Bangladesh is primarily an agriculture based country with agriculture accounting for 23.50% of the country’s GDP. About 62% of the people are engaged in agricultural product. Previous some decades Bangladesh is importing huge amount of rice, vegetables, fruits seed including hybrid variety and fertilizer from foreign countries. In Bangladesh only 10% of seeds used for crop production are produced by the government or semi government organizations. The rest (90%) of total requirements of the country are met by the farmer’s own seed of unknown quality with respect to quality and health standard. As many as quality less and 490 seed-borne diseases affecting the seed of 76 different important crops are established in the country and these cause yield losses annually. On the other hand adulated fertilizer may responsible for economic loose with decreasing soil fertility. Poor or quality less fertilizer has significant effect on our overall production. So, role of seed quality and fertilizers are vice versa. Development of quick and cheap earthen dish-newsprint technique of seed and fertilizer quality determination by using physical and chemicals methods have been described. Measures to overcome the activity, problems are discussed in this report. Standard storage condition both seeds and fertilizers are discussed.
A brief Study on Quality Control Attributes of Agricultural Inputs (seeds and fertilizers) by Md. Kamaruzzaman Shakil
1. Abstracts
Bangladesh is primarily an agriculture based country with agriculture accounting
for 23.50% of the country’s GDP. About 62% of the people are engaged in
agricultural product. Previous some decades Bangladesh is importing huge amount
of rice, vegetables, fruits seed including hybrid variety and fertilizer from foreign
countries. In Bangladesh only 10% of seeds used for crop production are produced
by the government or semi government organizations. The rest (90%) of total
requirements of the country are met by the farmer’s own seed of unknown quality
with respect to quality and health standard. As many as quality less and 490 seed-
borne diseases affecting the seed of 76 different important crops are established in
the country and these cause yield losses annually. On the other hand adulated
fertilizer may responsible for economic loose with decreasing soil fertility. Poor or
quality less fertilizer has significant effect on our overall production. So, role of
seed quality and fertilizers are vice versa. Development of quick and cheap earthen
dish-newsprint technique of seed and fertilizer quality determination by using
physical and chemicals methods have been described. Measures to overcome the
activity, problems are discussed in this report. Standard storage condition both
seeds and fertilizers are discussed
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2. Objectives of the Study
1. To sketch out appropriate quality control of seed is according to ISTA rules
and methods of fertilizer testing.
2. To provide standard guideline on storage practice both seeds and fertilizes.
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3. 1. Quality Control on Seed
1.1. Introduction
Seed is the biological unit for propagation, carries genetic characteristics from
generation to generation. Agriculturally, seeds are any part of the plant(vegetative
or reproductive) capable of giving birth to a new plant of its kind.Seed is the
foundation of agriculture.
Fig. Different parts of seed
1.2. Seed quality
Seed quality is a standard of excellence or the level of goodness in certain
characters or attributes that will determine the performance of seeds as judge by
the succeeding crop. It refers to the general excellence of crop as manifested in its
field performance by a certain satisfactory minimum standard for its consumption
and sale. An agricultural economist would regard seed quality as the sum total of
the characters or attributes of seed which influence it acceptability to buyers and
therefore the price they are willing to pay for it.
So, Quality seed ensure a uniform crop establishment with rational vigour and
population of seedlings per unit area of the field. It is only possible when seeds are
healthy means diseases free. The weaker and late emerging seedlings are poor in
vigorous, subsequently growth and productivity both in quality and quantity.
Therefore, the selection of good seed is of prime importance for rising crops and
ripening a rich harvest.
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4. 1.3. Importance of quality seed in crop production
Quality seed within variety gives good stand establishment in the soil which a turn
ensures a good crop production. A good seed also possess the capability of
surviving well under adverse field conditions encountered in planting season,
resists of diseases and insect pest attack and make the farming profitable. With the
use of quality seeds in the normal cultivation practices, yield of crops may be
increased up to 10-15%. No agricultural practice such as cultivation, irrigation,
fertilization, pesticide application can improve crop production beyond the set by
the quality seed. So maintaining general excellence of crop, it is very important to
maintain proper seed health and quality.
1.4. Quality Control (QC)
Quality Control is the systematic approach towards achievement and or
maintenance of quality standards. Quality control integrates random and
uncoordinated activities directed towards achievement and maintenance of quality
standards into a comprehensive and systematic programme. It does not permit vital
operations or procedures to be accomplished or ignored by chance.
1.5. Characteristics of quality Seed
A quality seed should possess the following characteristics-
The seeds should be of adaptable crop variety or hybrid.
The seeds should be pure (true to type) with high sowing quality (viable
seeds).
The seeds should be free from seed-borne diseases and physiological
disorders due to deficiency of plant nutrients.
The seed should be large (according to the variety), plump, bold, uniform in
size, shape, color, texture and weight means homogenous.
The seed should be clean and free from inert matter such as crushed rock,
dirt, grit, grit, chaff and trash.
The seed should be free from noxious or objectionable or satellite weed
seeds.
The seeds should be free from insects, insect eggs, spore etc. in or on the
seeds.
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5. The seed should be whole, not broken, crushed, peeled off, half rotten or
affected with damp.
The seed should be uniformly well matured and contain required amount of
moisture.
The seed should be germinated 80% and above.
1.6. Attributes of quality seed
Seed quality attributes are as follows-
1) Genetic purity
Purity of seed
2) Physical purity
3) Seed germination
4) Seed moisture
5) Seed viability
6) Seed vigour
7) Seed health***
8) Other – a. Maturity b. Size, c. Shape, d. Color, e. weight, f. Specific gravity,
g. Homogeneity
1.7. How seed quality determined?
For justification of seed quality and health in appropriate standard, testing is only
and actual way.
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6. 2. Seed Testing
Seed testing is the procedure by which the suitability of a seed to use as a planting
material is evaluated. It is the science of evaluating seed quality for agricultural
purpose.
2.1. Objectives of seed testing
Seed testing is required to achieve the following objectives for minimizing the
risks of planting low quality seeds.
To identify the quality problem and their probable cause
To determine their quality, that is, their suitability for planting
To determine the need for drying and processing and specific procedures
that should be used
To determine if seed meets established quality standards or labeling
specifications.
To establish quality and provide a basis for price and consumer
discrimination among lots in the market.
The primary aim of the seed testing is to obtain accurate and reproducible results
regarding the quality status of the seed samples submitted to the Seed Testing
Laboratories.
2.2. Importance of Seed Testing
The importance of seed testing was realized more than 100 years ago for assured
planting values.
Seed testing is required to assess the seed quality attributes of the seed lots
which have to be offered for sale.
Testing of seed to evaluate the planting value and the authenticity of the
certified lot.
Quality control of seed depends on the different seed testing protocols which
determine the genuineness of the cultivar.
These quality attributes are seed moisture content, germination and vigour,
physical and genetic purity, freedom from seed borne diseases and insect
infestation. In India, seed testing is done mainly for moisture, germination
and physical purity of seeds.
The testing of seed quality is carried out on seed samples drawn from seed
lot to be used for cultivation.
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7. The seed testing procedures which are described below are based mostly on
the international rules because most of our rules are based on, 1STA, 1996.
Economic yield of a crop depends on the quality of seeds which can be
evaluated by seed testing (1STA, 1996).
2.3. Seed sampling
In the seed quality studies proper sampling is essential for obtaining accurate and
reproducible results.
Extremely small representative portion of a given seed lot is called seed sample.
Fig. Inserting trier/probe to collect seed sample.
Almost equal amount of seeds should be taken from each container/bag. Drawing
of primary sample may vary from top, middle and bottom of the bag.
Fig. Different types of trier/probes for drawing seed samples
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8. The seed samples may be of the following categories-
Primary sample: The small quantity of seeds taken from one point in the
lot.
Composite sample: Mixture or combination of all the primary samples. The
primary samples are combined to make the composite sample which is
usually much bigger than the required amount and must be reduced.
Submitted sample: The properly reduced portion of a composite sample
submitted to the testing laboratory.
Working samples: Sub sample drawn properly from the submitted sample
for practical analysis – purity, germination, health status etc. This is actually
done for the required test. It should be ensured that the working sample is
true representative of the submitted sample. The amount of working sample
may be 400 seeds in replicates of 100 or 50 or 25 seeds.
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9. 3. Purity Test of Seed:
Seed purity denotes the composition of a particular seed lot. It is based on physical
determination of the component present and includes percentage by weight of pure
seed, other crop seed, weed seed and inert matter.
Objectives:
To ascertain the relative proportion of different component of a seed lot.
To identify the various species of seeds and inert particles constituting the
sample.
In accomplishing the objectives of the purity analysis, the sample the sample is
separated into the following component parts:
a. Pure seed
b. Other crop seed
c. Weed seed
d. Inert matter
Equipment required:
1. Working board or seed board, 2. Forceps, 3. Magnifying glass 4. Petri
dishes, 5. Analytical balance, 6. A fine needle.
Working sample size:
The sample size should be enough to contain 2500 seeds and subjected to
maximum amount of 1000g.
Working sample size for purity test:
Crops Weight (g)
Rice 50
Maize 500
Jute 10
Mustard 5
Lentil 50
Tobacco 0.5
Wheat 100
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10. Procedure:
1. Working sample was taken and seeds were separated on the working board.
2. All the 4 components (pure seed, other crop seed, weed seed and inert
matter) were separated carefully.
3. The individual fractions were then weighted independently by electric
balance.
4. The results were expressed in percentage.
Result can be expressed by the following symbolic example-
Let, total weight of working sample is W g.
Fractions Weight (g) Percentage
Pure seed W1 (W1×100)÷W
Other crop seed W2 (W2×100)÷W
Weed seed W3 (W3×100)÷W
Inert matter W4 (W4×100)÷W
Total W 100
Results:
Pure seed =………%
Other crop seed =…… %
Weed seed =……… %
Inert matter =……%
Expected pure seed of quality seed are …………%
Fig. Purity Board
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12. 4. Germination Test of Seed
Germination is a process in which a seed awakens from dormancy and starts to
sprout. In order to germinate light levels, oxygen availability, temperature and
moisture level must all be suitable. The first sign of germination is the protrusion
of the radicle often through the micropyle. The results of seed germination are
expressed in terms of percentage by count. The germination rate of a particular
seed lot is a key indicator as to how that seed will perform in the field.
Objections:
1. To ascertain the relative proportion of seeds in question of a seed sample
those are capable to produce normal seeding.
2. To determine the seed rate of any crop.
3. To determine the market price of seeds.
4. To determine the real value of seed (RVS) or pure live of seed (PLS)
To accomplish germination test,seedlings are evaluated and categorized as follows-
NormalSeedlings: that possesses essential structures that are indicative of
their ability to produce useful mature plants under favorable field conditions.
AbnormalSeedlings: that exhibit some form of growth but have insufficient
structures to judge a healthy plant e.g. missing roots or shoots.
Fresh Seeds:Seeds that have failed to germinate but have imbibed water.
They appear firm, fresh and capable of germination, but remain dormant.
Dormant Seeds: Viable seeds (other than hard seeds) that fail to germinate
when given the prescribed or recommended germination conditions.
Hard Seeds:Seeds that remains hard at the end of the prescribed test period,
because their seed coats are impermeable to water.
Dead Seeds:Seeds that cannot produce any part of a seedling.
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13. Testing parameter of some agricultural seeds:
Temperature Fist count Final count
Crops Substrata Light
(°C) (days) (days)
Rice BP,TP,S 20-30 - 5 14
Wheat S, BP 20 - 4 8
Maize S, BP 20-30 - 4 7
Jute S, TP 30 L 3 5
Tobacco TP 20-30,15-25 L 7 16
Cole crop S, BP 20-30 L 5 10
** TP= Top of paper, BP= Between of paper, S= Sand, L= Light
Methods for Testing Germination:
1. Petri dish method***, 2. Rolled towel method, 3. Folder paper towel method,
4. Sand method, 5. Rag doll method etc.
Material required:
1. Petri dishes, 2. Seeds, 3. Forceps, 4. Covering net, 5. Water, 6. Blotting
paper/filter paper, 7. Sand
Procedure (petridish method):
1. About 400 seeds were taken without any biasness and all the taken seed are
set at intervals for germination in the petridishes on a moist substratum.
2. The petridishes were then placed in the laboratory and number of seed set
and date were recorded.
3. Sufficient care was taken so that the seeds do not dried till the end of the
test.
4. Day to day observation and counting of seedling were necessary. Final
counting was done on the specific day.
Result can be expressed by the following symbolic example-
No. of normal seedlings
% Germination= × 100
No. of seeds set for germination
Result grading is as follows:
10 = 100% or perfect germination
9 = 90% or excellent
8 = 80% or good
6-7 = 60-70% or poor -- sow more thickly
5 or less = 50% or less -- throw the seed out!! Fig. Germination test
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14. 5. Moisture content of seed
The moisture content of a seed sample is loss fit weight of the seed sample when it
is dried. Seed moisture is expressed as percentage of weight of original sample.
Determination of moisture content play crucial role for maintaining proper quality
of seed in context of storage and remaining viability. Proper moisture content
increase shelf life of seed and reduce diseases infestation means with insects
attack.
Objectives:
1. To know the suitable drying condition of seed for preservation in storage.
2. To know the suitable time of harvesting of crops.
Methods of measuring moisture seed moisture:
There are different methods of measuring seed moisture content. They are as
follows-
Basic method:
a. Air oven dry method
b. Water oven dry method
c. Vacuum oven dry method
d. Toluene distillation method
Practical method:
a. The brown-duvel distillation method
b. Electric moisture meter
Practical methods for determining the moisture of seed are needed under many
circumstances where the basic method takes too much time.
Equipment required: Electric Moisture Meter.
Result: The moisture content of the supplied seed sample…………..%
Fig. Electric moisture meter
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15. 6. Viability test of seeds
Viability means that a seed is capable of germinating and producing a normal
seedling. Seed viability indicates that a seed contains structures and substances
including enzyme systems that give it the capacity to germinate under favorable
conditions. Such a viable seed may or may not be immediately germinable. Seed
viability is probably highest at the time of physiological maturity. The results are
expressed in terms of percentage.
Objectives:
To ascertain the proportion of living or dead seeds present in a seed sample.
Methods of testing:
1. Standard germination test, 2. Tetrazolium test (biochemical test) ***, 3.
Embryo excision test, 4.Electrical conductivity test, 5. Respiration test, 6.
KMnO4test, 7. X- ray test, 8. Free fatty acid test
Apparatus required:
1. Seed sample, 2. Petridishes, 3. Knife/Scissors, 4. Magnifying glass, 5.
Dropper and bottle, 6. Solution of Tetrazolium (0.1-0.5)
Tetrazolium test (TZ test):
The TZ test is a quick test used to estimate the germination potential of seed (seed
viability). This test distinguishes between viable and dead tissues of the embryo on
the basis of their relative respiration in the hydrated state.
The testing procedure is as follows-
1. The seed were soaked in water for overnight to allow absorption of soften
the embryo, endosperm and active the enzyme system.
2. Seed coats were then removed to expose the embryo and facilitate the
contact of the embryo with tetrazolium solution.
3. The seed (embryo) were then put in tetrazolium salt solution for two hours.
4. Then seeds were then washed repeatedly with distilled water.
5. Ultimately the seeds were examined under magnifying glass.
Observation:
Living seeds: red color or purple color of the embryo.
Dead seeds: No color will be occurred in embryo which indicates the dead seed. If
the embryo of seed is not stained but red color develops on the other parts then it
will be treated as dead seed.
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16. Calculation:
No. of living seeds
% Viable Seed = × 100
No. of seeds set for viability test
Expected percentage of seed viability is……………%
Fig. Tetrazolium tested living and dead seed sample
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17. 7. Vigour test of seeds
Seed vigour is the sum total of all attributes which resulted in quick, uniform and
early emergence of seedlings even in unfavorable environmental conditions. It is a
physiological property, which is determined by the genotype and is modified by
the environmental factors, which gives the ability of seeds to produce healthy
seedling rapidly in the soil.
Objectives:
1. To determine the suitability of seed as planting material.
2. To determine the vigour of seeds to face the stress conditions of the field.
3. To get idea about population of the seed.
Methods of testing:
1. Brick gravel test, 2. Seedlings evaluation test, 3. Paper piercing test, 4.
Accelerated aging, 5. Simplified flowerpot test etc.
Apparatus required:
1. Germination box, 2. Aluminium tray, 3. Sand, 4. Brick gravelof 2-3 mm
size, 5. Germinator, 6. Seed sample.
Brick Gravel test for Seed Vigour:
The test involves the use of a rather porous type brick gravel of 2 to 3 mm size. In
this test for small grains, about 30 mm layer of moist gravel is placed above the
seeds. This layer impedes the emergence of week, particularly diseased and
otherwise injured seedlings. The seedlings that emerge through the layer of brick
gravel are considered as vigorous.
Procedure:
1. At first fifty seeds were taken and the sand is sieved, moistured and filled in
the germination box leaving about 3 cm empty at the top.
2. Then the seed were placed on this moist sand.
3. Then a 30 mm layer of brick gravel was placed over the seeds.
4. The pot was then kept one week for observation.
5. Data collection.
Calculation:
No. Emerged Seedlings
% Viable Seed = × 100
No. of seeds Sown
Result:
% vigour of the seeds being tested were = ………
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18. 8. Seed Health Testing
Seed Health:
Seed health refers to the presence or absence of disease causing organisms such as
fungi, bacteria, nematodes, viruses etc. in, on or with the seed or seed lot. It
concerns the overall condition of seeds.
Seed health standard:
The maximum acceptable limit of the present of a pathogen in a given seed lot is
called seed health standard. It is the amount of inoculum available with the seed
results in the development of the disease in the field under favorable environmental
condition with acceptable limit.
Seed Health Test:
Seed health testing is a procedure by which it can be determined weather
seed/seeds is/are diseased or not. With this practice it can be determined whether a
seed or seed lot is diseased or contaminated so as to provide reliable information
pertaining to the field performance of the seeds and SCA or quarantine
requirements.
Objectives of seed health tests:
1. To know the seed health condition of the seed lot.
2. To meet the SCA and quarantine requirements.
3. To know the planting value of a seed lot.
4. To evaluate the food and feeding value of the seed.
5. To determine the storage quality of the seeds.
6. To determine the efficacy of the seed treatment.
Methods of seed health testing:
1. Inspection of dry seeds***, 2. Seed washing for suspension, 3. Whole embryo
count method, 4. Blotter method***, 5. Agar plate method, 6. Water agar
plate method, 7. The Freezing method, 8. Seedling symptom method, 9.
Serological test, 10. Growing on test***, 11. Field trials, 12. Inspection of
seed crops.
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19. 8.1. Dry inspection method
In this method, the seed sample are examined by naked eyes or hand lens
stereomicroscope and presence of fungi on the physical appearance of seeds, if
any, are observed and recorded.
The fruiting structures of fungi in the form of –
Acervuli, pycnidai, pericthecia, sclerotia on the seed surface or submerged in
the seed coat.
Sclerotia loosely mixed with seeds.
Part or completely smutted or bunted seeds.
Galled seeds.
Physical abnormalities include-
Shriveling of seed coat
Reduction or increased seed size
Discoloration or spots in the seeds
Advantages:
a. It is easy and quick method
b. It does not required complicated material.
Disadvantages:
a. Only those pathogen or fungi producing external symptoms and sign can be
identified.
b. Sometimes badly infected seed looks like healthy.
c. Variability of pathogen cannot be detected by this method.
Fig.Inspection of dry seeds by woman
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20. 8.2. Blotter method
The blotter method is one of the incubation methods where seeds are planted on
well water socked blotters (filter papers) and they are usually incubated for 7 days
at (20±2) º C under 12 hours altering cycles of light and darkness. At the end of the
incubation period, each seed is thoroughly examined under different
magnifications of a stereomicroscope for the growth of the fungi. Blotter method is
widely used for seed health testing. It is used for all kinds of seeds.
Procedure:
1. Take required number of plastic petridishes.
2. Disinfect the surface of the plates.
3. Place the seeds (25 seeds) in a petridish on three wet blotter papers in three
rows circularly (16+8+1).
4. Place the petridishes for incubation at 20º C in suitable condition.
5. Examine the fungi on seed under stereomicroscope.
6. Observe growth characters and identify the fungi.
7. Count the number of infected seeds and calculated percent seed infection.
Advantages:
1. Economics and useful method except dry inspection.
2. It is more natural type of test.
3. It can be widely used to detect many fungi pathogens from all kinds of seed.
Disadvantage:
1. It required skilled person.
2. Pathogenic bacteria cannot be detected.
3. The method may be hampered due to the fast growing of certain fungi over
the slow growing one.
Fig. Blotter method
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21. 8.3. Growing on Test
Procedure:
1. Some pots to be taken with sterilized and sand.
2. Seeds to be placed randomly on the pots.
3. Pots to be placed in glass house or green house for minimum three (3) weeks
Advantage:
1. This method is used when blotter method and agar plate method failed.
2. This method is for those crops which can produce symptoms in mature stage
e.g. lettuce mosaic virus.
3. Quarantine method is fulfills.
Disadvantages:
1. This method is closely, time consuming and laborious.
2. It requires space, green house facilities, proper management etc.
3. It required experience.
Fig. Growing on Test
Control of seed borne diseases:
1. Use of healthy seeds (disease free, lesion free etc.)
2. Seed treatment with suitable chemical
3. Hot water treatment
4. Washing of seeds with normal water
5. Drying of seed under clean sunshine (e.g. Rice)
6. Physical seed sorting.
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22. 9. General Principles of Quality Seed Production
Production of genetically pure and otherwise good quality seed, pedigree seed is an
exciting task requiring high technical skill comparatively heavy financial
investment. During seed production strict attention must be given on the
maintenance of genetic purity and other qualities of seeds. In other word, seed
production must be carried out under sterilized and well organized condition.
A. Genetic principles:
There are various steps suggested to maintenance of genetic purity during Seed
production. They are as follows-
1. Use of approved seed only in the quality seed multiplication.
2. Inspection and approval of fields prior to planting.
3. Field inspection and approval of growing crops at critical stages for
verification of genetic purity, detection of mixtures, weeds and free from
noxious weeds and seed borne diseases.
4. Providing adequate isolation distance to prevent contamination by natural
crossing or mechanical mixture.
5. Roughing of seed fields prior to the stage at which they could contaminate
the seed crop.
6. Avoiding genetic shifts by growing crops in areas in there adaptation only.
7. Adopting the generation system.
8. Sampling and sealing of cleaned lots.
9. Periodic testing of varieties for genetic purity.
10.Grow on test
11.Certification of seed crops to maintain genetic purity and quality of seed.
B. Agronomic Principles:
Agronomic principles which govern the quality of seed production and which are
controllable by men are given below:
1. Selection of an agro-climatic region:
A crop variety to be grown for seed production in an area must be adapted to the
photoperiod and temperature condition prevailing in that area.
2. Selection of seed plot:
Plot must be free from volunteer plants, weed, and have good soil texture and
fertility with free from soil borne diseases and pest.
3. Isolation of seed crops:
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23. The seed crop must be isolated from other nearby fields of the same crops and the
other contaminating crops as per requirement of the certification standards.
4. Preparation of land:
Good land preparation helps improved germination, good stand establishment and
destruction of potential weeds. It also aids in water management and good uniform
irrigation.
5. Selection of variety:
The variety of seed production must be carefully selected, should possess disease
resistance, earliness, grain quality, a higher yielder and adapted to the agro climatic
conditions of the region.
6. Seed selection:
The seed used for raising a seed crop should be of known purity, appropriate class
an invariably obtain from an authorized official agency.
7. Seed treatment:
Depending upon the requirement the following seed treatment may be given-
Chemical treatment
Bacterial inoculation for the legume
Seed treatment for breaking dormancy
8. Time of planting:
The seed crops should invariably be shown at their normal planting time.
Depending upon the incidence of diseases and pests, some adjustments could be
made, if necessary.
9. Seed rate:
Lower seed rates than usual for raising commercial crop are desirable because they
facilitate rouging operations and inspection of seed crops.
10.Method of sowing:
The most efficient and ideal method of sowing is by mechanical drilling.
11.Depth of sowing:
Depth of sowing is extremely important in ensuring good plant stand. Small seeds
should usually be planted shallow but large seed could be planted a little deeper.
12.Roughing:
Adequate and timely roughing is extremely important in seed production.
Roughing in most of the field crops may be done at many of the following stages
as per needs of the seed crop.
Vegetative/Pre- flowering stage
Flowering stage
Maturity stage
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24. 13.Supplementary pollination:
Provision of honey bees in hives in close proximity to the seed fields of crops
largely cross pollinated by insects, ensure good seed set thereby greatly increase
seed yields.
14.Weed control:
Good weed control is the basic requirement in producing good quality seed. Weeds
may cause contamination of seed crops, in addition to reduction in yield.
15.Disease and pest control:
Successful disease and insect control is another important factor in rising healthy
seed crops. Apart from reduction of yield, the quality of seeds from diseased and
insect damaged plants is invariably poor.
16.Nutrition:
In the nutrition of seed crops, nitrogen, phosphorus, potassium and several other
elements play an important role for proper development of plants and seed. It is,
therefore advisable to know and identify the nutritional requirement of seed crops
and apply adequate fertilizers. Nitrogen fertilizers should be applied 15% less of
recommended does for seed crops.
17.Irrigation:
Irrigation can be important at planting for seed crops on dry soils to ensure good
uniform germination and adequate crop stands. Excess moisture or prolonged
drought adversely affects germination and frequently results in crop stands.
18.Harvesting of seed crops:
It is the great importance to harvest a seed crop at the time that will allow both the
maximum yield and the best quality seed.
19.Drying of seeds:
In order to preserve seed viability and vigour it is necessary to dry seeds to safe
moisture content levels.
20. Storage of raw seeds:
The best method of sowing seed for short periods is in sacks or bags in ordinary
buildings godowns.
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25. 10. Quality control operation during seed processing:
After harvesting, seed must be processed to required levels of physical purity and
germination. Careful handling and specific procedures are necessary to maintain
seed vigour and genetic purity. A satisfactory shelf life is dependent upon safe
storage according to established environmental criteria both before and after
processing. Steps of seed processing are as followed:
Threshing:
For small-scale seed production, it is often not cost effective to purchase threshing
equipment because of the small volume of seed produced. A number of small
alternative seed companies, specializing in heirlooms and specialty seed, thresh
most, if not all of their seed by hand.
Fig. Threshing
Cleaning:
It is not necessary to have expensive seed cleaning equipment to clean seed for
small-scale production. Winnowing will still be necessary to remove smaller chaff.
Many seeds can be screened with several different mesh sizes of hardware cloth.
Hardware cloth is readily available in the following mesh sizes: 1/2", 3/8", 1/4",
and 1/8". The 1/2" and 1/4" mesh sizes are available at most hardware stores. The
3/8" and 1/8" mesh sizes are the most useful sizes, but are the most difficult to find.
Seed drying:
Drying is a normal part of the seed maturation process. Some seeds must dry down
to minimum moisture content before they can germinate. Low seed moisture
content is a pre-requisite for long-term storage, and is the most important factor
25
26. affecting longevity. Seeds lose viability and vigor during processing and storage
mainly because of high seed moisture content (seed moisture greater than 18%).
Conventionally sun drying is most popular method for seed drying but in
accidental case sometimes mechanical dryer are used.
Fig. Drying of seed (Sundry and Mechanical Dryer)
Sorting :
As you know, seed can vary dramatically in size even though it is within the same
seed lot. Climate, environment, and grower management practices strongly
influence the seed development every year. Varying genetics often result in seed
that is shaped and sized differently than other genetics. All of these factors are
taken into consideration during the sizing process.
Seed treatments:
Seed treatment can be a physical or chemical process.
1. Physical seed treatment-
Heat treatments are somewhat rare in rice, but can be accomplished using hot
water, dry heat or steam to kill seed borne pests and pathogens. Heat treatment can
injury or kill the seed, especially if it is old, injured or has a low heat tolerance.
Hot water treatment at 52-57ºC for 15 minutes can eradicate most of the soil borne
diseases.
2. Chemical treatment-
Fungicides, bactericides, insecticides, and nematicides can be applied as gases,
liquids or powder. No broad spectrum fungicides exist, so mixes may often be
used. While chemical seed treatment is not widely practiced, the most common
chemicals used are Benlate T and Homai. Seed treatment may be used to control
pests that are not actually seed borne pathogens.
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27. 11. Quality control of Seed in Storage
Seed quality can deteriorate rapidly without good storage conditions.The
principal purpose of seed storage is to preserveeconomic crops from one season to
another to fulfill desired objectives. Storagetemperature and moisture content are
the most importantfactors affecting seed longevity, with seed moisturecontent
usually being more influential than temperature. Seed quality is largely dependent
on storagetemperature, relative humidity, seed moisture content,length of storage,
type of seeds.
The two most important factors in seed storage are moisturecontent and
temperature.Of these two factors, seed moisture content isthe most
important.Every 1% decrease in seed moisture content doubles the storage life.
Every5°C decrease in seed storage temperature doubles the storage life.
Good seed storage results when seeds are kept dry (below 8 percent moisture) and
the temperature is kept low (below 40 degrees). When seed moisture and storage
temperature are low, the presence of oxygen has not been shown to be a factor in
seed longevity. Germination is unaffected by storage in atmospheres of nitrogen,
carbon dioxide, partial vacuum or air. Relative humidity (RH) influences the
moisture content of seed if it is not stored in moisture-proof containers. For
example, at 15 percent RH, seed will dry down to 6 percent moisture and will store
safely in this condition for several years. So that, Optimum Environment for
Seed Storage at 5 - 10 ºC and 25 - 35 % humidity.
11.1. Storage facility design
The design of storage facilities can be approached two ways: (1) creating a cold
storage environment or (2) using the conditioned storage concept.
Both approaches can achieve the desired result as long as conditions provide for
lower temperatures, give adequate ventilation, and exclude moisture as necessary.
Overall steps are as follows-
Cleaning the storage structure:
27
28. Cleaning out side of storage:
Disinfect used sacks:
Overhanging roof extensions on storage structures
28
29. 11.2. Lower temperatures:
Lower temperature can be facilitated in various ways. Simple solutions include
using reflective paint, increasing insulation, or using the more expensive approach
of cooling units. With cooling units, the issue of relative humidity must be
addressed.
11.3. Moisture exclusion:
Moisture content can bemaintained with the installation of dehumidification
systems. However, this approach can certainly increase thecost of a storage
facility. The two methods normally used fordehumidification involve using either
chemical desiccants or refrigeration units. Moisture removed through
refrigeration/heating units must exit the storage area.
11.4. Adequate ventilation:
Ventilation can beobtained with the use of various types of fans incombinationwith
correct venting for the room involved.
11.5. Controlling of Rats and other storage pest:
Rats may responsible for destruction of storage seeds. Sometimes different insect
pest cause deterioration of the quality of crops. There are two ways for preventing
rat and insect infestation. Frist one is mechanical prevention by which pest cannot
enter inside and second is converting storage environment unfavorable for pest. In
this why need efficient storage management and cleaning.
Fig. inside of storage
11.6. Security:
The storage room should be locked and access restricted to trained personnel.
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30. 12.Seed testing Organization in Bangladesh
SeedTesting Wing:
Seed testing wing is also an important wing comprising of
i) National Seed Testing Laboratory, Gazipur is headed by CST,
ii) Regional Seed Testing Laboratory (RSTL) Ishurdi, pabnais headed by
Agronomist.
iii) Agronomy department, all Agricultural University
Purity, Germination, Moisture and other tests are conducted by 6 seed Analysts in
two laboratories. Seed Analysts are fully responsible to analysis the Seed samples
which are collected from public, private and NGO's sector as well as market
monitoring samples. Chief seed technologist supervises and monitors the overall
activities of seed analysts. Actually seed testing wing involving to assurance of
quality seeds. If the test result of the sample comes in a close conformity with the
seed standard fixed by NSB, the representing seed lots of processing centers are
accepted for certification. In case of sub-standard value of test result, the seed lots
are rejected.
Another, top most seed health testing institute named “Seed Pathology Centre
(SPC)” at Bangladesh Agricultural University, Mymensingh.
More or less every private seed company’s has own research and development
(R&D) sector for improving material and method on context of quality assurance.
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31. 13. Quality Control on Fertilizer
13.1. Introduction
Towards the end of the nineteenth century, scientists began to worry about whether
the crop output would be enough to sustain a rapidly increasing population. The
best solution to this problem would be to increase crop yields with fertilizers.
Fertilizer has played a pivotal role in increasing agricultural production in any
country,more so in developing nations, where the population growth rate has
outstripped all othergrowth rates.
In Bangladesh, there are about 107 kinds of fertilizes used by farmers. The
increasing fertilizer demand, its cost and may be, at times its scarce
availabilitythrows up many problems pertaining to making available the right
quality of the fertilizersto the farmers. Farmers are not in a position to examine the
quality of fertilizers at thedealers point. Adulterated fertilizers can cause serious
damage to the soil and crops.The quality of fertilizers cannot be checked after its
application and, therefore it has to beensured, prior to its application and farmers
need to be protected from any malpractice.Simultaneously, importers have to be
protected against under harassment at the handsof enforcement machinery or
unscrupulous dealers.
The quality of a fertilizer is of huge significance in Bangladesh where above 75%
of people are employed in agriculture and on its output depends not only economic
prosperity but also livelihoods status.
The elaborate quality control mechanism that exists in Bangladesh ensures
identification of producer and seller of fertilizers. Nonetheless, concerns have been
raised from government and stake holders about the quality of fertilizers being sold
in the market, emphasizing the need for revamping the quality mechanism from
time to time.
13.2. Fertilizer
Fertilizers are generally defined as "any material, organic or inorganic, natural or
synthetic, which supplies one or more of the chemical elements required for the
plant growth".
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32. 13.3. Types of fertilizers:
Fertilizers are categorized into three broad categories –
Primary fertilizers
Popularly called chemical fertilizers containing nitrogen, phosphorous and
potassium i.e., N, P, K
Secondary fertilizers
Withsulphur, calcium and magnesium and Micro Nutrient Fertilizers (MNF)
providing zinc, boron, copper, iron, manganese, molybdenum etc.
While the primary fertilizers are required in larger amounts, the secondary
fertilizers and the MNFs are required in smaller quantities. The micro nutrients are
also called trace elements whose deficiency can affect food grain yield equally.
13.4. Quality of fertilizers:
Quality fertilizer means that fertilizer which able to provide desired nutrients at
place of application. The most critical issue concerns the quality of the fertilizers
provided to the farmers, and therefore, the quality control system that ensures
delivery of good quality fertilizers must be effectiveand efficient.
12.5. Quick detection of adulteration in fertilizers:
There are two methods for determination of fertilizer quality.
1. Chemical method
2. Physical method.
For effective enforcement of fertilizer quality the Government has set up Fertilizer
Testing Laboratories to test the fertilizer samples. These tests are authentic and
reliable. However, somephysical testing methods have been developed by the
SRDI which can help the farmers to know if the fertilizer is genuineor adulterated.
But applications of these methods need more skills and clear concept about the
characteristics of fertilizers. But these techniques are easy and overall costs of
testing are reasonable.
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33. 12.6. List of fertilizer analysis authority (Govt. approved)
Sl. No. Name of organization Address
1 Soil Resource Development Institute ( SRDI has Soil Building,
11 soil testing laboratory in different region of KrishiKhamarSarak,
Bangladesh) Dhaka-1215
2 Bangladesh Nuclear Agricultural Research Soil Science Division,
Institute BINA, Mymensingh
3 Bangladesh Agricultural Research Institute Soil Science Division,
BARI, Mymensingh
4 Bangladesh Standard Testing Institute BSTI, Tejgaon, Dhaka
5 Department of Soil, Water and Environment Dhaka University
6 Bangladesh Rice Research Institute Soil Science Division,
BRRI, Joydebpur,
Gazipur
12.7. Condition of storage facility for fertilizer
There are some conditions for good storage practice. During the time of storage,
sometimes mass quality deterioration occurred. Special care should be taken for
preventing quality deterioration by excess moisture and temperature.
Storage facility design:
Good fertilizer storage means Store dry fertilizers in a closed, locked building that
has a sealed, impermeable floor. Infrastructure designs are same as seeds.
Bagged Fertilizer Storage:
There is a widespread and often unquestioned belief that warehouses for storage of
bagged fertilizers should be freelyventilated.Most fertilizers contain water-soluble
salts, which have been proven to be effective in supplying mineral nutrients to
crops. All fertilizer materials are directly affected by water and can interact with
moisture in the atmosphere. The property used as an indicator of the degree of
likely interaction with atmospheric moisture is the critical relative humidity
(CRH) of the fertilizer.
33
34. It can be recommended that properly designed store house for bagged fertilizer not
be permanently ventilated, particularly where long term storage is involved. When
humidity levels are high, the storehouse should be kept as tightly closed as
possible. During period of high humidity, entry of such humid air should,
however, be minimized. During period of low humidity, essentially when the
weather is sunny and dry, ventilation should be maximized. This means that
doors, windows and ventilators should be opened and if available, extraction fans
or mechanical ventilation can be used.
Fig. Storage of Bagged fertilizer
Inventory and Recordkeeping:
Inventory should be actively maintained as chemicals are added or removed from
storage;containers should be dated when purchased; outdated materials should be
removed on a regularbasis.
Lighting
Electrical lighting should allow view into all areas and cabinets within the storage
area.
Monitoring
There should be monthly inspection of storage for 1) signs of container corrosion
or otherdamage - leaking or damaged containers should be repackaged as
appropriate, 2) faultyventilation, electrical, and fire suppression systems –
problems should be reported and corrected.
34
35. Handling of fertilizers:
Limit the handling of fertilizer to avoidthe deterioration of granule quality.Avoid
rough handling when unloading/loading with shovels and conveyor belts.Clean up
any spills immediately and makesure that no spilled product ends up in thewater or
sewage system.
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36. Recommendation
Quality control (QC) is an important concern in agribusiness. Using of quality
inputs e.g. seeds, fertilizer, pesticide etc play vital role in agricultural production.
Almost all agro business agency try to maintains their own quality through
establishing distinguish research and development (R&D) section. Making the
quality control monitoring and regulatory system morerealistic and in line with the
technical and organizational imperatives.
1. Strong and efficient quality control section (R&D) should be build up for
frequent test of quality during the time of entry, storage and packaging.
2. Proper training package should be introduced for further development to the
farmer level and respective processing unit.
3. In case of production of quality seeds in Bangladesh, farmers should follow
appropriate principles of production (genetic and agronomic).
4. A seed testing laboratory should be established for easy and quick
determination of seed quality.
5. Store house should be well designed and full equipped for storing seeds and
fertilizers. Seeds and fertilizers should not store together.
6. In time of packaging, weight should be checked appropriately.
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37. References
AEM Tier II Worksheet, Fertilizer Storage & Handling in the Greenhouse,
Agriculture Environmental Management (AEM)
AOSA. 2009. Seed Vigor Testing Handbook. Contribution No. 32 to the Handbook
onSeedTesting.
International Fertilizer Development Center.1979, Fertilizi Manual, Chapter XXII:
"Physical and Chemical Properties ot Fertilizers and Methods for Their
Determination." IFDC-R-1, Muscle Shoals, Alabama 35662, U.S.A.
International Rules for Seed Testing, Rules Edition 2012; ISBN 978-3-906549-69-
9 (Annexe to Chapter 7)
International rules of seed testing, ISTA, 2003
Official website of Ministry of agriculture, The people’s republic of Bangladesh
(http://www.moa.gov.bd/agencies/SCA.htm)
Official website of Seed certification Agency, The people’s republic of Bangladesh
(http://sca.gov.bd/PageDetails.aspx?PageID=2)
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38. Appendix
Elaboration of some terms used in this report.
CRH= Critical relative humidity
CST=Chief seed technologist
ISTA=The International Seed Testing Association that with it member laboratories
establishes the international standards and procedures for seed testing.
Pedigreed seed = Genetically pure seed of a known variety, developed with unique
characteristics such as disease resistance, or with special qualities for
Milling or malt markets.
QC= Quality control
R&D= Research and development
SCA= Seed certificate agency
SPC= Seed pathology center
SRDI= Soil resource development institute
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