Abstract

Dendrobium sonia is commonly used as flower cutting and planted in pots because of its beautiful color, however the process of growth usually lasts 13 months after planting at garden. Different ratio N: P: K, in combination with benzyl adenine (BA) and stress water were investigated to shorten the the flowering time of Dendrobium sonia. Dendrobium sonia plants (planted at garden 6 months), which were treated with N, P, K with high concentration of P, could shorten the flowering time but not much earlier than control plants. Dendrobium sonia which was sprayed N 50 mg/L + P 100 mg/L + K 50 mg/L and BA 100 mg/L had flower buds early (after 30 days), however the rate of flowering plant was low (20 %). Orchids, which were stopped watering in 2 weeks, sprayed the N 50 mg/L + P 100 mg/L + K 50 mg/L and BA 100 mg/L, had flower buds early (after 30 days) and the rate of flowering plant was high (73,3 %). Control plants which were sprayed N, P, K at 50 mg/L N+ 100 mg/L P+ 50 mg/L K had 13,3 % flowering plants after 120 days.