BIO-CONTROL BY COMPETITIONS
Fungistasis: Few antagonists are usually able to
overcome the fungistatic effect of soil that results from
the presence of metabolites produced by other species,
including plants, and to survive under very extreme
competitive conditions. Trichoderma strains grow
rapidly when inoculated in the soil, because they are
naturally resistant to many toxic compounds, including
herbicides, fungicides and insecticides such as DDT, and
phenolic compounds [16], and because the strains
recover very rapidly after the addition of sub-lethal
doses of some of these compounds. Resistance to toxic
compounds may be associated with the presence in
Trichoderma strains of ABC transport systems [17]. For
this reason, preparations of Trichoderma strains are
very efficient in controlling several phytopathogens,
such as R. solani, P. ultimum or Sclerotium rolfsii, when
alternated with methyl bromide, benomyl, captan or
other chemicals [18].