Stem rot of canola (Brassica napus ) caused by Sclerotinia sclerotiorum is one of the most serious of plant diseases. From 30 Trichoderma isolates, three different species T. harzianum-8, T. atroviride PTCC5220 and T. longibrachiatum PTCC5140, were selected on the basis of their highlevel of chitinase and/or glucanase activity, along with their rapid growth rate in vitro. These showed high growth inhibition of two phytopathogenic isolates of Sclerotinia sclerotiorum (S1and S2), with T. atroviride the greatest effect, reducing growth by 85-93%. They showed coilformation and penetration structures against the hyphae of the pathogenic isolates. T. atroviride PTCC5220 can be used for assessment of field biocontrol against S. sclerotiorum
