Study of the Effects of Different Concentrations of Copper, Manganese and Nickel on the Growth and Sporulation of some Trichoderma Species

To evaluate the effect of different concentrations of copper, manganese and nickel on the growth and sporulation of Trichoderma species of; T. harzianum, T.longibrachiatum and T. tomentosum, an experiment was carried out in vitro at 25oC±2 on soil extract agar medium of five replicates. The results revealed that among these species T. longibrachiatum had the highest growth rate (47.78mm) after 72 hours past. During this time nickel not only didn’t exhibit any inhibitory effect on T. longibrachiatum, but also increased the growth of the species (7%). Throughout the experiment, the inhibitory concentration of 50% (IC50) values for the copper and nickel and for the case of T. tomentosum was estimated at 32.22ppm after 96 hours past. The results showed that the sporulation of Trichoderma species on soil extract agar medium increased in the presence of heavy metals. Also in this study it was found that the absorption rate of heavy metals by Trichodema species depended not only on the fungal species but also on the metal type and its concentration, the highest absorption rate (48.67%) being observed at 1000ppm concentration of nickel on T. tomentosum.