAT SEEDLINGS BY TRICHODERMA-HARZIANUM

The effect of a parental strain of Trichoderma harzianum (B1) and its benomyl-tolerant mutants (1T and 4T) on the biological control of Fusa rium foot rot in wheat seedlings was investigated. In both a raw soil naturally infested with fusaria and in the raw soil artificially amend ed with the infection preparate of Fusarium culmorum, the greatest con trol, which was comparable with that of Vitavax 200 FF (a.i. carboxine + thiram), was achieved by the seed treatment with conidia of the mut ant 4T. Both mycoparasitism and antibiosis of the T. harzianum strains tested may likely take a part in the biocontrol of F. culmorum. The m ost effective mycoparasite was determined to be the mutant 1T that was able to penetrate hyphae of F. culmorum. All the tested strains of T. harzianum produced antibiotics capable of inhibiting mycelial growth of F. culmorum. The greatest inhibition of the pathogen's radial growt h (58.55%) was determined when the common influence both of volatile a nd non-volatile metabolites of 4T was tested.