Muhammad Munir, Mohammed Refdan Alhajhoj, Abdul Aziz Khakwani, and Jalal-ud-Din Baloch

pp. 247 - 254

Abstract

Experiments were carried out to study flowering response of Nasturtium under four distinct controlled photoperiods
(8, 11, 14, and 17 h.d^-1), shading materials (0, 20, 30 and 40%) and five temperature regimes (10, 15, 20, 25, and 30°C). A curvilinear facultative response was observed in all experiments. Cultivar ‘Empress of India’ took minimum time to flower when
grown under a 17 hr-photoperiod (57 days) however, it was significantly (P<0.05) increased when photoperiod decreased to
8h (83 days). Similarly, days taken to flowering were increased significantly (P<0.05) when plants were grown under low light
integrals (40%, 30%, and 20% shade). Flowering was delayed up to 17 days when plants were grown under intense shade
(40%). Temperature also had a significant effect on the developmental phases of flower as low temperature (10°C) decreased
flowering up to 46 days as compared to plants grown at 25°C. However, the quality of flowering plant (including plant height,
spread and leaf number, data not shown) was decreased at higher temperatures (25 and 30°C). Best quality plants were
obtained when grown between 15 to 20°C. These findings revealed a prospect of plant scheduling of the flowering time of
Nasturtium grown under short day photoperiod to extend their marketing period. A steady supply of this flowering annual
can be maintained in the market by grown them under different shades (low light integrals). Similarly, an optimum growing
temperature between 15-20°C would also be a beneficial effect on the quality of plant in the market.