The seasonal change of relative photoabsorption in green leaves of plants

The light absorption of chlorophyll comparatively with other pigments was determined with the coefficient of relative photoabsorption (CRPA) using the spectrophotometrical method in the ethanol extracts of green leaves. The research reveals that the CRPA varied from 7 to 10% during twenty-four hours period and reached its minimum and maximum at 4-8 a.m. and 2-4 p.m. respectively. At the beginning of summer season the CRPA grew and reached its maximum during the fruitage period, however its value dropped quickly at the end of vegetation period. The experiments demonstrated a strong correlation between the CRPA and the air temperature and the length of the daytime period. The CRPA could be used for the description of photosynthetic processes which are high-setnsitive to external factors and could be also prospectively used as a rather simple, quick, quite accurate and not reactive demanding indicator for express-analysis, control and monitoring of vegetative resources.