Seed science notes for IBPS AFO

Seed science notes

Seed science notes for IBPS AFO, NABARD, RRB SO, and other agriculture exams. These notes are presented in a concise, one-liner format for quick reference and efficient study.

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Self-Pollinated Crops

Crop	Foundation Seed	Certified Seed
Rice	3	3
Wheat	3	3
Soybean	3	3
Groundnut	3	3
Oat	3	3
Barley	3	3
Finger millet & other small millet	3	3
Barley Wheat & Paddy Hybrid	200	100
Black gram	10	5
Green gram	10	5
Chick pea	10	5
Field pea	10	5
Rajmah	10	5
Cow pea	10	5
Lathyrus	10	5
Lentil	10	5
Taramira	100	50
Sesame	100	50
Linseed	50	25
Tomato	50	25
Tobacco	3	3

Cross-Pollinated Crops

Crop	Foundation Seed	Certified Seed
Sunflower	400	200
Safflower	400	200
Sunflower Hybrid	600	400
Niger	400	200
Maize	400	200
Mustard / Rapeseed	400	200
Pearl millet	400	200
Pearl millet Hybrid	1000	200
Cabbage	1600	1000
Cauliflower	1600	1000
Cucurbits	1000	500
Cucurbits Hybrid	1500	1000
Onion	1000	400
Castor	600	300
Castor Hybrid	1000	300

Often Cross-Pollinated Crops

Crop	Foundation Seed	Certified Seed
Cotton	50	30
Jute	50	30
Red gram	250	100
Brinjal	200	100
Capsicum	500	250
Sorghum	200	100
Sorghum Hybrid	300	200
Okra	400	200
Chilli	400	200

Crop	Foundation Seed	Certified Seed
Berseem	400	100
Lucerne	400	100
Napier grass	10	10
Dhaincha	10	–
Mesta	50	30
Sunnhemp	250	100

Types of Maize and Isolation Distance (in meters)

Type of Maize	Isolation Distance
Maize (with same kernel colour and texture)	400
Maize (with different kernel colour and texture, and teosinte)	600
Maize Hybrid (with same kernel colour and texture)	200
Maize Hybrid (with different kernel colour and texture, and teosinte)	300

Seed science notes for IBPS AFO: One-Liner

Aspect	Details
Availability of quality seeds	Crucial for productivity and cultivar adoption.
Quality seed characteristics	Genetic purity, disease-free, free from admixtures, uniform size/shape/color.
Seed Production Definition	Systemized crop production with proper management techniques.
Benefits of Seed Production	Higher income, higher quality seed for next sowing.
Difference: Seed vs. Crop Production	Seed needs authenticity, isolation, technical skill, genetic purity, and specific maturity. Crop production focuses on yield.
Types of Seed Production	Varietal (single parent) and hybrid (multiple parents, controlled pollination).
Importance of Seed Production in India	Essential for food security and agricultural growth.
Role of High-Quality Seed	Key for yield and quality; poor seeds negate other inputs.
National Seeds Policy 2002	Emphasizes varietal development, seed production, and replacement rates.
Scope for Seed Export	Indian seeds suitable for similar agro-climatic zones; potential markets in Asia, Africa, and Latin America.
Strengths of Indian Seed Sector	Developed seed multiplication, certification agencies, varied agro-climatic zones, fast-growing private sector.
Weaknesses of Indian Seed Sector	Weather vulnerability, inappropriate data, isolation distance maintenance, low uptake of new varieties, inadequate breeder seeds.
Factors Affecting Seed Demand	Cropping pattern, climate, market demand, farm income, government policy, adoption of technology.
Demand Forecasting Importance	Critical to avoid overproduction or underproduction; impacts financial outcomes.
Seed Replacement Rate (SRR) Importance	Indicates frequency of farmers replacing seeds, crucial for demand forecasting.
Seed Multiplication Ratio	Ratio at which seed multiplies, important for calculating requirements.
Export Opportunities	Custom vegetable seed production and branded seed export.
Agri-Export Zones	Promote agricultural exports and provide sustained income to farmers.

Seed science notes :- Seed Certification Tag Colors

Seed Type	Tag Color
Breeder Seed	Golden Yellow
Foundation Seed	White
Registered Seed	Purple
Certified Seed	Blue

Key Agencies and Policies

Agency/Policy	Details
National Seeds Corporation (NSC)	Established in 1963; headquarters in New Delhi.
Indian Seed Act	Enacted in 1966; amended in 1972.
National Seed Policy	Established in 2002; focuses on varietal development and seed production.
Seed Certification Agencies	20 agencies with 96 laboratories ensuring seed quality.

National Seed Policy, 2002: Key Points

Aspect	Details
Basis of Regulation	Seed Act (1966), Seed Control Order (1983), New Policy on Seeds Development (1988).
Objectives of the Policy	Create conducive environment for seed industry growth, safeguard farmer interests, conserve agro-biodiversity.
Thrust Areas	Varietal development, Plant Varieties Protection (PVP), seed production, quality assurance, distribution, infrastructure, transgenic varieties, imports, exports, domestic industry promotion, monitoring.
Varietal Development and PVP	Implementation of IPR for R&D investment, establishment of PVPFRA, registration based on DUS characters, farmer, researcher, breeder, and community rights, benefit sharing.
Seed Production	Adherence to generation system, restructuring of public sector, seed village scheme, progressive seed replacement, seed banks, mini kits, crop insurance.
Quality Assurance	Enactment of New Seed Act, establishment of National Seed Board, maintenance of National Seeds Register, farmer rights, VCU registration.
Seed Distribution and Marketing	Registry subject to NSB, establishment of National Seed Grid, finance facilitation, improved distribution, marketing.
Infrastructure Facilities	Establishment of NSRTC, augmentation of processing/storage, computerized National Seed Grid.
Transgenic Plant Varieties	Testing for environment and biosafety, controlled import through NBPGR, infrastructure development.
Import and Export	Provision for high-quality imports, long-term export policy, export promotion zones, international market data bank.
Promotion of Domestic Industry	Incentives, financial support, tax rebates, import duty reduction, encouragement of memberships.
Strengthening of Monitoring System	DAC supervision for policy implementation.
Impact of Policy	Vital for doubling India’s food production.

Factor	Explanation
Developmental Variations	Differences in growth responses due to varying environmental conditions over generations can lead to shifts in the variety’s characteristics.
Mechanical Mixtures	Mixing of varieties during sowing, harvesting, and processing due to equipment contamination or adjacent fields growing different varieties.
Mutations	Natural genetic changes that may not significantly affect varieties but need monitoring.
Natural Crossing	Unintentional cross-fertilization with other varieties, pests, or diseased plants, particularly in sexually propagated crops.
Minor Genetic Variations	Small genetic changes within seemingly uniform varieties that may arise and be eliminated through selective breeding.
Selected Influence of Pest and Diseases	Susceptibility of new varieties to evolving pests and diseases, necessitating strict disease control measures during seed production.
The Techniques of the Plant Breeder	Issues such as premature release of unstable varieties, cytogenetic irregularities, and improper variety testing procedures.
Maintenance Practices for Genetic Purity	– Use approved seed and inspect fields before planting. – Regular field inspections for genetic purity. – Sampling and sealing of cleaned lots.
Genetic Purity Maintenance in Hybrid Seeds	– Maintenance of parent lines through self-pollination or sib-pollination. – Adequate isolation to prevent cross-contamination. – Regular roguing for off-types.
Nucleus Seed of Inbred Lines	– Preservation through selfing or sibbing. – Critical examination and roguing of uniform ears. – Bulk planting and storage under ideal conditions.
Nucleus Seed of Non-Inbred Lines	– Large-scale sibbing to maintain genetic diversity. – Roguing for off-types with thorough examination. – Bulk planting and careful handling of breeder’s seed.

Aspect	Seed	Grain
Definition	– Ripened ovule or fertilized matured ovule containing embryo	– Economic produce emphasizing supporting tissue
Characteristics	– Biological existence, genetic & physical purity, capability to regenerate into new plant	– Emphasis on supporting tissue, economic yield
Usage	– Sowing for crop production	– Consumption as food
Treatment	– Treated with pesticide/fungicide to protect against pests and fungi	– Not treated with chemicals
Respiration	– Low respiration rate and biological processes during storage	– No specific requirements
Certification	– Must be certified/truthfully labeled	– No such requirement
Conversion	– Should never be converted into grain unless necessary	– Can be converted into seed if needed
Quality Norms	– Must satisfy seed quality norms	– Quality norms not considered
Seed Quality	– Genetic, physical, physiological soundness, health status	– Not considered
Role in Agriculture	– Vital input for crop production, carrier of new technologies, tool for food supply, means for rehabilitation	– Economic produce, essential for food supply, utilized for various food products
Seed Quality Characteristics	– Genetic purity, physical cleanliness, physiological vigor, health status	– Determined by market demand, physical characteristics, taste, nutritional value, etc.
Importance of Quality Seed	– Ensures high and assured yield under stress conditions, boosts agricultural productivity	– Ensures consumer satisfaction, nutritional value, taste, etc.
Seed Multiplication	– Breeder seed, foundation seed, certified seed, multiplication stages	– Not applicable

Seed Quality Characteristics	Description
Physical Quality	– Cleanliness from debris – Uniform size, weight, and color
Genetic Purity	– True-to-type nature – Resembling the mother plant
Physiological Quality	– Seed germination and vigor
Seed Health	– Absence of infestation and fungal infection
Characteristics of Good Quality Seed	– High genetic purity – Physical purity – High germination rate – Vigor – Adequate storage capacity – Absence of pests/diseases – Optimal moisture content

Seed Classes	Description
Breeder Seed	– Seed or vegetatively propagated material directly controlled by the originating or sponsoring breeder or institution, which is the basic seed for recurring increase of foundation seed.
Foundation Seed	– Progeny of breeder seed, handled to maintain specific identity and genetic purity, produced under careful supervision of an agricultural experiment station. – Source of all other certified seed classes, either directly or through registered seed.
Registered Seed	– Progeny of foundation seed, handled to maintain genetic identity and purity, approved and certified by a certifying agency. – Quality suitable to produce certified seed.
Certified Seed	– Progeny of foundation seed. – Production handled to maintain genetic identity and physical purity according to specified standards. – Minimum genetic purity of 99%. – May be progeny of certified seed, not exceeding two generations beyond foundation seed, with certification agency approval.

Differences between Certified Seed and Truthful Labeled Seed	Certified Seed	Truthful Labeled Seed
Certification Status	Voluntary	Compulsory for notified varieties
Applicability	Only to notified kinds	Both notified and released varieties
Standards	Must satisfy both minimum field and seed standards	Tested for physical purity and germination
Sample Collection Authority	Seed certification officer, seed inspectors	Seed inspectors

Generation System of Seed Multiplication	Description
Three-Generation Model	– Breeder Seed -> Foundation Seed -> Certified Seed
Four-Generation Model	– Breeder Seed -> Foundation Seed (I) -> Foundation Seed (II) -> Certified Seed
Five-Generation Model	– Breeder Seed -> Foundation Seed (I) -> Foundation Seed (II) -> Certified Seed (I) -> Certified Seed (II)

Evolution of Seed
1. Evidence suggests that an algal scum formed on the land 1,200 million years ago.
2. To thrive and to avoid extinction, plants developed mechanisms and evolved seed plants around 200 million years ago.
3. The latest major group of plants to evolve were the grasses, emerging approximately 40 million years ago.
4. Grasses and many other plant groups evolved new metabolic mechanisms to survive the low CO2 and warm, dry conditions of the tropics over the last 10 million years.

Seed Development, Maturation, and Structure
Seed Development
– Pollination initiates the process, followed by fertilization.
– Formation of the zygote and endosperm ensures genetic continuity and nourishment.
– Reserve food material accumulates as the seed matures.
– Moisture content decreases, ensuring dormancy until germination.

Seed Structure and Functions
– Seeds are broadly classified as dicotyledons and monocotyledons based on the number of cotyledons.
– The seed coat, derived from ovule integuments, protects the embryo.
– The embryo consists of an embryonic axis and cotyledons, storing food reserves.
– Endosperm or cotyledons store reserve food materials, varying by seed type.

Seed Growth and Maturation (Examples: Wheat and Soybean)
– Wheat seeds attain maximum dry weight around 35 days after anthesis.
– Soybean seeds reach peak dry weight between 48 and 54 days post-flowering.
– Seed maturity is marked by reduced moisture content, ensuring dormancy.

Components of Seed

Components of Seed	Description
Seed Coat	– Outer covering of the seed, providing protection.
	– Develops from the 2 integuments of the ovule.
	– Testa: Outer layer, smooth or rough, formed from the outer integument.
	– Tegmen: Inner layer, formed from the inner integument.
Embryo	– Mature ovule consisting of an embryonic plant and stored food.
	– Surrounded by a protective coat.
	– Consists of plumule, radicle, and cotyledon(s).
	– Plumule: First terminal bud, gives rise to vegetative shoot.
	– Radicle: Rudimentary root, forms primary root of seedling.
	– Cotyledon(s): Compressed seed leaves, store food in dicots.
Endosperm	– Develops from endosperm nuclei, storing food for embryo.
	– Formed by fusion of two polar nuclei and one sperm nucleus.
Appendages of Seeds	– Some seeds have appendages attached to the seed coat.
	– Aid in dispersal or identification of genotypes.
Appendages	– Awn: Thorn-like projection at seed tip (e.g., Paddy).
	– Hilum: Scar on seed’s lateral side, marks attachment to placenta.
	– Micropyle: Opening where integuments meet at nucellar apex.
	– Chalaza: Region of integumentary origin opposite micropyle.
	– Raphe: Area between micropyle and chalaza.
	– Caruncle: White spongy outgrowth of micropyle (e.g., Castor).
	– Aril: Colored flesh mass outside seed (e.g., Nutmeg).
	– Hairs: Minute thread-like appendages on seed surface (e.g., Cotton).
	– Wings: Papery structure attached to seed coat (e.g., Moringa).

Seed science notes SEED DORMANCY

Components of Seed	Description
Seed Coat	– Outer covering of the seed providing protection.
	– Develops from the two integuments of the ovule.
	– Consists of the testa (outer layer) and tegmen (inner layer).
Embryo	– Fertilized mature ovule consisting of an embryonic plant with stored food.
	– Miniature plant consisting of plumule, radicle, and cotyledons.
	– Cotyledons are the seed leaves; one in monocots and two in dicots.
Radicle	– Rudimentary root of the plant compressed in the embryo.
	– Forms the primary root of the seedling and is enclosed in coleorhiza.
Plumule	– First terminal bud of the plant compressed in the embryo.
	– Gives rise to the first vegetative shoot of the plant and is enclosed in coleoptile.
Endosperm	– Develops from the endosperm nuclei and stores food for the embryo.
Appendages of Seeds	– Additional structures attached to the seed coat.
	– Includes awn, hilum, caruncle, aril, hairs, and wings.
Types of Dormancy	True Dormancy/Primary/Innate Dormancy:
	– Due to chemicals or anatomical features of the seed.
	Enforced Dormancy/Secondary Dormancy:
	– Due to unfavorable environmental conditions.
Examples	– Exposure of dry barley seeds to temperatures of 50-90°C.
	– Seven days of storage of winter barley at high moisture content at 20°C.
	– Placement of seeds under water in dark conditions for 3 days at 20°C.
Biological Significance of Dormancy	Advantages:
	– Prolongs storage of seeds, serving as a survival mechanism.
	– Allows seeds to pass through adverse situations or conditions.
	– Prevents in situ germination (vivipary).
	Disadvantages:
	– Uneven germination.
	– Difficulty in maintaining plant population.
	– Interference in seed testing procedures.
Classification of Dormancy	Exogenous Dormancy:
	– Due to seed features outside the embryo.
	Endogenous Dormancy:
	– Due to factors within the embryo.
	Combined Dormancy:
	– Resulting from a combination of factors acting together.
Methods of Breaking Dormancy	Natural Breaking of Dormancy:
	– Occurs when suitable environmental conditions are met.
	Treatments to Break Dormancy:
	1. Seed Coat Treatments: Aim to make hard seed coats permeable through scarification.
	2. Embryo Treatments:
	– Stratification: Incubating seeds at low temperatures over a moist substratum before transferring them to an optimum germination temperature.
	– High-temperature treatment: Incubation at elevated temperatures for a period.
	– Chemical treatments: Application of growth regulators or other chemicals to induce germination.
	3. Miscellaneous Approaches:
	– Exposing seeds to light, pressure treatment, infra-red radiation treatment, and magnetic treatment.

Factors affecting seed germination;

Component	Description
Seed Coat	Outer covering providing protection, formed from integuments of ovule. Comprises testa (outer layer) and tegmen (inner layer).
Embryo	Mature ovule consisting of embryonic plant, stored food, and protective coat. Contains plumule, radicle, and cotyledons.
Radicle	Rudimentary root compressed in the embryo, forming primary root of seedling. Enclosed in coleorhiza.
Plumule	First terminal bud of plant compressed in embryo, giving rise to first vegetative shoot. Enclosed in coleoptile.
Cotyledon	Compressed seed leaves; one in monocots (scutellum), two in dicots. Serve as storage tissue.
Endosperm	Develops from endosperm nuclei, storing food for developing embryo.
Appendages	Various structures attached to seed coat aiding in dispersal or identification (e.g., awn, hilum, caruncle, aril, hairs, wings).

Type of Dormancy	Description
True Dormancy (Primary)	Due to seed’s chemicals/anatomical features.
Enforced Dormancy (Secondary)	Due to unfavorable environmental conditions.

Advantages of Dormancy	Disadvantages of Dormancy
Prolongs seed storage, ensuring survival.	Non-uniform germination.
Enables seed to withstand adverse conditions.	Challenges in maintaining plant population.
Prevents vivipary (in situ germination).	Interference in seed testing procedures.

Classification of Dormancy by Nikolaeva (1969 and 1977)	Description
Exogenous Dormancy	– Impermeability of seed coat to water/gases. – Mechanical resistances of seed coat. – Inhibitors present in seed coat/endosperm.
Endogenous Dormancy	– Incomplete embryo development. – Inhibitors present within the embryo.
Combined Dormancy	Result of multiple factors acting together.

Methods of Breaking Dormancy	Description
Natural Breaking	Through environmental factors like moisture, temperature changes.
Treatments:	– Scarification: Making hard seed coat permeable to water or gases through physical or chemical means. Stratification: Incubating seeds at low temperature over moist substratum before germination.
	– High temperature treatment. Chemical treatments using growth regulators or other chemicals. – Miscellaneous approaches like light exposure, pressure, infrared radiation, and magnetic treatment.

Factors Affecting Seed Germination	Description
Internal Factors	– Seed Maturity. – Mechanical Damages.
External Factors	– Water: Essential for enzyme activation, breakdown, and translocation of reserve storage materials. – Oxygen: Required for respiration, with a supply needed for germination.
	– Temperature: Affects different phases of germination, with each seed having an optimum temperature range for germination.
	– Light: Necessary for germination in some species, with intensity and quality influencing the process.
	– Soil Factors: Include soil structure, texture, and temperature, all of which impact seed germination.

SEED PRODUCTION IN MAIZE

Characteristics	Description
Botanical Name	Zea mays
Chromosome Number	2n=20
Botanical Family	Poaceae
Inflorescence	Panicle cob (monoecious in nature)
Type of Flowers	Female: Cob (axillary inflorescence) <br> Male: Tassel (terminal inflorescence)
Husk	Enlarged leaf sheaths from each node, forming a protective covering around the inflorescence
Pollination	Cross pollination
Special Character	Protandry
Flowering Pattern	Tassel: Top to bottom Cob: Bottom to top
Anthesis	Pollen shedding begins 1 to 3 days before the silk emerge from the cob
Fertilization	Within 12 to 18 hrs after silk emergence
Silk Receptive	8-10 days
No. of Pollen in Tassel	2,50,00,000
Pollen Viability	12-18 hours
Male Flower Anthesis	6:00 am to 8:00 am
Duration of Flowering	2-14 days
Seed Types and Methods of Seed Production
Open Pollinated Varieties	Raise under isolation (400m in foundation seed stage, 200m in certified seed stage)
Synthetics	Varieties obtained by in-mating in all possible combinations
Composite Varieties	Produced by open pollination among several strains
Inbreds	True-breeding strains resulting from repeated selfing
Seed science notes Seed Multiplication and Production
Stages of Seed Multiplication	Breeder Seed, Foundation Seed, Certified Seed
Popular Varieties	CO1, K1, COH3, COH4 (for grain); African tall (fodder); COBC1 (for salad)
Best Seasons for Production	June – July, November – December, January – February
Land Requirement	Fertile land; previous crop should not be the same to avoid volunteer plants
Isolation Distance	Composite, Synthetics, OPV: Foundation Stage – 400m, Certified Stage – 200m
Pre-sowing Seed Treatment	Soaked in 2% KH2PO4 for 16 hours, treated with carbofuran 3G, chlorpyriphos, bavistin, azospirillum, or polycoat
Sowing	Spacing: 45 x 10 cm or 60 x 20 cm; seeds sown in ridges and furrows or under beds and channels
Nutrient Application	Basal (40:75:40 NPK kg/ha); 1st top at 20 DAS (50:0:0 kg/ha); 2nd top at 40 DAS (60:0:35 kg/ha)
Micronutrients	2% DAP sprayed at 50% flowering; zinc sulphate for Zn deficiency; micronutrient mixture for Fe deficiency
Weeding and Pest Management	Atrazine for weed control; monocrotophos for shoot fly; roguing for off types; various chemicals for pest management
Irrigation	Once in 10-15 days during critical stages for enhanced seed set and formation of bolder grains
Harvesting and Post-Harvest	Physiological maturity achieved 30-35 days after 50% flowering; seeds dried to 8-10% moisture content
Processing and Storage	Mechanical grading; seeds treated with protective chemicals; stored in gunny bags or moisture containers
Seed Standard	Foundation: 98% pure seed, 12% moisture max <br> Certified: Same as Foundation, plus 90% germination min
Mid Storage Correction	Seeds soaked in potassium di-hydrogen phosphate solution for 6 hours when germination falls below 5-10%

Seed science notes HYBRID SEED PRODUCTION IN MAIZE

Aspect	Details
Detasseling Technique	– Purpose: To create male sterility for hybrid seed production. – Time: Done when the tassel emerges but before anthesis (pollen shedding). – Procedure: Hold stem and base, pull out tassel in one motion, ensure complete removal of pollen parts without breaking leaves. – Precautions: Ensure complete removal to prevent contamination, perform uniformly and daily in the morning, avoid breaking top leaves, detassel only when fully emerged, mark male rows, watch for shedding tassels, drop detasseled tassels on-site, avoid carrying through the field.
System of Hybrid Seed Production	– Types of Hybrids: – Single cross – Double cross – Three-way cross – Double top crosses – Season: November-December, Mid-July, January-February, September-October. – Isolation Distance: Foundation Stage: 400m, Certified Stage: 200m. – Field Standards for Isolation: Modified based on kernel color, hybrid type, and blooming dates. – Stages of Seed Multiplication: – Breeder Seed – Foundation Seed – Certified Seed – Spacing and Planting Ratio: Varied based on hybrid type. – Fertilizer Application: Basal and foliar, specific recommendations. – Roguing: Periodic removal of off-types and shedding tassels during field inspections. – Harvesting and Post-Harvest Processes: Timing, threshing, cob sorting, drying, grading, and seed treatment. – Seed Standards: Physical purity, germination, moisture content, and others.
Production of Synthetic Cultivars	– Method: Controlled crosses between specific parents to create desirable gene combinations. – Advantages: Heterosis, gene combination, controlled breeding. – Disadvantages: Higher cost, time-consuming, lower productivity in certain methods.

SEED PRODUCTION TECHNIQUES IN PADDY VARIETIES

Aspect	Details
Phrenology
Botanical Name	Oryza sativa
Chromosome number [2n]	24
Family	Poaceae
Inflorescence	Panicle
Pollination	Self-Pollination
Panicle Emergence	4 –5 days after boot leaf emergence
Flower Opening Pattern	Tip of primary & secondary branches and proceeds downward
Duration of Flowering	6-8 days
Time of Anthesis	7.00 –10.00 A.M
Speciality with flowering	Flower remains open for 10 minutes and afterwards it closes.
Anther dehiscence	Either before or after flower opening [independent of spikelet opening]
Temperature favorable for flowering	24 – 28°C
Favorable RH for flowering	70-80%
Difference between day and night temperature	8-10°C
Stigma receptivity	3 days
Pollen viability	10 minutes
Stages of Seed Production	Details

Varietal seed production	In paddy, depending on the demand, 3 or 4 or 5 stages of seed multiplications are permitted under seed certification programme as follows.
	– Breeder seed – foundation seed – certified seed
	– Breeder seed – foundation seed stage 1 – foundation seed stage 2 – certified seed
	– Breeder seed – foundation seed stage 1 – foundation seed stage 2 – certified seed 1- certified seed 2
Principles of Seed Technology	Details

Land requirement	Ensure land is free of volunteer plants, and the previous crop is either different or the same certified variety. Ensure adequate irrigation and drainage.
Isolation	Maintain 3 meters isolation around the seed production plot for genetic purity.
Selection of seed	Use seed from authenticated sources; foundation seed (FS) should be used for certified seed production.
Selection of season	Details

Season	Select based on variety duration and water availability.
Varieties, Season, Duration, Popular Varieties	Details

Short duration varieties	Below 120 days; e.g., TKM9, CO 36, ADT 36
Medium duration varieties	130-135 days; e.g., Bhavani, CO43
Long duration varieties	More than 135 days; e.g., White Ponni
Seed Rate	Details

Variety/Type of cultivation	Seed rate (kg/ha)
Lowland Cultivation (Transplanting)	Short duration: 60, Medium duration: 40, Long duration: 30.
Broadcasting	80-100 kg/ha
Rainfed rice	75-100 kg/ha
Seed Management Technique	Details

Dormancy	Varies (0-30/45 days); can be broken by soaking in KNO3 or HNO3.
Seed Upgradation Technique	Use egg floatation technique for separating good quality seeds from low quality ones.
Sprouting of seeds (pre-germination)	Soak seeds for better establishment; sow in nursery by broadcasting.
Hardening and other seed management techniques	Harden seeds with KCl (1%) and pelleting with Azospirillum for dry land and upland paddy.
Nursery Management	Details

Area Required	20 cents (800m2) for raising one hectare of paddy.
Nutrient Management	Apply DAP before last puddling; basal application is required if seedlings are pulled out after 20-25 days.
Sowing	Maintain a thin film of water; sow sprouted seeds uniformly.
Water Management	Details

Drainage	Drain water 18-24 hours after sowing; maintain water level to 2.5 cm afterwards.
Irrigation	Saturate soil from third to fifth day; increase water depth to 1.5 cm from fifth day onwards.
Weed Management	Details

Pre-emergence herbicide	Use butachlor, thiobencarb, or pendimethalin to control weeds.
Pest Management (Nursery)	Control measures for insects and diseases including army worm, thrips, leaf folder, etc.
Transplanting	Details

Age of Transplanting	Varies with duration of varieties: Short duration (18-22 days), Medium (25-30 days), Long (35-40 days).
Gap Filling	Conducted 7-10 days after transplanting.
Top Dressing	Details

Application	Apply 25% of nitrogen and potassium as basal and remaining in three split doses at different growth stages.
Rouging	Maintain genetic purity by removing off-types and rouges.
Harvesting	Details

Preparation	Lodged plants avoided, irrigation withheld before harvest.
Pest Management (Pre-harvest)	Spray endosulphan to prevent storage pests.
Threshing and Drying	Details

Threshing	Beating plants on hard surface, mechanical threshing with care.
Drying	Seeds dried to 13% moisture, avoiding midday sun.

Aspect	Details
Storage	Paddy seeds store well up to 12-36 months, depending on genotypes; use HDPE or polylined gunny bags for prolonged storage. Avoid moisture levels above 10-12%.
Mid Storage Correction	Soak seeds in disodium phosphate solution for 16 hours if seed standard reduces by 5-10%; dry seeds back to original moisture content.
Seed Certification	Details

Land Requirement	Previous crop should not be the same; ensure no volunteer plants and maintain isolation.
Number of Inspections	Minimum of two inspections, one at flowering and one before or during harvest.
Field Standards	Ensure isolation from contaminants; maximum permitted levels for off types, weed seeds, and other contaminants.
Seed Standard	Ensure purity, germination, and moisture content meet standards for foundation and certified seed.
Physiological Maturity	Details

Symptoms of Maturity	Golden yellow color of ear heads and drooping symptom; typically 28-35 days after flowering.
Harvesting	Withhold irrigation one week before; delay may lead to shattering; stack bundled plants with ear heads facing outside.
Post-harvest Management	Details

Threshing	Be careful to avoid mechanical damage; thresh at proper moisture content (16-17%).
Winnowing and Drying	Clean seeds and winnow to remove dirt; dry seeds to 13% moisture; avoid drying between 12 noon to 2 pm.
Grading	Process seeds through seed cleaner cum grader; select seeds from middle sieve for seed purpose.
Seed Treatment	Details

Chemical Treatment	Treat with captan, thiram, or bavistin for long-term storage; use halogen mixture for eco-friendly treatment.
Fumigation	Fumigate with celphos for prophylactic measure, ensuring moisture content is below 10-12%.
Seed Yield	Details

Yield	Varies from 3000 to 7000 kg/ha depending on factors like genotypes, location, and management practices.

INTELLECTUAL PROPERTY RIGHTS (IPRs)

Intellectual Property Rights (IPRs)	Relevant to Agriculture
– Legal protection for creative or inventive ideas	– Patents, plant breeders’ rights, trademarks, geographical indications, trade secrets
– Two main categories: industrial property (patents, trademarks) and copyright-related rights (artistic works)	– Protect goods or services in agriculture
– Aim: Signal that innovation will be rewarded	– Patents crucial for plant, animal, and biotechnological processes
– Categories include patents, trademarks, geographical indications, industrial designs	– Biotechnology holds potential for agricultural advancement
– Protects artistic and literary works, performances, broadcasts	– Plant breeders’ rights reward conventional breeding efforts
– Includes sui generis rights for unique cases	– India’s Plant Variety Protection and Farmers’ Rights Act, 2001
– Legislation aims to balance breeders’ and farmers’ rights	– Balances breeders’ and farmers’ rights
– Protects researchers’ access to registered varieties	– Farmers recognized as conservers of agricultural biodiversity
– Public interest clauses exclude certain varieties from protection	– Researchers have rights to access and use registered varieties
– Compulsory licensing possible if seeds not available at reasonable prices	– Legislation aims to balance innovation and public interest

SEED DRYING

Topic	Details
Varietal Identification
Grow-Out Test	– Determines genetic purity status of seed lot.
	– Field applicability: pre/post-control for genetic contamination.
	– Required for seed certification (e.g., cotton, castor) in India.
Sampling	– Drawn simultaneously with other seed quality tests.
Submitted Sample Size	– Varies by species (e.g., maize: 1000g, wheat: 500g).
Working Sample Size	– Obtained through mixing/dividing submitted sample.
	– Minimum of 400 plants for observation.
Procedures	– Conducted in specified areas/nurseries.
	– Standard sample used for comparison.
	– Agronomic practices followed for specific crops.
Electrophoresis	– Method for cultivar identification based on protein banding.
	– Single seeds defatted and extracted for protein/isoenzymes.
	– Banding pattern used for differentiation.
Seed Drying	– Process to eliminate moisture for storage viability.
Stage of Moisture Elim.	– Surface moisture and internal migration stages.
Equilibrium Moisture	– Seed moisture equilibrium with surrounding atmosphere.
Drying Temperature	– Adjusted based on seed moisture content.
Methods	– Physical (sun drying) and mechanical (forced air, desiccants).
Mechanical Drying Types	– Batch dryers (horizontal, vertical) and continuous flow dryers.
Storage Structures	– Requirements for airflow, sealing, inspection, and fumigation.
Heated Air Drying	– Direct and indirect methods, with temperature considerations.
Air-Distribution Systems	– Main and lateral duct, perforated false floor.
Tempering	– Staged drying with resting periods for moisture equalization.

SEED PROCESSING

Aspect	Description
Seed Processing Steps	Cleaning: Removal of impurities; Drying: Adjust moisture levels; Grading: Sorting based on size, shape, weight; Treating: Application of fungicides, pesticides
Plant Layout Considerations	Types of crop seeds; Size of operation; Need for drying facilities; Selection of suitable equipment; Location and power source; Labor availability
Types of Processing Equipment	Air Screen Cleaner; Disc Separator; Indented Cylinder Separator; Specific Gravity Separator; Roll Mill; Magnetic Separator; Electronic Color Sorter; Spiral Separator
Precautions in Handling	Proper equipment adjustments; Maintenance; Monitoring; Correct drying parameters; Accurate chemical treatment dosage
Movement of Seed in Plant	Handling of seed along a defined path for easy management; Sensitive to quality loss at each step; Management crucial to prevent quality degradation
Physical Characteristics	Size grader; Length separator; Specific gravity separator; Shape separator; Surface texture separator; Color separator; Electrical conductivity separator; Liquid affinity separator
Analysis of Operation	Processing sequence determination; Matching capacity planning; Conveying system selection
Layout Types	Multistorey; Single level; Combined designs
Operation Analysis	Detailed planning to identify and remedy bottlenecks; Scale drawings, models, or templates for layout planning; Consideration of CPWD/PWD norms for construction
Requirements in Seed Processing	Complete separation; Minimum seed loss; Upgrading possible for any quality; Efficiency; Minimum requirements

SEED TREATMENT

Aspect	Description
Seed Treatment	Maintains seed quality by addressing environmental factors like moisture, temperature, and pests. Treating seeds with pesticides is the most efficient method to protect them. Safety precautions are crucial due to the toxicity of pesticides.
Definition of Treated Seed	Application of pesticides or processes to reduce, control, or repel disease organisms, insects, or pests affecting seeds or seedlings.
Types of Seed Treatment	A. Pre-sowing treatments to improve germination, vigor, and health. B. Pre-storage treatments to protect seeds during storage. C. Mid-storage treatments to reduce age-induced damage and restore vigor.
Pre-sowing Seed Treatments	I. Chemical treatments with nutrients. II. Insecticidal and fungicidal treatments to protect against diseases and pests. III. Special treatments like seed hardening, fortification, and osmotic priming.
Pre-storage Treatments	1. Halogenation. 2. Antioxidant treatment. 3. Seed sanitation.
Mid-storage Treatments	Hydration-dehydration: soaking seeds in water or solution, then drying to reduce age-induced damage.
Seed Treating Equipment	1. Dust Treater: Controls seed flow and applies powder. 2. Slurry Treater: Suspends wettable powder in water. 3. Direct Treaters (e.g., Panogen, Mist-O-Matic): Apply liquid treatment as mist or directly to seeds.
Seed Treatment Materials	Fungicides and insecticides in various forms like dusts, slurries, and liquids, with systemic options available.
Safety Precautions	Essential due to toxicity of chemicals. Treated seeds should be clearly labeled and not used for food or feed. Treatment areas should be well-ventilated, and protective clothing worn. Empty containers must be disposed of properly.
Special Seed Treatments	Seed hardening, fortification, moist sand conditioning, pelleting, infusion, osmotic priming, fluid drilling, separation of viable seeds.
Modes of Seed Treatment	Soaking, dipping, spraying, moisture equilibration, moist sand conditioning, hydration-dehydration.
Seed Treatment Insecticides	Applied to control insect damage during storage and in soil. Combinations may be used, but compatibility and sequence are crucial.
Seed Treatment Fungicides	Divided into seed disinfection, disinfestation, and protection categories. Systemic options are available.
Seed Treating Equipment (cont.)	4. Panogen Seed Treater: Applies liquid treatment through a revolving drum. 5. Mist-O-Matic Seed Treater: Applies treatment as mist to seeds.
Seed Hardening Treatment	Seeds hardened for drought or cold tolerance. Factors include seed ratio, duration of soaking, and method of drying.
Seed Fortification Treatment	Supplies nutrients to seeds for higher vigor and to overcome soil reactions.
Moist Sand Conditioning	Treatment method for certain seeds, with concentration adjusted as needed.
Seed Pelleting	Coats seeds with nutrients, used for increasing seed size, reducing seed rate, and aerial sowing.
Seed Infusion	Infuses nutrients and growth-promoting substances into seeds using organic solvents.
Osmotic Priming	Soaking seeds slowly to prevent soaking injury, resulting in uniform and early emergence.
Fluid Drilling	Coats germinated seeds with jelly for mechanical sowing to avoid damage.
Separation of Viable Seeds	Method to improve desired seed germination and plant population.

SEED STORAGE

Aspect	Details
Maintenance of Seed Vigor and Viability	– Seeds need to maintain viability from harvest to planting. – Different seed types require specific storage conditions. – Recalcitrant seeds, like Jack, Citrus, etc., require high moisture and senesce rapidly once dried. – Some seeds, like Pinus and Fraxinus, require an after-ripening process. – Aging often starts at physiological maturity, rendering seeds worthless if not adequately stored.
Purpose of Seed Storage	– Ensure good physical and physiological condition of seeds from harvest to planting. – Provide adequate plant stands and healthy, vigorous plants. – Allow marketing of unsold seeds in the following planting season. – Extended storage eliminates the need for annual seed production.
Stages/Segments of Seed Storage	1. Post-maturation/Pre-harvest segment (field storage). 2. Bulk seed segment (harvest to packaging). 3. Packaged seed segment (packaging to distribution). 4. Distribution/Marketing segment. 5. On-farm segment (purchase to planting).
Types of Storage	1. Commercial seed storage (8-9 months). 2. Carryover seeds (1-1.5 years). 3. Foundation stock and enforcement seed samples. 4. Germplasm seed storage (long-term).
Principles of Storage	1. Dry and cool conditions. 2. Effective storage pest control. 3. Proper sanitation. 4. Drying seeds to safe moisture.

Sanitation in Storage	– Seeds should be stored in seed warehouses, not in warehouses for chemicals, fertilizers, herbicides, or feed. – Continuous sanitation minimizes storage insect infestations.
	– If storage insects are present, using insecticides and fumigants alongside sanitation practices can alleviate the problem. – Infested lots should not be stored with others unless insects are eradicated.
	– In warehouses with concrete floors, seed bags should be stacked on wooden pallets to prevent moisture transmission. – Proper ventilation and protection against rodents are essential.
Storage Conditions	– Maintaining safe moisture content requires controlling relative humidity. – Three methods achieve this: location in low humidity regions, moisture-proof packaging, or dehumidification of storage areas.
Seed Packaging in Relation to Storage	– Seed packages act as small storage containers. – Container type depends on quantity, protection needed, cost, seed value, storage conditions, and drying facilities.
Seed Storage in Relation to Deterioration	– The purpose of seed storage is to minimize deterioration rate and preserve seed quality. – Deterioration leads to loss of germination and vigor. – Seed longevity varies by species and variety.
Storage Godowns and Maintenance	– Properly constructed and maintained storage areas protect seeds from external factors like climate, pests, and pathogens. – Godowns should be clean, dry, and adequately ventilated.
Storage Insect Management	– Hygiene maintenance in storehouses, reducing moisture content, and surface treatments with insecticides help control storage pests. – Fumigation with chemicals like phosphine and methyl bromide is effective.
Rodent Management in Storehouses	– Wire meshes on openings, rodent baits with anticoagulant rodenticides, and proper bait replacement strategies help control rodents.

HYBRID SEED PRODUCTION IN PADDY

Aspect	Description
Hybrid Seed Production Techniques
– CGMS System	Utilizes cytoplasmic genetic male sterility (CGMS) system.
– EGMS System (Two Line Method)	Involves environmental genetic male sterility (EGMS) system.
– Popular Hybrids	CORH1: (IR 62829A x IR 10198-66-2R) CORH2: IR 58025A x C 20R CORH3: TNAU CMS 2A X CB 87 R (110-115 days) ADTRH1: IR 58025A x IR 66R
– Genes involved in EGMS	One or two pairs of recessive nuclear genes (cytoplasm involved).
– Advantages of EGMS	No maintainer lines needed More choice of parents No negative effect on sterile cytoplasm
– Genes for fertility restoration (CGMS)	Rf1 and Rf2
Seed Multiplication Stages
– Breeder Seed	A (AxB), B, R lines are raised separately under isolation.
– Foundation Seed	A (AxB) and R lines raised separately under isolation.
– Certified Seed	A and R line are crossed under isolation to get hybrid.
Land and Isolation Requirements
– Space Isolation	Foundation seed stage: 20m Certified seed stage: 100m
– Time Isolation	20 days either earlier or later for other varieties compared with MS line.
– Barrier Isolation	30m of wood lot / tall crops Plastic sheets of 2m height
Season
– Kharif	May-June sowing
– Rabi	December-January sowing
– Preferred Season	Rabi, as it’s more suitable than kharif.
– Climatic Conditions	Daily mean temperature: 24 – 30oC Relative Humidity: 70 – 80% Difference between day and night temperature: 8-10oC
Seed Selection and Rate
– Seed Selection	Purchase from authenticated source with tag and bill.
– Foundation Stage	A & B lines
– Certified Stage	A & R lines
– Seed Rate	Female: 20 kg/ha Male: 10 kg/ha
Nursery Management
– Irrigation	Keep irrigation channels separately for the parental line.
– Fertilizer Application	Apply DAP @ 2 kg/cent as basal to get vigorous seedlings.
– Sowing	Staggered sowing for male twice or thrice with the interval of 10-15 days for effective seed setting.
Main Field Transplanting
– Spacing	Between A line: 15 x 15cm Between A and R line: 20 x 15cm Between R line: 30 x 15cm
– Age of Transplanting	A line: 25 days R line: 14, 18, 20 days
– Fertilizer Application	Hybrids: 150:60:60 N & K applied in 3 splits (1) during basal (2) active tillering (3) Panicle initiation.
Staggered Sowing of Parents
– Methods for Synchronization	Growth Duration Difference (GDD) method <br> Leaf Number Difference (LND) method <br> Effective Accumulated Temperature (EAT) method
Layout for Transplanting
– Row Ratio	8:2 or 10:2
– Factors Influencing Ratio	Plant height of the pollinator Growth and vigour of the pollinator Size of the panicle and amount of residual pollen Duration and angle of floret opening in CMS lines Stigma exertion of CMS line.
Prediction of Heading Date
– Method	By examining the development of young panicles.
– Criteria for Synchronization	Morphological features of young panicles.
Adjustment of Flowering Date
– Methods	Quick releasing nitrogen fertilizer (2% urea spray) Application of Gibberellin (GA3) Supplementary pollination Foliar spray Adjustments based on drainage or irrigation Removal of panicles from early developing parent
Roguing
– Purpose	Remove undesirable plants to maintain purity.
– Timing	At maximum tillering, at flowering, and just before harvesting.
Harvesting, Threshing, and Drying
– Harvesting Stage	When 90% green seeds turn to straw yellow color.
– Moisture Content	17-20%
– Drying	Reduce seed moisture content to 12%.
Seed Treatment and Storage
– Treatment	Thiram/captan @ 4 g/kg or with 5 gm halogen mixture.
– Storage	Short term: Gunny or cloth bag Long term: Polythene bag > 700 gauge
Seed Yield	Hybrid yield (F1): 800-1200 kg/ha
General Tips
– Nursery Period	Varies with short, medium, and long duration varieties.
– Grain Grading	Based on shape but not separable by mechanical grading.
– Carbohydrate Storage	Carbohydrates are main storage reserve, differentiating japonica and indica varieties.
– Split Husk	Problem in hybrid rice seed production, attributed to nutrient deficiency, synchronization defects, and genetic factors.

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Seed Science

Seed science notes for IBPS AFO