Study the Impact of Carbon and Nitrogen Sources on Some Biological Characteristics of Two Biocontrol Agents: Trichoderma harzianum and Trichoderma viride

The results indicate that the use of nitrogen sources and carbon sources significantly affected the growth of Trichoderma harzianum and Trichoderma viride. Aspartic acid achieved the highest colony area for T. harzianum (60.79 cm), while the highest colony area was for T. viride with alanine (51.50 cm) and the lowest with cysteine (28.26 cm). Arginine also showed a positive effect on the sprouting rate and biomass; the sprouting rate was 8.1 for T. harzianum and 10.2 for T. viride, while the biomass recorded the highest value of (0.230 g) for T. harzianum and (0.207 g) for T. viride. Glucose was the most effective source; T. harzianum colony area was (55.39 cm), followed by sucrose and fructose, while cellulose was the least effective (13.85 cm). Carbon sources also enhanced ant-pathogenic activity and reduced pH to 5.4 and 5.5 compared to the control groups (6.9 and 6.8).