In 1977 Precision Seed Coaters sister company Canadian Seed Coaters was established as the first seed coating company in Canada and the second major seed coating company in North America. At that time, the company specialized in coating forage legumes and turf grasses. Since then, markets for these have increased and as our technology expands and further distinct advantages are shown for coated turfgrasses, we are confident that this market will increase even further.

Our first formulations for coated turfgrasses were based on the results of extensive research work done in New Zealand. However when Precision Seed Coaters was established in Yuma Arizona in 1989 new coating methods and formulae had to be developed specifically for Bermuda Grass. Thus, even though good results have been obtained with coated turfgrasses, we are continually working to further improve our products. 

THEORY

Seed coating is a process designed to create a nutritious environment in the immediate vicinity of the germinating seed. This provides a "boost" for the seedling in its critical early stages of development. Phosphorus is the main nutrient supplied by the coating to the seedling.

In the past, some users have expected coated seed to allow them to ignore good seeding techniques, yet still obtain a dense healthy turf. Coated seed does provide major advantages but good cultivation techniques must still be followed. Obviously coating cannot alter the inherent genetic characteristics of the seed such as yielding capacity.

Coated seed benefits the plant in its critical seedling stage thus ensuring early vigour and maximum establishment. There is some carryover effect from this increased seedling vigour but once the fertilizer coat has been assimilated by the plant, it cannot be of any further direct benefit in its future development.

Research is continuing in an attempt to provide further benefits to the user. The increased use of agricultural chemicals and slow release fertilizers will undoubtedly offer additional advantages in the future. However, the present economic, nutrient and chemical benefits which are available to coated turfgrass users today make it a very worthwhile product. 

THE REASONS WHY

There are several obvious benefits in coating turfgrasses. These include:

1) Nutrient benefits

2) Agricultural chemical benefits

3) Protection from stress conditions and from birds and rodents

4) Ease of sowing

5) Economic benefits

1) Nutrient Benefits

Seed coating creates a nutritious environment around the germinating seed which increases seedling vigour during its critical early development. Up to 20% of all Precision Cote® grass seed coating is phosphatic fertilizer. Phosphorus is essential for plant growth and is especially critical for young seedlings as it ensures normal root development and vegetative growth during the early stages of establishment. Even in soils with phosphorus levels sufficiently high to sustain normal growth, localized placement is very beneficial. It is particularly desirable from the standpoint of accessibility to the establishing seedling and in order to reduce fixation. Phosphorus does not move in the soil, therefore the nearer it can be placed to the seed, the easier it can be utilized by the seedling. Lime, a second important component of the coat, can have a beneficial effect in low pH soils.

Although coated seed does have significant benefits, it should be emphasized that the coating does not negate the need for normal cultivation and fertilization techniques at seeding time.

2) Agricultural Chemicals

It is becoming increasingly obvious that one of the most important functions of a seed coating is to act as a carrier for agricultural chemicals. This aspect of coating is as important for turfgrasses as it is for other crops (e.g. canola seed). Recent research shows that seed coating is a simple, economical, safe and very reliable method of applying chemicals to the seed. 

3) Protection From Stress Conditions, Birds and Rodents

Coating offers a significant measure of protection from stress conditions. Such conditions include those created by lack of moisture, the effects of wind and sun, as well as nutritional deficiencies and acidic soils.

Birds and rodents do not recognize coated turfgrasses as food. This is due, in part, to the taste of the coating but to a greater extent, to the effect of the dyes used to color code the seed. These dyes serve a dual purpose in that they distinguish the individual species of seeds in the mix for the grower and are also unpalatable to birds and rodents thus reducing the amount of seed lost prior to germination.

4) Ease of Seeding

Colour coded turfgrasses are easily seen on the prepared seed bed, preventing overlapping when seeding. This helps to ensure an even coverage over the entire seed bed. In addition, coated seed is heavier than bare seed, which helps it make better contact with the soil. This is especially important if the soil is neither raked nor rolled following seeding. The increased weight of coated seed is also beneficial when aerial seeding large areas with revegetation mixes.

5) Economic Benefits

As with most coated forage seeds, Precision-Cote®  turfgrasses are often lower in cost, per pound of product, than bare seed.

RESEARCH

1) FIELD TRIALS

The initial aim of the field trials was to compare the performance of bare seed with coated seed, however, the trials also contained several formulation changes from our standard product which did produce some beneficial effects. The single most important fact to come out of our program was that existing coatings may be slightly slower to germinate than bare seed. Because the seeding rate used, in terms of number of seeds per square metre, was lower than the bare seed, the initial cover was not as dense as some of the bare seed plots. However, as the growing season progressed, the coated plots thickened noticeably and were a darker, healthier green than the bare seed. Our conclusion from the trial was that if we were able to speed up the germination of coated seed, it would match and surpass the bare seed more rapidly.

These plots remained in excellent conditions throughout their life. However, we did notice two differences between the bare and the coated plots:

a) the coated seed was faster to green up in the spring

b) the coated seed (particularly the fescue) had a much denser, healthier root system

2) LABORATORY TRIALS

In the laboratory, we were able to demonstrate dramatic improvements in germination, establishment and re-growth between various coating treatments and bare seed. Of the ten treatments in the trial, the bare seed was by far the worst. Initial harvests taken one month after seeding ranged up to about 15% above bare seed yield on most coated treatments. However, during the course of the re-growth of the plants, the worst coated seed treatment averaged 28% above the bare while the best treatment yielded a massive 79% more growth than bare seed. In actual fact, the greatest increase on a single cut was 130% over the bare seed. These results must be attributed to the phosphorus and lime as well as the fungicide additives in the coat. 

CONCLUSIONS