Chlorophyll content of sweet pea leaves was extracted by acetone from samples of cut leaf segments (0.59) taken on day 0 (at the beginning of experiment), day 3 and on the day when the vase-life of the control flowers was terminated (day 7). The samples were taken from the leaves in the upper part of the flowering stems. The samples were collected separately from each replicate and the average of the three replicates was calculated. Extraction in acetone was repeated until all pigments were extracted. The absorbance of the extracts was determined by a spectrophotometer (type GBC, UV/VIS 916, Australia). The chlorophyll content was determined according to Moran and Porath (1980) and calculated from a previously plotted standard curves and expressed in mg g−1 on dry weight (DW) basis. The equations for the determination of the concentrations of chl. a and chl. b are: