Gibberellin Modification of Flower Sex Expression in Cucumis sativus L.

Flower sex expression of cucumbers can be modified by treating seedlings with several growth-regulating substances. With the exception of gibberellin, chemicals tend to reduce the number, or suppress the development, of staminate flowers, and increase the number or accelerate the development of pistillate flowers. Gibberellin, in contrast, increases the number of staminate flowers in monoecious cucumbers and results in the formation of staminate flowers on gynoecious cucumbers which otherwise would produce only pistillate flowers. In promotive effects on staminate flower formation and vegetative extension, GA 4 is approximately tenfold more active than GA 3 .