TOPIC: Seed Hardening, Principle and Its Use In Dry Lands
B.L Manjunath (2010)
B. C. Patil (2014)
Ananthi, M., Selvaraju (2015)
S.MONDAL et al (2011)
TOPIC: Seed Hardening, Principle and
Its Use In Dry Lands
Dr. K.B.SUNEETHA DEVI,
Dept. Of .AGRONOMY.
Definition: The process of hydrating the
seed to initiate the pre-germinating
metabolism followed by dehydration which
fixes the biochemical events.
purpose: to impart resistance against stress
conditions like drought and cold , to the
Seeds are soaked in water and allowed to absorb
moisture up to 35 % of their weight and kept in
swollen condition for about 6 hrs. at 15 to 25oC.
Then seeds are spread out in a thin layer under
shade for 2 to 3 days to attain their original weight.
The treatment can be repeated for 3-4 times, which
depends on type of crops and their varieties.
Methods of seed hardening:
The treatment of alternate wetting and drying
of seeds as in case of water treatment have to be
carried out with chemicals and varied
Steps in seed hardening
Soaking in water or dilute solution of growth regulators
and chemicals for 1-12 hrs at
Sun drying to bring back to its original water
• During hardening, a no. of physiological
changes occur and modifies the protoplasmic
• More absorption of water cause incease in
elasticity of cell and development of efficient
Permits initial process of germination
Shade and sun drying-original water
Stop the germination
Rapid germination and quick establishment of
Increase in growth and productivity
Materials and chemicals used for seed hardening
Aqueous salt solutions like chlorides of Na, Ca, K, sulphates
of Na, KNO3.
Growth regulators like GA, kinetin, 2 chloroethyl phosphoric
acid, ascorbic acid.
Vitamins like B3, Nicotinic acid, pantothenic acid.
Plant products like garlic extract, coconut water.
Osmotic priming materials like D. Mannitol, PEP etc.
Recommended seed hardening practices in field crops
under dry lands.
Rice KCl 1 10
Pearl millet KCl or NaCl 2 16
Finger millet CaCl2 0.5 Until visibility
Maize H2O - 12-16
Pigeon pea Zn (SO4)2 100 ppm 4
PULSES ( Green gram & Black gram):
•4 kg of wood ash is collected , powdered.
•30% Acacia gum is added and mixed thoroughly.
•8kg of black gram or green gram seed is spread
over paste .
•Sun dried for 5 hours and then sown before onset
– It increases the speed of germination and
– It increases the seedling vigour.
– The uniformity of seedling emergence.
– Increases the root growth.
– Flowering occurs 2-3 days earlier.
– Uniform seed set and maturity.
– Increases the yield.
• Leguminous seeds less response to wetting
and drying, over soaking –soaking injury.
• Prolonged soaking-accumilation of toxic
• Chemicals should not give additional effects.