During the UV period (70das) the two-factor analysis of variance indicated a high significant impact of light intensity (p≤0.01) from 120s until 180s,a high significant impact of UV light (p≤0.01) from 80s until 100s and a significant interaction of both factors (p≤0.05) from 80s until 100s .At 77 das a high significant impact of light intensity(p≤0.01) could be proven from 100s until 220 s.There was no longer a significant UV effect,although an interaction of light intensity and UV irradiation could be seen at 60s.