Orchids are most attractive flowers with diversity in plant characters, flower colour, size, shape and blooming time. North Eastern India is the hot spot of orchids naturally growing in the undisturbed forest areas. Over the years, a well organized commercial orchid culture has been developed in Sikkim. However in Tripura, orchid culture for commercial purpose on a large scale has not been adopted by the flower growers. In the recent years, selected farmers have started orchid culture in the state. Considering the suitable agro-climatic conditions of Tripura and scope of orchid culture for livelihood improvement, different type of orchids have been collected at ICAR Research Complex for NEH Region, Tripura Centre for their relative performance evaluation in the state.
Orchids are found in tropical, subtropical and in temperate areas. In general, favourable temperature requirement is 15-300C in day and 10-200C in night depending upon the orchid species. Tropical orchids like Dendrobium, Vanda and Phelaenopsis require 21-290C in day and 18-210C in night. Whereas, Cattleya and Oncidium require 18-210C in day and 12-170C in night. Relative humidity should be40-75% RH. Grows well under low intensity light and partial shade. Moderate to heavy rainfall with moist growing conditions. The climate of Tripura is characterized by tropical hot and humid summer (RH:60-80%), mild winter and experiences heavy rainfall during the monsoon season. Temperature ranges from 20-350C in summer and rainy season and 5-220C in winter. Rain forests are distributed in all parts of the state and different species of orchids grows naturally on forest trees.
Suitable Orchids for Tripura
Orchid species collected are Dendrobium, Cattleya, Cymbidium, Vanda, Mokara and Phelaenopsis apart from some local wild collections. The most suitable species for Tripura is Dendrobium for good quality cut flower production. There are many colour and size variation in this species. Variety Sonia 17 and Sonia 28 have been found to be very good in terms of flower spike length (40-55 cm) and flower size. Other colour ranges are pink, white, orange, yellow and red etc. and flowering is continued through out the year. Vase life is approx. 15-20 days and also has a long pot flower life for about 45-50 days. Cymbidium species requires cool temperature (7-100C) to set flower bud and in the winter and flowering takes place in spring season. Similarly, Cattleya species is cool temperature orchid and flowering takes place in winter. Flowering during August was also recorded under Tripura condition with pot flower life of about 35-45 days. Phalaenopsis can be grown in warm climate, however, requires low temperature (120C) for flower initiation. Under Tripura condition, pick flowering is during spring. Vanda is another warm climate orchid and Mokara is a hybrid orchid under Vanda. Though, Dendrobium has been found to be very good for cut flower, however, all these orchid species are very much suitable for cut as well as pot plant purpose. Each orchid pot plant is sold for Rs. 500-1000 depending on the size of plant and pot.
- Potting media is prepared combining soil, sand, cocochips, leaf mould, tree dried bark, saw dust, brick pieces, charcoal dust/chips, wood pieces and dried cow dung/vermicompost.
- A good mixture of coco peat, bark and brick pieces (1:1:1) tightly bundled with coconut husk is good for Dendrobium.
- Coco chips, coco peat and brick pieces (3:3:1) or charcoal chips, leaf mould, loamy soils and sand are also mixed for Cymbidium.
- Brick chips, coco chips, leaf mould (1:1:1) and flat stone pieces are used for Cattleya.
- All the media components are well treated with formalin 40% (1.5-2%) separately. Formalin is drenched into theheap @ 200-250ml/ 10L water and the heap is covered with black polyethylene sheet for 7 days. Media is then turned and left for 4-6 days. Such treated soil is free from all types of soil born insects-diseases.
- Orchids are planted in containers or some are tied on the tree trunk/ branches. Orchid can be planted directly on the ground in the pit containing orchid media.
- Containers may be earthen pot, ceramic pot, plastics pot, wooden logs, wooden frame made baskets, galvanized wire baskets and bamboo made baskets. These are soaked in water for 1-2 hrs before filling in the container.
- Coconut husk made blocks containing charcoal chips are also used specially for Dendrobium.
- There should be sufficient holes for water drainage from the media and for hanging purpose light weight containers are used. Flat stone or broken clay pot pieces are put at the base of the container and then, filled with coconut husk chips, charcoal and brick chips on after another.
- Finally saw dust is put on these media. Small plantlets or off shoots are carefully planted in pots or even cuttings of root and stem are also inserted into the potting mix. At the time of planting the stem should be erected upward and may be supported with bamboo stick.