A SEED-CONTAINING WATER IMBIBING TABLET OR CAPSULE AND METHODS UTILISING SAME

COMPRIME OU CAPSULE CONTENANT UNE SEMENCE ET IMBIBANT DE L'EAU ET METHODES D'UTILISATION

English Abstract

A tableted plant growth media which incorporates various
forestry or agricultural seeds, along with the appropriate
fertilizers, minerals and nutrients for enhanced growth. Also
present are various water-retentive polymers such as cross-linked
polyacrylamide, hydroxypropyl methylcellulose and
microcrystalline cellulose.

French Abstract

Milieu de croissance végétale, sous forme de comprimés, renfermant diverses semences forestières ou agricoles, avec les engrais, les minéraux et les nutriments appropriés pour une meilleure croissance. Sont également présents divers polymères rétenteurs d'eau, à l'état réticulé, comme un polyacrylamide, de l'hydroxypropylméthylcellulose et de la cellulose microcristallisée.

Claims

The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:
1. A plantable water imbibing seed-containing tablet
or capsule, weighing at least one-half gram, which in use
upon contact with rainfall or moisture starts to slowly
hydrate and form a controlled release gel capsule,
enveloping the seed, for slowly feeding the germinating seed
over a period of one year, said tablet being formed from
an intimate mixture of solid dry particles comprising a
combination of various water-retentive polymers that are
slowly biodegradable over five years by soil bacteria, said
combination constituting the major ingredients of said
tablet, and further comprising at least one water-insoluble
hydratable polymer constituting the major ingredient(s) by
dry weight of said combination with the balance being made up
of water-soluble and water-insoluble materials to provide a
combination of seed growth enhancement agents that are
respectively of variable water solubility and are to a large
extent capable of being broken down into water-soluble
substances by the continued action of soil bacteria, and a
seed selected from any forestry or agricultural or
horticulture seed stock that requires no pre-germination or
sedimentation process before planting, or is already
pre-germinated before tabletting.
2. A plantable tablet according to claim 1 wherein
the tablet contains talc and magnesium stearate in an amount
of 3% to 6% by weight of the tablet as a tabletting
lubricant.
3. A plantable tablet according to claim 1 wherein
the seed growth enhancement agents include water-soluble
fertilisers in concentrations ranging from 5 to 20% by
weight of the tablet.
18

4. A plantable tablet according to claim 3 wherein
the fertilizers are selected from mono/diammonium phosphate,
caustic potash, potassium nitrate, K2S and P2O5, and
mixtures thereof.
5. A plantable tablet according to claim 1 wherein
the water-insoluble hydratable polymer is a crosslinkable
polymer selected from the group consisting of poly(ethylene
glycol), poly(vinyl pyrrolidone), polyacrylamide,
hydrophilic urethane polymers, vinyl resins, poly(vinyl)
alcohol), vinyl ester/unsaturated carboxylic acid ester
copolymers or copolymers thereof with ethylene, and
hydrolysed hydroxyalkyl acrylate/acrylamide copolymers.
6. A plantable water imbibing seed-containing tablet
according to Claim 1 wherein the tablet is directly
plantable and is made up of essentially dry components
in a tabletted form of from 0.5 to 5g in weight and
comprises a water-retentive polymer selected from the
group consisting of polymers having the formula (A):
<IMG> ,
wherein R represents hydrogen or alkyl groups.
7. A plantable tablet according to claim 1 or claim 6
wherein said tablet contains additive materials selected
from natural polymers, synthetic soluble polymers, growth
regulating agents, soil conditioning agents, dispersants,
wetting agents, denitrification inhibitors, pH altering
compounds, energy sources, nutrients, trace elements,
microorganisms, enzymes, pheromones, phytohormones,
fertilisers, herbicides, fungicides, insecticides, iron
chelators, pesticide antidotes and safeners, inert fillers,
excipients, lubricants and non-harmful tabletting aids.
19

8. A plantable tablet according to claim 1 wherein
the water-insoluble hydratable polymer is a polyacrylamide
copolymer/hydroxypropylmethylcellulose complex capable of
absorbing from 3 to 4 times its dry weight in water.
9. A plantable tablet according to claim 1 wherein
the water-insoluble hydratable polymer is biodegradable.
10. A plantable tablet according to claim 1 wherein
the water-insoluble hydratable polymer upon hydration forms
a swollen slow-release gel capsule.
11. A plantable tablet according to claim 1 or claim 6
containing water-soluble fertilizers selected from the group
consisting of mono/diammonium phosphate, caustic potash, and
KNO3, at concentrations ranging from 5 to 20% by weight of
the tablet.
12. A plantable tablet according to claim 1 or claim 6
containing a microorganism selected from the group
consisting of Pseudomonas species, Bacillus thuringiensis,
Mycorrhizal fungi, Rhizobia species, Bacillus subtilis and
Actinomycetales species.
13. A plantable tablet according to claim 1 or claim 6
containing a growth factor selected from the group
consisting of giberellic acid, cytokinins, naphthalene
acetic acid, indolebutyric acid and indole acetic acid.
14. A plantable tablet according to claim 1 comprising
water-retentive polymers selected from the group consisting
of polymers having the formula A:
<IMG>
wherein R represents hydrogen or alkyl groups,
which is present at a concentration of 20.50 to 85.0% by
weight of the tablet.

15. A plantable tablet according to claim 1 wherein
the water-retentive polymers are cross-linked polyacrylamide
copolymers.
16. A plantable tablet according to claim 1 wherein
the water-retentive polymers are cross-linked polyacrylamide
copolymers mixed with compounds of the formula A:
<IMG>
wherein R represents hydrogen or alkyl groups.
17. A plantable tablet according to claim 1 wherein
the water-retentive polymers are cross-linked polyacrylamide
copolymers mixed with hydroxypropylmethyl-cellulose.
18. A plantable tablet according to claim 1 including
additives selected from copper sulphate, thiram, captan,
benomyl, metalaxyl, carbofuran, acephate, malathion,
pronamid and ethyl dipropyl thiocarbamate.
19. A plantable tablet according to claim 1 including
additives selected from sugars, carbohydrates, adenosine
triphosphate, calcium, magnesium, amino acids and
micronutrients.
20. A plantable tablet according to claim 1 comprising
a nitrogen-containing agent of the formula
<IMG>
which is present in concentrations of 3.50 to 5.0% by weight
of the tablet.
21

21. A plantable tablet according to claim 1 containing
micronutrients or agriculturally modified minerals, such as
vermiculite or perlite, in concentrations ranging from 1 to 3%
by weight of the tablet.
22. A seed growth enhancement tablet weighing at least
one-half gram, for slowly feeding germinating seeds over a
period of one year, comprising:
a tabletted intimate mixture of solid dry particles
of the following ingredients,
a combination of water-soluble and non-soluble
fertilizers, specifically mono/diammonium phosphate,
potash, KNO3 and P2O5 in an amount of from 5% to 20%,
talc and magnesium stearate as the tabletting
lubricant in an amount of 3% to 6%,
a combination of two water retentive polymers
selected from the group consisting of cross-linked
polyacrylamides and hydroxypropylmethyl cellulose
constituting the major ingredient of said tablet,
the amounts of each polymer being sufficient to
present in total an amount of up to 85% by weight of
the tablet, a nitrogen containing additive of the
formula
<IMG>
present in concentrations of 0.50% to 5.0% by weight
of the tablet,
various micronutrients, growth hormones and trace
22

elements present in trace amounts of from 0.002% by
weight of the tablet, said tablet on contact with
rainfall or moisture starts to slowly hydrate and
form a controlled release gel capsule, enveloping
the seed.
23. A plantable seed growth enhancement tablet having a
composition according to claim 1 or claim 6 comprising a
plurality of shaped forms each containing differing seed
enhancement agents and designed to be sown together or
assembled to form a complete tablet containing a seed selected
from any forestry or agricultural or horticultural seed stock,
whereby said tablet on contact with rainfall or moisture,
starts to slowly hydrate and form a controlled release gel
capsule, enveloping the seed.
24. A method of replanting or seeding areas comprising
the sowing of a seed-containing tablet substantially as
claimed in any of Claims 1-23.
25. A method of germinating seeds in greenhouses,
comprising placing a low expansion gel tablet, containing a
selected seed, directly into soil in expanded polystyrene foam
formed containers, the tablets comprising an intimate mixture
of solid dry particles of a water retentive polymer having low
expansion rates, that is very slowly water soluble and to a
large extent capable of being broken down into water soluble
substances by the continued action of soil bacteria, said
polymer composition constituting the major ingredient by
weight of the ingredients of said tablet, talc in the amount
of 2% to 5% by weight as a tabletting lubricant which does not
interfere with water penetration and disintegration of the
tablet, a combination of various fertilizers and soil
enhancement additives, and a seed type specific to the
fertilizers and additives contained in the tablet.
23

Description

CA 02000620 1999-02-02
A Seed-Containing Water Imbibing Tablet or Capsule
and Methods Utilising Same
This invention relates to new compositions of matter for
use in a tablet form which encapsulates seeds, fertilizers and
water-retentive polymers to facilitate the planting of seeds
and particularly provides both methods and means for
facilitating same.
There has been a desire to improve methods of planting
and propagating plants for agricultural and forestry purposes
for generations. This need has been addressed largely by ever
increasingly sophisticated technology and expensive scientific
research. The necessity to provide simple inexpensive
solutions has become all the more acute recently with
intensifying difficulties in maintaining crops in certain
regions of the world to provide adequate food supplies and now
widespread concerns over the ecological damage arising from
deforestation. The current demand is not only to solve the
problems or alleviate the difficulties of the present
situation but also to do so in an environmentally acceptable
manner.
It is widely recognised that plants in general, once
established in a suitable environment, are for the most part
self-sufficient and relatively easily cultivated. The most
significant difficulties and highest losses of potential crops
arise in establishing the plant in the first instance.
Therefore attention is currently directed at ways of ensuring
that the plant seeds become established as plantlets.
Research is being vigorously pursued into genetic
engineering of plants to improve their probability of survival
to mature plants which can be harvested. Other lines of
research being followed include tissue culture cloning
methods, e.g. the callus culture method which involves
extensive preliminary laboratory preparation work and
expensive controlled culture environment before it is even
possible to consider planting the young plant. Various other
culture techniques exist but they too suffer from the
drawbacks of expense and labour intensive preparation
procedures. Despite these obvious disadvantages workers in

CA 02000620 1999-02-02
the field have not been discouraged from developing still
further laboratory initiated methods. Thus Lion K.K. of Japan
have developed a technique for coating somatic embryos with
gelling agents combined with nutrients, which technique is
described in JP-A-61-40 708. Of course the use of gelling
agents for seed coatings is known. Clarence C. Dannelly
discloses in US-A-4 249 343 various compositions of water-
insoluble but water-sensitive polymeric microgel. This gel
when used as a coating for seeds provides protection for the
seeds, and may be used to carry various materials such as
fertilizers and pesticides. However, the polymer used does
not dissolve when contacted with water. The binding forces at
the interface between the particles of the coating having a
greater sensitivity to water than the binding forces which
maintain the particles intact. Whereby contact with water
destroys the continuity of the coating, causing it to
disintegrate. In that patent, the seed coating is applied in
a liquid form and allowed to dry before planting. Therefore
any carried materials must be incorporated into the gel and
seed at the same time. The presence of liquid in this media
produces initial seed damage at time of coating. Also there
is no available dissolved material once the seed is planted,
due to the gel "falling" off upon water contact. Basically,
the problem is that the polymer absorbs the active nutrients
but does not release them to promote controlled release, over
time. Once planted, the seed nutrients carried in the gel are
leached away after the first rainfall.
An object of the present invention is to obviate or
mitigate the aforesaid disadvantages and provide improved
methods for planting seed. A further object of the invention
is to provide means for delivering with the seed to be planted
nutrients remaining available to the seed over a prolonged
period of time. It is a still further object of the invention
to provide means of delivering with the seed during planting
means for enhancing the environment in the locus of the seed
after planting which means develops a gel-like body that
extends around the root zone of the seed and

_ 2 ~
developing seedling which provides a reservoir for water to
feed the growing seed.
According to the present invention, there is provided a
plantable water imbibing seed-containing tablet or capsule,
weighing at least one-half gram, which is use upon contact
with rainfall or moisture starts to slowly hydrate and form a
controlled released gel capsule, enveloping the seed, for
slowly feeding the germinating seed over a period of one year,
said tablet being formed from an intimate mixture of solid dry
particles comprising a combination of various water-retentive
polymers that are slowly biodegradable over five years by soil
bacteria, said combination constituting the major ingredients
of said tablet, and further comprising at least one water-
insoluble hydratable polymer constituting the major
ingredient(s) by dry weight of said combination with the
balance being made up of water-soluble and water-insoluble
materials to provide a combination of seed growth enhancement
agents that are respectively of variable water solubility and
are to a large extent capable of being broken down into water-
soluble substances by the continued action of soil bacteria,
and a seed selected from any forestry or agricultural or
horticulture seed stock that requires no pre-germination or
sedimentation process before planting, or is already pre-
germinated before tabletting.
According to the present invention, there is also
provided a seed growth enhancement tablet weighing at least
one-half gram, for slowly feeding germinating seeds over a
period of one year, comprising:
a tabletted intimate mixture of solid dry particles of
the followiny ingredients,
a combination of water-soluble and non-soluble
fertilizers, specifically mono/diammonium phosphate, potash,
KN03 and P205 in the amount of from 5~ to 20~,
talc and magnesium stearate as the tabletting lubricant
in an amount of 3% to 6~,
C: ~

2 ~ @ ~
a combination of two water retentive polymers selected
from the group consisting of cross-linked polyacrylamides and
hydroxypropylmethyl cellulose constituting the major
ingredient of said tablet, the amounts of each polymer being
sufficient to present in total an amount of up to 85~ by
weight of the tablet,
a nitrogen containing additive of the formula
/CH3 C2H5
~NHCOCH2~J -CH2 ~ (C6H5COO)
~H3 C2H5
present in concentrations of 0.50 to 5.0~ by weight of the
tablet, various micronutrients, growth hormones and trace
elements present in trace amounts of from 0.002~ by weight of
the tablet, said tablet on contact with rainfall or moisture
starts to slowly hydrate and form a controlled release gel
capsule, enveloping the seed.
According to the present invention, there is also
provided a method of replanting or seeding areas comprising
the sowing of a seed-containing tablet of the present
invention.
According to the present invention, there is also
provided a method of germinating seeds in greenhouses,
comprising placing a low expansion gel tablet, containing a
selected seed, directly into soil in expanded polystyrene foam
formed containers, the tablets comprising an intimate mixture
of solid dry particles of a water retentive polymer having low
expansion rates, that is very slowly water soluble and to a
large extent capable of being broken down into water soluble
substances by a continued action of soil bacteria, said
,~
~J

fi ~ ~
_
polymer composition constituting the major ingredient by
weight of the ingredients of said tablet, talc in the amount
of 2% to 5% by weight as a tabletting lubricant which does not
interfere with water penetration and disintegration of the
tablet, a combination of various fertilizers and soil
enhancement additives, and a seed type specific to the
fertilizers and additives contained in the tablet.
The seed growth enhancement agents may be additive
materials selected from natural polymers, synthetic soluble
polymers, growth regulating agents, soil conditioning agents,
dispersants, wetting agents, denitrification inhibitors, pH
altering compounds, energy sources, nutrients, trace elements,
microorganisms, enzymes, pheromones, phytohormones,
fertilisers, herbicides, fungicides, insecticides, iron
chelators, pesticide antidotes and safeners, inert fillers,
excipients, lubricants and non-harmful tableting aids.
In forming the tablet it is preferred to include a
tableting lubricant which does not interfere with water
penetration and disintegration of the tablet, e.g. talc and
magnesium stearate in the amount of 3% to 6% by weight of the
tablet may be utilised.
In this invention, the insoluble water-retentive
polymer(s) preferably constitute up to 85% by weight of the
dry composition, and where combinations are used the
respective polymers may each range upwardly from 5% of the dry
composition, more preferably the polymer content is about 40%
of the dry mixture for a polymer such as polyacrylamide.
Ideally the water-retentive polymers are slowly biodegradable,
and are able to absorb, hold and release over time, up to 400
times their own weight in water, whereby upon planting either
by ground or aerial means, and upon rainfall or moisture
contact hydration occurs to form a gelled capsule enveloping
the seed.

Advantageously the plantable tablet is based on a seed
growth media made from a mixture of cross-linked polyacryl-
amides and hydroxypropylmethyl-celluloses.
As mentioned above the delivery form of the tablet is
variable and in some instances the particles may be provided
as components compressed into shaped parts that connect or fit
together. In that case the shaped parts may range from about
0.05 to 50 grams in weight and may have the structure of
pellets, capsules, tablets, briquets in various, circular,
triangular, square shapes in both short and elongated forms;
may be solid or contain one or more holes. The possibilities
for variation in delivery shape and form are numerous and the
person skilled in the art will be able to select the most
convenient delivery form taking into account such factors as
intended manner of sowing i.e. mechanically or manually,
ingredient interactions and compatibilities, size of seed,
intended storage period prior to sowing etc. For the purposes
of further discussion of the invention, references
hereinafter, unless otherwise stated, will be to tablet or
pellet forms of the plantable tablet including the seed.
Preferably the plantable tablet for of the invention
contains water-soluble fertilizers in concentrations ranging
from 5 to 20~ by weight of the tablet, and may also contain a
growth factor selected from the group consisting of giberellic
acid, cytokinins, naphthalene acetic acid, indolebutyric acid
and indole acetic acid.
It is particularly preferred that the plantable tablet
contains water-retentive polymers which are cross-linked
polyacrylamide copoly~ers.
C~

' -
The plantable tablet may also comprise a nitrogen-
containing agent of the formula
~ H3 C2H5
NHCOCH21 -CH2 ~ (C6H5COO)-
CH3 C2H5
which is present in concentrations of 3.50 to 5.0~ by weight
of the tablet, and may also contain micronutrients or
agriculturally modified minerals, such as vermiculite or
perlite, in concentrations ranging from 1 to 3~ by weight of
the tablet.
In summary one may hereby obtain a tabletted or
encapsulated media for enhanced growth of germinating seed
containing a specific agricultural or forestry application
seed, together with fertilizers, micro-nutrients and growth-
enhancement agents, and a biodegradable polymer complex whichupon contact with an aqueous medium, forms a gel composition
of water containing fertilizers of both high and low water
solubility held in a homogeneous network of swollen,
hydrophilic, cross-linked polyacrylamide/hydroxypropyl-
methylcellulose, complexes. Eventually, the water is slowlyreleased in a controlled fashion, leaving a polyacrylamide
mass that can be rehydrated completely in less than an hour.
The rate of water released during dry periods eliminates the
risk of seed rot. A large quantity of the water is evaporated
before the seed can absorb excessive amounts. Thus the seed
is provided with a controlled zone around it which changes
slowly despite whatever radical environmental conditions in
the surrounding soil may occur.
C

2~Q~
The above mentioned seed, fertilizers and water-retentive
polymers, when dry mixed with the proper binders, lubricants,
disintegrants and compressed into a tablet form, can be either
applied directly into the ground using various planting
machinery or spread by various aerial application methods.
This allows the seeding and fertilization of areas that would
otherwise be inaccessible.
The soil tablet, upon water addition, is formed into a
body of elastomeric cross-linked polymer that binds a
1 5
/
- /
'~
;
~.... .~

CA 02000620 1999-02-02
certain quantity of water, resulting in a cohesive gelled
mass. The amount of bound water can range from 300-400% by
weight of the polyacrylamide copolymer/hydroxypropyl-
methylcellulose complex.
One advantage of this tablet is the ability to give up
the major portion of its water to seed germination, thereby
aiding and abetting their growth. Additionally, the polymer
gel can optionally contain plant growth additives such as
agricultural modified minerals, buffers and fertilizers.
These will be taken up slowly in a controlled release fashion
with minimum chemical "dumping" and assimilated as required by
the seed. Fertilizers operable herein can be water insoluble,
producing a longer release curve, or soluble such as ammonium
and diammonium phosphate, KNO3, K2S, P2Os and potash. The
preferred polymer to form the tablet is a synthetic organic
material such as cross-linked polyacrylamide or
hydroxypropylmethyl-cellulose. However, other polymers can
also be used alone or mixed and selection may be made from
crosslinkable polymers capable of forming a rehydratable water
retentive matrix wherein the water-insoluble hydratable
polymer is a crosslinkable polymer selected from the group
consisting of poly(ethylene glycol), poly(vinyl pyrrolidone),
polyacrylamide, hydrophilic urethane polymers, vinyl resins,
poly(vinyl alcohol), vinyl ester/unsaturated carboxylic acid
ester copolymers or copolymers thereof with ethylene, and
hydrolysed hydroxyalkyl acrylate/acrylamide copolymers. Upon
reaction with water, these polymers provide a gel body that
extends around the root zone where it is placed. Such a gel
structure securely holds the seed nutrients and fertilizers,
while providing a reservoir of water to feed the growing seed,
and eliminating the majority of leaching normally present. Of
course the presence of the water-insoluble polymers does not
exclude the possibility of including certain water-soluble
polymers as listed, and for the purposes to be described,
hereinbelow.
The seed contained in the tablet, can become encapsulated
in the said gel matrix upon moisture or

CA 02000620 1999-02-02
rainfall contact with the polymeric media originally present
as dry components of the tablet which thereafter provide an
appropriate encapsulation matrix, hereafter termed "gel". In
general, upon hydration a gel should allow embryo respiration
by permitting diffusion of gases. The gel should also be
strong enough to resist external abrasion and adverse forces,
yet be pliable enough to allow the growth of the embryo and
its germination at the appropriate time. It may be desirable
to use various gels in combination, either as a mixture or in
layers, to achieve the desired results. The gel selected must
be able to retain and hold a considerable amount of "free
water" which is able to participate in the physiological
process of germination. Any gel to be used in the dry tablet
matrix would usually include the following characteristics
upon hydration with moisture:
1. A compliance adequate to protect and cushion the seed.
2. An outer surface to provide a protective barrier to
mechanical stress, facilitate handling and maintain seed
viability.
3. Sufficient gel strength to maintain capsule integrity,
but still allow the radicles and roots to break out during
germination and for the additives to be contained and
released.
4. Once hydrated, the interior material would have
solubility or emulsion forming characteristics such that it
can accept or contain additives.
Some of the suitable gels include, but are not limited to
those listed in the Table 1 hereinbelow.

CA 02000620 1999-02-02
TABLE 1: GEL AGENTS
I. NATURAL POLYMERS
A. IONIC BONDS (Requires Complexing Agents)
Alginate with polypectate
Sodium pectate
Furcellaran
Dextran
Guar Gum
Sodium alginate with gelatin
B. HYDROPHOBIC INTERACTIONS
Amylose Gelatin
Gum Ghatti Agar Starch
Agarose Amylopectin
Ti Gum Agar with Gelatin
Cornhull Gum Wheat Gum
Chitin Dextrin
Starch
Gum Arabic
II. CHEMICALLY MODIFIED NATURAL POLYMERS
A. IONIC BONDS (Requires Complexing Agents)
Ethyl succinylated cellulose
Succinylated zein
Carboxymethylcellulose
B. HYDROPHOBIC INTERACTIONS
Methylcellulose
Hydroxyethyl cellulose
Hydroxypropylmethyl cellulose
C. COVALENT BONDS
Gelatin with glutaraldehyde
III. SY~Ln~11C POLYMERS
A. COVALENT BONDS
Polyacrylamide
B. HYDROPHOBIC INTERACTIONS
Polyethylene glycol
Hydrophilic urethane
Polyvinylpyrrolidone
Polyvinyl acetate
Polyoxyethylene
Vinyl resins
Hydron (RTM)
C. IONIC BONDS
Sodium poly (styrene sulphonate) + poly (vinyl
methyl pyridinium) chloride
Sodium poly (styrene sulphonate) + poly (vinyl
benzyl trimethyl ammonium) chloride
Vinyl acetate homopolymer (Bordon poly Co)
Polyvinyl alcohol resin (Gelvatol -RTM)
11

CA 02000620 1999-02-02
It has been recognized that plant establishment,
growth, and development may be enhanced by addition of
additives to the soil, to the rhizosphere of the plant, and
to the surface of the plant. It has been demonstrated that
controlled release of the additives may provide enhancement
to plant growth.
Nitrogen containing nutrients such as that of the
formula C28H34N2O3 below may be included in the make-up of
the tablet:
- -
/CH3 C2H5
~ COCH2N -CH2 ~ (C6HsCOO)~
CH3 C2H5
In the present invention additives which have been
found to be useful by adding to the tablet matrix along with
the seeds, include pesticides including insecticides
herbicides, and fungicides any and all being selected with
the objective of enhancing the seed germination environment,
pesticide counteracting agents including inhibitors and
antidotes, water-soluble and insoluble fertilizers,
vitamins, energy sources, simple sugars, carbohydrates,
starches, modified starches, cellulose ethers, amino acids,
adenosine triphosphate, micronutrients, magnesium, calcium
and trace elements, enzymes, growth promoters, growth
regulators, phytohormones, pheromones, soil and water
conditioners, dispersants, denitrification inhibitors,
wetting agents, pH controllers, metal chelating agents,
safeners, and dry-cultured micro-organisms including
bacteria and fungi. When considering fertilisers, a
combination of water-soluble and water-insoluble fertilizers
is preferred; specifically diammonium phosphate, potash,
triple phosphate and potassium sulphide.
The following Table 2 lists preferred additives to be
used in the invention.

CA 02000620 1999-02-02
TABLE 2: ADDITIVES TO TABLET MATRIX
I PESTICIDES
.
A. FUNGICIDES
Copper sulphate
Benomyl
Thiram
Metalaxyl
Captan
B. INSECTICIDES
Carbofuran
Malathion
Acephate
C. HERBICIDES
Pronamid
Ethyl dipropyl thiocarbamate
II FERTILIZERS AND NUTRIENTS
.
Nitrogen Calcium
Phosphorus Magnesium
Potassium Amino acids
Sulphur Micronutrients
III. ENERGY SOURCES
Sugars
ATP
Carbohydrates
IV. MICROORGANISMS
Pseudomonas species
Rhizobia species
Bacillus thuringiensis
Bacillus subtilis
Mycorrhizal fungi
Actinomycetales species
V. GROWTH REGULATORS AND HORMONES
Giberellic acid
Naphthalene acetic acid
Cytok; n; n~
Indole acetic acid
VI. OTHER BIOLOGICALLY ACTIVE COMPOUNDS
Denitrification inhibitors
Enzymes
Iron chelators
Pesticide antidotes
Pheromones
VII. OTHER INERT COMPOUNDS
Soil and water conditioners
Wetting agents
Dispersants
pH altering compounds
13

CA 02000620 1999-02-02
The selected additives are added into the dry powder matrix,
and therefore must be in a powder or crystal form to be
used. Liquid additives cannot be used as such in this
invention. Specific additives can be added to the tablet
mixture at concentrations specific for the application rates
of the particular additive. Fertilizers, for example, can
be added at a concentration of 0.01 to 1.0 gram per 1.5 gram
seed tablet. Pesticides, for example, can be added to the
polymer dry mix in amounts of from 0.002 to 0.30 grams
active ingredient per gram. Microorganisms, for example,
can be added at a concentration of 1 x 1012 microorganisms
per gram.
It is contemplated that the tablet or capsule could
contain non-toxic chemicals that would deter animals or
birds from ingesting the gel containing the seed.
By use of such tablets the invention provides a method
of increasing seed survivability, which is the main object
of the present invention, yet involves a non-complex
application procedure whereby a leach-resistant tablet that
slowly releases water, fertilizers and micronutrients in a
controlled fashion can be applied with seeding machinery or
by aerial dispersal. Additionally the invention provides a
tablet which is totally biodegradable, non-phytotoxic and
contains ingredients that promote seed growth. With due
consideration to these aspects, the invention utilises
polysaccharides or cellulose derivatives such as the
following (Compound A) at from 20.5 to 85~ by dry weight of
the tablet of the invention
H OR CH2OR
H < ~ / ~ ~ \ -~~
CH2OR H OR n
wherein R represents hydrogen or alkyl groups,
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.
which when dry mixed with the proper seed, fertilizers,
micronutrients, binders, lubricants and compressed into a
tablet form, can be directly or aerially dispersed;
resulting in enhanced seed survivability.
Various testing with this particular gelling compound
in a 1987-88 study in South Florida on the survival and
growth effects on Ligustrum and Hibiscus transplants, was
conducted with seed plantings made throughout the year, in
both wet and dry seasons. Results showed that the survival
rate of all three species was increased, when compared to
controls. In addition, the average growth rate was also
greater due partly to the fact that the soil conditions
around the gel-seed was noticeably softer to the touch than
the untreated soils.
Another study in Western Massachusetts, at the
University of Massachusett's research nursery, again tried
to determine survival and condition effects on various
forestry seed. The following seeds were used:
Eastern white pine (Pinus strobus)
White spruce (Picea alba)
Colorado blue spruce (P pungus)
Eastern hemlock (Tsuga canadensis)
Red spirea (pirea foobelli)
Yellow targ dogwood (Cornus lutea)
Results show that very few plants were lost in both
test and control treatments. However, the gel-treated
seedlings were consistently rated higher in condition.
The invention will now be described further by way of
the following illustrative examples.

2 ~
EXAMPLE 1
A water-retentive, fertilizer containing, seed growth
enhancement tablet of this tablet is made from the following
components (excluding selected seed):
~ BY WEIGHT
Compound A 10.0
Cross-Linked-
Polyacrylamide copolymer 40.00
Carnauba Wax 10.0
Mono-Ammonium Phosphate 10.0
Potash 20.0
Melogel Starch (trade-mark) 5.0
Magnesium Stearate 2.0
Talc 3.0
TOTAL 100.0
This composition is thoroughly mixed dry and then
pelleted dry into tablets, which may be from 1/2 gram to 5.0
grams in size. The talc and magnesium stearate act as tablet
lubricants during manufacturer, ensuring release from the
tabletting cavity without acting to water proof the tablet.
The above formula is a scientifically balanced low-
toxicity seed supplement with long-lasting water-retentive
characteristics, which meet the problems of drought, nutrient
depletion, leaching and fertilizer dumping. The latter is
accomplished through a controlled release of the soluble
fertilizer to the seed environment, by the cross-linked
polyacrylamide/hydroxy-propylmethylcellulose complex. The
very nature of the tablet also decreases leaching loss of
nutrients.
EXAMPLE 2
A tablet oriented specifically for greenhouse seed growth
that incorporates a much higher concentration of compound A.
Since the majority of nursery stock is grown in expanded,
cellular polystyrene shaped containers, the gelling
characteristics of the cross-linked polyacrylamide
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CA 02000620 1999-02-02
copolymer would actually damage seed stock by blocking gas
exchange. The compound A tablet would form a gel only
covering the surface of the tablet itself. There will be no
significant swelling or increase in gel mass by this tablet.
5 Composition excluding seed:
~ BY WEIGHT
Compound A 40.0
Carnauba Wax 20.0
Mono-Ammonium Phosphate5.0
10 Potash 10.0
Melogel starch 20.0
Magnesium Stearate 2.0
Talc 3.0
TOTAL 100.0
This composition is also thoroughly mixed dry and then
pelleted dry into tablets, which are from 1/2 to 5.0 grams
in size. This formula is a low-toxicity plant tablet with
long-lasting water-retentive characteristics that meets the
2~ ~rcbl_~s
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