POSTHARVEST LONGEVITY OF THE LEAVES OF THE CALLA LILY (Zantedeschia Spreng.)

Effect of growth regulators on postharvest longevity of Zantedeschia albomaculata /Hook/ Baill.) leaves was evaluated in studiem. The aim of 3 experiments to evaluate the effect of topolin used in two forms: meta-methoxytopolin (MemT) and its riboside (MemTR) on postharvest longevity of ‘Albomaculata’ leaves. In the first experiment, the topolins were used in water solutions at concentrations of 25, 50 and 75 mg·dm-3 for 4-hour conditioning of leaves, which were then placed in distilled water. In the second experiment, their solutions at concentrations of 25 and 50 mg·dm-3 were employed for 24-hour conditioning of leaves in a cold room at a temperature of 5°C and for a short, seconds-long immersion of leaf blades. In the third experiments, the scheme of the second experiment was employed again, except that here the solutions contained not only the topolins but also gibberellic acid at the same concentrations. In the experiments the control was leaves placed in distilled water after cutting. MemT and MemTR affect the postharvest longevity and quality of conditioned leaves of the cultivar Albomaculata. At concentrations of 25–75 mg·dm-3 they extend their longevity and inhibit protein degradation, but have no effect on their greenness index. Applied at concentrations of 25–50 mg·dm-3 to soak leaf blades for a few seconds, both growth regulators improve the longevity of the leaves more effectively than their 24-hour conditioning. The combination of MemT with GA3 at concentrations of 25 + 25 and 50 + 50 mg·dm-3 to soak leaf blades for a few seconds extends the postharvest longevity of the leaves by an average of 14–24 days and inhibits protein degradation, but has unfavourable effect on their greenness index.