Seed Certification - Why you should buy only certified seed

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• Last Updated on Wednesday, 14 March 2012 15:37
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Many people don't fully understand what is meant by seed certification, or what benefits certified seed offers to those who want to establish a crop or pasture from seed. Some think it means that the seed is of better quality, which is usually interpreted to mean that it has a higher germination than uncertified seed, or it has fewer, or even no, weed seeds. Neither of these assumptions is true.

Certification actually means that you will obtain seed which is as close as possible to the genetic make-up of the variety as selected by the breeder.

Plant breeders in Australia and overseas are working very hard to produce "better" varieties of crop and pasture plants. Just what is "better" varies greatly, and depends on the species and the environment in which it is to be grown. Usually it means higher yield in a crop plant or more leaf for a pasture. It can also mean enhanced pest or disease resistance; better processing quality for a crop plant; earlier or later maturity; better resistance to environmental stresses like very acid soil; or resistance to frost, heat or drought. The new variety might be better able to compete with weeds, or be resistant to a specific herbicide, or retain its seed better, and so on. There is an almost endless list of characteristics which might make a new variety better than an older variety it is intended to replace.

Plant breeding is a long, painstaking and very expensive process. New varieties of almost any species can take 8 to 12 years to produce. When breeders are satisfied they have an improved product they will produce commercial quantities of seed for sale. A new variety typically has a 5 - 15 year commercial life, and tens of thousands of tonnes of seed might be required during that time.

Unless conditions are carefully managed, each time seed is sown to produce further seed, there is a risk that the special characteristics which made that new variety valuable can be lost. This can be through:

• Physical contamination with inferior plants or seed, caused by planting the new variety in a paddock where other varieties of that same species have grown recently, or if seed of the new variety is mixed with inferior seed in the header, trucks or silos, or at the seed cleaning plant.
• Cross Pollination – in this case, pollen from other, possibly inferior, varieties pollinates the flower of the new variety, and so the resulting harvested seed is a mixture of the new variety and the other variety. The resultant seed will never produce plants which had all the characteristics which the breeder selected.
• Natural selection – in this case, the new variety is sown in an environment where some of the population of the new variety is selectively killed, or selectively favoured. For example after a series of very wet or very dry seasons, the plants surviving could represent only a proportion of the genetic potential of the new variety. Over a longer time, the plants still present will be those that were able to survive in that environment, and may not carry all the characteristics which the breeder selected and which made the variety valuable. Thus seed harvested from that paddock, will not reflect the full range of the characteristics which the breeder selected.

Seed Certification is designed to minimise the opportunities to lose or diminish the characteristics which make a variety valuable.

There are certification "Rules" for every species and these must be followed by the seed grower if his seed is to be certified.  The rules include requirements such as:

• the paddock must not have grown plants of that particular species for a certain period - usually 1 to 3 years;
• the seed crop may have to be inspected after seedling establishment to see what plants are growing between the rows from seed set by plants grown in the paddock in previous years, or a strip must be left unsown so the Certification Officer can see clearly what other plants are establishing in the paddock;
• there is a limited number of generations which can be used to produce Certified Seed - Breeders Seed must be sown to produce Pre-Basic Seed, which must in turn be used to produce Basic Seed and this seed is then sown to produce Certified Seed;
• the seed grower must prove to the Certification Agency that the seed of the appropraite generation has been sown;
• there is a limit to the number of harvests that can be taken from a seed crop of perennial species - this is usually between four and six harvests (but in some circumstances may be more) and after the set number of harvests the seed crop cannot be used to produce Certified Seed;
• there is a limit on the establishment of seedlings within a crop of perennial species because these seedlings represent the next generation and cannot be permitted to represent more than a small proportion of the total plant population of the seed crop;
• seed crop paddocks must be isolated from plants of the same species which may flower at the same time, so as to prevent cross pollination - this isolation may be as much as 400 metres for early generation crops (Pre-Basic and Basic) of some species;
• headers, seed transporting and handling equipment and silos must be thoroughtly cleaned before being used for certified seed;
• very good records must be kept of the harvested seed, both on farm and in the seed processing plant, to provide assurance to the certification agency that the seed is not mixed with other varieties of that species.

If the rules are followed, there is a high level of certainty that the plants grown from Certified Seed will have all the characteristics selected by the plant breeder.  It is the role of the certification agency, authorised by ASA, to oversee the production of certified seed and ensure the rules are followed.  This ensures that buyers of certified seed get the benefits offered by that variety.

When you buy seed which has been certified by an ASA-authorised certification agency, you have the assurance that an independent authority is continually overseeing the standards and processes designed to give the buyer seed which is as genetically close as possible to the seed originally selected by the breeder.

There is no such certainty with uncertified seed. Even with the best will in the world by the seed grower and seed merchant, the seed may be quite different from that of the variety which the grower wants - simply because there is no system in place to ensure that it is the variety you want.  If the grower of the seed or the merchant are less than honourable you really have no idea what seed you are buying.  For example in subterranean clover you might be buying seed of an old high-estrogen variety which could cause considerable problems to your breeding ewes.  The fact that uncertified seed has a variety name on it provides no assurance that it is in fact that variety.

The exception to this is proprietary varieties, where a company's reputation as a relaible supplier is at stake if their products perform poorly.  Such companies survive by their reputation and hence impose internal rules on the production of their seed, similar to those of the independent ASA-authorised certification agencies.   

Regardless of what seed you buy, always ask to see the 'test certificate' showing the results of tests conducted in the seed testing laboratory.  This will provide information on the physical quality of the seed - its germination, the identity of any other seed which may be present, and more.   See the article "Understanding a seed testing certificate" for more information.