Seed:

• A seed is the mature fertilized ovule of a flowering plant. It is a structure that contains the embryo of the plant, along with stored nutrients and a protective seed coat.
• Seed is an embryonic part covered in a seed coat often containing some food. It is formed from the ripened ovule of a plant after fertilization.
• Seeds are essential for the reproduction and propagation of plants. They can be found in fruits, cones, or other structures, depending on the plant species.
• In agriculture, seeds are sown to grow new plants. They serve as the starting point for the development of a new plant, containing all the genetic information needed for the plant to grow and produce fruits or grains.
• Seeds can be produced for various purposes, including agricultural crops, ornamental plants, and forestry.

Grain

• A grain is a small edible fruit usually hard on the outside, harvested from crops. Grains basically grow in a cluster on top of the mature plant.
• Grain refers to the small, hard, dry seed or fruit of a crop,
• Grains are rich in carbohydrates and are a significant source of energy for human and animal consumption. They also contain other nutrients like proteins, vitamins, and minerals.

Seed Selection; Based on plant size, quantity of grains, fruit size or colour, disease resistance etc. seeds can be selected. Farmers also need to check the germination period, nutrients required so that the selected seeds will be beneficial in terms of yield and finance. Some seeds are sources of diseases; they can be used after proper treatment like chemical or hot water treatments etc. A careful observation of crops and their yield in first year may help farmers to choose best strains of seeds for successive years. Hence for high yield, sow best seeds.

a) Classification of Seed

i) Nuclear seed: This is the hundred percent genetically pure seed with physical purity and produced by the original breeder/Institute /State Agriculture University (SAU) from basic nucleus seed stock. A pedigree certificate is issued by the producing breeder.

ii) Breeder seed: This is also hundred percent physical and genetic pure. This seed is used for production of foundation seed. A golden yellow colour certificate is issued for this category of seed by the producing breeder.

iii) Foundation seed: The progeny of breeder seed. A white colour certificate is issued for foundation seed by seed certification agencies.

iv) Registered seed : Registered seed shall be the progeny of foundation seed.. A purple colour certificate is issued for this category of seed.

v) Certified seed: The progeny of foundation seed. A blue colour certificate is issued by seed certification agency for this category of seed.

vi) Labelled Seed: The seed notified under Section 5 of the Seeds Act, 1966, such seed sold in the market has to be labelled as prescribed under Section 6(a) and (b) of the Seeds Act Such seed is called Labelled Seed.

b) Based on Function:

• Orthodox Seeds: These seeds can tolerate drying and are suitable for storage. Examples include most grains and legumes.
• Recalcitrant Seeds: These seeds cannot endure drying and must be planted shortly after maturity. Examples include some tropical fruits like cocoa and lychee.

c) Based on Origin:

• Dicotyledonous Seeds (Dicots): These seeds have two cotyledons (seed leaves). Examples include beans, sunflowers, and roses.
• Monocotyledonous Seeds (Monocots): These seeds have a single cotyledon. Examples include grasses, lilies, and orchids.

d) Based on Germination:

• Epigeal Germination: In this type, the cotyledons emerge above the soil during germination. Examples include beans and sunflowers.
• Hypogeal Germination: Here, the cotyledons remain below the soil surface. Examples include peas and peanuts.

Sowing:

Sowing is the placing of a specific quantity of seeds in the soil for germination and growth while planting is the placing of plant propagules (may be seedlings, cuttings, rhizomes, clones, tubers etc.) in the soil to grow as plants

Methods of Sowing: Seeds are sown directly in the field (seed bed) or in the nursery (nursery bed) where seedlings are raised and transplanted later. Direct seeding may be done by…

i) Broad casting –

• Broad casting is the scattering or spreading of the seeds on the soil, which may or may not be incorporated into the soil.
• Broadcasting of seeds may be done by hand, mechanical spreader or aeroplane.
• Broadcasting is the easy, quick and cheap method of seeding.
• The difficulties observed in broadcasting are uneven distribution, improper placement of seeds and less soil cover and compaction.

ii) Dibbling

• It is the placing of seeds in a hole or pit made at a predetermined spacing and depth with a dibbler or planter or very often by hand.
• Dibbling is laborious, time consuming and expensive compared to broadcasting, but it requires less seeds and, gives rapid and uniform germination with good seedling vigour.

iii) Drilling 

• It is a practice of dropping seeds in a definite depth, covered with soil and compacted.
• Sowing implements like seed drill or seed cum fertilizer drill are used.
• Manures, fertilizers, soil amendments, pesticides, etc. may be applied along with seeds.
• It requires more time, energy and cost, but maintains uniform population per unit area.
• Rows are set according to the requirements.

iv) Sowing behind the country plough;

• It is an operation in which seeds are placed in the plough furrow either continuously or at required spacing by a man working behind a plough.
• When the plough takes the next adjacent furrow, the seeds in the previous furrow are closed by the soil closing the furrow.
• Depth of sowing is adjusted by adjusting the depth of the plough furrow. e.g., ground nut sowing in dry land areas of Tamil Nadu.

v) Planting – Placing seeds or seed material firmly in the soil to grow.

vi) Transplanting –

• Planting seedlings in the main field after pulling out from the nursery. It is done to reduce the main field duration of the crops facilitating to grow more number of crops in an year.
• It is easy to give extra care for tender seedlings.
• For small seeded crops like rice and ragi which require shallow sowing and frequent irrigation for proper germination, raising nursery is the easiest way.