Seed Storage – its Importance and Storage Methods
“Seed storage may be defined as the preservation of viable seed from the time of collection until they are required for sowing”.
Importance of Seed Storage:
- To preserve seeds finer conditions that best retain germinative energy during the interval between collection and tome of sowing
- To protect seeds from damage by rodents, birds, and insects.
- To preserve qualities of seeds collected during a year of heavy seed crops to furnish a supply during years of little or no crop
Factors influencing Storage:
- Fully ripened seeds will retain viability longer than seeds collected when immature
- Seeds of high initial viability will store better than those with low initial viability
- Seeds with hard, impermeable seed coats will retain viability longer than those with soft, permeable seed coats.
- Undamaged seed will retain viability better in storage than seed physically damaged during collection of processing.
- Lower the moisture content (i.e. 32%) and lower the temperature (i.e. 40OC), longer will be the period of viability.
Others Factors include:
- Moisture Content
- Maturity of Seed
- Oxygen and other factors
- Longevity of Seed
Seed Store or Seed Bank:
- A permanent seed store should be built in any division where the raising of large-scale plantations is a part of normal work.
- Seed store should be well ventilated, with shelves for seed storing.
- The floor should be cemented and damp proof.
- The openings should be guarded with wire netting to exclude rats, mice, and squirrels.
- Other facilities like water, electricity, should be available for seed testing stratification etc.
- From species to species there are great differences in capability to survive storage some species may survive for long periods under all conditions.
- Store only new, mature, healthy and well-dried seeds
- Keep them in dry and cool place to extend their viability
- Seed easily reabsorb moisture. To maintain dryness, keep seeds in an airtight container like tins, cans or glass jars with tight fittings.
- Put in some moisture absorbing material. Dry wood ash, dry charcoal, or small pieces of newspaper
- The drying material should take up about one-fourth of the container space
- Label the containers with the type of seed, place, and date of collection
- If possible, include the initiate percent viability of the seeds. This information will help you to learn about how much each type of seed loses viability b/w collection and planting
- Protect seeds from insects and fungi
- Protect from rodents and birds during storage
Seed with Natural Longevity:
- Acacia nilotica and Robinia pseudoacacia belong to leguminous spp that can be stored for very long periods, these have very hard, impermeable seed coat, and moisture content is normally low.
FACTORS AFFECTING THE STORAGE LIFE OF SEED:
- Genetic Effects
- Pre Harvest Effects
There are some factors which also affect the longevity and viability of seed, these are as follows:
- Mineral nutrition
- Soil moisture
KINDS OF SEED:
Seeds that can be dried, without damage, to low moisture contents (5 – 10%)
Can be stored at subfreezing temperature 2 to 5 OC
Their longevity increases with reductions in both moisture content and temperature
Examples: Pines, Acacia, Eucalyptus, Casuarina, etc.
Seeds that do not survive to dry to any larger degree, and are thus not amenable to long-term storage
Can’t be stored in airtight containers
Storage must be above freezing
E.g. Quercus, Aesculus, Mango, Neem, etc
Seeds those are more tolerant of desiccation than recalcitrant, though that tolerance is much more limited than is the case with orthodox seeds
They generally lose viability more rapidly at low temperature
Can be stored at a subfreezing temperature
E.g. Walnut, fir, Populus, Salix, etc
TYPES OF STORAGE:
- Good for orthodox seeds
- At room temp for few week or months or at cool temp for longer periods
- Store seed in piles, sacks, or containers
- Work well in a cool climate with low humidity
- Optimum temp 32 – 41 OF
- Used for recalcitrant seed
- Used for a short period
- The basic requirement is good ventilation to prevent heating and fungal growth
- For uniform moisture conditions, the seeds are mixed with a moist medium, like sand, cloth, charcoal, sawdust
- Moisture requirement 11 – 40%
- Temp requirements 32 – 50O F
List of Tree Seeds their seeding period, viability and no. of seeds per Kg.
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