Culture's Story: November 2020

What is Seed Processing?

Seed Processing is an important part of the entire technology involved in ensuring available high-quality seed. It refers to the manual and/or mechanical up-gradation of the physical quality of seed. It assures the farmers of high-quality seed with minimum adulteration. Seed processing comprises all the operations after harvest that aim at maximizing seed viability, vigor, and health by some processes like- seed cleaning, drying treatment, packaging storage, etc.

Purpose of seed processing

To increase the life of a seed. To reduce the low vigorous seed. To improve the uniformity of seed. To improve seed purity by removing unfilled or fractured seed, inert matter, weed seed, other crop seed

Principles of seed processing

Homogeneity comes by processing. Homogeneity helps uniform plants come in the next generation of crops.

By suitable processing method Heterogeneity may reduce.

Quality of seed can be improved by this way- Drying of seeds, Separations of other seeds

By elimination of poor quality seed

Fumigation of seed.

To identify seed quality, seed testing is a major part of seed processing

Seed Testing

In the seed industry seed testing is performed to determine seed quality. Generally, four tests are done to identify the status of seed quality. These are Moisture test, germination test, Purity test, and dry inspection test/physical inspection.

1. Moisture Test

To identify the percentage of water percentage in the seed. In the seed industry seed moisture tests done by using a digital moisture meter. The ideal seed moisture for storage is a maximum of 12% for cereals and a maximum of 8% for vegetable seed maintained. Physiological activity accelerates due to high moisture in the seed. As a result, respiration rates become high and seed life/longevity deteriorate. Seed loses its vigor and viability. So, the seed unable to use for the next season.

2. Germination test

To determine the percentage of seeds that germinated. On a commercial basis generally, tests are done by 4 replication and no. of 100 seed for each replication. To distribution seed in the market, the ideal germination percentage is 80% and above. Good germinated seed gives assurance to produce better seedlings which give higher production. More acreage can cover with the low quantity of high germinated seed.

3. Purity test

To identity percentage of pure seed present in the seed lot. Seed lot contain pure seed, unfilled grain, inert matter, insects, other crop seed, etc. Ideal seed purity is for hybrid seed 99% and OP (open-pollinated) seed 98% to distribution.

4. Dry inspection/physical inspection

Preliminary idea to rejection or acceptance of seed by eye inspection. Parameters are- Colour, Brightness, spots, insect infestation, shape, size, thousand grain weight, odor, varietal mixture etc.

List of some crops with quality parameters followed commercially in the seed industry

Sl.	Name of crops	Max. Moisture %	Min. Purity %	Min. Germination %
1	Ash gourd	7	99	70
2	Bitter gourd	7	99	70, 80
3	Bottle gourd	7	99	70, 80
4	Chilli	9	98	80
5	Brinjal	8	98	80
6	Cucumber	7	99	70, 80
7	Carrot	8	96	70
8	Country bean	9	98	80
9	Cauliflower	7	98	80
10	Coriander	10	99	75
11	Indian spinach	9	98	70
12	English spinach	9	98	70
13	Kang kong	7	98	70
14	Khira	7	99	70
15	Okra	10	97 / 99	75
16	Ridge gourd	7	99	80
17	Red amaranth	8	98	70
18	Radish	8	98	80
19	Stem amaranth	8	98	70
20	Green amaranth	8	98	70
21	Spong gourd	7	98	70
22	Sweet gourd	7	99	70
23	Water melon	7	98	70
24	Tomato	8	98	70, 80
25	YLB	9	98	85
26	Grass	12	98	90
27	Rice	12	95	90
28	Wheat	12	95	90
29	Maize	12	95	90
30	Mustard	10	99	95

Seed Processing Methods/How to Processes Seed?

There are some methods to process the seeds

Seed Drying

Seed Cleaning/Seed Grading

Seed Fumigation

Seed Treatment

Seed packaging

Seed labeling

rice seed drying process, Culture's Story

Seed Drying

Reduction of seed moisture content up to a safer level is called seed drying

Main objectives of seed drying are to maintain seed viability and vigor for a longer period during storage

Drying is required to control insect, pest attack due to the low moisture percentage of seed

To protect seed quality deterioration by limiting respiration of seed

Proper drying of seed damage insect egg mass and enhance seed germination

Two types of drying methods are used. One is natural drying (Sun-drying) another is mechanical drying

List of save moisture of some seeds to longer time storage

Cereal Crops seeds like- Rice seed, Wheat Seed, Maize seed, fodder crop seed ≤12%

Vegetable Crops seed mostly ≤8%

Grading machine, Culture's Story

Seed Cleaning/Seed Grading

This is the process of removal of crop debris, insect/pest, and low-quality seed.

By cleaning/grading uniform seeds are separated

To economical use of storage space and avoid infestation of insects and infection of diseases cleaning/grading to be done.

Seed should be dry before cleaning to avoid mechanical damage.

Cleaning/grading should be done immediately after harvesting to maintain quality.

Picture of the seed Fumigation process

Seed Fumigation

This process helps to protect seed from stored insects like- Rice weevil, Rice moth, Red flour beetle, ledger grain beetle, etc.

Presence of insect deteriorated the market value of the seed. Insects also create colonies in the seed lot to live.

One of the main cause of seed damage is presence of insects.

Fumigation is done usually by using ‘’Aluminum Phosphide’’. After using Aluminum phosphide tablet in an adequate dose with cover seed lot by air proof fumigation sheet for at least 72 hrs.

Rice/wheat seed treatment machine vegetable seed treatment machine

Seed Treatment

Seed treatment is a process which eliminates/reduce inoculum levels and/or disease development from seed-borne fungi that are present on or within seeds, without affecting the viability and germination/emergence capacity of seed.

Seed treatment helps to remove inoculum of soil which near or adjacent of seed.

Now a day in seed treatment inset controlling agent also used.

Widely used chemical for seed treatment are Vitaflow (Thirum Carboxin).

Seed treatment also is done by bio-agent like Trichoderma.

Auto packaging machine Continuous sealer

Seed Packaging

Seed packaging is the process of filling, weighing and sewing of bag or packet with seed and

It should provide maximum possible protection from moisture, rain, sunlight, heat, insect pests, moulds etc.

It should provide the necessary facility for inspection, disinfection, and easier to loading, unloading.

It should protect grain from excessive moisture and temperature favorable to both inset and mold development.

It should be economical to marketing and suitable for a seed

It should be easy to transport and carrying.

Widely used seed packaging materials/carrier are poly pack (1gm to 5kg), Jute bag (10kg to 50kg) etc.

Picture of seed labeling

Seed Labeling

Providing basic quality information with crop name, variety, and class including seller’s name, production area so that consumers can make intelligent purchases of seed products is called seed labeling.

Labeling may print on the bag/packet or associate a paper tag with the bag/packet.

Seed preservation in Bulk Seed preservation in Packet

Seed Preservation and seed store management

Seed preservation is needed due to after long time use of the seed. During the preservation of seed, store management is important to conserve seed quality.

Store should be clean all time which helps to prevent insect attacks in the seed lot.

Light and aeration facilities should be maintained in the store

Store should be dry and damp free. The store should be at room temperature.

Seed sacs should be placed on wooden structure not on direct floor.

Floor should be made of concrete. Storage seed moisture should be for cereal 12% and for vegetable 8%

Regular checking of insect/pest must be done.

Seed Fumigation required if insect found.

To learn more click the link below-

https://www.bioversityinternational.org/

https://en.wikipedia.org/wiki/Seed_testing

http://ecoursesonline.iasri.res.in/

http://www.indianacrop.org/ICIA/Media/ICIA/Presentations/