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Orchid historically important versatile flower crop

Post by on Sunday, August 15, 2021

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 Orchids popularly called as angle flower is one of the best creations of the nature. The flower of orchid is valued for its beauty and lasts longer. Orchids comprise near about 9 percent of our flora and are largest botanical family of India. Nearly 1300 species and 140 genera of orchids are found in India. Among these 200 species occur in northwestern Himalayas, 800 species in northeastern India and about 300 species in the Western Ghats. Cymbidium is ranked among 10 cut flowers in the world and Dendrobium is the most widely growing tropical orchid. Cymbidium is grown mostly in northeastern region of India.
 
Center of origin: - Indo- Malayan, Tropical America and Australia. 
Flower having natural long life of 3-5weeks, price stability; market demand, and uses in vase; bouquet; cut flower; garland and landscaping are the important features of orchids.
 
Classification 
Classification based on growing environment 
 
1. Temperate orchid:-
These orchids thrive best at day temperature of 15-21 0C and night temperature of 10-12 0C. e g Cymbidium and Paphiopedilum. 
 
2. Sub-tropical orchids:-
These require day temperature of 18-21 0C and night temperature of 15-18 0C. e g. Cattleya and Oncidium 
 
3. Tropical orchids:-
These require day temperature of 21 0C to 29 0C and night temperature of 18-21 0C e g.  Phalaenopsis, Vanda, Dendrobium etc.
 
Based on habitate
1. Epiphytic orchids
These orchids are fast-growing in association with any support (natural tree) and the roots are clinging type. These have aerial root system which store water and are photosynthetically active. During dry period these bear flowers but shed the leaves e g Dendrobium ; Vanda etc
 
2. Lithophytic orchids
These are shade and moisture loving orchids e.g. Cymbidium etc.
 
3. Terrestrial orchids
These are xerophytes in nature. The annual shoots give rise to leaves and inflorescence.
 
4. Saprophytic orchids
The characteristic of this group is the presence of underground rhizomes with or without roots. The presence of roots falls in neotha and absence in epipogium group. These orchids lack green leaves.
 
Based on nature of growth 
1. Monopodial orchids: -
Single stemmed growth is the feature of these orchids e gAranda, Vandal, Phaleonopsis.
 
2. Sympodial orchids: -
Multi-stemmed growth is the characteristic feature of these orchids e g Cymbidium and Dendrobium.
 
Varieties 
Cymbidium:-
Peter Pan, Angelica Advent, Dingwall Mutant
Dendrobium 
Sonia 17, Sonia 28 Mutant, Dorine White, Sabine etc.
Orchid House and Its Management: 
A free-standing flat-roof orchid house shaded by spit bamboo or wooden batten is recommended for housing orchids suitable for warm climate. The temperature range suitable for most of those orchids is 65 to 850F. For satisfactory growth of orchids, atmospheric humidity should not be less than 30 per cent at night and 70 to 80 per cent during the daytime. Monopodial orchids like Vanda, Phalaenopsis require high humidity, whereas sympodial type e.g. Cattleya, Laelia or those with leathery leaves need less humidity. The atmospheric humidity will increase if small tanks or lily pools are located inside the orchid house and the floor space is covered with sand, soil, cinder, etc. instead of concrete. Free circulation of air is needed for the orchids to grow and flower and light intensity ranging between 1500 to 2000 feet candle in midday is good enough for most of the orchids.
Orchid house climate and rooting media:
Orchid house is maintained as per the type of orchid which range from tropical, subtropical to temperate, however plenty of diffused light, high humidity and fresh air circulation is need for all. Shade of 50-60 % is ideal. Majority of the orchids are day-neutral. Perforated clay parts, plastic pots are suitable for growing orchids. Charcoal, brick pieces, crocks (broken pots and broken tiles) and granite chips are good rooting media. 
 
Propagation:
Seeds, tissue culture and cuttings are the methods of orchid propagation. Orchid seeds are small and are dust-like around 1300 to 4000000 seeds per capsule are produced. The colour of seed varies. In natural conditions, an orchid seed gets infected with fungus, orchid mycorrhizae and germinates. Orchid seed do not utilize their own food or may do this process slowly. Thus up to proto corm stage it uses its own food and then it depends upon the mycorrhizal fungus which provides it essential elements. Thus when the seeds are grown under controlled conditions, the standard media like knudsons C-medium and Vein and Went medium are used which contains calcium nitrate, sucrose etc. essential for germination. A seed sown takes 30-35 day to reach 2 leaf stages and after attaining 4 leaf stage seedlings are transplanted.Vegetative propagation of hybrids of Cymbidium, Phalaenopsis and Cattleya is done by meristem culture and a large number of plantlets develop from a small piece of growing apex. Air layering is practised on the monopodial types like Vanda.
Cuttings of 8-12 cm long possessing one or more roots are used for propagation. Monopodial orchids are propagated by top cuttings and sympodial by division. 
Potting and Media:
Under natural conditions, terrestrial orchids are found growing in forest soils composed of rich humus, accumulated from the falling leaves over a period of time. Depending on the growth habit, i.e. terrestrial or epiphytic, orchids are potted in a wide variety of media and compost. Epiphytes like Cattleya, Epidendrum, Phalaenopsis Vanda, Dendrobium, Rhynchostylis, etc., are planted on a very light rooting media, consisting of various kinds of tree fern fibre or on larger pieces of hard charcoal. Orchids grow better if undisturbed, Phalenopsis, Vanda, Laelia and some species of Dendrobium should not be repotted unless it is absolutely necessary. Cattleya and many Dendrobium species and hybrid need repotting when roots become pot-bound.
Manuring and fertilization:- 
Use of graded fertilizers like NPK 20:20:20 along with coconut water (20-25 %) is recommended. Orchids love acidic medium.
  Liquid fertilizers are preferred in case of orchids, as orchids are slow-growing, slow-release fertilizers like Osmocote can be used to get very good results. Usage of fertilizers depends upon the stage of growth. During vegetative growth, large quantity of nitrogen should be reduced and amount of phosphate increased. One of the, most important liquid fertilizer for epiphytic orchids is Ohio WP solution.
 
Composition of Ohio WP solution fertilizer (g)
Potassium nitrate: 2.63
Ammonium sulphate: 0.44
Magnesium sulphate: 2.04
Monocalcium phosphate: 1.09
Calcium sulphate: 4.86
Ferrous sulphate: 0.50
Manganese sulphate: 1 %
Water : 4 lit
 
Irrigation:-
Plants should be irrigated 2-3 times a day and in no case plants should dry up. Plants in active growth require more water. Similarly plants grown in pots require less irrigation than the plants grown in baskets. Care should be taken not to damage plants by powerful jets of water. Atmospheric humidity influences evaporation of moisture from the compost and orchids, in general, prefer high relative humidity. Alkaline water is injurious to orchids and slight acidic water or at pH up to 7 should be used.
 
Management:-
Check sanitation, diseased and dried parts, water stagnation, proper aeration etc.
 
Harvesting:-
Spikes are harvested when the flowers are fully open.
 
Yield:-
 4-6 spikes per plant per year are obtained.
 
Storage: After harvesting stems are kept in bucket containing water and stored 
    under a temperature between  7-12 0C
 
Orchid cultivation:-
General recommendation:
The orchid aria or orchid house is a place where orchids are grown under protected conditions. Naturally orchid grows under the shade of trees in wild form. An orchid aria has a specific character that it has a central tank filled with water which helps in rising humidity as orchid are high humidity loving plants. The temperatures of the house are maintained as per the type of orchid. The fluctuation of temperature helps in better growth and flowering.
Apart from the protected cultivation orchids like Vanda, Aranda etc. can be cultivated under open field conditions. Trenches are prepared in which crocks, brick pieces, etc are used as rooting media and plants are grown under this condition.
The humidity is maintained 80 percent during day and 30 percent during nighttime for successful results. Watering is given two to three times a day as it should be ensured that plant root system does not dry off. The injury of plant through forced watering should be avoided. The ideal light for orchids is considered indirect light. During establishing stage or during young stages plants require less light and with the advanced stage of plant growth the light requirement is more. The poor light-receiving plants give poor growth. However, the duration of light required varies from orchid to orchid, for example around 800 foot-candles light is suitable for cultivation of Vanda and Aranda. 
The orchids such as Phalaenopsis require around 300 foot candles of light. Another group of orchids called Cattleya possess both short day as well as long day liking plants. If we will count and assess overall population of orchid species and duration of light, it is concluded that the majority is day neutral in nature. Any type of orchid cultivation is done under a pot or any other container, but the criteria for selecting a container includes its well aerated, well drained containers which can hold a plant in a safe condition. As far as repotting (technique of moving a plant from one location to another) is concerned it should not be done frequently. The minimum duration for repotting is about 3 years e.g. in cymbidium. There are such species of orchids as well e.g Vanda which gets adverse effects under frequent repotting. Maintain optimum nutrients.  
 
Orchid plant:
Orchid plant is a perennial herb. There are species are grown on ground and are called as terrestrial orchids. Lithophytes are orchids which grow on rocks, epiphytic group grows on trees, etc, semi-aquatic are those which grow in water, and saprophytes are such orchids which grow on organic matter which is decomposed. 
Apart from this there are other groups of orchids viz. sympodial, monopodial and pseudo monopodial. Sympodial are characterized by branched stem while as monopodial has single stem. The groups which produce pseudo bulbs for storage of water and nutrients which help plant to coup up during adverse conditions are called pseudo monopodials. Inflorescence of orchids is either terminal or lateral. The flower of orchid from floral biology point of view consists of three sepals, three petals and reproductive part called gynostemium.
 
Procedure of cultivation:
Orchid selection should be made on the basis of type of orchid in a particular area which varies from temperate, tropical to subtropical conditions; the containers used for orchids may be used clay, wooden, baskets etc. Potting media used for the cultivation of orchid should be well aerated, well-drained, should hold plant firmly, should be well sterilized, physiologically inactive and should have excellent water holding capacity. Perlite, coca peat, vermiculate, sphagnum mass, crocks, brick pieces etc. are commonly used rooting media for orchids. Potting and repotting of the plant should be done as per the type of orchids, 
 
 Nutrients and orchids
Nitrogen improves leaf number, size of spike and flowering deficiency of nitrogen causes yellowing of older leaves, and stunted growth and excess nitrogen application cause flowering delay.  Phosphorus deficiency causes dark green colour of leaves and stunted growth and it is needed for proper growth and flowering at optimum levels. Potassium deficiency causes scorching and death of leaves. Similarly any deficiency of micronutrients will adversely affect plant growth and development. Integrated use of organic and inorganic manures helps in providing proper nutrition to plants. Among organic sources FYM, poultry pallet, bone meal, and dried leaves are commonly used for orchids. 
 
 
 
 

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