The Role of Leaves as Inhibitors of Flower Induction in Strawberry: With one Figure in the Text

The effects of various defoliation treatments on flower initiationwere studied in the strawberry var. Talisman, which is a facultativeshort-day plant, with particular reference to differences inthe inductive capacity of leaves of differing maturity. Plants from which all mature leaves had been removed to leaveonly two immature leaves flowered in longer photoperiods thanintact controls, and conversely plants bearing only three fullymature and no immature leaves required a shorter photoperiodfor flower initiation than intact plants. Intact plants in constant darkness and totally defoliated plantsin continuous light both initiated flowers, but intact plantsin continuous light failed to flower. It is submitted that these results provide evidence that thephotoperiodic control of flowering in this plant operates througha flower inhibitor produced in the leaves. They also show that although leaves of any maturity are ableto inhibit flower initiation, under some conditions mature leavesare more inhibitory than immature, and that the inhibitory activityof any leaf decreases with decreasing photoperiod.