Seed Dormancy in Fruit Crops
· 2026-10-02 22:14:44 · 4 views · 0 downloads
Seed Dormancy in Fruit CropsSeed DormancyAlive conditions but in rest with reduced metabolism of seed, bud etc.
Two Types
Alive conditions but in rest with reduced metabolism of seed, bud etc.
Two Types
1. Primary Dormancy
The conditions that exist within the seed to prevent seed germination at the time of it mature in the plant.
Causes:
a) Seed coat: Presence of hard seed coat which inhibits penetration of water & O₂ required for germination. E.g.: Ber, guava, walnut.
b) Chemicals: Presence of chemical inhibitors (ABA) in most of the temperate fruits (apple, pear, peach & walnut).
c) Deep dormancy: Temperate plants typically type of deep dormancy staying dormant until conditions are favourable for germination. Chilling is required to overcome deep dormancy.
2. Secondary Dormancy
Dormancy that develops within the moist seed after it is removed from the plant.
Causes:
Extreme temperature.
Prolonged darkness or light.
Water stress.
Dry conditions.
Mechanism of DormancyDormancy is the resulting of the slowing down of the metabolic activity this may be due to slow oxidation of auxin.
Ethylene production & enzyme activity (α & β-mamose) around the embryo weakened the embryo.
UtilizationTo overcome severe cold & frost during winter temperate fruits.
Dormancy is the resulting of the slowing down of the metabolic activity this may be due to slow oxidation of auxin.
Ethylene production & enzyme activity (α & β-mamose) around the embryo weakened the embryo.
To overcome severe cold & frost during winter temperate fruits.
| Seed Dormancy | Bud Dormancy |
|---|---|
| No germination | Cessation of growth |
| Rest | Quiescence |
| Internal factor | External factor |
Overcome Seed Dormancy1. ScarificationProcess of breaking, scratching or softing the seed covering to make it permeable to water & gases.
Mechanical scarification: Ber, peach, walnut.
By hot water: 77–100°C hot water and immediately removed and soak gradually in cool water for 12–24 hours. E.g.: Guava, strawberry.
By acid: Treating guava seeds with concentrated H₂SO₄ for 3 minutes & 5–6 hours in ber.
0.25% Nitric acid or H₂O₂ – strawberry.
The seed are kept in a warm moist media for 1–4 minute.
2. StratificationAlso called as moist chilling.
Seeds are subjected to a period of chilling to after ripen the embryo.
Seeds are subjected to low temperature to break dormancy – apple, pear.
Imbibed seeds are kept in moist media and stored in refrigerator (0–7°C) for a certain period (1–5 months).
Process of breaking, scratching or softing the seed covering to make it permeable to water & gases.
Mechanical scarification: Ber, peach, walnut.
By hot water: 77–100°C hot water and immediately removed and soak gradually in cool water for 12–24 hours. E.g.: Guava, strawberry.
By acid: Treating guava seeds with concentrated H₂SO₄ for 3 minutes & 5–6 hours in ber.
0.25% Nitric acid or H₂O₂ – strawberry.
The seed are kept in a warm moist media for 1–4 minute.
2. StratificationAlso called as moist chilling.
Seeds are subjected to a period of chilling to after ripen the embryo.
Seeds are subjected to low temperature to break dormancy – apple, pear.
Imbibed seeds are kept in moist media and stored in refrigerator (0–7°C) for a certain period (1–5 months).
Also called as moist chilling.
Seeds are subjected to a period of chilling to after ripen the embryo.
Seeds are subjected to low temperature to break dormancy – apple, pear.
Imbibed seeds are kept in moist media and stored in refrigerator (0–7°C) for a certain period (1–5 months).
| Crop | Optimum Temperature (°C) | Period of Treatment (Days) |
|---|---|---|
| Apple | 3 | 70–80 |
| Pear | 3 | 70–80 |
| Plum | 3 | 70–80 |
| Peach | 5 | 60–100 |
| Grape | 5 | 90 |
| Cherry | 3 | 180 |
3. LeachingLeaching of inhibitors like phenolic substance, gelletophous etc. with washing in running water.
4. Hormonal TreatmentApple, peach, cherry, strawberry, hazel nut – GA₃ @ 100–500 ppm for 20–24 hours.
Guava, strawberry – ethereal @ 500 ppm.
Apple, peach – BA @ 10–20 ppm.
5. Chemical TreatmentGuava, ber – KNO₃ solution @ 0.2%.
Grape, peach, plum – thiourea @ 500 ppm.
6. Light / TemperaturePhoto dormancy: Red light for dormancy – strawberry.
Thermodormancy: Optimum temperature for germination is 15–30°C.
7. Seed PrimingPapaya.
Seed Storage
Leaching of inhibitors like phenolic substance, gelletophous etc. with washing in running water.
Apple, peach, cherry, strawberry, hazel nut – GA₃ @ 100–500 ppm for 20–24 hours.
Guava, strawberry – ethereal @ 500 ppm.
Apple, peach – BA @ 10–20 ppm.
5. Chemical TreatmentGuava, ber – KNO₃ solution @ 0.2%.
Grape, peach, plum – thiourea @ 500 ppm.
6. Light / TemperaturePhoto dormancy: Red light for dormancy – strawberry.
Thermodormancy: Optimum temperature for germination is 15–30°C.
7. Seed PrimingPapaya.
Seed Storage
Guava, ber – KNO₃ solution @ 0.2%.
Grape, peach, plum – thiourea @ 500 ppm.
Photo dormancy: Red light for dormancy – strawberry.
Thermodormancy: Optimum temperature for germination is 15–30°C.
7. Seed PrimingPapaya.
Seed Storage
Papaya.
1. Orthodox Seed
Seed remain viable for long time at low temperature.
2. Recalcitrant
Seed does not remain viable for long time at low temperature so they should be sown immediately after extraction.
E.g.: Mango, citrus, litchi, loquat, mangosteen, avocado, jack fruit, rambutan, Barbados cherry and tea.