Studi sulla senescenza fiorale e fogliare della violacciocca recisa

Leaf yellowing and petal senescence are the main physiological disorders that define the postharvest life of many cut flowers. Cytokinins and thidiazuron (TDZ) are able to inhibit leaf yellowing in some cut flowers and potted plants. Since TDZ is less effective on preventing chlorophyll losses during dark storage, it was tested in combination with other plant growth regulators with the aim of finding out eventual synergic effects. Cut stock flowers (Matthiola incana L.), obtained from local growers, were placed in light and in dark conditions after treatment with the following solutions: water (control) or vase solution containing 5-10 μM TDZ, 50-100 μM 1-naphtalene acetic acid (NAA), 150 mg L-1 8-hydroxyquinoline (8-HQS), or combinations of NAA or 8-HQS with TDZ. All chemicals were applied as pulse treatments for 24 h under standard environmental conditions. The effect of treatments was evaluated by chlorophyll content, vase life and ethylene production. Results confirmed that TDZ was able to delay leaf yellowing in light during the whole experimental period (30 days), while in darkness conditions it delayed chlorophyll losses until 10-12 days. All combinations tested did not show any additional benefit both in light and dark condition. In conclusion, TDZ alone was the best treatment for improving the vase life of cut stock flowers.