Title of Invention

"POLYMERIC SEED COATS BASED ON BIOACTIVE BOTANICALS"

Abstract Polymeric seed coats and a method of obtaining the same are described. The coats comprise an array of synthetic or natural polymers, their derivatives, and polymer clay adducts, either alone or in various combinations, with or without the formulation auxiliaries. The coats incorporating biopesticides, with or without concomitant auxiliaries are also described. The biopesticides include more particularly the botanicals, both in crude or pure form, exemplified by various plant parts, extracts, bioactive neem meliacins or non-meliacins, bioactives from other plants, their derivatives and the likes. The preparation of seed coats involves, besides the polymeric carriers and bioactive molecules, the surfactants, solvents etc. to yield powder, slurry or the likes. These provide situation specific sustenance of seed quality or active ingredient release and are a valuable input in agriculture, particularly the organic agriculture..
Full Text 4. DESCRIPTION
Field of invention: This invention relates to the development of polymeric seed coats with or without the bioactive botanicals for improving the shelf life and germination of seeds and enhancing the overall seed quality, plant viability and vigour. More particularly, it relates to neem based polymeric coats and falls in the area of agrochemicals.
Back ground and prior art of the invention
Seeds during their storage and cultivation are exposed to various biotic and abiotic stresses. The former are exemplified by insects, various pathogens, nematodes and other organisms that are detrimental to seed quality, germination and plant growth. The abiotic stresses include temperature, moisture, humidity, light etc. that may similarly show detrimental effect on seed quality and performance. Several reports in literature highlight that coating seeds with various organic and inorganic materials mitigates the effects of such stresses. Both solid and liquid formulations with or without active ingredient (s) have been used as seed treatment for combating the stresses. More particularly, the solid powders, either as such or dissolution or suspension in water, have been employed. This technology has undergone transformation over the years and is being currently replaced by polymer coats. Such coats not only provideprotection against various stresses but also helps in improving/introducing uniformity in crop stands. Most of the technologies employed for achieving the objective are well guarded industrial secret.
Field crops, including, maize, and the oilseeds namely rape and sunflower are now being treated with polymer film coatings in Europe (Barlett, 1994), and there is much global interest in its application to these crops in the U.S.A. Polymer film coating has been applied to commercial sugarbeet, Beta vulgaris L. seeds as an effective delivery system for agrochemicals (Duan and Burris, 1997). Attractive features of this technology include reduced dust-off of chemicals, more uniform coverage of individual seeds, and improved flowability through the planter. The

potential of use of film coatings as moisture barrier for seeds stored at high humidity was demonstrated by McGee et al, (1988). A polyvinylidene chloride copolymer emulsion coat applied to maize and soybean seeds has been reported to control effectively the fungi invasion during storage for three months. Maize seed coatied with temperature responsive polymer to regulate seed germination are also reported (Johnson et al., 1999). Lee-Sheong Chun et al, 1996 reported the effect of polymer coating on seed vigour in rice.
Film coating has also been studied as a means of delivering insecticides such as benfuracarb, chlorpyrifos, chlorfenvinphos and others. The concentration of these insecticides and other active ingredients present in the seed coat was often limited due to the direct phytotoxic effect of the insecticides on the seed.
It is well known that biocidal material can be incorporated into elastomeric polymer matrices that enable its release at a rate which improves its effective duration and the pest destruction efficiency. US patent No 3417181 demonstrates that toxicant can be dissolved in an elastomer matrix and caused to release through a diffusion/dissolution mechanism when exposed to water. Several matrices involving different mechanisms of release have been tested for preparing controlled release formulations of pesticides (Murphy and Barrett, 1990; Schrieber, et al., 1993; Fernandez-Perez, et al., 1993; Parmar, et al, 1998; Kumar et al., 2002, 2003; Choudhary et al., 2006). Phorate based controlled release products have been successfully developed and their applicability demonstrated in small-scale field studies to control Atherigona soccata, Chilo partellus and Cnaphalocrocis medinalis in maize, sorghum and rice respectively (Panwar et al., 1999; Kumar et al., 2003).
Turnblad et al. in U.S. Pat. Nos. 5,849,320 and 5,876,739, disclosed insecticidal coatings comprising a polymer binder, an insecticide and a filler, where the binder formed a matrix for the insecticide and the filler. Application of such a coating to a seed and the optional subsequent application of a protective polymer overcoating were also described. This invention relates to an insecticidal coating for a seed comprising one or more binders selected from the group consisting of polymers and copolymers of polyvinyl acetate, methyl cellulose,

polyvinyl alcohol, vinylidene chloride, acrylic, cellulose, polyvinylpyrrolidone and
polysaccharides and an insecticidally effective amount of an insecticide,
preferably an organophosphate, phenyl pyrazole or pyrethroid, wherein the
binder forms a matrix for the insecticide.
In a preferred embodiment, the invention concerns an insecticidal coating for corn seed comprising a binder in an amount from about 0.01 to about 15% of the weight of the seed wherein the said binder is a vinyl acetate-ethylene copolymer or polymer or copolymer of vinylidene chloride, an insecticide in an amount from about 0.005 to about 50% of the weight of the seed and selected from the group consisting of terbufos, chlorpyrifos, fipronil, tefluthrin, chloroethoxyfos and tebupirimfos wherein the said binder forms a matrix for the insecticide
US patent No 134012 describes a method of controlling the release rate
of an agricultural active ingredient from seeds that have been treated with that
active. It involves providing a seed that has been treated with the active
ingredient, applying to the treated seed a film that includes an emulsion of a
polymer in a liquid in which both the agriculturally active ingredient and the
polymer have low levels of solubility, and then curing the film to form a water
insoluble polymer coating on the surface of the treated seed. The polymer is
selected from the group consisting of acrylonitrile-butadiene-styrene terpolymer
(ABS); ABS modified polyvinylchloride; ABS-polycarbonate blends; acrylic resins
and co-polymers: poly(methacrylate), poly(ethylmethacrylate),
poly(methylmethacrylate), methylmethacrylate or ethylmethacrylate copolymers with other unsaturated monomers; casein; cellulosic polymers: ethyl cellulose, cellulose acetate, cellulose acetatebutyrate; ethylene vinyl acetate polymers and copolymers; poly(ethylene glycol); poly(vinylpyrrolidone); acetylated mono-, di-, and tri-glycerides; poly(phosphazene); chlorinated natural rubber; polybutadiene; polyurethane; vinylidene chloride polymers and copolymers; styrene-butadiene copolymers; styrene-acrylic copolymers; alkylvinylether polymers and copolymers; cellulose acetate phthalates; epoxides; ethylene copolymers; ethylene-vinyl acetate-methacrylic acid, ethylene-acrylic acid copolymers;

methylpentene polymers; modified phenylene oxides; polyamides; melamine formaldehydes; phenolformaldehydes; phenolic resins; poly(orthoesters); poly(cyanoacrylates); polydioxanone; polycarbonates; polyesters; polystyrene; polystyrene copolymers: poly(styrene-co maleic anhydride); urea-formaldehyde; urethanes; vinyl resins: vinyl chloride-vinyl acetate copolymers, polyvinyl chloride and mixtures of two or more of these. The agricultural active ingredient is selected from the group consisting of pyrethrins including, fenvalerate, esfenvalerate, permethrin, cypermethrin, (beta-cypermethrin, theta cypermethrin, zetacypermethrin), deltamethrin, fenpropathrin, tau-fluvalinate, tefluthrin, flumethrin, cyfluthrin, beta cyfluthrin, transfluthrin, acrinathrin, alpha-cypermethrin, cycloprothrin, cyhalothrin, lambda cyhalothrin, bifenthrin, kadethrin, bioresmethrin, phenothrin, empenthrin, cyphenothrin, prallethrin, imiprothrin, allethrin, bioallethrin, and ZX18901; oxadiazine derivatives thiamethoxam; chloronicotinyl insecticides including acetamiprid, imidacloprid and nitenpyram; nitroguanidine, including TI-435; pyrroles; pyrazoles chlorfenapyr, fenpyroximate and tebufenpyrad ; phenyl pyrazoles including fipronil; diacylhydrazines including halofenozide , methoxyfenozide and tebufenozide ; triazoles including amitrole and triazamate; biological/fermentation products including avermectin (abamectin) and spinosad (XDE-105); organophosphate insecticides including acephate, chlorpyrifos, chlorpyrifos-methyl, diazinon, fenamiphos, and malathion; and carbamate insecticides including aldicarb, carbaryl, carbofuran, oxamyl, and thiodicarb.
US patent No. 6,858,634 (2005) reports controlled release formulations for pesticides and herbicides that contain an active ingredient, a matrix polymer and a matrix polymer plasticizer which is present in an amount sufficient to provide a release rate for the active ingredient from the formulation that matches a selected release rate. Methods for making and using the formulation, and seeds and plants that have been treated with the formulation are also included, the matrix polymer is selected from the group consisting of acrylonitrile-butadiene-styrene terpolymer (ABS); ABS modified polyvinylchloride; ABS-polycarbonate blends;

acrylic resins and copolymers; poly(methacrylate), poly(ethylmethacrylate), poly(methylmethacrylate), methylmethacrylate or ethylmethacrylate copolymers with other unsaturated monomers; casein; cellulosic polymers: ethyl cellulose, cellulose acetate, cellulose acetatebutyrate; ethyl vinyl acetate polymers and copolymers; poly(ethylene glycol); poly(vinylpyrrolidone); acetylated mono-, di-, and tri-glycerides; poly(phosphazene); chlorinated natural rubber; polybutadiene; polyurethane; vinylidene chloride polymers and copolymers; styrene-butadiene copolymers; styrene-acrylic copolymers; alkylvinylether polymers and copolymers; cellulose acetate phthalates; epoxides; ethylene copolymers: ethylene-vinyl acetate-methacrylic acid, ethylene-acrylic acid copolymers; methylpentene polymers; modified phenylene oxides; polyamides; melamine formaldehydes; phenolformaldehydes; phenolic resins; poly(orthoesters); poly(cyanoacrylates); polydioxanone; polycarbonates; polyesters; polystyrene; polystyrene copolymers: poly(styrene-co maleic anhydride); urea-formaldehyde; urethanes; vinyl resins: vinyl chloride-vinyl acetate copolymers, polyvinyl chloride; biodegradable polyesters; starch-polyester alloys; styrene-maleic anhydride copolymers; poly(methylvinyl ether-maleic acid); starch; starch-PCL blends; polylactic acid (PLA)-starch blends; polylactic acid; poly(lactic acid-glycolic acid) copolymers; cellulose esters; cellulose acetate butyrate; starch esters; starch ester-aliphatic polyester blends; modified corn starch; polycaprolactone; poly(n-amylmethacrylate); ethyl cellulose; wood rosin; polyanhydrides; polyvinylalcohol (PVOH); polyhydroxybutyrate-valerate (PHBV); biodegradable aliphatic polyesters; polyhydroxybutyrate (PHB); biodegradable aliphatic polyesters (BIONOLLE); and mixtures of two or more of these.
Azole fungicide is selected from the group consisting of azaconazole, BAS 480F (epoxiconazole), biternatol, bromuconazole, cyproconazole, difenoconazole, diniconazole, fenbuconazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, imazalil, imibenconazole, ipconazole, metconazole, myclobutanil, paclobutrazol, perfuazoate, penconazole, prochloraz, propiconazole, tebuconazole, tetraconazole, triadimefon, triadimenol, triflumizole,

triticonazole and uniconazole.
Heavy reliance of crop or seed protection methods on synthetic pesticides has at times, led to the development of pest resistance, elimination of naturally occurring biological agents, pest resurgence, and several undesirable effects on environment as well as non-target organisms. Global efforts have, therefore, been directed to look for safer alternatives. A search for alternative methods of pest control to protect seeds, therefore, is an important domain for exploration.
Natural pesticides, particularly those of botanical origin, have come out as a viable option to the synthetics (Parmar and Walia, 2001). Besides being renewable in nature, these are reportedly ecofriendly and generally devoid of the drawbacks associated with their synthetic counter parts. The Controlled Release (CR) technology has also been used to prepare the CR formulation of synthetic pesticides. However, recent work shows that botanicals can also play an equally important role to protect seeds/ plants against biotic and abiotic stresses.
In this context, Azadirachta indica A. Juss (Meliaceae), the Indian neem tree has attracted special attention of the scientific community all over the world because of its use as pesticides and allied agrochemicals. It is a versatile tree containing a large number of chemically complex and biologically active compounds. Neem products are reported to cause toxicological, behavioral and physiological responses in over five hundred species of insect pests (Singh and Schmutterer, 2002). Of late, these have gained significance worldwide because of their spectacular pest control activity as insect antifeedant at higher concentrations and insect bio-regulator at lower ones. Apart from insects, the fungi, nematodes, viruses and protozoa- the other major enemies of crops and animals, are also sensitive to neem derivatives. Its major secondary metabolite azadirachtin-A, has been rated as the most potent naturally occurring botanical pesticide. Among the various Azadirachtin(s), aza-A, B, H and E are the most active as antifeedant and insect growth regulator. Azadirachtin-A is incidentally classified as a biorational insecticide by US-EPA and is exempted from residue tolerance requirements on food crops as long as the dosage does not exceed 50

g a.i./ha, per application. Currently, azadirachtin-A has been registered in USA, India and many other countries of American and European continents. The suggested application rates for azadirachtin-A generally range from 12.5 g to 40g a.i/ha. It can, therefore, be rated as one of the most active and safe pesticidal molecule.
The effectiveness of the plant protection agents depends on the type of formulation, efficiency of spray mechanism that provides effective coverage and penetrability of the active compound in to the canopy of the plants. It is reported that aerial spray leaves 20-30 % of wastage of product during the spray which results in loss of valuable active ingredients. So far, azadirachtin-A has been widely formulated in liquid forms to be applied as emulsion or solution to agricultural crops. Various organic solvents and other inorganic additives have been used as carriers in order to make a cost effective and efficacious delivery system. The commercial use of such carriers is rather limited since many solvents are reported to be deleterious in causing degradation of Azadirachtin-A. Dureja (1999) has studied the degradation of azadirachtin-A in various solvents during 25 days at 29± 1 °C. The results revealed 50% degradation of azadirachtin-A in methanol and acetone, 75-80% in methylene chloride and chloroform and about 85% in ethanol and water. US patent No. 5001146 reveals that azadirachtin-A stability is improved by adjusting the concentration of polar aprotic solvent to at least 50% by volume and by decreasing water content to less than 15% by volume. This patent also suggests that azadirachtin-stability depends upon the type of solvent employed for its formulation. Kumar and Parmar (1999) have reported that shelf life of azadirachtin-A on solid carriers and neem oil may be improved by using stabilizers. Parmar et al (2005) reported that by employing different polymeric matrices, the shelf life of azadirachtin-A could be increased.
Normal emulsifiable concentrate pesticide formulations contain various petroleum based solvents which are sometimes phytotoxic to the crops. The use of such solvents even at the lower rates demands large amount of surfactant (s) and other additives for a good performance and shelf life, which raises the cost of

the formulation. The use of a broader range of ingredients and the associated problem of instability in the liquid formulations is a serious matter of concern for the success of commercial azadirachtin-A containing crop protection agents. Moreover, Azadirachtin-A is photolabile and tends to degrade fast on plant surfaces.
Borer type and insects with hard scale bodies are difficult to control through a foliar application of liquid products, primarily due to a lack of proper contact. Compounds that possess systemic property are ideal for the control of such insects. Azadirachtin-A is reported to possess systemic property and is readily absorbed by the plants through the leaves as well as the roots. A system to deliver the azadirachtin-A in to the plant rhizosphere will ensure effective protection of plants against borers, scaly sucking insects, nematodes, soil fungi etc. Even though the aqueous emulsions of formulations containing Azadirachtin-A can be applied to the soil, these tend to degrade faster owing to their direct exposure to water and soil. The chemical is, therefore, unavailable for longer periods of protection. Hence, an effective, efficient and economical use of Azadirachtin-A is not possible with any of the existing liquid formulations as these are meant primarily for foliar application. There is a need for an efficient delivery system to transfer azadirachtin-A to the plant rhizosphere without any significant loss. Subsequently, the product may get released slowly for plant protection. This can be fulfilled through a seed coat formulation, which has been designed for delivering systemic plant protecting agent into agricultural crops.
During storage, seeds are infested with fungal pathogens and stored insect pests. This leads to deterioration in seed germination, seed vigour etc. To overcome the problem, the seeds are coated with synthetic fungicides or seed protectant chemicals. Neem leaves and oil have also been used to treat seeds since times immemorial. It has now been established that the meliacins are primarily responsible for the fungicidal, ovicidal, antifeedant, insecticidal etc. activities of the neem products. Therefore, a seed coat formulation based on meliacins deserved an exploration to check the deterioration of seed quality through prevention of fungal and insect infestation.

The present invention has provided a composition that comprises of botanical bioactive materials, and other formulants. The process for preparation of said composition enables overcoming the limitations of the prior art. Seed coats based on botanical pesticide of the present invention will help in improving germination, viability, plantability of a seed or vigour of an agronomic plant that is grown from a treated seed that is planted in a pest infested location, by preventing the fungal / nematode/insect infestation that is a pest for the agronomic plant and against which a meliacin compound has bioactivity. Object of invention
An object of the invention is to prepare polymeric seed coats with or without the bioactive botanicals for improving the shelf life and germination of seeds and enhancing the overall seed quality, plant viability and vigour. Another objective is to exemplify the use patterns for some of the products developed for their practical application. Novelty
Use of meliacins with or without polymer is not a prior art as a seed coat formulation. Therefore, there is a need to develop non phytotoxic, effective, efficient and stable seed coat formulations containing azadirachtin-A/ other meliacins or other similar bioactive neem materials or other bioactive botanicals for improving germination, viability, plantability of seed /or vigour of an agronomic plant that is grown from a seed. Seed coats based on bioactive plant product of the present invention will help in improving germination, viability, plantability /or vigour of an agronomic plant that is grown from a seed that is treated with such a product and planted in a location having infested by fungal / nematode/insect or any other recognized pest for the agronomic plant and against which the bioactive compound in reference has ability to combat. These products are also useful in improving the storability of the seed by checking fungal/insect /other pest infestation during storage. Additionally, such products are safe to handle and cost effective. These provide invaluable input in the present day organic agriculture also.

The invention
Methods of preparation of seed coats
The method of making the subject formulation is not critical. Any method can be
used so long as it results in a product having the advantageous properties of the
subject formulation. It is preferred, however, that the subject formulation be made
by intermixing the matrix polymer and the active ingredient with a sufficient
amount of the matrix polymer plasticizer to form a mixture, and then forming the
mixture into micro particles having a release rate for the active ingredient that
matches a selectively desired release rate when the formulation is in the
application environment. Suitable methods for mixing ingredients and forming
micro particles and microcapsules are known in the art, and several of these are
described by Theis, C, in the chapter on Microencapsulation, at pp. 628-651, in
Vol. 16 of Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Ed., John
Wiley & Sons, New York (1995).
In the present invention, prior to preparing the suspension/emulsion, the size of
the polymer, surfactant and azadirachtin-A concentrate/ reduced azadirachtin-A
concentrate/ other neem meliacin/any bioactive neem derivative/other botanical
particles was standardized. It was reduced in planetary ball mill, the ingredients
mixed together and solvent was added to it. A wet grind was prepared consisting
of polymer, water / organic solvent and surfactants with and without azadirachtin-
A / reduced azadirachtin-A concentrate/ other neem meliacin/any bioactive neem
derivative/other botanical concentrates in a Remi mixer at 3000 rpm for 10
minutes or till the time the coating suspension/ emulsion was ready for
application to the seed.
Different seed coating formulations
Several types of polymers were employed to obtain the different recipes. For
example:
Type I. Polymer (soluble in water), binder and surfactant
Type II. Polymer (soluble in organic solvent), binder and surfactant
Type III. Polymer (soluble in water), binder, surfactant and azadirachtin-A/
reduced azadirachtin-A concentrate/ other neem meliacin/any bioactive neem

derivative/other botanical.
Type IV. Polymer (soluble in organic solvent), binder, surfactant and
azadirachtin-A / reduced azadirachtin-A concentrate/ other neem meliacin/any
bioactive neem derivative/other botanical.
A wet grind was prepared consisting of polymer, water / organic solvent and
surfactant in a Remi mixer at 3000 rpmthe desired time, say about 10 minutes.
The emulsion/ suspension concentrate thus obtained was used directly to coat
the seeds.
Example 1. Gum acacia / gum tragacanth (4.0 g), sodium lauryl sulphate (0.10
g) and sodium lignosuphonate (0.15 g) mixture was added to water (10 ml) and a
wet grind was prepared. Azadirachtin-A or reduced azadirachtin-A concentrate
(0.8 g; 25 %, azadirachtin-A) or calculated amount of any other neem bioactive
material or another botanical was dissolved in 5 ml dichloromethane in a
separate beaker. The organic solution was then poured into the aqueous solution
over a period of about 30 seconds while agitating the mixture thoroughly
employing a glass rod. The resultant mixture was used directly for application to
seeds
Example 2. Methyl cellulose (4.0 g), sodium lauryl sulphate (0.10 g) and sodium
lignosuphonate (0.15 g) mixture was added to water (40 ml) and a wet grind was
prepared and used.
Example 3. Poly vinyl acetate / rosin (4.0 g), sodium lauryl sulphate (0.10 g) and
sodium lignosuphonate (0.15 g), azadirachtin-A concentrate (0.8 g) mixture was
added to 50 ml acetone and a wet grind was prepared. Allowed the solution to
evaporate (approx. 50% volume) making the solution more concentrated. The
slurry was used for coating. Any other botanical derivative could also be used in
place of azadirachtin-A after minor variations.
Example 4. Gum acacia / gum tragacanth (4.0 g), sodium lauryl sulphate (0.10
g) and sodium lignosuphonate (0.15 g) azadirachtin-A /reduced azadirachtin-A
concentrate (0.8 g) were mixed. The mixture was blended and particles were
reduced in laboratory model planetary ball mill. The recipe was dissolved in water
at the time of application.

Example 5. Poly vinyl acetate / rosin (4.0 g), sodium lauryl sulphate (0.10 g) and sodium Iignosuphonate (0.15 g) azadirachtin-A /reduced azadirachtin-A concentrate (0.8 g) were mixed. The mixture was blended and particles were reduced in laboratory model planetary ball mill. The recipe was dissolved in organic solvents ie acetone at the time of application.
Note: It may noted that those well versed with the art of the subject matter can make innumerable modifications/ minor changes to suite the product for specific use or application. However, the basic principal upholds.
Seed coating: The composition can be applied to seeds by one or more means known to those skilled in the art A known weight of seeds can be introduced into the treatment equipment (such as a tumbler, a mixer, or a pan granulator). A known volume of seed treatment composition can be introduced into the treatment equipment at a rate that allows the seed treatment composition to be applied evenly over the seeds. During the application, the seed can be mixed, for example by spinning or tumbling. The seed can optionally be dried or partially dried during the tumbling operation. After complete coating, the treated sample can be removed to an area for further drying or additional processing, use, or storage. The coating formed is non-phytotoxic to coated seed. Example 6. Soybean seed (400g) was introduced in the tumbler and the seed treatment composition as prepared above was added to it. The seed is tumbled until it is coated with the treatment composition. The coated seeds were immediately transferred to an aluminium foil and spread uniformly and separated manually to prevent clogging. The seeds were air-dried with the help of a warm blower.
Degradation of azadirachtin-A on seed coats during storage The soybean seeds coated with azadirachtin-A-based seed coats were stored in laboratory under ambient condition for six months. Time for loss of 50% azadirachtin-A (t1/2) in different seed coats was determined in triplicate. Five-gram seeds were drawn at 0, 1, 2, 3, 4, 5, 6 months of storage for determination of azadirachtin-A by HPLC. The seed coated with azadirachtin-A alone served as control.

Azadirachtin-A was lost more rapidly from the seed coated with azadirachtin-A alone than for any of the seeds having a polymer coating (Tablel). The degradation rate varied significantly according to the type of polymer. The t1/2 of azadirachtin-A in different polymeric seed coats ranged from 4.37 to 11.22 months under laboratory storage condition and increased by nearly 1.3 to 3.3 times as compared to azadirachtin-A alone. Amongst polymeric coats, the faster degradation of azadirachtin-A was observed in gum acacia (4.37 months) and slowest in poly ethyl methacrylate (11.22 months).
Table 1. Half-life t1/2 (months) of azadirachtin-A in different seed coat
formulations and technical azadirachtin-A during storage
(Table Removed)


Seed Quality Assessment
In seeds storage studies, the effect of different polymers on seed quality parameters and the efficacy of the polymers as carriers of pesticide was assessed in comparison to uncoated seeds. The coated and uncoated (control) seeds of 700g each lots were packed in cloth bags and stored under ambient condition. Observations were taken on different seed attributes during storage at different time intervals as follows:
Seed Germination
The germinability of seeds was determined by using the filter paper method (ISTA, 2004). One hundred and fifty seeds in eight replications were placed between two layers of moist germination papers with the help of counting board. The germination papers were then rolled carefully without disturbing the position of seeds. They were then wrapped in a sheet of wax paper to reduce the surface evaporation of moisture from germination papers and placed in germinator chambers at 25°C in an upright position. After eight days, germinated seeds were evaluated for normal seedlings, abnormal seedlings and dead seeds. The result of the germination test was calculated as the average of four 100 seed replicates (sub-replicates of 50 seeds were combined into 100 seeds replicates) and was expressed as percentage by number of normal seedlings.
Number of Normal Seedlings
Percentage of seed germination= X 100
Total Number of Seeds
Seeds coated with poly ethyl methacrylate (PEM) and PEM+ azadirachtin-A have shown significantly higher germination (95%) over the other treatments and the

lowest germination was observed in the non-coated seeds (89%). The seeds coated with poly ethyl methacrylate, gum acacia, ethyl cellulose, hydroxy ethyl cellulose, poly vinyl acetate, poly vinyl chloride, poly vinyl pyrollidone either alone or in combination with azadirachtin-A have improved the germination percentage over the uncoated seeds.
Seed Vigour
Vigour of the coated seeds was assessed based on germination percentage; seedling length and seedling dry weight as suggested by Abdul-Baki and Anderson (1973).
Vigour Index
Seedlings used for recording seedling length from each replication were subsequently dried in oven at 90°C for 24 hours after removing the seeds and the dry weight was expressed in mg per five seedlings. In the thus obtained seedling dry weight and germination percentage were used to calculate the Vl2 using the following formula:
Vigour lndex2 = Germination (%) X Seedling dry weight (mg)
Over six months of storage, seed vigour reduced drastically in case of control from 20116 to 12261. But seeds coated with polymer and polymer + azadirachtin-A combinations have retained better seed vigour well above that of control even after six months of storage. In each month of storage, statistical analysis revealed the significant differences for seed vigour over uncoated and coated seeds. Among the different polymers, the seeds coated with poly ethyl methacrylate maintained high seed vigour in each month of storage followed by poly vinyl acetate and poly vinyl pyrollidone. Similarly, seeds coated using poly ethyl methacrylate combined with azadirachtin-A have shown significantly higher seed vigour index at each month of storage over all other coated and uncoated seeds.

Field emergence
Fifty coated seeds were assessed for field emergence by sowing the seeds in earthen pot and the number of seedlings emerging eight days after sowing was observed. The percentage seedlings emerged eight days after sowing was calculated using the following formula:
(Formula Removed)
Total number of seeds sown Field emergence tests were carried out at bimonthly intervals. The emergence reduced from 75.33 to 52.00 % over a period of six months. Seeds coated with polymers and polymers with azadirachtin-A showed significantly higher field emergence during each month of storage. Here also the seeds coated with poly ethyl methacrylate showed the maximum field emergence (>70%).
Determination of Seed Health
During the entire storage period, seed health was assessed following the standard blotter method (ISTA 1999) at one-month interval. For each treatment hundred seeds were used during the different storage intervals. Twenty seeds each were placed in plastic petri plates of 15 cm diameter containing a layer of three well-moistened blotters. These plates were then incubated at 20 ± 2°C temperature under an alternating cycle of 12 hours darkness and 12 hours light of near Ultra Violet (NUV) for seven days. After incubation, the seeds were examined under stereo binocular microscope for the presence of associated mycoflora and number of seeds showing the fungal infection were counted and expressed in percentage as follows:
(Formula Removed)
The identity of mycoflora was confirmed with the aid of compound microscope, referring to pertinent literature.
Eight different storage fungi have been observed in this experiment in which Alternaria alternata was the predominant one. During six months of storage, the infected seeds increased rapidly from 17 to 41.66 % in control compared to the coated seeds. During initial months, the azadirachtin-A treated seeds showed no fungal infection, along with THIRAM 75 DS. However over a period of six months further proliferation of storage fungi was observed though it was lesser in comparison to control.
Present investigations revealed that the polymer coated seeds in general deteriorate at slower pace when compared to control that has been manifested in high germination percentage over control (Tables 2, 3 and 4). This is mainly because the coated seeds maintain high vigour due to slower deterioration compared to control. The polymer coats acted as moisture barriers and checked the degradation of Azadirachtin-A. Apart from this, the polymer coatings also prevent proliferation of storage fungi over the period of storage. Among all the polymers tested, poly ethyl methacrylate, poly vinyl acetate and poly vinyl pyrrolidone were found to be significantly superior (P = 0.01) in maintaining the soybean seed quality. On perusal of correlation matrix (seed germination, seed vigour, seed moisture and azadirachtin-A), it was observed that the azadirachtin-A has significant positive correlation with seed germination (0.8776), seed vigour (0.7240) and negative correlation (-0.7368) with moisture content of seed.

Table 2. Effect of polymer coats on germination, field emergence, infected seeds and vigour of soybean seed after 6 months.
(Table Removed)

Means with the same letter are not significantly different
Table 3. Effect of polymer and azadirachtin-a coats on germination, field emergence,
infected seeds and vigour of soybean seed.
(Table Removed)
Means with the same letter are not significantly different

Table 4. Correlation between azadirachtin-A and various seed quality parameters.
(Table Removed)
Literature cited
1. Asrar, J., Essinger, Jr. and James F. (2005) Controlled release formulations and methods for their production and use. US patent No. 6858634.
2. Barlett, D.H. (1994) Review of current and future seed treatment usage in oilseed rape. In Seed Treatment: Progress and Prospects Mono. 57, BCPC, Thornton Health, UK. 159-168 p.
3. Carter, C.G., Hull, Jr., Luthra, N.P. and Walter, J.F. (1991) Storage stable azadirachtin formulation. US patent No. 5001146.
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13. Kumar, J., Chalapathi Rao, N.B.V., Singh, V.S. and Parmar, B. S. (2003) Field appraisal of controlled release formulation of phorate against the rice leaf folder, Cnaphalocrocis medinalis (Guenee). Annals PI. Prot. Sci., 11 (1): 129-133.
14. Lee-SheongChun; Chung-DhunHwa; Kim-JinHee, Song-Dong Seog; Lee, Sc, Chung, C.H., Kim, J.H. and Song, D.S. (1996) Effects of polymer coating on seed vigour in rice. Korean J. Crop Sci., 41(3): 274-285.
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We claim,
1. The polymeric seed coats characterized in that a polymer matrix comprising either of alkyl acrylates; polyethylene glycols and derivatives; polyvinylpyrrolidones; polyvinyl chlorides; cellulose or starch or their derivatives, wood rosin, gums or the likes, or mixtures of either two or more polymers, derivatives of polymers, polymer clay adducts or their combinations is employed, without or with 0.01 to 10 percent of a biopesticide incorporated in the matrix by dry blending or employing polar or / and non-polar solvents or blends of polar / non-polar solvents and a need based addition of 0.05 to 10 percent of surfactants to obtain a homogeneous powder or slurry , providing seed coats at 0.1 to 5 percent(seed basis) of the polymer alone or the polymer containing monolithically dispersed 0.01 to 10 percent of the bioactive ingredient for situation specific sustenance of seed quality or active ingredient release.
2. The polymeric seed coats as claimed in claim 1 wherein the polymer matrix is either of alkyl acrylates such as poly(methacrylate), poly(methylmethacrylate), poly(ethylmethacrylate), methylmethacrylate or ethylmethacrylate copolymers with other unsaturated monomers; poly(ethylene) glycols and derivatives; polystyrene; poly(vinyl) pyrrolidones; poly(vinyl) chlorides; poly(vinyl) acetate polymers and copolymers; poly(vinyl) alcohols; cellulose or its derivatives such as methyl cellulose, carboxymethyl cellulose( CMC), ethyl cellulose, hydroxyethyl cellulose, cellulose acetate, cellulose acetatebutyrate; starch and its derivatives such as starch xanthate. starch adduct; wood rosin; gums such as guar, acacia, tragacanth; or mixtures of two or more polymers, derivatives of polymers, polymer clay adducts or their combinations.

3. The polymeric seed coats as claimed in claims 1 and 2 wherein the polymer clay adducts are exemplified by CMC-kaolinite, CMC- Fuller's earth, CMC bentonite and the likes.
4. The polymeric seed coats as claimed in claim 1 wherein the biopesticides are exemplified by pesticides of biological origin, more particularly the botanicals, either in crude form ( leaves, seeds, kernels, their extracts and the likes ) or in pure form as exemplified by the pure bioactive ingredients such as neem
meliacins (azadirachtins. salannin, nimbin or others) or non meliacins, or bioactive ingredients from other plants, their derivatives, and the likes.
5. The polymeric seed coats as claimed in claim 1 wherein incorporation of the bioactive ingredient(s) in the polymer matrix at 0.01 to 10 percent, mass by mass, is achieved by dry blending as exemplified by the use of laboratory mixer, ball mill, blender cum pulverizer and the likes or by employing solvents such as polar solvents as exemplified by methanol, ethanol, isopropyl alcohol, n-propanol, sec-butanol. t-butanoi, acetone, methyl ketone, methyl isobutyl ketone,water and the likes, or non-polar solvents as exemplified by n-hexane, aromax, cyclohexanone, ceenine, iso-octane. ethyl acetate, dichloromethane, chloroform and the likes or blends of polar or/and non-polar solvents.
6. The polymeric seed coats as claimed in claim 1 wherein the surfactants employed to impart properties of suspension, dispersion, emulsification, sticking and the likes to the homogeneous powder or slurry are anionics as exemplified by alkyl sulphates, alkyl ether sulphonates or sulphates, alkyl aryl sulphonates or sulphosuccinates, preferably naphthalene sulphonate, lignosulphonate, the amine salt of dodecyl benzene sulphonic acid, a salt of dioctyl sulphosuccinate, a salt of lauryl sulphate or a salt of the ethoxylated alcohol half ester sulphosuccinic acid; or non-ionics as exemplified by linear or branched ethoxylated alcohols, ethoxylated alkylphenols, block copolymers of ethylene oxide and propylene oxide, and the likes, preferably the non-ionic surfactants containing between 3-40 ethylene oxide repeat units and a hydrophobic moiety which may be linear or branched C. sub. 11- C sub. 15 secondary alcohols, nonylphenol or octylphenol, or block copolymers of ethylene oxide or propylene oxide, or the blends of ionics or/and non-ionics, in the ratio of 1:9 to 9:1, incorporated in the seed coats at 0.05 to 10 percent, mass by mass.
7. The polymeric seed coats as claimed in claim 1 wherein the seed coats comprise either the polymer alone, at 0.1 to 5 percent, seed basis, or with the auxiliaries, or the polymer containing monolithic dispersions of the biopesticide alone, at 0.01 to 10 percent of the biopesticide, polymer basis, or along with the auxiliaries, as homogeneous powder or slurry for application on seeds as such or after appropriate dilution, with a need based utilization of the various application aids.
8. The polymeric seed coats as claimed in any of the above claims and exemplified in the body of the application for use in treatment of agricultural crops like cotton, corn, soybean, sugar beet, bean, tomato, potato, tobacco, rice, wheat, sunflower, the brassica family, the Solanaceae family, sorghum, barley, lentils, melons, cucumber or any other similar crop for situation specific sustenance of seed quality, active ingredient release, protection against various pathogens and other pests during storage of the seed or on its cultivation in field, with improvement in viability, germination, plantability, storability of the genetic material

Documents:

1746-DEL-2006-Abstract-(24-12-2008).pdf

1746-del-2006-abstract.pdf

1746-DEL-2006-Claims-(11-11-2010).pdf

1746-del-2006-Claims-(24-05-2010).pdf

1746-DEL-2006-Claims-(24-12-2008).pdf

1746-del-2006-claims.pdf

1746-DEL-2006-Correspondence-Others-(02-06-2010).pdf

1746-DEL-2006-Correspondence-Others-(24-05-2010).pdf

1746-DEL-2006-Description (Complete)-(24-12-2008).pdf

1746-del-2006-description (complete).pdf

1746-del-2006-form-1.pdf

1746-del-2006-form-18.pdf

1746-DEL-2006-Form-2-(24-12-2008).pdf

1746-del-2006-form-2.pdf

1746-DEL-2006-Form-3-(24-12-2008).pdf

1746-DEL-2006-Others-Document-(24-12-2008).pdf

1746-delnp-2006-Correspondence-Others-(11-11-2010).pdf


Patent Number 244542
Indian Patent Application Number 1746/DEL/2006
PG Journal Number 51/2010
Publication Date 17-Dec-2010
Grant Date 10-Dec-2010
Date of Filing 31-Jul-2006
Name of Patentee INDIAN COUNCIL OF AGRICULTURAL RESEARCH
Applicant Address KRISHI BHAWAN, DR. RAJENDRA PRASAD ROAD, NEW DELHI - 110001
Inventors:
# Inventor's Name Inventor's Address
1 DR. JITENDRA KUMAR DIVISION OF AGRICULTURAL CHEMICALS, INDIAN AGRICULTURAL RESEARCH INSTITUTE, NEW DELHI-110012
2 MR. NISAR KEYATH DIVISION OF AGRICULTURAL CHEMICALS, INDIAN AGRICULTURAL RESEARCH INSTITUTE, NEW DELHI-110012
3 DR. SURESH WALIA DIVISION OF AGRICULTURAL CHEMICALS, INDIAN AGRICULTURAL RESEARCH INSTITUTE, NEW DELHI-110012
4 DR. BALRAJ SINGH PARMAR DIVISION OF AGRICULTURAL CHEMICALS, INDIAN AGRICULTURAL RESEARCH INSTITUTE, NEW DELHI-110012
5 DR. ARUN KUMAR MADURAI BASAPPA DIVISION OF AGRICULTURAL CHEMICALS, INDIAN AGRICULTURAL RESEARCH INSTITUTE, NEW DELHI-110012
PCT International Classification Number A01C1/06
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA