Seed Storage - Structures - Introduction, Types Of Storage & Storage Structures

By TamilNadu Agricultural University on 23 Feb 2019 | read
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                                                STORAGE STRUCTURES

Introduction

To cope with the current and future demand of the increasing population for the food grains, it is emphasized to reduce the loss of seeds during and after harvest. seeds are stored for varying periods to ensure proper and balanced public distribution through out the year. Post harvest losses in India are estimated to be around 10 per cent, of which the losses during storage alone are estimated to be 6.58 per cent. But, with the advent of improved agricultural technology, the producer can afford to store the seeds for longer period with minimum loss.

For best storage performance,
1. The produce must be thoroughly cleaned and graded,
2. Dried to the safe storage moisture level of 10-12 % for cereals and 7-9% for   oil seeds (on wet basis) for a safe storage period of 6-12 months.
3. Storage structures should to be properly repaired, cleaned and disinfected,
4. Structures should bear the load of seeds stored and do not permit contact/
   exchange with outside humid air,
5. Structures should be constructed in the coolest part of the house/ farm.


An ideal storage facility should satisfy the following requirements

1. It should provide maximum possible protection from ground moisture, rain, insect pests, moulds, rodents, birds, fore etc.,
2. It should provide the necessary facility for inspection, disinfection, loading, unloading, cleaning and reconditioning.
3. It should protect grain from excessive moisture and temperature favourable to both insect and mould development,
4. It should be economical and suitable for a particular situation

Types of storage

Seeds can be stored in bulk or in bags

(a) Bulk (open) storage

It is preferred over bag storage for the following reasons
  • Large quantities of food grain can be stored
  • No difficulty in loading and unloading of grain
  • No need to purchase storage containers like gunnies
  • Insect incidence is less than bag storage, even this can be eliminated by fumigation in situ
  • Avoids waste from leaking bags
  • Easy inspections- saves labour and time.


(b) Bag storage

Commodities are mostly stored in gunnies. Storage in bags requires considerable labour, but the minimum investment is enough on permanent structures and equipment. The storage in  bags has the advantage of being short-term storage.

  • Bag storage can be done under a roof alvanized iron sheets, a plastic covering where grain is intended for very early onward  movement. Bags can be easily handled for marketing purpose.
  • There is no sweating of bags as they are arranged in racks with proper interbag space, but, initial cost is high and they can easily pickup infestation and retain even after treatment.

Storage structures used by the farmers

Gunny bagsMud and earthen structures
  • Gunny bags of different capacities (35, 50, 75 and 100 kg) with or without inside plastic lining
  • Mostly used for short term storage
  • Generally farmers prefer gunny bags for storage of farm cary over seeds
  • Clay, straw and cow dung- 3:3:1. Earthen structures are made, sun dried and then burnt in fire. Used for storage of Paddy, wheat, sorghum,oil seeds and pulses.
  • Life 8- 10 years. During rainy season develop cracks and moisture absorption followed by insect and mould infestation.
  • Capacity is 5 to 10 q
 
Bamboo structuresWooden structures
  • Split bamboo woven in the form of a cylinder with wide base and narrow mouth
  • Used for the seeds of Paddy, wheat and sorghum
  • Life 4-5 years. Weight loss due to insect attack is 5 % in paddy and 15 % in sorghum.
  • Capacity is 500 Kg
  • Local wood is painted black. At the top, 30 cm x 20 cm in let and at the bottom 30 cm x15cm outlet is provided
  • Life15- 20 years. Neither airtight nor moisture proof.
  • Used for stoage of paddy seeds with the capacity of 10 q


Miscellaneous plant materials (Paddy straw storage structure and Bottle gourd shells)
  • Paddy straw is wound in the form of rope to varying diameter (30–100q)
  • Stem of vitex and pigeon pea stalks wound like a bin and both sides are plastered with mud and cow dung (1-2 q).
  • Bottle gourd empty shells are used (2-5 kg)
  • Not insect and rat proof. Temporary structure only for storage of small  quantity of seed lots.

Paddy RopePaddy straw storage structureBottle gourd shells

Metal corrugated G.I. sheets

Underground structures

  • Sheets of about 3 m high are held vertically along one edge and edges of the other sheets are overlapped and bolted to each other.
  • Thus the circle with 2-4 m dia. is completed with many such sheets. They are covered on the top with the plain M.S. or G.I. sheets.
  • Circular pits vary from 100– 400cm in depth and 50 – 100 cm dia at neck and 250 – 300 cm at the bottom.
  • For filling and emptying there is an opening at the top. Before filling the sides and bottom are packed with straw and husk. After filling the pit is gain covered with straw and stone, the finally with mud.
  • Used for stoage of cereals with the capacity of 100- 200 q.It is safe against insects but, loss of seed viability and handling difficulties made it out of date.

Brick structures
  • It is a rectangular, structures built as part of the house, with brick in cement or lime mortar having a wall thickness of 40 –50 cm.
  • At the top 50x 50 cm inlet and at bottom 15 x15cm outlet is provided.
  • Used for storage of Paddy, sorghum and wheat seeds. Life 25- 30 years. High initial cost, not insect and moisture proof. Capacity is 25- 30 q

Hessian cloth bags : Split bamboo woven in the form of a cylinder with wide base and narrow mouth

Sanitation

Seeds undergo deterioration due to aging in storage. This is accelerated by climatic factors and external biotic factors like insects and pathogen. In addition to seed borne pathogen and storage insects, seeds are damaged by birds and rats for their feed. Clean and hygienic godowns protect the seed from external insects and preserve the seed. Hence care should be taken in construction of godown. The points to be noted are as follows.


  • Seed godown should be in a place where transport facilities are easily available.
  • Seed godowns should not be constructed in areas near seashore. Since the high RH of atmospheric air accelerate the deterioration of seed.
  • Seed godown should not be constructed in low lying water stagnating areas.
  • Seed godown should be constructed in places where atmospheric RH is low, free circulation of air is possible, sunlight is adequate and elevated in nature.
  • The ventilators should be at bottom for free air circulation.
  • Ground moisture should not reach the floor.
  • Should be rat proof with wire mesh
  • Should not be near industries as smoke is injurious


                                            Seed storage godown



 

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