QUALITY SEED PRODUCTION IN RICE VARIETY
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Land Requirement
Land should be free of volunteer plants. The previous crop should not be the other varieties of the same crop. It can be the same variety, if it is certified as per the procedures of certification agency.
Field Standards
A. General Requirements
Isolation
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Rice seed production fields shall be isolated from the contaminants by allowing the isolation distance as specified below.
Contaminants |
Minimum distance (meters) |
Foundation |
Certified |
Fields of other varieties |
3 |
3 |
Fields of the same variety not conforming to varietal purity requirements for certification |
3 |
3 |
B. Specific requirements
Factor
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Maximum permitted (%)* |
Foundation |
Certified |
Off-types |
0.050 |
0.200 |
**Objectionable weed plants |
0.010 |
0.020 |
*Standards for off-types and objectionable weeds shall be met at the final inspection.
**Objectionable weed shall be: Wild rice (Oryza sativa L. var. fatua Prain) (Syn. O. sativa L.f. spontanea Rosch.)
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Land Preparation
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Pre-sowing Seed Management
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In dormant cultivars, break the seed dormancy by soaking the seeds in equal volume of 0.1 N conc. HNO3 or 0.5 % KNO3 for 12 - 16 h.
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Upgrade the seeds by specific gravity grading method with salt solution by dissolving
1.5 kg of common salt in 10 lit of water. Remove the floaters, and use the sinkers for sowing after repeated washing with water.
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For rainfed or direct sowing, harden the seeds by soaking in equal volume of 1% KCl solution for 16 h, and dry back the seeds to original moisture content.
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For sowing in saline / sodic soils, soak the seeds in equal volume of 80 micro molar of sodium nitroprusside for 16 h.
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Specific gravity grading in rice seeds
Method of Planting |
- SRI method can be adopted.
Recommendation for planting under saline soil condition
- Incorporation of green manure like daincha in soil.
- Shallow planting at 3 - 4 seedlings / hill.
- Basal application of gypsum @ 500 kg / ha.
- Foliar spray with 0.5 % FeSO 4 and ZnSO4 at tillering stage.
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Planting |
Fertilizer recommendation for different duration varieties
- Short duration : NPK @ 120:40:40 kg / ha
- Medium duration : NPK @ 150:50:60 kg / ha
- Long duration : NPK @ 150:50:80 kg / ha
Recommendation for Zinc deficient soils
- Apply ZnSO4 @ 25 kg / ha.
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Fertilizer Application |
Roguing space
- Leave a roguing space of 30 cm for every 150 cm.
Roguing space in rice seed crop Roguing
Field inspection
Foliar application
- Foliar spray of 2 % DAP at boot leaf stage and at 5 - 10% flowering.
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Harvesting |
Threshing
Drying
Grading
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For getting better seed quality, size grade the seeds using 1.3 mm x 19 mm oblong sieve.
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Size graded seeds may be upgraded by density grading using specific gravity separator.
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Heavy and medium fractions with 90 - 92% recovery are selected for seed purpose.
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Physiological maturity indices in rice
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Pre-storage Seed Treatment |
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Treat the seeds with carbendazim @ 2 g / kg of seed.
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Treat the seeds with halogen mixture @ 3 g / kg (CaOCl2 + CaCO3+ arappu (Albizzia amara) leaf powder mixed in the ratio of 5:4:1) as eco-friendly treatment.
Storage
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Store the seeds in gunny or cloth bags for short term storage (8 - 9 months) with a seed moisture content of 12 - 13 %.
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Store the seeds in polylined gunny bag for medium term storage (12 - 15 months) with a seed moisture content of 8 - 9 %.
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Store the seeds in 700 gauge polythene bag for long term storage (more than
15 months) with a seed moisture content of less than 8 %.
Seed Standards
Factor |
Standards for each class |
Foundation |
Certified |
Pure seed (minimum) |
98.0% |
98.0% |
Inert matter (maximum) |
2.0% |
2.0% |
Huskless seeds (maximum) |
2.0% |
2.0% |
Other crop seeds (maximum) |
10/kg |
20/kg |
Other distinguishable varieties (maximum) |
10/kg |
20/kg |
Total weed seeds (maximum) |
10/kg |
20/kg |
Objectionable weed seeds (maximum) |
2/kg |
5/kg |
Seeds infected by paddy bunt (Neovossia horrida (Tak.) Padwick & Azmatulla Khan. (maximum) |
0.10%
(by number) |
0.50%
(by number) |
Germination (minimum) |
80% |
80% |
Moisture (maximum) |
13.0% |
13.0% |
For vapour-proof containers (maximum) |
8.0% |
8.0% |
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Packing and storage of rice seeds |
Source
The Professor and Head
Department of Seed Science & Technology
TNAU, Coimbatore-641003.
Phone:0422-6611363
Email: seed@tnau.ac.in
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