Inhibition of flower bud abscission and ethylene evolution by light and silver thiosulphate in Lilium

The ethylene evolution from 3 cm‐long flower buds of Lilium X ‘Enchantment’ increased when the plants were placed in darkness. Also shortening the daily light period led to an increase in ethylene evolution from the buds. Dark‐enhanced ethylene evolution could only be evoked in flower buds between 2 and 3.5 cm long. Flower bud abscission induced by dakrness could be prevented by injecting silver thiosulphate into the flower buds, or by using plants grown from bulbs previously immersed in a silver thiosulphate solution. It is suggested that light‐controlled flower bud abscission in Lilium X ‘Enchantment’ is mediated by ethylene, and that an increase in ethylene evolution in darkness is a consequence of the influence of light on ethylene action rather than a direct influence on ethylene biosynthesis.