Price and Quality of Good Seed in Agronomic Production

High-quality seed acts as the catalyst for agricultural productivity, amplifying the responsiveness of crops to applied agro-inputs such as fertilizers, irrigation, and plant protection chemicals. Although quality seeds command a higher initial purchase price relative to farmer-saved grain, their incremental cost is negligible when amortized across total crop yield and economic returns.

• Investment Multiplier: Seed is a primary, non-divisible technology input; a superior seed lot guarantees higher germination percentages, eliminating gap-filling costs and reducing required seed rates.
• Input Efficiency: Certified seeds of high-yielding varieties (HYVs) and hybrids exhibit uniform emergence and vigour, maximizing nutrient uptake efficiency from applied fertilizers like urea and diammonium phosphate (DAP).
• Risk Mitigation: Premium pricing reflects rigorous seed production standards, rouging, field inspections, and laboratory testing, which collectively protect farmers from crop failure due to seed-borne pathogens or weed seed contamination.

Seed quality is a multidimensional attribute evaluated through distinct biological and physical parameters governed by the Seed Act (1966) and Minimum Seed Certification Standards (Indian Minimum Seed Certification Standards - IMSCS).

• Physical Purity (%): Measures the proportion of pure seed of the designated crop species in a sample, free from inert matter, weed seeds, and other crop seeds. Minimum physical purity for most cereals is maintained at 98%.
• Germination Percentage (%): The emergence and development from the seed embryo of those essential structures which indicate its ability to produce a normal plant under favourable field conditions. For Triticum aestivum (wheat) and Oryza sativa (paddy), minimum germination is 85%.
• Genetic Purity (%): The true-to-type nature of the seed lot, ensuring that offspring retain the exact phenotypic and genotypic characteristics of the cultivar. Maintained through strict isolation distances and rouging of off-types during flowering.
• Seed Moisture Content (%): Crucial for safe storage. Safe moisture levels for orthodox seeds like cereals range between 10-12%, while oilseeds like Glycine max (soybean) and Arachis hypogaea (groundnut) require 7-8% to prevent lipid peroxidation and fungal infestation.

Seed multiplication follows a structured hierarchical system to maintain genetic identity and purity while scaling up volume for commercial distribution to farming communities.

• Nucleus Seed: The initial quantum of seed derived from a single plant or plant selection, maintained by the originating plant breeder or institution. It has 100% genetic purity and no tag.
• Breeder Seed: Seed produced directly from nucleus seed under the supervision of the plant breeder. It is supervised by monitoring committees and carries a Golden Yellow tag.
• Foundation Seed: Progeny of breeder seed handled to maintain specific genetic identity and purity. It is produced by state seed corporations, agricultural universities, or designated agencies and carries a White tag.
• Certified Seed: Progeny of foundation seed (or occasionally registered seed) handled to maintain satisfactory genetic identity and purity, approved and certified by the State Seed Certification Agency. It carries an Azure Blue tag for commercial sale to farmers.

Seed viability refers to whether a seed is alive and capable of germinating under optimal conditions, whereas seed vigour encompasses the sum total of properties that determine the potential level of activity and performance of the seed or seed lot during germination and seedling emergence.

• Tetrazolium (TZ) Test: A rapid biochemical test utilizing 2,3,5-triphenyl tetrazolium chloride to evaluate seed viability by staining living tissues red due to the reduction of tetrazolium salt by respiring dehydrogenase enzymes.
• Accelerated Ageing Test: A stress test used to evaluate seed vigour by exposing seeds to high temperature (41-45°C) and high relative humidity (nearly 100%) for a short duration before standard germination testing.
• Causes of Deterioration: Mechanical damage during threshing (especially in legumes like Cicer arietinum and soybean), insect damage by Callosobruchus chinensis, high storage humidity leading to fungal invasion by Aspergillus and Penicillium species, and natural lipid auto-oxidation.

Pre-sowing seed treatments enhance field emergence, protect against soil-borne and seed-borne pathogens, and stimulate early seedling vigour.

• Fungicidal Seed Dressing: Application of systemic and contact fungicides such as Carbendazim or Thiram at 2.0 to 2.5 g per kg of seed to control seed-borne fungal pathogens like Ustilago nuda (loose smut of wheat).
• Inoculation with Biofertilizers: Coating legume seeds with Rhizobium strains and cereal seeds with Azospirillum or Azotobacter cultures using jaggery slurry to enhance biological nitrogen fixation.
• Seed Priming: Soaking seeds in water or osmotic solutions (hydropriming, halopriming) for predefined durations to initiate early metabolic events of germination without radicle emergence, ensuring synchronized field emergence.