Protected cultivation of Dendrobium (orchid )

Introduction

Scientific Name :- Dendrobium spp.

Family :- Orchidaceae

Chromosome number :- 38(x:-19)

Origin place :- Tropical countries( India & Shri lanka )

Protected structures

• High tech green houses /orchidarium .

Temperature

• Day – 15.5-21˚C

• Night – 10-15.5˚C

Light

• 2400-3600 ft candles.

Relative humidity

• 40-75%

• Carbon di oxide concentration :- 2000-2300 ppm

• Some of the most suitable containers used are (1) Pots, (2) Baskets, (3) Wooden logs, (4) Tree ferns, (5) Coconut husks,

• Clay pots are generally used for orchids, The pot size may vary from thumb size to 20 inch pots

GROWING MEDIA

• Most common potting mixture consists of charcoal, broken pieces of bricks and tiles, coconut husk and fiber.

Sterilization of Media

• Methyl Bromide @ 25-30g/sqmt

• Formalin @ 3-7%

• Basamid (Dazomet) @30-40g/sqmt Bed .

Varieties

• Mme popdadour,

• Mme Vipar,

• Hieng Beauty Sonia 17,

• Sonia 18,

• Kasem Gold,

• Sabine Red,

• Snow White,

CONVENTIONAL METHODS :-

• Dendrobium is propagated through :-

A . Divisions B. Offshoots C . Back bulbs

MICROPROPAGATION

In-vitro seed culture-:

• tissue culture plants,

Spacing

• Plant density/meter square -: 100-150

NUTRITION

• Orchids growing in nature do not need much of manuring but those grown in the orchidariums need spraying in the liquid forms.

• Fertilizer doses should be dilute. The plants will burn by over fertilizer which can be seen as burnt leaf tips. One of the liquid spray’s which gives healthy growth is the Ohio spray.

• Composition of Ohio solution made up for 4.5 lt. of water.

• Potassium nitrate 2.63g

• Ammonium sulphate 0.44g

• Magnesium sulphate 2.04g

• Monocalcium phosphate 1.00g

• Calcium sulphate 4.86g

• Iron sulphate 0.50g

• Manganese sulphate 0.25ml.

Irrigation Systems

• Good quality water is very important requirement to grow orchids successfully

• Mist or fogging system.

• pH of water :- 5.5,

• Watering needs depend on the potting media and the growing conditions.

• A potting media should never be wet but just evenly moist.

Cultural operations

Re-potting -:

• Repotting times do not vary very much but should usually be at the beginning of the active growing season or at least when the new roots appear.

• Re-potting done Every alternate year-Dendrobium

Plant protection

• Pest: Aphids, Mealy bugs, scales, slugs & snails, spider mites.

Control :- use insecticides ( imidacloropid) to control insect pest ,

• Diseases: Block rot, leaf spot, Petal blight, yellowing,

Control :- use fungicides( DM:-45, Ridomil) to control fungi , and for bacteria :- streptocyclin

Harvesting stage

• Fully developed flowers of good quality are harvested.

Yield :- depends upon varieties

Post-harvest handling

GRADING-:

• There are no standard grades for Dendrobiumflowers and their prices are fixed according to the size.

• Grading is done mainly on length of the flower spike, flower number and size and arrangement of flowers on the spike.

• Sometimes the number of lateral branches on the inflorescence is also taken into consideration.

STORAGE

• If these are to be cut they should be stored at 5-7o C.

• This temperature most Dendrobium flowers can be stored for 10 to 14 days.

• Plastic film storage is attractive and can be utilized.

PACKAGING

• An ideal package should be air tight, water proof, strong enough to withstand handling and small in volume.

• Standard florist boxes are used for the packing of Cattleya flowers.

• Keeping of a wet cotton at the cut end of the flower stem which is wrapped with a polythene wrapper helps to maintain humidity.