WO2013126874A2

WO2013126874A2 - Seed coating composition and related methods

Info

Publication number: WO2013126874A2
Application number: PCT/US2013/027605
Authority: WO
Inventors: Trias JOSEP
Original assignee: COATING SUPPLY Inc
Current assignee: COATING SUPPLY Inc
Priority date: 2012-02-24
Filing date: 2013-02-25
Publication date: 2013-08-29
Anticipated expiration: 2014-08-24
Also published as: WO2013126874A3

Description

SEED COATING COMPOSITION AND RELATED METHODS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This claims the benefit of U.S. provisional Application No. 61/602,753, filed February 24, 2012 and titled "Composition and Method for Repairing or Alleviating Damage to Seed Pericarp, " which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The invention relates to seed coatings and, more particularly, to seed coatings that inhibit water penetration into seeds.

BACKGROUND

[0003] Many seeds are susceptible to being damaged during harvesting and processing. The thickness and quality of the seed pericarp often varies with the location of the production area, fertilization, chemicals, level of irrigation, crop density, genetically based variations, harvesting environment, post harvesting handling, resulting in different levels of seed pericarp thickness and/or partially perforated seed pericarps that will interfere with the natural rate of imbibition and permeability to water and air prior to or during the germination process .

[0004] Seed imbibition is primarily controlled by the seed pericarp and seed membranes. The control mainly covers the speed of imbibition, the degree of permeability to air and water, susceptibility to external disease infections, parasites, response to the pesticides used, shelf life and the physiological performance of the seed before or during germination. Also the seed pericarp and seed membrane controls seedling vigor, stand establishment and the final number of useful plants. When the seed pericarp is damaged the seed's ability to control imbibition and the other functions mentioned above is diminished according to the degree of damage.

SUMMARY

[0005] In view of the foregoing, the inventor has developed a seed coating composition comprising a fluorosilane solution that may be used to regulate the amount of water that permeates into plant propagules to which it is applied by forming a hydrophobic layer over at least a portion of the plant propagule. This is particularly advantageous for use on damage prone seeds and/or on seeds planted in flood prone areas.

[0006] In a first embodiment of the invention, a method of coating plant propagules comprises blending plant propagules with a coating composition comprising a fluorosilane solution and drying the fluorosilane solution to form a hydrophobic layer around the plant propagules. The hydrophobic surface may comprise a material selected from the group consisting of hexamethyldisilazane, dimethyldichlorosilane, polydimethylsiloxane, and a combination thereof.

[0007] In a second embodiment of the invention, a method of reducing water permeability of a pericarp of a seed comprises coating at least a portion of the seed with a coating composition comprising a fluorosilane solution and allowing the fluorosilane solution to dry to form a hydrophobic layer over the coated portion .

[0008] In certain embodiments, the coating composition further comprises fumed silica having a hydrophobic surface.

[0009] In certain embodiments, these methods may further comprise, at least partially coating the plant propagules with fumed silica having a hydrophobic surface prior to blending the plant propagules with the fluorosilane solution. In some case, drying the fluorosilane solution to form a hydrophobic layer around the plant propagules produces a fluorosilane film around the fumed silica coating.

[0010] In certain embodiments, coating the plant propagule with the coating composition comprising the fluorosilane solution is achieved by spraying the fluorosilane solution about the plant propagule .

[0011] In certain embodiments, the fluorosilane solution is aqueous .

[0012] In certain embodiments, the fluorosilane comprises fluorinated alkyl groups attached to at least some of the Si atoms .

[0013] In certain embodiments, the fluorosilane solution comprises ethyl cellulose and water.

[0014] These and other objects, aspects, and advantages of the present invention will be better appreciated in view of the following detailed description of preferred embodiments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0015] In the Summary above and in the Detailed Description of Preferred Embodiments, reference is made to particular features (including method steps) of the invention. Where a particular feature is disclosed in the context of a particular aspect or embodiment of the invention, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects and embodiments of the invention, and in the invention generally.

[0016] The term "comprises" is used herein to mean that other ingredients, features, steps, etc. are optionally present. When reference is made herein to a method comprising two or more defined steps, the steps can be carried in any order or simultaneously (except where the context excludes that possibility) , and the method can include one or more steps which are carried out before any of the defined steps, between two of the defined steps, or after all of the defined steps (except where the context excludes that possibility) .

[0017] In this section, the invention will be described more fully with reference to certain preferred embodiments. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey preferred embodiments of the invention to those skilled in the art.

[0018] The method aspects of the invention generally involve the use of a coating composition that includes a fluorosilane solution that, when dry, forms a hydrophobic layer over the material it is used to coat. When used to coat plant propagules, such as seeds or any other plant material used to propogate plants, the hydrophobic layer inhibits the flow of water into the plant propagule. This is particularly advantageous for seeds that are often damaged during processing or are genetically prone to being damaged, which prevents them from being able to regulate how much water reaches the embryo. As a result, damaged seeds often become useless due to hypoxia or anoxia, lowering of the final germination, and/or decreasing germination under water or heat stress. The hydrophobic layer, in effect, replaces the damaged portion of the plant propagule with a material that inhibits water from infiltrating the seeds too quickly or with too much volume.

[0019] Fluorosilane is a silane compound that includes one or more fluorine functional groups bound thereto. Suitable fluorosilanes include those having at least one triamino group of the general formula shown in Formula la

[NH_x(CH₂)_aNH_y(CH₂)_bNH_z]- (la) where the triamino group is bound to at least one silicon atom via at least one further N— attached alkylene group having 1 to 4 carbon atoms. Here a and b may be identical or different and are an integer from 1 to 6, x is 0 or 1 or 2, y is 0 or 1, z is 0 or 1 or 2, with the proviso that (x+y+z)<4. At least one Si—C— attached fluoroalkyl having Formula lb

F₃C(CF₂)_r(CH₂)_s - (lb), in which r is an integer from 0 to 18 and s is 0 or 2 is attached. These organosiloxanes are described in additional detail in U.S. Patent No. 8,101,682, which is incorporated by reference in its entirety.

[0020] Thes organosiloxanes are capable of forming oligomeric and polymeric organosiloxane units to form aggregates.

[0021] Other suitable fluorosilanes include fluoroalkyl- functional organopolysiloxanes having Formula III

RO[Si(A) (CH₃)_z (OR) i-_zO]_a[Si (B)R²)_y(OR) j__y

0]i,[Si(C) (CH₃)0]_c[Si(D) (OR)0]_d(HX)_e (I)

which A is an aminoalkyl radical derived from Formula II

(H₂N (CH₂) _f (NH)_g(CH₂)¾Si (OR) 3-z(CH₃) _z (II)

where 0<f<6, g=0 if f=0 and g=l if f>0, 0<h<6, and 0≤z<l, and B is a fluoroalkyl radical derived from Formula III

R¹-Y_1B-(CH₂)2Si(R2)y(OR)₃-_y (III)

R¹ being a mono-, oligo- or perfluorinated alkyl group having 1 to 9 carbon atoms or a mono-, oligo- or perfluorinated aryl group, Y being a CH2-, 0-, or S group, R² being a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms or an aryl group, m being 0 or 1 and 0<y<l, and C is an alkyl radical derived from Formula IV

R-Si (CH₃) (OR) 2 (IV)

and D is likewise an alkyl radical, but derived from Formula V R³-Si(0R)₃ (V)

R³ in the above formulae being a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, R³ in the above formulae being identical or different at each occurrence, R in the above formulae being a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms or an aryl group, and R in the above formulae being identical or different at each occurrence, and HX being an acid, X being an organic or inorganic acid radical, and 0<y<l, 0<z≤l, a>0, b>0, c>0, d≥0, e>0 and (a+b+c+d) >2.

[0022] Also suitable are oligomerized organopolysiloxane cocondensates obtainable by mixing an organosilane having Formula II, in which f is 0 or an integer from 1 to 6, g is 0 if f is 0 and g is 1 if f is other than 0, h is an integer from 1 to 6, z is 0, 1 or 2, and the remaining radicals are as defined above, with a fluoro-functional organosilane having Formula III, in which y is 0 or 1, and/or with at least one organosilane of Formula IV and/ or one organosilane of Formula V, in a molar ratio M= [a/ (b+c+d) ] >0.1, a being the sum of the numbers of moles of organosilanes of Formula II, b, if appropriate, being the sum of the numbers of moles of organosilanes of Formula III, c, if appropriate, being the sum of the numbers of moles of organosilanes of Formula IV, and d, if appropriate, being the sum of the numbers of moles of organosilanes of Formula V; adding water or an acid, and an alcohol, if desired, to the mixture; and carrying out oligomerization.

[0023] Some preferred organosiloxanes include hydroxyl groups and/or alkoxy groups as further functionalities. The presence of hydroxyl and/ or alkoxy groups can generally be controlled by way of the amount of water supplied during preparation and the completeness of the removal of alcohol. Furthermore, the organosiloxanes of the invention can also include alkyl groups having 1 to 16 carbon atoms.

[0024] A thickener may be added to the fluorosilane solution. Preferably, the thickener is a polymeric or cellulosic material. Preferred thickeners include, but are not limited to ethylcelluloses, such as hydroxyethylcelluloses .

[0025] The fluorosilane solution preferably also includes a solvent. Water is particularly preferred, but other solvents may also be used. Suitable solvents include those will dissolve the fluorosilane and the thickener Examples of other solvents organic solvents such as alcohols, for example. Combinations of water and other solvents may also be employed.

[0026] A preferred source of fluorosilane is PROTECTOSIL® ANTIGRAFFITI® which is commercially available from Evonik Degussa .

[0027] In certain embodiments of the invention, the coating composition also includes fumed silica that has been surface functionalized to render it hydrophobic. Preferred materials attached to the fumed silica surfaces to render them hydrophobic include hexamethyldisilazane, dimethyldichlorosilane, and polydimethylsiloxane and a combination thereof. Hydrophobic fumed silica is used to enhance the hydrophobicity of the seed coating relative to the when the fluorosilane is used alone. Preferred fumed silica sources include CAB-O-SIL® TS-530, TS-610, and TS-720, which are commercially available from Cabot, Corp.

[0028] A portion of the coating composition, if desired, may also include magnesium stearate or other stearates or laureates. Magnesium stearate is a conventional water repellant used in seed coatings .

[0029] The coating composition may further comprise one or more biologically active ingredients such as fertilizers, fungicides, insecticides, biocides, herbicides, growth promoters, hormones, markers or combinations thereof.

[0030] As non-limiting examples, the following are a list of biologically active ingredients that may be used in the coating composition: disulfoton, Fipronil, Clothiamidin, Lindane, Methiocarb, Fipronil, Phoxim, Bendiocarb, Benfuracarb, Diazinon, Iraidacloprid, Furathiocarb, Isazofos, Thiametoxam, Pirimiphos- raethyl, Acephate, Thiacloprid, Fosthiazate, Cyfluthrin +

Imidacloprid, Terbufos, Dimethoate, Cypermethrin+Thiamethoxam, Methamidophos, Methaldehide, Vamidothion, Carbosulfan, Methomyl, Monocrotophos , Bitertanol, Carboxin, Diniconazole, Ethirimol, F500/Bosaliol, Fenitropan, Fenpiclonil, Fludioxonil , Flutriafol , Fuberidazole, Guazatine, Hexaconazole, Imazadil/Imazalil ,

Iminoctadine, Iprodione, Methfuroxam, Nuarimol, Niclosamid, Oxine Copper, Thiodicarb, Oxycarboxin, Quintozene, Tebuconazole , Tetraconazole, Thiabendazole, Triadimenol , Fludioxonil ,

Triticonazole, Etridiazole, Metalaxyl, Pencycuron, Methyl Tolclofos, Thiram, Benalaxyl, Captan, Tritosulfuron,

Oxadixyl/Oxydixyl , Tolciofos-methyl , Validamycin,

Hymexazol, Oxolinic acid, Tefluthrin, Tebupirimfos , Pefurazoate, Pyroquilon, Tecloftalam, Propamocarb, Trifumizole, Triflumizole, Fosetyl cyproconazole, Carboxin+thiram, Cartboxin+thiran, acibenzolar-S-methyl , disulfoton + triadimenol, acibenzolar-S-methyl , carbendazim + chlorothalonil , metconazole, cartap, thiophanate-methyl , chlorothalonil + thiophanate-methyl, bromuconazole , fenpropimorph, cymoxanil + mancozeb, carbendazim + thiram, mancozeb + thiophanate-methyl, cymoxanil + famoxadone, chlorothalonil + metalaxyl-M, pyroquilon, dimethomorph, benalaxyl + mancozeb, kasugamycin, oxycarboxin, flutriafol, propiconazole, quintozene, imibenconazole, fludioxonil + metalaxyl-M, epoxiconazole+ pyraclostrobin, epoxiconazole, fluquinconazole, oxycarboxin, triticonazole, fenarimol, triforine, difenoconazole , flutriafol, propiconazole + trifloxystrobin, kresoxim-methyl thiabendazole, triflumizole, cyprodinil, procymidone, propiconazole + trifloxystrobin, kresoxim-methyl , thiabendazole, triflumizole, cyprodinil, flutriafol, and combinations thereof.

[0031] Also, a combination of fungicides and insecticide-like products may be used in the coating composition. Examples include FarMore D200 (Mefenoxam and Fudioxinil) , Captan (N- trichloromethyl thio-4-cyclohexane-l, 2-dicarboximide) , Thiram

(Proseed), FarMore D300 (Azoxystrobin, Mefenoxan and Fluidioxomil) or FarMore DI 400 (Thiamethoxam, Azoxystrobin, Methenoxam and Fludioxomil) from Harris Moran, or combinations of F500 (as Headline or Opera) and Bosalid, Tritosulfuron, Metalaxyl, Chlorfenapyr, Dimoxystrobin, Metrafenone, Orystrobin, Topramezone and Metaflumizone from BASF alone or combined with StompAqua (Prowl H20) . The Serenade or Serenade Max line also from BASF, is also possible to use. Spinosad and Cruiser (both from Syngenta) as FarMore FI500 seed treatment can also be added, also Maxim ( Fludioxonil+Mefonoxam) , Dividend 3FS

(difenoconazole) , Apron (Mefonoxan) , Rovral (carbendazime iprodione) , all alone or combined to up to concentrations of about 10 % w/w.

[0032] As non-limiting examples, the following are a list of biocides that may be used in the coating composition: hypochlorite, chlorine and chlorine gas, methicillin, tetracyclins, ampicillins, penicillins, hydantoin, hypochlorous acid, sodium dichloro-s-triazinetrione, trichloro-s- triazinetrione, copper alloys, vircon, hydrogen peroxide, oxolinic acid, ammonia, or herbicides such as Roundup.

[0033] As non-limiting examples, the following are a list of growth promoters that may be used in the coating composition: Ethephon, Ethrel, Ethylene, Humic Acid, Polypeptides, Amino acids, Alginates, Peat Most, Potassium Nitrate, chelates, Magnesium Suphate, macro and micro plant nutients and fertilizer. [0034] As non-limiting examples, the following are a list of hormones that may used in the coating composition: Gibberilic Acid, kinetin's, Naphthalene-Acetic Acid, Cytokinin, Ethylene, Abscise Acid, Auxins, Indole Butyric Acid, or combinations thereof .

[0035] As non-limiting examples, the following are a list of markers that may be used in the coating composition: one or more of Rhodamine, Diazonium salts, Anthraquinone , Coumarin, Thriphrnylmethane, phthalocyanine, natural and artificial nanoparticles, or pigments, including mica pigments.

[0036] In certain embodiments the coating composition includes seed pelleting materials such as a seed pelleting powder. Preferably, the seed pelleting powder includes one or more inert materials with at least one of the inert materials having a high surface area. Suitable materials for the seed pelleting powder include, but are not limited to: clays, diatomaceous earth, perlite, pumice, quartz, talc, bentonite, mica, metal stearate, metal laureates, metal palmitates, metal saturated fats, silica fumed, smectite, montmorillonite, feldspars, kaolin, antifoaming agents, glycerin, alcohols, silicone, carbonates, zeolites, fertilizers, harpins, wood powder, glass spherules, starch, cellulose, or combinations thereof. A particularly preferred seed pelleting powder CS-MJ-01 made with perlite, diatomaceous earth, mica, and silica quartz from Coating Supply, Inc., Palm City FL., which can be purchased from. CS-MJ-01 is commercially available from Coating Supply, Inc, 8010 SW Jack James Drive, Stuart, Florida 34997.

[0037] The relative concentrations of the ingredients in the coating composition will depend on the type of plant propagule, severity of damage to the plant propagule, and typical environment in which the plant propagule is planted. This is because the hydrophobicity of the seed coating composition should be engineered to allow enough water to penetrate the plant propagule so that a plant will grow therefrom, but will prevent too much water from penetrating into the plant propagule, causing anoxia or hypoxia. The water permeability of the coating composition is adjusted by including more or less of the fluorosilane solution and, if used, fumed silica. More of either results in a more hydrophobic or more water impermeable coating.

[0038] In accordance with a first method aspect of the invention, a method of coating plant propagules comprises blending plant propagules with a coating composition comprising a fluorosilane solution and drying the fluorosilane solution to form a hydrophobic layer around the plant propagules. The hydrophobic layer advantageously inhibits the flow of water past the exterior surface of the plant propagule into the plant propagule, but allows enough water to penetrate the plant propagule to allow plant to grow therefrom. Accordingly, the hydrophobic layer is preferably somewhat water permeable.

[0039] There are various conventional blending means that may be used. These include combining the fluorsilane solution and plant propagules together in a container and co-agitating them so that the fluorsilane solution substantially coats all of the individual plant propagules. The fluorsilane solution can be poured into the container and mixed with the plant propagules or be sprayed onto the plant propagules. A preferred blending means includes mixing the plant propagules and fluorosilane solution together in a rotary seed coating machine.

[0040] In certain embodiments, the first method aspect of the invention further comprises at least partially coating the plant propagules with fumed silica having a hydrophobic surface prior to blending the plant propagules with the fluorosilane solution. In such embodiments drying the fluorosilane solution to form a hydrophobic layer around the plant propagules typically produces a fluorosilane film around the fumed silica coating. In this case the fumed silica coating forms an interior coating layer around the plant propagule and the dried fluorosilane solution forms an exterior film layer about the fumed silica coating layer. Also in such embodiments, it is preferred to first coat the plant propagule with the fumed silica coating, with or without other coating composition materials, and then spray the fluorosilane solution over the coated plant propagule. This allows the fluorosilane solution to form a thin film about the plant propagule .

[0041] Alternatively, the fumed silica material and fluorosilane solution are combined and mixed with the plant propagules at the same time, such that the flourosilanes are distributed throughout the coating composition.

[0042] The fumed silica employed in this method aspect has, as described above, a hydrophobic surface, that preferably includes a material selected from the group consisting of hexamethyldisilazane, dimethyldichlorosilane, polydimethylsiloxane, and a combination thereof.

[0043] As discussed above, the fluorosilane solution used in this method preferably includes fluorinated alkyl groups attached to at least some of the Si atoms. The fluorosilane solution may also include an ethylcellulose based thickener and water. The ethylcellulose based thickener is particularly advantageous as it helps the fluorosilane solution form a film when dried.

[0044] In accordance with a second method aspect of the invention, a method of reducing water permeability of a pericarp of a seed comprises coating at least a portion of the seed with a coating composition comprising a fluorosilane solution and allowing the fluorosilane solution to dry to form a hydrophobic layer over the coated portion. The fluorosilane solution in this second method aspect of the invention is as described in connection with the first method aspect of the invention. Namely, it may be aqueous and may include fluorinated alkyl groups attached to at least some of the Si atoms. Also, the fluorosilane solution used in this method may include fluorinated alkyl groups attached to at least some of the Si atoms. The fluorosilane solution may also include an ethylcellulose based thickener and water.

[0045] There are various conventional coating means that may be used. These include combining the fluorsilane solution and seeds together in a container and co-agitating them so that the fluorsilane solution substantially coats all of the individual seeds. The fluorsilane solution can be poured into the container and mixed with the seeds or be sprayed onto the plant propagules . A preferred coating means includes mixing the seeds and fluorosilane solution together in a rotary seed coating machine. Alternatively, the fumed silica material and fluorosilane solution are combined and mixed with the plant propagules at the same time, such that the flourosilanes are distributed throughout the coating composition.

[0046] In certain embodiments, the method of reducing water permeability of a pericarp of a seed also includes coating the seed with a fumed silica composition comprising the fumed silica having a hydrophobic surface. As previously described, the hydrophobic surface may include a material selected from the group consisting of hexamethyldisilazane, dimethyldichlorosilane , polydimethylsiloxane, and a combination thereof. In a more particular embodiment, the seed is coated the seed with the fumed silica composition having a hydrophobic surface, wherein the fluorosilane comprises fluorinated alkyl groups attached to at least some of the Si atoms.

[0047] In certain embodiments, the second method aspect of the invention further comprises at least partially coating the seeds with fumed silica having a hydrophobic surface prior to blending the seeds with the fluorosilane solution. In such embodiments drying the fluorosilane solution to form a hydrophobic layer around the seeds typically produces a fluorosilane film around the fumed silica coating. In this case the fumed silica coating forms an interior coating layer around the seed and the dried fluorosilane solution forms an exterior film layer about the fumed silica coating layer. Also in such embodiments, is preferred to first coat the seeds with the fumed silica coating, with or without other coating composition materials, and then spray the fluorosilane solution over the coated seeds. This allows the fluorosilane solution to form a thin film about the seeds .

[0048] In any of the method aspects of the invention in which drying is involved, drying may be achieved by any conventional drying means, such as heating, using compresses gas, or simply by allowing sufficient time to dry in the ambient atmosphere. Some suitable drying processes are provided in the examples section, but those particular drying processes are, in no way, the only ones that may be used.

EXAMPLES

[0049] The following examples are provided for the purpose of illustration and do not limit the scope of the invention in any way .

[0050] The experiments were performed to determine whether coating seeds with a coating composition including a fluorsilane solution would regulate movement of water into the seed and alleviate the level of damage to a specific seed lot. Several trials were conducted on different crops, with different levels of damage and with different water repellent materials.

Example 1 : Corn Seeds [0051] Corn seed of a variety used for the Mexican market was chosen because it is susceptible to mechanical damage. As a result, it is often poor or insufficient when sowing in Mexico in lowland areas that are frequently exposed to flooding during the sowing season. The chosen seed was tested under the standard corn ISTA germination test. An additional test was made to verify the germination and U.T. (U.T. = Usable Transplants) under a hypoxic environment by exposing the seed for 24, 36, 48 and 72 hours periods to a fully submerged water environment, followed by transferring the wet seeds to germination testing paper for an ISTA rules germination test.

[0052] For these experiments corn seed was either manually extracted from the corn cob very gently to minimize damage to the pericarp or industrially extracted from the corn cob to mimic typical processing conditions.

[0053] The following samples were applied (per kg to the seeds .

• Cocktail A 1: 3 gram slurry of CAB-O-SIL ® TS530 mixed with 3 mL of methanol;

• Cocktail A2 : 3 gram of magnesium stearate with 3 mL of

methanol ;

• Cocktail A3: 9 grams of PROTECTOSIL® ANTIGRAFFITI® mixed with 0.25 gram of rhodamine pigment;

• Cocktail Bl : 3 gram slurry of CAB-O-SIL ® TS530 mixed with 3 mL of methanol, 1 gram of Poncho, 0.5 grams of binder (polyvinyl alcohol), 0.5 grams of TMTD (Thiram) , and 0.5 grams of Rhodamine; and

• Cocktail B2 : a 3 gram slurry of magnesium stearate mixed with 3 mL of methanol, plus 1 gram of Poncho, plus 0.5 grams of binder (polyvinyl alcohol), plus 0.5 grams of TMTD (Thiram,) and 0.5 grams of Rhodamine. [0054] The seeds were coated with each sample in a rotary coating machine and were dried in a fluid bed dryer. The seed sample weight was one kg/sample. The application time was between 45 to 60 seconds, in order to achieve uniformity of the samples. After applying the different cocktails, the corn seed was dried at room temperature without forced air.

[0055] The seeds were tested via a soak test by fully immersing the seeds in water for 24 hours at 20 Celsius. Afterwards, the seeds were tested according by ISTA rules.

[0056] The seeds were also field tested by sowing both treated and untreated seeds in the field, flooding the field with water, then allowing the field to drain. The field temperature average was 23 Celsius. The temperature ranged from a minimum of 12 C at night and a maximum of 27 Celsius during the day.

TABLE 1

Test Results on Corn Seeds

Sample Tested ISTA Test Soak Test Field Test

Control hand extracted 96% 92% 88%

Control industrially extracted 93% 56% 43%

3 g TS-530 powder 94% 71% 76%

3 g. Mg Stearate powder 95% 52% 46%

6 g. cocktail Al 94% 90% 92%

6 g. cocktail A2 95% 84% 88%

9.25 g cocktail A3 98% 94% 90%

8 g cocktail Bl 92% 47% 71%

8 g cocktail B2 95% 52% 52%

[0057] These results show that the coating compositions including fumed silica (CAB-0- ^•SIL ® TS- ^■530) and fluorosilane solution (PROTECTOSIL® ANTIGRAFFITI®) clearly performed much better than those containing the conventional water repellant material, magnesium stearate.

Example 2 : Tomato Seeds

[0058] Tomato seed of the Florida variety was tested in these experiments. Materials used included CAB-O-SIL ® TS530 as the fumed silica source, PROTECTOSIL® AN T I G RA F F I T I ® as the fluorosilane solution source, magnesium stearate, TMTD (Thiram) , CS-MJ-01, polyvinyl acetate (100 mL/liter of solution), polyvinyl alcohol (90 gr/liter of solution) and water. The CAB-O-SIL ® TS530 was mixed with CS-MJ-01 at a rate of 4.5% wt. In cocktail A, the PROTECTOSIL® ANTIGRAFFITI® was applied as a wetting agent by directly spraying it at rate of 150 mL per kg of coating powder (CS-MJ-01 ) during the pelleting process (total 34 g 1000 seeds) with pre-coating only with water. Cocktail B was prepared in a similar manner, but a pre- coating of PROTECTOSIL® ANTIGRAFFITI® at 50 mL per kg of raw seed was applied before applying the CS-MJ-01 using the PROTECTOSIL® ANTIGRAFFITI® as a wetting agent. In another sample, PROTECTOSIL® ANTIGRAFFITI® at 25 mL per kilogram of raw seed was applied directly to the seeds by spraying. The magnesium stearate was mixed at 4.5% wt with CS-MJ-01. 2.75 to 3.5 mm diameter pellets were made, then dried at 36 Celsius for 2 hours, to a final absolute moisture % of the pellet of 2.0%-2.5% wt, measured by an infrared moisture analyzer.

[0059] The tests were conducted at 25 Celsius, with standard 70% moisture content for the paper test and at 95% water saturated germination paper test (WET) in both tests inside sealed containers. Additional test were conducted on peat moss with similar results.

TABLE 2

Test Results on Tomato Seeds Thermo gradient table germination data 25 C 30 C

after 7 days:

Control 92% 61%

4.5 g TS-530 powder/ kg of seed 96% 75%

4.5 g Mg stearate powder / kg of seed 94% 80%

34 g cocktail A / kg 95% 99%

34 g cocktail B / kg 92% 93%

25 mL of PROTECTOSIL® ANTIGRAFFITI® 96% 92%

[0060] The results show that the seeds coated with the fluorosilane solution outperformed the seeds coated with fumed silica and magnesium stearate.

Example 3 : Lettuce Seeds

[0061] Market available lettuce seeds (Winterhaven) were used in these experiments. CAB-O-SIL ® TS-530 was the source of fumed silica. PROTECTOSIL® ANTIGRAFFITI® was the source of the fluorosilane solution. Other materials used include magnesium stearate, TMTD (Thiram) , FLORS- 18, and water. FLORS-18 is a seed coating powder composed of perlite, diatomaceous earth, silica quartz, and smectites and is commercially available from Coating Supply, Inc., Palm City FL. The CAB-O-SIL ® TS-530 was mixed with FLORS-18 at a rate of 2.5% by weight, the magnesium stearate was mixed at 2.5% by weight with FLORS-18. The PROTECTOSIL® ANTIGRAFFITI® was applied as a wetting agent during the pelleting process at a rate of 50 mL per kg of coating powder using water as pre-coating wetting agent (Cocktail Al) and using PROTECTOSIL® ANTIGRAFFITI® as initial pre-coating wetting agent (Cocktail A2) . In both samples, the final pellet weight was at 36 grams per 1000 pellets. Pellets were also made using water alone (Cocktail A3) .

[0062] Lettuce seeds were coated using a traditional coating pan during the initial coating phase and moved to a rotary seed coater for enlargement for a period of 45 minutes. The final pellet size was 3.0 to 3.5 mm diameter. In all samples 1.2 g of Thiram/TMTD per kg of seed and 50 gram of Imidaclopride per kg of seed was applied during the finishing process of the coating. The pellets were dried for 1.5 hrs in a cabinet dryer at 32-34 Celsius and a final absolute moisture of 1.5%-1.75%, measured using an infrared moisture analyzer.

TABLE 3

Test Results on Lettuce Seeds

Thermogradient table germination data

after 72 hours:

20 C 25 C 30 C

Control - raw seed 99% 92% 58%

1.5 g TS-530 powder/ kg of seed 99% 95% 74%

1.5 g Mg stearate powder / kg of seed 100% 96% 86%

36 g cocktail Al/ kg 97% 99% 95%

36 g cocktail A2 / kg 99% 99% 100%

5 g cocktail A3/ kg (Control pellet) 100% 96% 91%

[0063] These data show that both the CAB-O-SIL ® TS-530, and PROTECTOSIL® ANTIGRAFFITI® and the magnesium stearate performed better at higher germination temperature than the control raw seed on the thermo gradient table, but the seeds coated with the fluorosilane solution outperformed the seeds coated with fumed silica and magnesium stearate.

[0064] The invention has been described above with reference to preferred embodiments. Unless otherwise defined, all technical and scientific terms used herein are intended to have the same meaning as commonly understood in the art to which this invention pertains and at the time of its filing. Although various methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described. However, the skilled should understand that the methods and materials used and described are examples and may not be the only ones suitable for use in the invention.

[0065] Accordingly, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough, complete, and will fully convey the scope of the invention to those skilled in the art. Therefore, in the specification set forth above there have been disclosed typical preferred embodiments of the invention, and although specific terms are employed, the terms are used in a descriptive sense only and not for purposes of limitation. The invention has been described in some detail, but it will be apparent that various modifications and changes can be made within the spirit and scope of the invention as described in the foregoing specification and the appended claims.

Claims

THAT WHICH IS CLAIMED IS:

1. A method of coating plant propagules, the method comprising blending plant propagules with a coating composition comprising a fluorosilane solution and drying the fluorosilane solution to form a hydrophobic layer around the plant propagules.

2. The method of claim 1, further comprising, at least partially coating the plant propagules with fumed silica having a hydrophobic surface prior to blending the plant propagules with the fluorosilane solution.

3. The method of claim 2, wherein drying the fluorosilane solution to form a hydrophobic layer around the plant propagules produces a fluorosilane film around the fumed silica coating.

4. The method of claim 1, wherein the coating composition further comprises fumed silica having a hydrophobic surface.

5. The method of claim 4, wherein the hydrophobic surface comprises a material selected from the group consisting of hexamethyldisilazane, dimethyldichlorosilane, polydimethylsiloxane, and a combination thereof.

6. The method of claim 1, wherein coating the plant propagule with the coating composition comprising the fluorosilane solution is achieved by spraying the fluorosilane solution about the plant propagule .

7. The method of claim 1, wherein the fluorosilane solution is aqueous .

8. The method of claim 1, wherein the fluorosilane comprises fluorinated alkyl groups attached to at least some of the Si atoms .

9. The method of claim 1, wherein the fluorosilane solution comprises ethyl cellulose and water.

10. A method of reducing water permeability of a pericarp of a seed, the method comprising coating at least a portion of the seed with a coating composition comprising a fluorosilane solution and allowing the fluorosilane solution to dry to form a hydrophobic layer over the coated portion.

11. The method of claim 10, wherein the fluorosilane solution is aqueous .

12. The method of claim 10, wherein the fluorosilane comprises fluorinated alkyl groups attached to at least some of the Si atoms .

13. The method of claim 10, further comprising coating the seed with a fumed silica composition comprising fumed silica having a hydrophobic surface.

14. The method of claim 13, wherein the hydrophobic surface comprises a material selected from the group consisting of hexamethyldisilazane, dimethyldichlorosilane, polydimethylsiloxane, and a combination thereof.

15. The method of claim 10, further comprising coating the seed with a fumed silica composition comprising fumed silica having a hydrophobic surface and wherein the fluorosilane comprises fluorinated alkyl groups attached to at least some of the Si atoms .

16. The method of claim 10, wherein coating the portion of the seed with the coating composition comprising the fluorosilane solution is achieved by spraying the fluorosilane solution about the seed.