Annals of Botany 61: 283-288, 1988
© 1988 Annals of Botany Company
RESEARCH-ARTICLE |
Photoperiod and Temperature Effects on Late Developmental Stages of Stylosanthes guianensis
Department of Agriculture, University of Queensland St Lucia 4067, Australia
* Present address: Faculty of Agriculture, King Mongkut's Institute of Technology, Ladkrabang, Bangkok, Thailand.
Accepted: 7 October 1987
Seedlings of Stylosanthes guianensis var. guianensis cv. Cook and S. guianensis var. pauciflora cv. Bandeirante were defoliated and placed in a naturally lit glasshouse at 23/18 °C, 28/23 °C or 33/28 °C (day/night). After exposure to 14 h days and after floral induction with 30 cycles of 11 h, plants were allocated to 11, 12, 13 or 14 h during flowering and seed formation.
Floral initiation occurred after 10–15 short-day cycles. Flower appearance was hastened by warm temperatures and spike number per plant at 20 d after flower appearance was negatively related to temperature and greater in Cook than in Bandeirante. Exposure to 13- and 14-h days reduced the continued differentiation of inflorescences in Bandeirante, and in Cook in warm temperatures. Floret number per spike was greatest at 23/18 °C and a higher proportion of florets aborted in Bandeirante at 33/ 28 °C. Variations in seed setting of the bi-articulate loment of Bandeirante are described. Highest potential seed yield occurred if after floral induction 11 or 12 h days were maintained with 23/18 °C or 28/23 °C temperatures.
Photoperiod, temperature, development, Stylosanthes guianensis, flowering