Seed Treatment :: Special


Live seed separation in Groundnut

Farmer friendly specific gravity grading in paddy

Polymer coating

Rhizobial coating

Botanical seed pelleting in greengram

Seed priming

Seed hardening for drought tolerance

Acid delinting in cotton

Designer seed


What is?
Groundnut seed are classified as micro biotic due to their fast deteriorating nature due to its oil content. It also has production problems that lead to the yield of poor quality seeds. But in groundnut for getting required yield plant population has to be maintained (33plants / sq.m.) This warrants the need of sowing good quality seed selection technique is the live seed separation. Hence live seed separation technique is the separation of germinable seed from dead seed.


  • Separate the pest attacked, brokened and immmatured seeds
  • Soak the seeds in equal volume of 0.5% CaCl2 salt solution for 6 hrs.
  • For preparation of 0.5% CaCl2 solution we have to dissolve 125gm of CaCl2 in 25 lit of water.


  • Keep the seeds in between gunny bags in thin layer for about 16 hrs.
  • After 16hrs the live seeds radicle might have germinate up to 5mm.
  • Separate those germinated seeds from that seed lot and dry it in shade.
  • For every 2hrs internal the germinated seeds can be separated from that lot for about 3-5 times.
  • That seeds can be dried in the shade.
  • The remaining ungerminated seeds are considered as dead ones.
  • Further these germinated seeds are treated with either Carbendazim (Fungicide) or Rhizobium.
  • Sprouted seeds can be used for sowing.



Separation of live seeds from dead seeds


  • Do no spread as thick layer
  • Avoid fungal spread in the gunny bag
  • Do not allow to over sprout
  • Shade dry the seed of each interval of collection separately



  • Dead seeds are used for domestic purpose especially for oil extraction.
  • Seed rate will be reduced.
  • Calcium deficiency can be overcome by soaking the seeds in CaCl2 solution.
  • About 10-15% of the yield can be increased.


    What is?

    Rice seeds, which have been harvested in the right stage, processed precisely and packed carefully, are stored under ambient conditions for sowing during the next season. The differential inherent vigour of the individual seeds leads to variation in the rate of deterioration among the seeds during storage. Due to this differential deterioration, individual seeds of a seed lot will vary in seed density.

    Vigorous seeds will posses higher density when compared to insect damaged, decayed, moldy and empty seeds. The lower density seeds may be similar to high vigour seeds in size and shape. Prior to sowing, the good quality high density seeds have to be separated from the poor quality seeds because seed vigour is important in determining crop performance.

    Based on the density principle the seeds are floated using salt solution and the quality seeds are separated (the high vigour seeds sink and low vigour seeds float)


    • Take 10 litres of water in plastic bucket of 15 litres capacity.
    • Drop a fresh egg in water.
    • Add commercial common salt, little by little into the water and allow it to dissolve. (@2 kg / 10 litres of water)
    • Watch the egg to raise up as the density of the solution increases.
    • Stop adding salt when the surface of the egg of a size equivalent 25 paise coin, is visible above the solution. Now the density of the water is suitable for separation of good quality seeds.
    • Add 10 kg of rice seeds in this salt solution.
    • Remove the seeds floating on the surface.
    • Collect the seeds sunk in the salt solution and wash them.
    • Shades dry the seed and use for sowing.



    Rice upgradation by egg floatation technique


    • Don’t over soak
    • Don’t use more salt
    • Salt water can be reused
    • drying should be proper


    • Separates immature and ill filled seeds
    • Enhances field emergence
    • Can be adopted both for transplanted and dry crop
    • Improves the yield
    • Check on pathogen infection


What is?

It is the process of coating the seeds with polymers of different colours along with nutrients and plant protectants to increase the aesthetic values of the seed with required benefits.


  • Coat the seeds with polykote (3 g + 5ml water / kg) after proper dilution
  • Mix fungicide (Carbendazim 2g) and pesticide (Imidachloprid 2 ml / Kg) with the polykote to increase the resistance to the pest and diseases.
  • Shade the seed before using / storing
    Seed cote                                   Polymer Coated Seeds



Treatment details

Colour of polymer Dose of polymer (g/kg) Volume of water (ml)
Paddy Yellow 3 3
Maize Pink 3 5
Sorghum Pink 3 5
Cumbu Pink 3 5
Soybean Yellow 4 5
Sunflower Black 4 5
Tomato Red 6 20
Bhendi Green 5 5


  • Polykote gives uniform colour and shape to the seeds and also increases5 to 10 percent of germination % and vigour index.
  • Improved seedling emergence and vigour.
  • Protection against pest and disease during storage.
  • Free from environment pollution
  • Avoid wastage of seed treating chemicals.
  • Polykote can be used for all agricultural and horticultural crops.           


What is?
Rhizobial coating is to enriching the rhizosphere microenvironment with organic nutrients for early establishment.


  • Take the seeds in a plastic tray
  • Add proper quantity of adhesive (cool maida 10% gruel) to the seeds or jaggery
  • Shake gently so that the adhesive spreads evenly on all the seeds
  • Sprinkle the required biofertilizer (Rhizobium, Azospirillum, Azotobactor) evenly over the seeds and continue shaking.
  • The wet seed surface will attract the biofertilizer and result in even coating over the seeds
  • Roll the seed for uniformity
  • Shade dry the seed

Seed rhizobial coating with 10% maida gruel @ 200-300ml/ kg of seeds and coating with biofertilizer @ 200-300 g per kg of seed improve the field emergence of green gram, black gram, cotton, tomato and brinjal.


  • Seeds should not spill while shaking
  • Adhesive should not be added excess. Since it will lead to formation of seed dumps.
  • Inadequate application of adhesive will result in uneven seed coating
  • Separate the seeds dumps formed, if any manually.
  • Empty the seeds on a sheet of paper and allow it to dry for a day.


  • It improves fertility at rhizosphere region with organic matter.
  • The mechanical planting of seeds is facilitated.
  • Seed are uniform in size and shape
  • Easy handling of seed
  • In mechanical separation seed flow easily which prevent dumping together
  • Small and irregular shaped seeds can be handled easily by pelleting which changes the shape of the seeds.
  • Permits precision planting in very small seeds which results in uniform seedling emergence
  • Improved ballistics properties. Pelleting increases the weight of seed therefore increase the capacity of aerially sown seed to penetrate in to standing vegetation in tree species.
  • Handling of small seeds is made easy which in turn reduces the seed rate.


Pelleting is enclosing of seed in a filler material using an adhesive with bioactive chemicals to ensure singling of seed and size increases for easy handling.


  • Take the seeds in plastic tray
  • Add a small quantity of adhesive (10% maida solution) to the seeds
  • Shake gently, in such a way the adhesive spreads evenly on parts of each seed
  • Add filler material (Arappu leaf powder) evenly over the seeds and continue shaking until the uniform coating is ensured
  • Separate the seed dumps if any
  • Remove the excess filler material by sieving
  • Dry under shade to expel moisture


  • Small and irregular shape seeds can be handled easily
  • Precision sowing of seeds is possible as size and weight of seeds are increased
  • Increased physiological seed quality characters




What is?

Seed priming is the process of controlled hydration of seeds to a level that permits pre-germinative metabolic activity to proceed, but prevents actual emergence of the radicle.

Types of priming

  • Hydro priming (use of water double the volume of seed)
  • Halo priming (use of salt solution-NaCl)
  • Osmo priming (use of osmotic solution – PEG)
  • Sand matric priming – (use of moist sand)


For the first three methods soak the seed in the respective solution of definite concentration for needed duration and dry back the seed to original moisture content.
For the fourth method mix the seeds with moist sand of required water holding capacity, place it in perforated plastic covers and keep it deep in the tray filled with moist sand of same water holding capacity.


Comparison of control and primed bhendi seeds

Creation of different WHC (Water Holding Capacity)
30% WHC – 90ml of water / kg of dry sand
40% WHC – 120 ml of water / kg of dry seed
60% WHC – 180 ml of water / kg of dry seed
80% WHC – 240 ml of water / kg of dry seed
100% WHC – 300 ml of water / kg of dry seed

Crop Seed priming techniques
Tomato Hydro priming (48hrs)
Brinjal Sand matric 80% (3 days)
Chillies Sand matric 80% (3 days)
Onion Sand matric 80% (3 days)
Carrot Hydro priming (36hrs)
Beetroot Hydro priming (12hrs)
Bhendi Sand matric60% (3hrs)
Radish Hydro priming (12hrs)
Mustard Hydro priming (12hrs)


  • Enhances the germination percentage
  • Enhances the speed and uniformity of germination
  • Improves the resistance towards water and temperature stress
  • Increases the shelf life of seed
  • Highly suitable for small seeds
  • Enhances the yield


What is?

Seed hardening is physiological preconditioning of the seed by hydration to with stand drought under rainfed condition.


  • Soak the seed in water or in chemical solution for definite duration in proper seed to solution ratio
  • Shade drying to bring back the seed to original moisture content



    • It increases the speed of germination and germination percentage
    • It increases the seeding vigour.
    • The uniformity of seedling emergence.
    • Increases the root growth.
    • Flowering occurs 2-3 days earlier.
    • Uniform seed set and maturity.
    • Increases the yield.

Factors influencing

  • Concentration of the chemical
  • Selection of chemical
  • Duration of soaking
  • Seed to solution ratio

Hardening technique for various crop

Crop Chemical and concentration Methodology
Pearl millet 2% potassium
Dissolve 20 gm of salt in 1000 ml of water. Soak 1 kg of seed in 650 ml of this solution for 10 hours and dry back to original moisture.
Sorghum 2% potassium
Dissolve 20 gm of salt in 1000ml of water. Soak 1 kg of seed in 650 ml of the solution for 16 hours and dry back to original moisture or weight.
Cotton 2% Potassium
Dissolve 20 gm of salt in 1000 ml of water. Soak 1 kg of seed in 650 ml of this solution for 10 hours and dry back to original moisture.
Sunflower Potassium chloride Dissolve 20 gm of salt in 1000 ml of water. Soak 1 kg of seed in 650 ml of this solution for 12 hours and dry back to original moisture.
Black gram & Green gram 100ppm Zinc
100ppm Manganese sulphate
Dissolve 1000mg of salt in 1000ml of water. Soak 1 kg of seed in 350 ml of the solution for 3 hours and dry back to original moisture or weight.
Ragi 0.2% Sodium
Dissolve 2 g of salt in 1000ml of water. Soak 1 kg of seed in 700 ml of solution for 6 hrs and dry back to original moisture content or weight.
Groundnut 0.5% calcium
Dissolve 5 g of salt in 1000ml of water. Soak 1 kg of seed in 300 ml of solution for 4 hours and dry back to original moisture or weight.
Redgram 100ppm Zinc
Dissolve 1000mg salt in 1000ml of water. Soak 1 kg of seed in 300 ml of solution for 4 hrs and dry back to original moisture or weight.
Bengal gram 1% potassium
 dihydrogen  phosphate
Dissolve 10g salt in 1000ml of water. Soak 1 kg of seed in 350 ml of solution for 4 hrs and dry back to original moisture or weight


What is?

In cotton, seeds are removed from kapas the fruiting body which has both seed and lint. In the separated seed, seed coat will have hairy outgrowth and this is the genetic characteristic feature of the seed. These seeds are known as fuzzy seed as the hair like growth is known as fuzz.

Normally these fuzzy cotton seeds are used for sowing purpose and these seeds creates problems on sowing as

  • Maintenance plant population in the field mainly due to difficulty in recognition of contaminates, broken seeds, diseased seeds, insect infected seeds, immature seeds etc.
  • Non free flowing nature of the fuzzy seed make the sowing difficult
  • More seed rate
  • Lesser storability   
    Hence separation of seed from the lint to increase the free flowing nature of the seed proper removal of the fuzz, the external hair from the seed coat is necessary, which could be obtained through the process known as delinting.
    Delinting is the process of removal of fuzz from the seed coat in cotton i.e. it is a crop specific seed management technique.


  • Take one kg of the cotton (fuzzy seeds) in a plastic bucket
  • Add concentration H2SO4 at the rate of 100ml / kg of seed
  • While additions it should be constant stirring by using wooden stick for 2-3 minutes to facilitate uniform coverage and better treatment effect.
  • After 3 minutes all seeds will turn into coffee brown in colour
  • Wash the seeds immediately for 4-5 times with cold water until the acid nature of the seed is removed.
  • Care should be taken while washing the improper washing will affect the viability of the seed.
  • After thorough washing the entire seed should be placed in water in 1: 10 ratio to remove floaters.
  • For complete removal of acid seeds can be dipped in 0.5% calcium chloride solution for 10-15 minutes.
  • The sinkers seeds can be used for sowing purpose.
  • For large scale delinting of cotton, cotton delinting machine can be used.
Factors influencing
  • Type of acid
  • Seed size / varietal character
  • Efficiency of persons
  • Washing
  • Neutralising


  • Don’t  use hand while mixing use wooden poles
  • Use plastic bucket only
  • Mix the seeds for only 2-3 minutes and not more than that as excess acid will kill the seed
  • Give through washing
  • Dry the seed to low moisture content for longer storability
  • Remove the broken and immature seed


  • Seed borne pathogens are eliminated
  • Destroyed boll worm eggs on the seed coat
  • Remove the inhibitors in the pericarp
  • Increase seed germination and vigour
  • Reduce the seed rate
  • Make seed free flowing
  • Make mechanical sowing feasible
  • Storability is more

Acid delinting in cotton



Designer seed is an integrated pre-sowing seed treatment that involves addition of nutrients, plant protectants and bioinoculants to enhance seed quality viz., speed of emergence and establishment.


Coat the hardened (ZnSO4 0.5%) black gram seeds were coated with polykote @3g + 5ml water / kg and was followed by Imidachloprid (5g/kg), Trichoderma viride (4g / kg). finally seeds were coated with Rhizobium (20g / kg) and Azophos (120g /kg)






  • Increase in speed of germination
  • Improved vigour of seedling
  • Reduced cost of plant protection
  • Resistant to pest and disease
  • Increased yield
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