Abstract

Lyophilized and non-lyophilized toxins produced from Trichoderma species were investigated against Ceratocystis paradoxa mycelial growth at different concentrations in-vitro. Lyophilized toxin inhibition on C. paradoxa by T. viride(28.14 and 28.14%) and T. polysporum (28.88 and 28.88%) at 70 and 100% concentrations were significant (p = 0.005) compared with T. hamatum (20.37 and 21.48 %) and T. aureoviride (20.00 and 20.37%) six days after incubation. Non-lyophilized phytotoxin inhibition on C. paradoxa mycelia by T. viride (21.85 and 23.335%) and T. polysporum (22.22 and 22.59%) at 70 and 100% were also significant (p = 0.005) when compared with T. hamatum (16.29 and 18.14%) andT. aureoviride (17.03 and 17.77%) 6 days after incubation. The mycelial growth ofC. paradoxa was stimulated by T. hamatum and T. aureoviride at 20 and 50% concentrations with lyophilized and non-lyophilized phytotoxins. The lyophilized phytotoxin exhibited better control of C. paradoxa compared with non-lyophilized and the control treatments. Using gas chromatography-mass spectrometry, column fraction isolated from T. viride R_f value 0.51 was deduced to be 1, 2-benzendicaboxylic acid. It is responsible for the inhibitory action on C. paradocamycelia. This compound produced by T. viride depended on type of fungus strain and standard used.

Key words: GC-MS, inhibition, mycelia, 1, 2-benzendicarboxylic acid.