Advances in the flowering technology used in the Philippine mango industry
Professorial Chair Lecture
SEARCA Professorial Chair Lecture
Place
Department of Horticulture, UPLB, College, Laguna
Date
6-27-2003
Abstract
Results form five years of research involving three projects in three locations were presented to validate key assumptions of a model on mango flowering. Essentially, the model assumes that; one, gibberellic acid (GA) is a floral inhibitor that prevents a competent mango tree from flowering, two, decreased GA levels beyond a certain threshold leads to the development of floral initials probably through the accumulation of carbohydrates, and three, floral bud break occurs when shoot apices are sprayed with "flower-inducing" chemicals like potassium nitrate, thiourea or ethylene. Paclobutrazol was applied at 0.5, 1.0, and 1.5 g active ingredient per meter canopy diameter to try to inhibit gibberellic acid (GA) biosynthesis. The GA-like levels were measured using the dwarf rice bioassay. Treated apical shoots were examined for the presence of floral initials. The metabolic fate of applied nitrates was also probed using the ethylene biosynthesis inhibitor, aminooxyacetic acid. Paclobutrazol application drastically reduced GA-like levels which resulted in the initiation of more floral primordia at an earlier time. Preformed floral buds were already present at the time of the inductive spray suggesting the potassium nitrate acts by inducing bud break of quiescent pre-existing buds. Inhibitors of ethylene biosynthesis failed to inhibit the KNO3 - induced flowering of 'Carabao' mango, suggesting that ethylene does not mediate the effect of applied nitrate.
The metabolic fate of the nitrate awaits elucidation.
Location
UPLB Main Library Special Collections Section (USCS)
College
College of Agriculture and Food Science (CAFS)
Language
English
Recommended citation
Protacio, Calixto M., "Advances in the flowering technology used in the Philippine mango industry" (2003). Professorial Chair Lecture. 918.
https://www.ukdr.uplb.edu.ph/professorial_lectures/918
