The Plant-Physiological Basis of Flower Induction in the Control of Fruit Production

Abstract

In the last four years, research has focused on off-season flower induction of longan, lychee and mango trees (Chapter 3.3). In order to achieve control over the flower induction process of fruit trees, it is necessary to address the key factors responsible for the transition from vegetative to generative bud development. Various, partly competing theories have been developed in the past about the physiological ‘Who’s Who’ in flower induction (Bernier et al., 1993). One theory favours the role of carbohydrates, which need to be present in sufficient amounts as a prerequisite for flower induction (Sachs, 1977). Other theories of flower induction focus either on the genetic control of a developmental switch from vegetative to generative development (Levy and Dean, 1998), control by particular hormones (Bernier et al., 2002), the existence of specific promoting or inhibiting factors or a mixture of both. However these theories do not apply to adult perennial fruit trees (Goldschmidt and Samach, 2004). Knowledge and understanding of the hormonal changes associated with the treatments previously described (Chapter 3.3) can be beneficial for future trials to induce flowering in mango, lychee and other fruit trees.