Authors: Ravi kumawat, Madhu Choudhary, Kana Ram Kumawat
Seed is the basic input for agriculture. Seed is treated to enhance seed longevity, establish optimum and uniform plant population of healthy plants with reduced seed rate. It is of following types.
1. Seed invigoration
Pre storage treatment
A. Halogenation
B. Antioxidant treatment
Mid storage treatment
A. Hydration-dehydration
2. Pre sowing treatment
Germination and vigour augmentation
A. Seed fortification
B. Dry permeation or seed infusion
C. Seed hardening
D. Seed priming
E. Irradiation
F. Magnetic seed treatment
3. Seed coating treatment
A. Seed pelleting
B. Film coating
C. Seed colouring
D. Fluid drilling or Gel seeding
E. Seed sanitation
F. Designe
1. Seed invigoration: To maintain seed longevity
A. Halogenation: Replacement of one hydrogen atom with halogen is known as halogenations. The compounds chlorine, bromine and iodine are known as halogen compounds. In seed technology pre storage seed treatment by halogens at room temperature is termed as halogenations. The halogen is absorbed by unsaturated fatty acid of the seed and reduces the physiology deterioration of seed. A halogens compound also has antimicrobial activities thus protect the seed from pathogens.
B. Dry dressing: application of halogen compounds like chlorine, bromine and iodine to seed before seeds storage as dry dusting to stabilize the lipoprotein biomembrane.
C. Antioxidant treatment: wet or dry treatment of seed with antioxidant substances viz., A, C, E, and butylated hydroxytoulence before storage to delay the physiological ageing is known as Antioxidant treatment.
D. Hydration-dehydration: low and medium vigorous, non- leguminous seeds are soaked in water with or without adding chemicals like sodium and potassium phosphate, potassium iodide for short duration raise the shelf life of seed.
2. Pre sowing treatment
A. Seed fortification/ infusion: process of enriching the seed with simple water or bioactive chemicals viz., micronutrient. Groeth regulators, vitamins, and seed protectants to improve germination and seedling vigour is known as seed fortification.
e.g. Soaking of rice seed in 1 % KCI for 16 hours
Soaking of soybean seeds in 0.25M CaCI2
B. Dry permeation: Soaking of seeds in organic solvents to improve the germination and vigour of the seed by infusing bioactive chemicals into the seed is known as dry permeation.
C. Seed hardening: hydration of seed to initiate the pre germinative metabolism followed by dehydration to fix the biochemical events is known as seed hardening. It has specialized effect to withstand abiotic stresses at the time of germination and field emergence.
D. Seed priming: controlled hydration of seeds through a carrier or high molecular solute to a level that stars pre metabolic activity followed by dehydration to check emergence of the radicle is known as seed priming.
E. Osmo-priming: Soaking of seed in osmotic solutions viz., PEG, Glycerol, Mannitol, KNO 3 etc.
A. Hydro- priming: it is hardening of seeds in water under anaerobic condition .
B. Halo- priming: Soaking of seed in salt solutions
C. Bio- priming: seed coating with biological agents like bacteria.
Effect of priming on seed germination
Increased rate of germination
Greater germination uniformity
Increased germination percentage
Wider temperature range for germination percentage
Advancement of maturity
Weakening of barriers to embryos growth
Increased protein synthesis
F. irradiation: irradiation of air dried seed by lower dose of gamma radiation for shorter period before sowing increase the germination and vigour.
G. Magnetic seed treatment: Exposure of seeds to a magnetic field for specified duration improves germination and vigour.
3. Seed coating treatment
A. Seed pelleting: enclosing or encapsulation of small seed with inert (clay, CaCl2 , verimuculate) to produce a globular unit of standard size is known as seed pelleting.
Advantages of seed pelleting
A. Sowing of seed
- Mechanical planting
- Easy handling of small and irregular seeds
- Reduce seed rate
- Uniform field emergence
B. Protection
- Pelleting with fungicides and inseticides provide protection against soil and seed borne pathogens and field insects.
- Prevent seeds against store grain pest.
- Prevent seeds against rodents.
- Enhanced seedling vigour when pelleted with fertilizers by nourishing the seedlings
- Assured germination against abiotic stress
- Reduce environmental pollution
- Precise and accurate use of pesticides
B. Film coating: a continuous layer of chemical is coated on the surface of the seed without altering the shape or size. The advantage of film coating over other coating process is the minimum emission of dust particles, minimum loss of coated material, high retention capacity of chemical, less hazardous tom operate. film coating involves application of vinyl chloride+ vinyl acetate+ ethylene+ acetylene with 30 % cellulose as a stabilizing substances followed by immediately drying.
C. Film colouring: presie amount of natural or artificial dyes or pigments is applied directly on the surface of seed.
- Brand identification
- Distinct and attractive look
- Improvement in storability
- Enhance vigour and germination
- Identification of the seeds of parental lines of A, B, R lines in hybrid
D. Fluid drilling or Gel seeding: mixing of germinated seeds in viscous gel
(alginate gel), which is sown with an appropriate seed drill to maintain the seed moisture of the pre germinated seed and to prevent injury to emerged radicle.
E. Seed sanitation: treatment of seed with pesticides for disinfestataion or disinfectation from various seed borne pest and storage insect pest is known as seed sanitation.
F. Designer seed: Coating of all the possible useful active ingredients on the seed with an adhesive is known as designer seed. The sequence of the treatment is fungicides + insecticide+ micronutrient+ clolouring agents.
About Author / Additional Info:
I am pursuing Ph. D from MPUAT, Udaipur