Encapsulation of Herbicides to Reduce Crop Injury

• US 20100248963A1
• Filed: 02/15/2010
• Published: 09/30/2010
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Monsanto Technology LLC (Bayer AG)
• Original Assignee: Monsanto Technology LLC (Bayer AG)
• Inventors: Herr, Amanda C., Bussler, Brett H., Prosch, S. Douglas, Becher, David Z., Abraham, William
• Granted Patent: US 9,877,478 B2
• Time in Patent Office: Days
• US Class Current: 504/127
• CPC Class Codes: A01N 2300/00 Combinations or mixtures of active ingredients covered by classes A01N27/00 - A01N65/48 with other active or formulation relevant ingredients, e.g. specific carrier materials or surfactants, covered by classes A01N25/00 - A01N65/48
• CPC Class Codes: A01N 25/28 Microcapsules or nanocapsules
• CPC Class Codes: A01N 37/26 containing the group; Thio analogues thereof

Abstract

Methods of reducing injury to crop foliage and achieving weed control using encapsulated acetamide herbicides are described. Herbicidal microcapsules comprising herbicide core material and a shell wall encapsulating the core material are also described. The microcapsules provide reduced crop injury through controlled herbicide release.

Claims

1. A particulate microencapsulated acetamide herbicide comprising:

a water-immiscible core material comprising the acetamide herbicide and

a microcapsule having a shell wall comprising a polyurea, the microcapsule containing the core material,

wherein the shell wall is formed in a polymerization medium by a polymerization reaction between a polyisocyanate component comprising a polyisocyanate or mixture of polyisocyanates and a polyamine component comprising a polyamine or mixture of polyamines to form the polyurea,

wherein the ratio of amine molar equivalents contained in the polyamine component to isocyanate molar equivalents contained in the polyisocyanate component is at least 1.1;

1, and

wherein a population of the microcapsules has a mean particle size of at least about 7 μ

m.

3. The microencapsulated acetamide herbicide of claim 1 wherein a population of the microcapsules has a mean particle size range of from about 8 μ

m to about 12 μ

m.

4. The microencapsulated acetamide herbicide of claim 1 wherein the molar equivalents ratio is from about 1.15:

1 to about 1.7;

1.

5. The microencapsulated acetamide herbicide of claim 1 wherein the polyamine component consists essentially of a principal polyamine.

16. The microencapsulated acetamide herbicide of claim 1 wherein the acetamide herbicide is selected from the group consisting of acetochlor, alachlor, butachlor, butenachlor, delachlor, diethatyl, dimethachlor, dimethenamid, dimethenamid-P, mefenacet, metazochlor, metolachlor, S-metolachlor, napropamide, pretilachlor, pronamide, propachlor, propisochlor, prynachlor, terbuchlor, thenylchlor and xylachlor, salts and esters thereof, and mixtures thereof.

17. The microencapsulated acetamide herbicide of claim 16 wherein the herbicide is selected from the group consisting of acetochlor, alachlor, metolachlor, S-metolachlor, dimethenamid, dimethenamid-P and butachlor.

18. The microencapsulated acetamide herbicide of claim 17 wherein the herbicide is acetochlor.

19. The microencapsulated acetamide herbicide of claim 1 wherein the shell wall is of limited permeability, and the nature and composition of said shell wall and encapsulated acetamide is such that, when an aqueous slurry consisting of 1% by weight of the encapsulated acetamide herbicide in an aqueous medium consisting of deionized water is subjected to agitation at a rate sufficient to maintain the particles in suspension without mechanical rupturing, the acetamide content of the aqueous medium remains less than 100 ppm after agitation for 6 hours at 25°

C., and less than 150 ppm acetamide after agitation for 24 hours at 25°

C.

68. An aqueous mixture comprising the microencapsulated acetamide herbicide of claim 1, the aqueous mixture in the form of a concentrate or diluted spray application mixture.

70. The aqueous mixture of claim 68 further comprising one or more co-herbicides selected from acetyl CoA carboxylase inhibitors, organophosphorus herbicides, auxins, photosystem II inhibitors, ALS inhibitors, protoporphyrinogen oxidase inhibitors and carotenoid biosynthesis inhibitors, salts and esters thereof, and mixtures thereof.

74. The aqueous mixture of claim 70 wherein the co-herbicide is the photosystem II inhibitor atrazine.

81. A method of controlling weeds in a field of crop plants, the method comprising:

forming an application mixture comprising the particulate microencapsulated acetamide herbicide as set forth in claim 1 and

applying the application mixture in a herbicidally effective amount post-emergent to the crop plants.

82. The method of claim 81 wherein the application mixture is applied pre-emergent to the weeds.

83. The method of claim 81 wherein the crop plant is selected from the group consisting of corn, peanuts, potatoes, soybeans, canola, sugarbeets and cotton.

86. The method of claim 8185 wherein the crop plants have one or more herbicide tolerant traits.

87. The method of claim 8186 wherein the application mixture further comprises glyphosate co-herbicide and the crop plants are transgenic glyphosate-tolerant crop plants, the application mixture further comprises dicamba co-herbicide and the crop plants are transgenic dicamba-tolerant crop plants or the application mixture further comprises glufosinate co-herbicide and the crop plants are transgenic glufosinate-tolerant crop plants.

90. The method of claim 87 wherein the application mixture further comprises glyphosate co-herbicide and the crop plants comprise transgenic glyphosate-tolerant cotton plants having increased glyphosate tolerance in vegetative and reproductive tissues such that application of the herbicidal glyphosate application mixture to said crop and weeds in said field when at least five leaf nodes are present on a cotton plant of said crop does not incur significant glyphosate-mediated reproductive injury to said plant of said crop.

93. The method of claim 90 wherein the genome of the transgenic glyphosate-tolerant cotton plants comprises one or more DNA molecules selected from the group consisting of SEQ ID NO:

1, SEQ ID NO;

2, SEQ ID NO;

3, and SEQ ID NO;

4;

or

the genome of the transgenic glyphosate-tolerant cotton plants in a DNA amplification method produces an amplicon comprising SEQ ID NO;

1 or SEQ ID NO;

2;

or

the transgenic glyphosate-tolerant cotton plants comprise a glyphosate tolerant trait that is genetically linked to a complement of a marker polynucleic acid, and the marker polynucleic acid molecule is homologous or complementary to a DNA molecule selected from the group consisting of SEQ ID NO;

1 and SEQ ID NO;

2.

94. The method of claim 90 wherein the crop of transgenic glyphosate-tolerant cotton plants comprises cotton plants grown from seed of cotton event designated MON 88913 and having representative seed deposited with American Type Culture Collection (ATCC) with Accession No. PTA-4854 or glyphosate-tolerant progeny thereof.

95. The method of claim 90 wherein the crop plants comprise transgenic glyphosate-tolerant cotton plants grown from seed of cotton event designated 1445 or glyphosate-tolerant progeny thereof.

96. The method of claim 81 wherein a rate of crop injury of no more than 20% is maintained for the time period of from 1 day to 28 days after applying the application mixture to crop plants in the growth stage range of from crop emergence to the six-leaf growth stage;

and

a rate of weed control of at least 60% is achieved for the time period of from application of the application mixture to 12 weeks after application of the application mixture.

97. The method of claim 96 wherein the rate of weed control is at least 70% and the rate of crop injury is no more than 5%.

116. The method of claim 81 wherein the weeds comprise one or more glyphosate resistant species, 2,4-D resistant species, dicamba resistant species and/or ALS inhibitor herbicide resistant species.

117. The method of claim 116 wherein the weeds comprise one or more glyphosate resistant species.

118. The method of claim 117 where the glyphosate-resistant weed species is selected from the group consisting of Amaranthus palmeri, Amaranthus rudis, Ambrosia artemisiifolia, Ambrosia trifida, Conyza bonariensis, Conyza canadensis, Digitaria insularis, Echinochloa colona, Eleusine indica, Euphorbia heterophylla, Lolium multiflorum, Lolium rigidum, Plantago Ianceolata, Sorghum halepense, and Urochloa panicoides.

123. The method of claim 81 wherein the application mixture further comprises one or more co-herbicides selected from acetyl CoA carboxylase inhibitors, organophosphorus herbicides, auxins, photosystem II inhibitors, ALS inhibitors, protoporphyrinogen oxidase inhibitors and carotenoid biosynthesis inhibitors, salts and esters thereof, and mixtures thereof.

127. The method of claim 123 wherein the co-herbicide is the photosystem II inhibitor atrazine.

2. (canceled)

6-15. -15. (canceled)

20-45. -45. (canceled)

46. A particulate microencapsulated acetamide herbicide comprising:

a water-immiscible core material comprising the acetamide herbicide and

a microcapsule having a shell wall comprising a polyurea, the microcapsule containing the core material,

wherein the shell wall is formed in a polymerization medium by a polymerization reaction between a polyisocyanate component comprising a polyisocyanate or mixture of polyisocyanates and a polyamine component comprising a polyamine or mixture of polyamines to form the polyurea,

wherein a population of the microcapsules has a mean particle size of at least about 7 μ

m, and

wherein the shell wall is of limited permeability, and the nature and composition of said shell wall and encapsulated acetamide is such that, when an aqueous slurry consisting of 1% by weight of the encapsulated acetamide herbicide in an aqueous medium consisting of deionized water is subjected to agitation at a rate sufficient to maintain the particles in suspension without mechanical rupturing, the acetamide content of the aqueous medium remains less than 100 ppm after agitation for 6 hours at 25°

C., and less than 150 ppm acetamide after agitation for 24 hours at 25°

C.

48. The microencapsulated acetamide herbicide of claim 46 wherein the acetamide content of the aqueous medium remains less than 60 ppm after 6 hours, and less than 100 ppm after 24 hours.

51. The microencapsulated acetamide herbicide of claim 46 wherein a population of the microcapsules has a mean particle size range of from about 8 μ

m to about 12 μ

m.

53. The microencapsulated acetamide herbicide of claim 46 wherein the ratio of amine molar equivalents contained in the polyamine component to isocyanate molar equivalents contained in the polyisocyanate component is from 1.1:

1 to about 1.7;

1.

54. The microencapsulated acetamide herbicide of claim 46 wherein the polyamine component consists essentially of a principal polyamine.

65. The microencapsulated acetamide herbicide of claim 46 wherein the acetamide herbicide is selected from the group consisting of acetochlor, alachlor, butachlor, butenachlor, delachlor, diethatyl, dimethachlor, dimethenamid, dimethenamid-P, mefenacet, metazochlor, metolachlor, S-metolachlor, napropamide, pretilachlor, pronamide, propachlor, propisochlor, prynachlor, terbuchlor, thenylchlor and xylachlor, salts and esters thereof, and mixtures thereof.

66. The microencapsulated acetamide herbicide of claim 65 wherein the herbicide is selected from the group consisting of acetochlor, alachlor, metolachlor, S-metolachlor, dimethenamid, dimethenamid-P and butachlor.

67. The microencapsulated acetamide herbicide of claim 66 wherein the herbicide is acetochlor.

194. A method of controlling weeds in a field of crop plants, the method comprising:

forming an application mixture comprising the particulate microencapsulated acetamide herbicide as set forth in claim 46 and

applying the application mixture in a herbicidally effective amount post-emergent to the crop plants.

195. The method of claim 194 wherein the application mixture is applied pre-emergent to the weeds.

196. The method of claim 194 wherein the crop plant is selected from the group consisting of corn, peanuts, potatoes, soybeans, canola, sugarbeets and cotton.

197. The method of claim 194 wherein the crop plants have one or more herbicide tolerant traits.

198. The method of claim 194 wherein the application mixture further comprises glyphosate co-herbicide and the crop plants are transgenic glyphosate-tolerant crop plants, the application mixture further comprises dicamba co-herbicide and the crop plants are transgenic dicamba-tolerant crop plants or the application mixture further comprises glufosinate co-herbicide and the crop plants are transgenic glufosinate-tolerant crop plants.

199. The method of claim 198 wherein the application mixture further comprises glyphosate co-herbicide and the crop plants comprise transgenic glyphosate-tolerant cotton plants having increased glyphosate tolerance in vegetative and reproductive tissues such that application of a herbicidal glyphosate formulation to said crop and weeds in said field when at least five leaf nodes are present on a cotton plant of said crop does not incur significant glyphosate-mediated reproductive injury to said plant of said crop.

200. The method of claim 199 wherein the genome of the transgenic glyphosate-tolerant cotton plants comprises one or more DNA molecules selected from the group consisting of SEQ ID NO:

1, SEQ ID NO;

2, SEQ ID NO;

3, and SEQ ID NO;

4;

or

the genome of the transgenic glyphosate-tolerant cotton plants in a DNA amplification method produces an amplicon comprising SEQ ID NO;

1 or SEQ ID NO;

2;

or

the transgenic glyphosate-tolerant cotton plants comprise a glyphosate tolerant trait that is genetically linked to a complement of a marker polynucleic acid, and the marker polynucleic acid molecule is homologous or complementary to a DNA molecule selected from the group consisting of SEQ ID NO;

1 and SEQ ID NO;

2.

201. The method of claim 199 wherein the crop of transgenic glyphosate-tolerant cotton plants comprises cotton plants grown from seed of cotton event designated MON 88913 and having representative seed deposited with American Type Culture Collection (ATCC) with Accession No. PTA-4854 or glyphosate-tolerant progeny thereof.

202. The method of claim 199 wherein the crop of transgenic glyphosate-tolerant cotton plants comprises cotton plants grown from seed of cotton event designated 1445 or glyphosate-tolerant progeny thereof.

203. The method of claim 194 wherein a rate of crop injury of no more than 20% is maintained for the time period of from 1 day to 28 days after applying the application mixture to crop plants in the growth stage range of from crop emergence to the six-leaf growth stage;

and

a rate of weed control of at least 60% is achieved for the time period of from application of the application mixture to 12 weeks after application of the application mixture.

204. The method of claim 203 wherein the rate of weed control is at least 70% and the rate of crop injury is no more than 5%.

205. The method of claim 194 wherein the weeds comprise one or more glyphosate resistant species, 2,4-D resistant species, dicamba resistant species and/or ALS inhibitor herbicide resistant species.

206. The method of claim 205 wherein the weeds comprise one or more glyphosate resistant species.

207. The method of claim 206 where the glyphosate-resistant weed species is selected from the group consisting of Amaranthus palmeri, Amaranthus rudis, Ambrosia artemisiifolia, Ambrosia trifida, Conyza bonariensis, Conyza canadensis, Digitaria insularis, Echinochloa colona, Eleusine indica, Euphorbia heterophylla, Lolium multiflorum, Lolium rigidum, Plantago Ianceolata, Sorghum halepense, and Urochloa panicoides.

208. The method of claim 194 wherein the application mixture further comprises one or more co-herbicides selected from acetyl CoA carboxylase inhibitors, organophosphorus herbicides, auxins, photosystem II inhibitors, ALS inhibitors, protoporphyrinogen oxidase inhibitors and carotenoid biosynthesis inhibitors, salts and esters thereof, and mixtures thereof.

209. The method of claim 208 wherein the co-herbicide is the photosystem II inhibitor atrazine.

47. (canceled)

49. (canceled)

50. (canceled)

52. (canceled)

55-64. -64. (canceled)

69. (canceled)

71-73. -73. (canceled)

75-80. -80. (canceled)

84-85. -85. (canceled)

88-89. -89. (canceled)

91-92. -92. (canceled)

98-115. -115. (canceled)

119-122. -122. (canceled)

124-126. -126. (canceled)

128-146. -146. (canceled)

147. A method of controlling commercially important weeds located in a field of crop plants, the method comprising:

forming an application mixture comprising a particulate encapsulated acetamide herbicide composition and

applying the application mixture in a herbicidally effective amount post-emergent to the crop plants and pre-emergent to the weeds wherein

the rate of crop injury is no more than 20% for the time period of from 1 day to 28 days after applying the application mixture to crop plants in the growth stage range of from crop emergence to the six-leaf growth stage and

the rate of weed control is at least 60% for the time period of from application of the application mixture to 12 weeks after application of the application mixture.

148-193. -193. (canceled)