Purpose, Principles, Types, and Stages of Seed Storage

1. Purpose, Principles, Types and Stages of
Seed Storage
(SST 513)
Prof. Kumari Rajani
Department of Seed Science & Technology
Bihar Agricultural University, Sabour

2. Seed Storage may be defined as the preservation of viable seeds
from the time of harvesting until they are required for sowing.
(Holmes and Buszewicz 1958)
Introduction
The purpose of seed storage is to maintain the seed in
good physical and physiological condition from the
time they are harvested until the time they are planted.
Prof. Kumari Rajani

3. 1. To preserve planting stocks from one season until the next
2. To maintain the seed in good physical and physiological condition
from the time they are harvested until the time they are planted
3. To store unsold seed “carry over” seeds for 2 or more years for
marketing during the second planting season after harvest
Purpose of Seed Storage
4. To preserve small quantities of desired genetic stocks for longtime
storage
5. To store for extended periods so as to eliminate the need to
produce the seed every season
6. To store for extended periods to improve the percentage and
rapidity of germination by providing enough time for a “natural”
release from dormancy
Prof. Kumari Rajani

4. Objectives for Seed Storage
1.Very short periods (overwinter): between production and sowing
2.Several years (10 or less): to ensure a reliable supply of seeds in
In the more comprehensive view
the absence of annual crops
3.Long periods (10 to 50+ years): for germplasm conservation
Prof. Kumari Rajani

5.  The types of storage needed can be related to the time of storage
expected
Broadly it can be classified into 4 types-
a) Storage of commercial truthfully labelled and certified seed
Types of storage
a) Storage of commercial truthfully labelled and certified seed
b) Storage of carry over seeds
c) Storage of foundation seed stocks and enforcement seed samples
d) Storage of germplasm seeds
Prof. Kumari Rajani

6.  This storage of commercial seed requires the largest storage need
from harvest until planting
 About 75-80 % of the seed produced are stored for about 6-9
months
 Seed must be dried to 14 % moisture content for starchy seed and
Storage of commercial seeds
 Seed must be dried to 14 % moisture content for starchy seed and
11 percent for oilseeds
Prof. Kumari Rajani

7.  About 20-25 per cent of stored seed may have to be carried over
through one season to the second planting time.
 The storage period may range 1-1½ year.
 Storage of seeds in metal bins with tight fitting lids or in a moisture
proof bag will solve the problems of moisture penetration,
Carryover seeds
proof bag will solve the problems of moisture penetration,
provided the seeds are already dry enough for sealed storage.
Prof. Kumari Rajani

8.  It is desirable to store foundation and enforcement seeds for
several years since genetic drift are minimized by reproducing
foundation or stock seeds
 Since the quantity of seeds involved is not large, the storage room
is only a small part of the total storage area and in fact, is often a
small room within a large warehouse
Foundation stock and enforcement seed sample
 Relative humidity and temperature combination has to be provided
for maintaining the viability
 A combination of 25 % RH at 30°C temperature or less or a RH of
about 45 % at 20°C or less will be ideal
 The required RH can be achieved by making the room moisture
proof and by using a dehumidifier
Prof. Kumari Rajani

9.  Germplasm seeds are required to be kept for many years, perhaps
very long periods
 Basic requirements for such long term storage are the coldest
temperature economically possible and seed moisture is in
equilibrium with 20-25 per cent RH
Germplasm seed storage
 Germplasm storage built up so far have rooms which can be
maintained at 5°C to 10°C and 20 % RH
 In addition, the stored samples are dried to perfect moisture level
Prof. Kumari Rajani

10. The seeds are considered to be in storage from the moment they
reach physiological maturity until they germinate, or until they are
thrown away because they are dead or otherwise worthless.
The entire storage period can be conveniently divided into following
stages.
1) Storage on plants (period from physiological maturity until
Stages of Seed Storage
1) Storage on plants (period from physiological maturity until
harvest)
2) Harvest, until processed and stored in a warehouse.
3) In storages (Warehouses).
4) In transit (rail wagons, trucks, carts, railway sheds , etc)
5) In retail stores (packaging to ditsribution)
6) On the user’s farm (period from purchasing to sowing)
The seed quality, i.e germination and vigour, can be considerably
affected at any of the stages mentioned above, unless sound
principles involved in seed storage are practiced and the seeds
properly handled. Prof. Kumari Rajani

11. In the natural environment and when stored at ambient room
conditions, seeds respond to constantly changing relative humidity
and temperatures.
Maintaining seeds under controlled conditions lowers metabolic
activity, thereby reducing the aging process and increasing longevity
of the seed lot.
Principles involved in Seed Storage
of the seed lot.
For most seeds, a cool and dry environment is preferred and for
orthodox seeds the cooler and drier the greater the longevity that can
be achieved.
Prof. Kumari Rajani

12. James’Rule:
The arithmetic sum of temperature in °F
and percent relative humidity (HR)
should not exceed 100 with not more
than half contributed by temperature
Temp (oF) + RH (%) < 100
Thumb Rules for Seed Storage
Harrington’s Rule:
1. Seed longevity decreases by one-
half for every 1% increase in seed
moisture content.
(Range: 5 and 14% MC )
1. Seed longevity decreases by one-
half for every 5oC (10oF) increase in
temperature.
(Range: 0 to 50oC)
Prof. Kumari Rajani

13. 1.Seed longevity is controlled by seed moisture content and storage
temperature. For maximum storage life these two conditions must
be carefully controlled. Therefore, seed storage condition should be
dry and cool
2.Effective storage pest control
3.Proper sanitation in seed stores
Principles involved in Seed Storage
3.Proper sanitation in seed stores
4.Before placing seeds into storage they should be dried to safe
moisture limits, appropriate for the storage system
5.Storing of high quality seed only, i.e well cleaned, treated as well as
of high germination with vigour and good pre-storage history
6.Determine seed storage needs in view of period or length of storage
time, and prevailing climate of the area during storage period
Prof. Kumari Rajani