Abstract
After a short irradiation at 366 nm with 200 lx, the intensity of conidiation ofTrichoderma viride colonies grown in the dark increased for the first 10 s proportionally with time. The increase slowed down after 10 s—6 min of exposure and after 10–60 min of irradiation the conidiation intensity began to decrease. When photo-induced by daylight, the conidiation started at a high rate after 25 h and persisted even after 48 h. The conidiation had no circadian character and its periodicity depended on the periodicity of photo-induction. Its intensity was also influenced by the carbon sources used, a maximum being reached with glucose (1–2 %). Higher glucose concentrations inhibited conidiation but had no influence on growth of colonies.