UPMSP Vocational Seed Production Technology key terms

The share of seeds in a tested sample that produce normal seedlings under specified conditions, expressed as a percentage of the seeds sown. It is the core measure of planting value and is reported on the seed label.

The proportion of a seed lot that is both the correct species and capable of germinating, calculated by multiplying purity percentage by germination percentage and dividing by 100. Used to compare lots and set sowing rates.

The percentage by weight of a seed lot made up of the named species, excluding inert matter, weed seeds and other crop seeds. Determined by laboratory separation and weighing of components.

Material in a seed lot that is not seed, such as broken seed coats, chaff, soil, stones and stem fragments. It reduces purity and is separated and weighed during purity analysis.

A definite quantity of seed of one variety and one class, produced and handled so that it is as uniform as practicable, and identified by a lot number. Sampling and testing are done per lot.

The reduced portion drawn from a submitted sample in the laboratory, of the exact weight prescribed for the test being done. It must be representative of the lot for results to be valid.

A small quantity of seed taken at one point in a lot with a probe or by hand. Several primary samples are combined into a composite sample that is then reduced and submitted to the laboratory.

A rapid viability test in which seeds are soaked in a tetrazolium salt solution; living tissue stains red while dead tissue stays colourless. It gives a quick estimate of viability, useful when dormancy prevents a normal germination test.

A condition in which viable seeds fail to germinate even when given moisture, warmth and air, because of hard seed coats, immature embryos or internal inhibitors. It may be broken by scarification, chilling or light treatments.

Seed that remains impermeable to water because of an unusually tough seed coat, so it does not swell or germinate in a normal test. Common in legumes; reported separately in germination results.

Any treatment that breaks, scratches or softens a hard seed coat so water can enter and germination can begin. Methods include mechanical abrasion, hot water soaking and acid treatment.

The sum of properties that determine how quickly and uniformly seeds germinate and how well seedlings establish under adverse field conditions. High-vigour lots perform better than germination percentage alone predicts.

A vigour test in which seeds are held at high temperature and high humidity for a set period, then germinated. Lots that keep high germination after this stress are judged more vigorous and store better.

The degree to which a seed lot represents the true characteristics of its variety, free from off-types, mixtures and contamination. It is maintained by isolation, roguing and careful seed multiplication.

The proportion of plants or seeds in a lot that belong to the declared variety and show its typical characters. Assessed in field inspection and by grow-out or laboratory tests.

A plant or seed that differs from the described characteristics of the variety, whether through genetic segregation, mutation, admixture or contamination. Off-types are removed during roguing and counted in field inspection.

The deliberate removal of off-type plants, diseased plants and weeds from a seed crop before they shed pollen or set seed. It protects genetic purity and is usually repeated at several growth stages.

The minimum separation, in metres, required between a seed crop and other crops or varieties that could cross-pollinate it or contaminate its seed. The distance depends on species, pollinating agent and seed class.

Transfer of pollen from the flower of one plant to the stigma of a flower on a different plant, producing seed with mixed parentage. It is the main reason isolation distances are enforced in seed crops.

Transfer of pollen within the same flower or between flowers of the same plant, so seed is largely true to the parent. Self-pollinated crops need shorter isolation distances than cross-pollinated ones.

The stage of a variety in the multiplication chain, such as breeder, foundation, registered and certified seed. Each class has its own field standards and must be grown from seed of the preceding class.

Seed produced from breeder seed under strict supervision, with high genetic purity, and used to sow certified seed crops. It is the main source of stock for commercial seed multiplication.

Seed directly controlled by the originating plant breeder or institution, representing the purest available source of a variety. It is used to produce foundation seed and is not sold to farmers.

An official system that verifies seed production follows prescribed field and laboratory standards, then issues a certificate and tag for the lot. It covers source seed, field inspection, processing and testing.

A trained inspector's check of a growing seed crop for isolation, off-types, weeds and disease against prescribed standards. The result decides whether the crop is accepted for certification.

A test in which a sample of the seed lot is planted and the resulting plants are examined for varietal characters and off-types. It confirms genetic purity when field history or appearance is in doubt.

The water present in seed, usually expressed as a percentage of fresh weight. It governs storability, insect and fungal damage, and mechanical injury during threshing and processing.

Controlled removal of water from seed after harvest to bring moisture down to a safe level for storage. It must be gradual and at moderate temperature to avoid cracking or loss of viability.

Storage in airtight containers or bags so that respiration of insects and seed depletes oxygen and stops further damage. It protects seed without chemicals provided moisture is already low.

The moisture level at which a seed lot is held in store, kept low enough to slow respiration, mould growth and insect activity. Safe limits vary by crop and by whether containers are sealed.

Application of fungicides, insecticides, or biological or physical agents to seed before sowing or storage to control seed-borne pests and diseases. Treated seed must be clearly labelled and never used as food.

A disease carried on or inside seed that can infect the next crop or spread in storage. Examples include loose smut of wheat and bacterial blight; control relies on clean seed, roguing and treatment.

The sequence of operations after harvest that cleans, sizes, grades, treats and packages seed to raise purity and uniformity. It includes drying, cleaning, grading and sometimes pelleting or priming.

The label fixed to a seed container giving species, variety, lot number, class, germination, purity, date of test and producer details. It is the buyer's legal record of what the lot contains.

Seed sold with a label stating its true quality, such as germination and purity, without going through full certification. The seller is legally responsible for the accuracy of the stated figures.

The lowest germination, purity, moisture and other quality values a seed lot must meet to be legally sold. Standards are set by national seed legislation and differ by crop and class.

A written agreement between a seed company and a grower setting the crop, area, price, quality standards, delivery terms and inspection rights. It defines who bears risk and who owns the harvested seed.

The total expense of growing, harvesting, processing and testing a seed crop, divided by the saleable seed output. It determines whether a seed enterprise is profitable and guides pricing decisions.

Gross income from a seed crop or enterprise minus its variable costs, such as seed, fertiliser, labour and processing. It is used to compare enterprises and plan the farm's cropping programme.

Clothing and equipment worn to protect a worker from hazards, such as gloves, boots, goggles, dust masks and aprons. It is essential when handling treated seed, chemicals and dusty grain.