Effects of NPK and 6-Benzylaminopurine on Growth and Flowering of Two Orchid Genera

The rising demand for herbal medicine and environmental degradation necessitates the development of more productive management practices for many valuable orchid species. The nitrogen, phosphorous and potassium (NPK) fertilisation and 6-benzylaminopurine (BAP) application has been advised as a practice to address these trends. However, it is not known that at what rate the plant would efficiently endorse the growth. Performance of three NPK ratios, viz., (10:10:10), (20:10:15) and (30:10:15), with three dosages, i.e. 1, 2 and 3 g/l, for each ratio and nine concentrations, i.e. 15, 25, 50, 75, 100, 125, 150, 175 and 200 mg/l, of BAP supplement on two rare orchids Dendrobiumdensiflorum and Phaiustankervilleae was evaluated in green house conditions. At 1 g/l of (30:10:15) ratio NPK application, both the species showed significantly highest plant height, leaf length, leaf width and number of leaves. Shortest time interval from inflorescence emergence to first flower opening was observed when 200 mg/l of BAP was applied. The results indicate that NPK with high N and K promote vegetative growth and the cytokinin (BAP), at a concentration of 200 mg/l, has a great potential for speeding up flowering process in both the genera.