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INTRODUCTION
In 1977 Canadian
Seed Coaters Limited was established as the first seed
coating company in Canada. At that time, we specialized in coating
forage legumes as indeed we still do. However, in 1978 we also
commenced coating turfgrasses. 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, Canada’s climatic
conditions demand that coating methods and formulae must be
developed specifically for Canadian conditions. 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 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 colour 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, Prill-On®
and Precision-Cote®
turfgrasses are
usually lower in cost, per kilo 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
It is very obvious
that coated turfgrasses are becoming increasingly popular with
growers. With further research and development on the part of Canadian
Seed Coaters Limited, and the co-operation of research
institutes throughout North America, this acceptance will continue
to increase. It is also obvious (from the results of our trials)
that thePrill-On®
and Precision-Cote®
products being offered today have
definite advantages over bare seed. Further field trials and
continued research and development, will ensure tomorrow’s Prill-On®
and Precision-Cote®
coated turfgrasses are far superior to bare seed.
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