Effect of leaf age, duration of cool temperature treatment, and photoperiod on bud dormancy release and floral initiation in mango.
Núñez-Elisea R., Davenport T. L.
Author Affiliation: University of Florida, IFAS, Tropical Research & Education Center, 18905 SW 280th St., Homestead, FL 33031-3314, USA.
Scientia Horticulturae 62 : 63-73
Abstract : Floral induction in apical buds of container-grown Tommy Atkins mango trees occurred after a cool temperature regime of 18° day/10°C night with a 12-h photoperiod was imposed for a minimum period of 3 weeks on trees bearing leaves at least 7 weeks old. Growth of induced buds during exposure to the cool temperature regime appeared to be necessary for floral initiation, since buds resuming growth in warm temperatures (about 28° day/22° night) immediately after receiving an inductive, cool temperature treatment produced a vegetative flush. Trees bearing younger leaves or chemically forced (thidiazuron or ammonium nitrate application) to resume growth prior to completing 3 weeks of cool temperature treatment also produced vegetative growth instead of inflorescences. Cool temperatures of 18° day/10° night with either 11-, 12-, 13-, or 24-h photoperiods resulted in floral initiation, whereas only vegetative growth occurred with warm temperatures of 30° day/25° night using 11- or 13-h photoperiods. Results of this study suggest that floral induction of Tommy Atkins mango occurred during bud dormancy in cool temperatures around 15°, and that warm temperatures near 30° prevented floral initiation of induced buds. Cool temperatures rather than a short photoperiod caused floral induction, whereas warm temperatures rather than a long photoperiod inhibited flowering.