Vegetative and floral bud abortion in cucumber plants: Hormonal and environmental effects

The acropetal, zonal pattern of axillary buds along the main shoot of the cucumber plant, which includes bare nodes (no appreciable development), staminate, mixed and, lastly, pistillate (or hermaphrodite) ones, is described in monoecious, gynoecious, andromonoecious and hermaphrodite genotypic lines grown at various seasons and treated with gibberellin (GA_{4 + 7}) or with an ethylene-releasing compound (CEPA, 2-chloroethyl phosphonic acid).Under optimal growing-conditions, GA given to gynoecious and hermaphrodite plants mimicked summer conditions by increasing the number of basal bare nodes and the proportion of abortive female buds and staminate buds. CEPA given to monoecious and andromonoecious plants generally imitated winter conditions by decreasing the proportion of bare and abortive nodes, and increasing female tendency.Bud abortion was also noticed under sub-optimal growing-conditions (low light intensities and relatively low temperatures) during the winter. This seems to be physiologically unrelated to the above mentioned phenomena.