BUD INITIATION AND MORPHOGENESIS IN 'TOMMY ATKINS' MANGO AS AFFECTED BY TEMPERATURE AND TRIAZOLE GROWTH RETARDANTS
A chilling or warm temperature regime and the triazole retardants, paclobutrazol (PBZ) and uniconazole (UCZ), were tested on mango (Mangifera indica L. cv. Tommy Atkins) trees to study vegetative and reproductive developmental responses. Containerized trees were sprayed with 2,000 mg· l-1 PBZ or 500 mg· l-1 UCZ during the spring, and one month later subjected to either 18°C/10°C or 30°C/25°C (day/night, 12-h photoperiod). Non-sprayed trees served as controls for each temperature regime. Trees were subjected to the corresponding temperature regime until all shoot apices had initiated apical buds (75 days). With chilling alone, floral (74%), mixed (11%), and vegetative buds (15%) were initiated. With chilling plus PBZ or UCZ, only floral (>90%) and mixed buds (<10%) were initiated, and bud break was advanced by nearly 3 weeks in relation to chilling alone. No flowering occurred at 30°C/25°C despite triazole sprays, but the triazoles reduced vegetative flushing and internode length. Results show that temperature defined bud morphogenesis. Chilling, and not PBZ or UCZ, induced reproductive morphogenesis, whereas warm temperatures caused only vegetative growth. Involvement in floral induction of a putative floral stimulus is discussed.
Nunez-Elisea, R., Davenport, T.L. and Caldeira, M.L. (1993). BUD INITIATION AND MORPHOGENESIS IN 'TOMMY ATKINS' MANGO AS AFFECTED BY TEMPERATURE AND TRIAZOLE GROWTH RETARDANTS. Acta Hortic. 341, 192-198
Mangifera indica L., chilling, floral induction, floral stimulus, paclobutrazol, uniconazole