Effects of exposing freesia corms to ethylene or to smoke on dormancy-breaking and flowering

Ethylene (C₂H₄), applied at an early stage of the high-temperature treatment for dormancy breaking, promoted sprouting. Five μl l^?1 of C₂H₄, applied during 2 days, replaced 2 weeks of high temperatures. The promotive effect of C₂H₄ diminished with increasing exposure period and no difference was found between the effects of 5 and 50 μl l^?1. The promotive effect of exposing corms to smoke was slightly lower than that of C₂H₄. Neither had an adverse effect on flowering and both resulted in shorter leaf length and rigid growth, which could be useful for solving the problems of leafiness during winter.