Effect of plant size on growth and flower production of Phaius tankervilleae (Banks ex L'Hérit.) Blume - an endangered orchid of North-Eastern India

A pot experiment was conducted at Horticultural Research Station, Kahikuchi, Guwahati, to study the effect of different sizes of plants on vegetative growth and flower production of Phaius tankervilleae. Five different plants with varying sizes and numbers of pseudo bulb were adopted as treatments which were replicated 4 times. The flowers bloom from April and the experiment shows T3 produces the maximum number of spikes (2.38) per plant and earliest spike initiation (250.77) days while T5 produces the least number of spikes (0.5) plants and took longest days for spike initiation with (255.13) days. Meanwhile, T1 produce more new pseudo bulbs (4.0) and the least number was seen in T5 with (2.14). But T5 plants produced the biggest new pseudo bulbs (2.85cm diameter). Irrespective of the numbers of the pseudo bulb, plants with bigger pseudo bulb produced a bigger plant, long spike, more spike, bigger and more number of flowers which are a superior trait for a good quality cut flower. Beyond the production of flowers, this experiment further promotes the multiplication of pseudo bulbs, which are necessary for increasing the population of the plants for restoring and conserving the plant population without further exploitation.