AU716873B2

AU716873B2 - Process for the preparation of rice seed for sowing

Info

Publication number: AU716873B2
Application number: AU54608/96A
Authority: AU
Inventors: Carla Klittich
Original assignee: Rhone Poulenc Agrochimie SA
Current assignee: Bayer CropScience SA
Priority date: 1995-06-08
Filing date: 1996-05-29
Publication date: 2000-03-09
Anticipated expiration: 2016-05-29
Also published as: ITMI961143A1; PT101877A; IT1283095B1; ITMI961143A0; PT101877B; BR9601799A; AR002412A1; AU5460896A

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S): Rhone-Poulenc Agrochimie ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

INVENTION TITLE: Process for the preparation of rice seed for sowing 0@

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*SO S The following statement is a full description of of performing it known to me/us:this invention, including the best method *5

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4. Z9 The present invention relates to a process for the preparation of rice seed for sowing.

Rice crops are attacked by a number of pests. A useful method of protecting rice and rice seed and rice crop is to apply one or more phytoprotection products to the seed by different methods such as coating, soaking or dipping. Said seed can be dry seed or soaked seed or pregerminated soaked seed. Although it is well known that dry or ungerminated seeds can be coated with a phytoprotection product and subsequently sown, a common practice is to pregerminate rice seed by soaking the seed in water containing one or more phytoprotection products followed by a period in which the soaked, treated seed is allowed to drain and produce a radicle. (The period during which the seed is soaked, drained and during which a radicle is produced is called the pregermination period and the resulting composition, that is, a seed from 15 which a radicle has been produced before it is sown is a pregerminated seed.) This is a most efficient and attractive way of seed treatment, but there remains the problem of the disposal of hazardous waste water despite efforts to minimize the concentration of the phytoprotection product or the volume of the liquid. Another potential hazard of this conventional seed soaking method is the generation of seeds that are treated but unused for any 00020 reason. Said unused seeds can be hazardous waste.

Rice seeds are commonly sown by dropping pregerminated seeds from an airplane over a flooded rice propagation area. Webster et. al., in the publication Hilgardia 1973 vol. 41 pages 689-698, indicates that sowing pregerminated rice seed in such a manner "introduces complications not experienced with seed treatments in other cereals." They further recommend 25 treating rice seeds with a phytoprotection product either before soaking said rice seeds or during the soaking process. Nonetheless, when these seed treatment methods are utilised with the required volumes of seed, very large volumes of hazardous liquid waste can be generated.

0 Patent publication WO 93/1705 describes a process in which pregerminated seed can be coated by a foam and one or more phytoprotection compositions. However, the said publication is silent about the growth conditions of the pregerminated seed and rice seed is specifically not exemplified or mentioned. In addition, the aforementioned problem of unused, treated seed is not obviated. Webster et.al., vide supra, however describe treating pregerminated seed with the fungicides Captan, Captofol, or Thiram after the soaking process and obtaining no increase in plant stand, i.e. no advantage.

An object of the instant invention is to provide a highly effective method of preparing rice seeds for sowing.

la Another object of the instant invention is to provide a highly effective method of preparing rice seeds for sowing, for example by plane.

Another object of the instant invention is to provide a process for the preparation of rice seed for sowing in large quantities that reduces or minimizes or even avoids altogether the generation of hazardous, unusable seed.

Another object of the instant invention is to provide a process for the preparation of rice seed for sowing that reduces or minimises or even avoids the problem of liquid waste.

Another object of the instant invention is to minimize the exposure of humans to phytoprotection products.

Another object of the instant invention is to provide a rapid method for the treatment of pregerminated rice seed by a phytoprotection product.

Another object of the instant invention is to provide a method of protection of pregerminated rice seed against fungal pathogens.

O

o.Another object of the instant invention is to provide a method of protection of rice seed 15 against insecticidal pests which is effective over a substantial period of time.

.ee• Another object of the instant invention is to provide a method of protection of rice seed which avoids the disadvantages of the known methods.

It has now been found that the objects can be met in whole or in part by the means of the instant invention. These and other objects will better appear during the description of the invention.

There is now provided a method of preparation of rice seed for sowing comprising the following steps: :o the said seed is pregerminated in water containing substantially no phytoprotection S product at a temperature and during a period of time sufficient to produce a radicle having a size such that the said radicle is not substantially damaged in a subsequent seed treatment process; and mixing the said pregerminated seed with an effective amount of a phytoprotection S product.

A preferred embodiment of the invention is that the amount of said pregerminated seed is appropriate for sowing from the air, usually sowed in quantities between 10 and 20000 kg, more preferably between 100 to 1500 kg. The treatment of such large quantities in such a short period of time and with minimum damage to the grains is especially a difficult problem. Said pregermination process is preferably contained in one or more bags. Bags are water permeable containers that are optionally deformable, preferably able to contain between 10 and 1000 kg of seed before soaking. Sowing from the air generally entails the loading of an aircraft, preferably -2an airplane, followed by flying over the field to be sown and distributing the seed to be sown.

Another type of aircraft suitable for sowing is a helicopter.

Another preferred embodiment of the invention is that the size of the radicle is between 0.1 to 15 mm, more preferably between 1 to 5 mm.

The mixing of said seed with the phytoprotection product generally takes place at or near within about 50 kilometers of) an airport or airstrip, preferably within the legal boundaries of an airport used by said planes for sowing. Said mixing can optionally take place in a mixing apparatus that is in or on a truck, trailer, or other movable device suitable for transporting said mixing apparatus. In another aspect of the invention, said seed to be pregerminated and mixed with a phytoprotection product is transported by crane or forklift or hopper mechanism at each stage. Another mode of transportation contemplated in the invention of the said seed at each or any stage of the method is by use of an auger.

S: By the term "phytoprotection product" is meant a material which may be used to provide S 15 an effective protection of rice seeds from pests' attacks. The invention is mainly directed to the @000 protection of seeds and plants derived from such seeds from insect attacks, particularly rice water weevil, as well as from fungal attacks. The phytoprotection products which may be used according to the present invention may also be such materials as biocontrol agents, that is S biological substances that protect seeds and plants derived from such seeds from insect and 20 fungal attacks and/or provide nutritients to said seeds or plants derived from said seeds. Another se type of phytoprotection product contemplated by the invention are of the class of macronutrients and micronutrients, that is substances that function as a plant food.

The phytoprotection product which may be used to coat the rice seed is preferably a S liquid, which may be aqueous or non aqueous, in order to improve the speed of application. It may be fairly diverse in nature and is defined in practice so as to be able to ensure the coating 0 °o upon the seed of the required effective amount of active material. It is preferably other than a S gel. The preferred formulations used in the invention can vary, for example a solution, suspension, emulsion, or the like with a viscosity less than 500 centipoises. The formulation used o in the invention thus comprises, as necessary constituents, the active material and solvent, 3 usually water; it optionally and additionally contains other customary constituents used in S. agrochemical formulations, for example those described in Patent Applications WO 87/3781, 93/6089, 94/21606 as well as in European patent application 295117. However, among the compositions described in this known art, it is preferable to choose those which are more suited to rice seed coating. For example, sticking agents such as low molecular weight polymer often effectively promote sticking of the insecticidally-active material upon the seed. The aqueous formulations used in the invention may also comprise another non-aqueous liquid phase.

-3- According to a particularly preferred feature of the invention, the time from the end of pregermination period to the mixing of the pregerminated seed with the phytoprotection product is less than twenty four hours, preferably less than eight hours. In another aspect of the invention, the time from the end of the pregermination period to the sowing of the seed is less than -forty-eight hours, preferably less than twenty-four hours even more preferably less than eight hours.

In another aspect of the invention, the pregermination of rice seed is preferably provoked or activated during a period of time comprised during about half a day of to several days, preferably during a period comprised between one day and three days.

The following representative insecticidally active materials may be used: [(6-chloro-3-pyridyl)methyl]-N 2 -cyano-N'-methylacetamidine (acetamiprid); 1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine (imidacloprid); 2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate (carbofuran); 0,0 diethyl 0-3,5,6-trichloro-2-pyridiyl phosphorothioate (chlorpyrifos); :15 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea (diflubenzuron); 0000 A pyrethroid such as (S)-a-cyano-3-phenoxybenzyl (S)-2-(4-chlorophenyl)-3methylbutyrate (esfenvalerate);or [1 a(S*),3a(Z)]-(±)-cyano(3-phenoxyphenyl)methyl 3-(2-chloro-3,3,3-trifluoro- 1propenyl)-2,2-dimethylcyclopropanecarboxylate (lambda-cyhalothrin);and an insecticidal I -aryl pyrazole, an insecticidal 1 -aryl pyrrole, or an insecticidal 1 -aryl imidazole.

The 1-arylpyrazoles which can be used according to the instant invention are preferably compounds of formula

N

00 *R,

(I)

in which:

R

1 is CN or methyl; R2 is S(0),R 3 -4-

R

3 is alkyl or haloalkyl;

R

4 represents a hydrogen or halogen atom or a member of a group consisting of NR 5

R

6 S(O)mR 7

C(O)R

7

C(O)O-R

7 alkyl, haloalkyl, OR 8 and -N=C(R 9 )(Rio);

R

5 and R 6 independently represent the hydrogen atom or an alkyl, haloalkyl, C(O)alkyl, alkoxycarbonyl or S(O)rCF 3 radical; or R 5 and R 6 can together form a divalent alkylene radical which can be interrupted by one or two divalent heteroatoms, such as oxygen or sulfur;

R

7 represents an alkyl or haloalkyl radical;

R

8 represents an alkyl or haloalkyl radical or a hydrogen atom;

R

9 represents an alkyl radical or hydrogen atom; Rio represents a phenyl or heteroaryl group which is unsubstituted or substituted by one or more halogen atoms or a member of the group consisting of OH, -O-alkyl, -S-alkyl, cyano, and alkyl; X represents a trivalent nitrogen atom or a C-R 1 2 radical, the other three valences of the carbon atom forming part of the aromatic ring; 15 RI and R 12 represent, independently of one another, a hydrogen or halogen atom;

R

1 3 represents a halogen atom or a haloalkyl, haloalkoxy, S(O)qCF 3 or SF 5 group; Sm, n, q, and r represent, independently of one another, an integer equal to 0, 1, or 2; provided that, when R 1 is methyl, then R 3 is haloalkyl, R 4 is NH 2

R

11 is Cl, R 1 3 is CF 3 and X isN.

A preferred group of effective 1-arylpyrazoles of the present invention is that wherein:

R

1 is CN;

R

3 is a haloalkyl radical; S R4 is NH 2 X is C-RI 2

R

11 and R 12 represent, independently of one another, a halogen atom;and Ri3 is a haloalkyl radical.

A most preferred compound is 5-amino-l-(2,6-dichloro-a,ca,a-trifluoro-p-tolyl)-4trifluoromethylsulfinylpyrazole-3-carbonitrile, also known as fipronil.

Compounds of formula may be prepared according to known processes, for example as described in International Patent Publications No. WO 87/3781, 93/6089, and 94/21606 as well as in European Patent Applications 0295117, 0403300, 0385809 or 0679650, German Patent Publication 19511269 and United States Patents 5,232,940 and 5,236,938 or other process according to the knowledge of a man skilled in the art of chemical synthesis.

Representative fungicides that may be used in the method of the invention include the following: 1,2-ethanediylbis [carbamodithioato]]1(2-)] manganese mixture with ethanediylbis [carbamodithioato] zinc (mancozeb); methyl I -(butylcarbamoyl)benzimidazol-2-ylcarbamate (benomyl); 3-(3 ,5-dichlorophenyl)-N-( 1-isopropyl)-2,4-dioxoimidazolidine-l1-carboxamide (iprodione); ethyl hydrogen phosphonate (fosetyl); ethyl hydrogen phosphonate aluminum salt (fosetyl-aluminum); tetramethylthiuram disulfide (thiram); 1-[2-(2,4-dichlorophenyl)-4-propyl- 1,3-dioxolan-2-yl]methyl- 1H-i ,2,4-triazole (propiconazole); 00* (±)-E-5-(4-chlorobenzylidene)-2,2-dimethyl-1-(1H-1 ,2,4-triazol-1ylmethyl)cyclopentanol (triticonazole); 5 ,6-dihydro-2-methyl-1I,4-oxathi-ine-3-carboxanilide (carboxin); .***methyl N-(2-methoxyacetyl)-N-(2,6-xylyl)-DL-alaninate (metalaxyl); methyl {2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl)}-3-methoxyacrylate (azoxystrobin);or a copper fungicide, such as but not limited to dicopper chloride trihydroxide.

Representative biocontrol agents that may be used in the method of the invention include: :Bacillus thuringiensis; Bacillus subtilis; Pseudomonas spp.; Rhizobiun spp.; Azospirillumspp.; Beauveria spp.

Micronutrients and Macronutrients that may be used according to the invention include: Iron chelates; Zinc chelates; Manganese chelates; -6- Nitrogen.

In another aspect ot the invention, phytoprotection products may be mixed with the above said seed separately, together or in any combination as specified in standard reference material for those skilled in the art of the application of phytoprotection products The amount of phytoprotection product, preferably an insecticidally active material, may depend very much on the particular product being used. Generally the amount of active ingredient which is applied to the pregerminated seed is between about 2 and 1000 g/q (gram of active ingredient per quintal of germinated seed), preferably (especially for the 1-aryl pyrazoles or imidacloprid) between about 5 and 800 still more preferably between 5 and 100 g/q.

The following examples are descriptive, and are not to be taken as limiting examples.

Other choices of materials, methods, and organisms will be obvious to those skilled in the art in light of the teaching herein.

Example 1 Rice seeds (227 kg) were soaked at 25 oC in water for 24 hours. The seed was removed from water and allowed to drain for 30 hours. The seeds were drained completely, allowed to absorb excess water, and was allowed to germinate up to the point of having emerging radicles whose size was between 1 and 8 mm.

These seeds were treated by thorough machine mixing with a latex polymer formulation containing about 3% of fipronil. The thus obtained pregerminated seeds appeared undamaged :20 and had a normal coating of compound A.

Seed was tested for germination in an incubator and also flown onto a flooded field under standard agricultural practices. The treated seeds behaved the same as untreated seeds-stand establishment was the same as untreated seed.

Example 2 One thousand pounds of rice seed (450 kg) was pregerminated in one bag by soaking the bag in water for twenty four hours followed by draining for twenty four hours. The seed was treated immediately with mancozeb in a slurry at a rate of 19-22 fluid ounces (570-630 mL) per hundred pounds (45 kg) of seed. The seed was flown onto flooded fields where it established an acceptable stand of rice plants.

1 Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and or variations such as "comprises" or "comprising", will be nderstood to imply the inclusion of a stated integer or step or group of integers or steps but not oxclusion of any other integer or step or group of integers or steps.

-7- Thr~

Claims

1. A method of preparation of rice seed for sowing comprising the following steps: the said seed is pregerminated in water containing substantially no phytoprotection product at a temperature and during a period of time sufficient to produce a radicle having a size such that the said radicle is not substantially damaged in a subsequent seed treatment process; and mixing the said pregerminated seed with an effective amount of a phytoprotection product.

2. A method according to claim 1 wherein the amount of said pregerminated seed is appropriate for sowing from the air.

3. A method according to claim 1 or claim 2 wherein the amount of seed for sowing is in the range of 10 to 20000 kg,

4. A method according to claim 1 or 2 wherein the amount of seed for sowing is in the range of 100 to 1500 kg. A method according to any one of the foregoing claims wherein the pregermination of the seed is performed in one or more bags.

6. A method according to any one of the foregoing claims wherein the pregerminated seed is S mixed with the phytoprotection product at or near an airport or an airstrip.

7. A method according to any one of the foregoing claims wherein the pregermination period is about a half a day to several.days.

8. A method according to any one of the foregoing claims wherein the pregermination period is between one day and three days.

9. A method according to any one of the foregoing claims wherein the size ofthe radicle is from 0.1 to 15 mm.

10. A method according to any one of the foregoing claims wherein the time from the end of the pregermination period to the mixing of the pregerminated seed with the phytoprotection product is less than twenty-four hours,

11. A method according to claim 10 wherein the time is less than eight hours.

12. A method according to any one of the foregoing claims wherein the time from the end of the pregermination period to the sowing of the seed is less than forty-eight hours.

13. A method according to claim 12 wherein the time is less than 24 hours, 14A method according to any one of the foregoing claims wherein the phytoprotection product is an insecticidal composition. A method according to clain 14 wherein the insecticidal compostion is: (E,).N'.{(6-chloro-3 -pyridyl )methyi]-N 2 -cyano-N'-methylacetamnidine (acetamniprid); I -(6-chloro-3-pyridylmethyl)-N-nitroiinidazolidin-2-ylideneamine (imidacloprid); 2,3-dihydro-2,2-dirnethylbenzofuran-7-yI methylcarbamate (carbofuran); 0,0-diethyl 0-3,5 ,6-trichloro-2-pyridiyl phosphorothioate (chlorpyrifos); 1 -(4-chlorophenyl)-J -(2,6-difluorobenzoyl)urea (diflubenzuron); (S)-a-cyano-3-pheioxybenzyl (S)-2-(4-chloropheny)-3-mnethylbutyrate (esfenvalerate); [I a(S)3t(Z)]-()-yano(3-phnoxyphenyl)methyI 3 -(2-chloro.3,3 ,3-trifluoro- i propcnyl)-2,2- dimethylcyclopropanecarboxylate (tambda-cyhalothxrin); or an insecticidal I -arylpyrazole, an insecticidal I1-arylpyrrole or an insecticidal I -aryliniidazole.

16. A method according either claim 14 or claim 15 wherein the insecticidal composition is compound of formnula R2 R2 i. R3 is aly r4lak *9- 9 5 R n 4 R 7 represents an alkyl or haloalkyl radical; RS represents an alkl or haloalcyl radical or a hydrogen atom; R9 represents an alkyl radical or hydrogen atom; RIO represents a phenyl or heteroaryl group which is unsubstituted or substituted by one or more halogen atoms or a member of the group consisting of 011I, -0-alkyl, -S-alkyl, cyano, and alkyl; X represents a trivalent nitrogen atom or a C-R 1 radical, the other three valences of the carbon atom f'ormning part of the aromatic ring; j R, 1 and Rj 2 represent, independently of one another, a hydrogen or halogen atom; R 13 represents a halogen atom or a haloalkyl, haloalkoxy, S(O)qCF 3 or SF 5 group; m, n, q, and r represent, independently of one another, an integer equal to 0, 1, or 2; provided that, when R, is methyl, then R 3 is haloalkyl, R 4 is NH 2 R, I is Cl, R 1 3 is CF 3 and X is N. 17, A method according to claim 16 wherein the insecticidal coznpostion is a compound of formula wherein: R, is CN; R 3 is a haloalkyl radical; R4is NH 2 X is C-a 12 R, 1 and R1 2 represent, independently of one another, a halogen atom;and R 1 3 is a haloalkyl radical. IS. A method according claim 16 or claim l7wNherein the insecticidal composition is amino- I -(,-ihooaactilooptll--rilooehlufyprzl--abntie

19. A method according to any one of the foregoing claims wherein the phytoprotection product is an fungicidal composition. A method according to claim 19 wherein the fungicidal composition is one of the following: ,2-ethanediylbis [carbarnodithiaato]](2-)]mlalganese mnixture with ethnnediylbis[carbamodithioato]](2-)zinC (mnaneozeb), 10 methyl 1 -(burylcarbanoyI)berZiI idazOl-2-ylcabarnte (beziomyl); 3 -(3,5-dicbloropheny1)-N-(l .isopropyl)-2,4-dioxoirnidazolidil1-carboxamide (iprodione); ethyl hydrogen phosphoriate (fosetyI); ethyl hydrogen phosphonate aluminum salt (fosetyl-alumnintur); tetramethylthiurani disulfide (thiram); .(2.(2,4-dichlorophenyl-4-propyl- ,3 -dioxolan-2-yl]methyt- 1 H-i ,2,-triazole (propiconazole); -(4-chlorobcnzylidene)-2,.2-dimethyl' 1-Cl H-i ,2,4-triazol- I-ylmethyl)cyclopentanol (triticonazole); 5,6-dihydro-2-methyl-1I,4-oxathi-ine-3-carboxaflil ide (carboxin); methyl N-(2.rnethoxyacety)-N.(2,6-xyly)-DL-alaliate (metalaxyl); methyl [6-(2-cyanophenoxy)pyrimlidil-4-yloxyIphanfl) -3-methoxyacry late (azoxystrobin); a copper fungicide.

21. A method according to any one of claims i to 14 and claim 19 wherein the phytoprotection product is a biocontrol. agent.

22. A method according to claim 21. wherein the phytoprotection product is a biocoritrol agent selected from the group consisting of. Bacil lug thuringlensis; Bacillus subtilis; Pseudornonas spp.; Rbizobiuin sp,-, AZospirillurn sV2.;=nd :23. A method according to any one of claims l-13whcrein the phytoprotection product is a macronutrient or a mioronutrient.

24. A method according to claim 23 wherein the phytoprotection product is a macronutrient or a micronutrient selected from the group consisting of Iron chelates, Zinc chelates, Manganese cholates, Nitrogen. 11 Q:\PERUvlS\182330.05/ 1 5/00 A method according to any one of the foregoing claims wherein the composition is a liquid composition with a viscosity less than 500 centipoises. 2. A method according to any of the foregoing claims wherein the rate of seed treatment is between 2 and 1000 grams of phytoprotection product per quintal,

27. A method according to claim 26 wherein the rate of treatment is between 5 and 800 grms per quintal.

28. A method according to claim 1, substantially as hereinbefore described with reference to the Examples. Dated this 5th day of January 2000 Rhone-Poulenc Agrochimie By its Patent Attorneys Davies Collison Cave