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1. AMITY INSTITUTE OF ORGANIC
AGRICULTURE
Seed Production Technology
FACTORS AFFECTING SEED LONGEVITY
IN STORAGE

2. GROUP MEMBER :-
ANKITA[A014119119097]
ASHISH[A014119119098]
ANURAG[A014119119099]
PRABHNEET[A014119119100]
SIMRAN[A014119119101]
SUBMITTED TO :-
Dr Deepak Rameshwar Sapkal

3. CONTENT
1.Kind (or) variety of seed – Prabhneet
2.Initial seed quality – Prabhneet
3.Moisture content – Anurag
4.Relative humidity and temperature during storage - Ankita
5.Provenance – Ashish
6.The activity of organisms associated with seeds in storage -
Simran

4. • Barton (1941) found that the seeds of high initial viability are much more
resistant to unfavourable storage environmental conditions than low viable
seed.
• Once seed start to deteriorate it proceeds rapidly. The seed which injured
mechanically suffered a lot and loses its viability and vigour very quickly.
• The seed lots having vigorous, undeteriorated seeds store longer
than deteriorated lots.
Seed vigour and
Deterioration

5. Which type of seeds should be carried over?
• The important implication of this is that only high quality seed should be carried over.
• The mediocre quality seed may be retained only for the next plating seasons.
• The low quality seed should invariably be rejected.
Severity of Damage
Depending upon the severity of damage, or degree of deterioration, E. g
extent of weathering damage, mechanical injury, flat, wrinkled or otherwise
damaged seed, even seed lots of good germination, at the beginning of
storage, can and do decline rapidly within a few months.

6. Seed Shape
and Size
• Generally small seeds escape
injury whereas large seeds are
more likely to be extensively
damaged (e.g) bean, lima-
bean and soybean.
• Spherical seeds usually give
more protection than flat or
irregularly shaped seeds

7. MOISTURE CONTENT
The most important factor influencing seed viability during storage is the moisture content and
the rate of deterioration increases, as the seed moisture content increases. The drier the seed
the higher will be the storage life.
Seed moisture content (%) Storage life
11-13 ½ year
10-12 1 year
9-11 2 years
8-10 4 years
 Biological activity in the seeds

8.  Extending the shelf life of seeds
 Harrington’s thumb rule
 Exceptions in this rule in a few crops like chillies, brinjal and bhendi
 Safe moisture content again depends upon the period of storage, storage structures, kind and variety of
seed and the packaging materials used
 For cereals under open storage, seed drying upto 10 per cent moisture content appears quite
satisfactory
 The storage in sealed containers during upto 4-8% moisture content depending upon the particular kind
of seed may be necessary.
 Use of desiccants

9. RELATIVE HUMIDITY AND TEMPERATURE DURING
STORAGE
 Acceptable temperatures for storing collections in a working environment range from 65-70°
Fahrenheit with levels of relative humidity in the range of 45-50%.
 These conditions can be most evenly maintained in inside rooms, away from heat sources such
as heating pipes and radiators, windows and exterior walls.
 Relative humidity changes when temperatures change. Because warm air can hold more water
vapor than cool air, relative humidity falls when the temperature rises if no moisture is added to
the air.
 Temperature determines the respiration rate of produce, and therefore changes in gas
atmospheres within packages, which may influence pathogen growth.
 Reducing the storage temperature also reduces the growth of the mesophilic spoilage microflora

10. When assessing archival storage, the environmental
parameters can be measured by taking on-the-spot
readings using, for example, thermometers and
hygrometers.
 This can quickly establish whether or not the
storage area meets the agreed optimum conditions,
and will help to identify any particular areas of
concern.
In the long term, monitoring equipment can be used
to record readings over a period of time so that daily
and seasonal fluctuations can be identified.
 If environmental control measures have been
introduced then it is advisable to continuously monitor
the environment so as to assess their efficacy.

11. PROVENANCE
• It has already been stated that a number of factors, operating before and during harvest can affect seed
viability.
• It is suprising then that samples of seed obtained from different sources may show differences in viability
behaviour.
• It is not always easy to know and satisfactorily assess what the causes of these differences are, or even
sometimes to know how important they are, because of wide variability between samples from different
sources.
• The seed begins its existence before it is harvest.
• it is only to be expected that seeds harvested in different pre-harvest condition which will have caused
different amounts of deterioration by the time seeds are harvested.
• The seeds harvested in different climates at different times show differences in viability. Because they
would have been subjected to different pre harvest conditions which will have caused different amounts
of deterioration by the time, the seeds are harvested.
• eg., Red clover seeds grown in Canada stored for 4 years with 80 per cent germination whereas, seeds
grown in England and New Zealand stored only for 3 years with per cent germination. This is due to
different climatic conditions and soil types prevailing in different places

12. ACTIVITY OF
ORGANISUM
ASSOCIATED WITH
SEED IN STROAGE
• Bacteria- Fungi-Mites- Insects- Rodents- and Birds.
• The activity of all these organism can lead to damage
resulting in loss of vigor or viability or, particularly in the
case of rodents, to complete loss of seed.
INTRODUCTION
• The important consideration in the control of seed micro
flora, is the relative humidity of the inter-seed
atmosphere.
• Researches indicate that all storage fungi are completely
inactive below 62 percent relative humidity and that
there is very little activity below about 75 percent
relative humidity upwards.
BACTERIA AND FUNGI

13. RODENTS AND BIRDS
There is no insect activity at seed moisture contents below 8 percent , but if grain is infected,
increased activity may generally be expected up to about 15 % moisture content.
The optimum temperatures for insect activity of more important storage insects ranges from 28 to 38
0 C. The temperatures below 17 to 22 0 C are considered unsafe for insect activity.
INSECTS AND MITES
Birds can be a constant source of seed loss, if even small openings exist at the lanes, or between the
roof tiles.
 All openings should be sealed, or screened, if needed for ventilation.
Rats and other rodents are more serious problems.