GUMMOSIS OF TULIP BULBS CAUSED BY ETHYLENE
Gummosis of tulip bulbs was evaluated on the basis of the total area of the gum blisters formed. Very small quantities of ethylene proved to be able to cause gummosis. A concentration of about 0.1 ppm appeared to be a threshold value for bulbs in a highly responsive stage. The 'Apeldoorn' bulbs showed maximal reaction two to four weeks after lifting. Only certain cultivars, for instance 'Apeldoorn', 'Enterprise', and 'Bartigon', were reactive; others, for instance 'White Sail' and 'Red Champion', showed hardly any effect due to ethylene. The gummosis process appeared to be temperature dependent.
Kamerbeek, G.A., Verlind, A.L. and Schipper, J.A. (1971). GUMMOSIS OF TULIP BULBS CAUSED BY ETHYLENE. Acta Hortic. 23, 167-172