WO2019226604A1

WO2019226604A1 - Selective herbicidal compositions and methods

Info

Publication number: WO2019226604A1
Application number: PCT/US2019/033234
Authority: WO
Inventors: James Nabors
Original assignee: James Nabors
Priority date: 2018-05-21
Filing date: 2019-05-21
Publication date: 2019-11-28

Abstract

Disclosed are selective herbicidal compositions and methods for control of annual bluegrass (Poa annua) and rough bluegrass (Poa trivialis) weeds. The compositions comprise trialkylbenzyl ammonium salts of the chemical formula below, at a concentration between 0.1% and 1.4%, C₆H₅-CH₂-N(+)R₁R₂R₃ X(-) wherein, R₁ and R₂ are each independently C₁ to C₄ alkyl; R₃ is C₈ to C₁₈ alkyl or alkenyl; and X is chloride or another agriculturally acceptable anion. The compositions of the present invention have been found to exhibit strong herbicidal effects on these bluegrass weeds, without significant negative effects on desirable turf plants.

Description

Selective Herbicidal Compositions and Methods Related Applications

This application claims the benefit of U.S. Provisional Application Ser. No. 62/762,807, filed May 21 , 2018, U.S. Provisional Application Ser. No. 62/917,403, filed December 10, 2018, and U.S.

Provisional Application Ser. No. 62/918,563, filed February 6, 2019, all of which are incorporated by reference herein.

Field of Invention

The current disclosure generally relates to herbicides, and more specifically to methods of controlling annual bluegrass and rough bluegrass.

Background

The elimination of weeds and other undesirable plants is an important market with a substantial economic value. Products in this market include both non-selective and selective herbicides. A non- selective herbicide (e.g., glyphosate or glufosinate) is designed to kill any vegetation to which it is applied, while a selective herbicide is designed to kill undesired vegetation in the application area without a significant adverse effect on desired plants. Non-selective products can be very effective in removal of weeds in certain situations. However, in a situation where the locus of the weed is a highly valued area of turf, it will be very beneficial to have an herbicide product that is both effective and selective for elimination of the weed.

Annual bluegrass is a weed that is widely found in lawns and golf course turf. Annual bluegrass can be a problem in residential and commercial lawns because it dies back in hot weather, which can make unsightly brown spots in the lawn during the height of summer. It also thrives during cool weather, when many lawn grasses are dying back, which means that it can invade the lawn and spread rapidly at these susceptible times. A single annual bluegrass plant can produce hundreds of seeds. Without effective removal of the weeds before they produce a vast crop of seeds, the desirable plants in the lawn may be overrun by the weeds in the next season. Annual

bluegrass populations have reached a very high level on many golf courses in recent years. Control of this weed presents very significant technical and economic challenges for golf course turf superintendents.

Rough bluegrass is a perennial cool-season weed that is also widely distributed in turf. While there are significant differences in plant characteristics from annual bluegrass, rough bluegrass shares many of the undesirable traits from the perspective of turf specialists. It thrives in cool weather and dies back as summer heat arrives, leaving unsightly bare spots in the turf. Unlike annual bluegrass, rough bluegrass isn’t actually gone. The plant stems survive underground and reappear in fall as a light green weed that creates thick mats of stems, choking out areas of lawn. Because of the difference in color, texture and growth habit from desirable turf grasses, the large patches of this weed are very visible and unattractive. Without control measures these patches will remain until summer, when the growth cycle is repeated.

Trialkylbenzyl ammonium salts have been disclosed in, e.g., United States Patent Application Publication US 2012/0046172, incorporated by reference herein, as non-selective herbicides when applied to plants at a concentration greater than 1 .5%. These compositions, as non-selective herbicides, were intended for control of weeds in industrial or railway sites; for eradication of plants in mulched areas, around paths, trees or fences; and use in agricultural fields for burndown of weeds before planting or crop emergence. Examples presented in US 2012/0046172 use 2% and 3% solutions of trialkylbenzyl ammonium salts showing strong desiccation effects on several weed species when applied alone. Trialkylbenzyl ammonium salts have also been previously known for their bactericidal/algaecidal properties, and beneficial growth regulation effects on crop plants, at concentrations below the 1 .5% level as indicated in US 2012/0046172. US 2012/0046172 does not disclose herbicidal activity on annual bluegrass and rough bluegrass using trialkylbenzyl ammonium salts.

While there are some products available for control or suppression of these bluegrass weeds, opportunities for improvement continue to exist. It would be most beneficial to provide new solutions to address these needs, for example, compositions and methods for effective control of annual bluegrass and rough bluegrass that are economic and selective in their action.

Summary

By way of brief summary, the current invention is directed to selective herbicide compositions for control of annual bluegrass and rough bluegrass. In some embodiments, the current invention includes compositions comprising trialkylbenzyl ammonium salts of the chemical formula below, at a concentration between 0.1 % and 1 .4%,

CeH5-CH2-N(+)Ri R₂R3 X(-) wherein, Ri and R are each independently Ci to C alkyl; R is Cs to Cis alkyl or alkenyl; and X is chloride or another agriculturally acceptable anion. Compositions of the present invention have been found to provide unexpected herbicidal effects on annual bluegrass and rough bluegrass weeds while showing minimal negative effects on desirable turf plants. Important turf plants that show limited phytotoxicity effects, for compositions within the scope of the present invention, include tall fescue (festuca arundinacea), dormant bermudagrass (Cynodon dactylon), actively growing bermudagrass and creeping bentgrass (agrostis stolonifera). The tolerance of these turf species is enhanced at the preferred and most preferred salt concentration levels, while the herbicidal activity for the undesired bluegrass weeds remains quite strong. These compositions will be especially valuable for selective control of annual bluegrass and rough bluegrass weeds in turf. The term“turf refers to, but is not limited to, residential and institutional lawns, athletic fields, parks, sod farms, golf course fairways, roughs, tees and greens.

It may be desirable for an increased spectrum of weeds controlled, or herbicide resistance measures, to include other selective herbicides. Preferred postemergence candidates include, but are not limited to, auxinic herbicides (e.g., quinclorac, dicamba, 2,4-D), aryloxyphenoxypropionic herbicides (e.g., fenoxaprop and fluazifop), sulfonylureas (e.g., flazasulfuron, foramsulfuron, trifloxysulfuron, rimsulfuron, chlorsulfuron), triazines (e.g., simazine, atrazine), flumioxazin, amicarbazone, methiozolin, metribuzin, ethofumesate and bispyribac. It may also be desirable to include a selective preemergence herbicide to extend the time period and/or spectrum of control for the compositions. Preferred preemergence herbicides include, but are not limited to, indaziflam, prodiamine, metolachlor, s-metolachlor, dimethenamide, pronamide, dithiopyr, oryzalin, oxadiazon, mesotrione, bensulide, benefin and pendimethalin.

The compositions may further include surface active agents, antifreeze agents, antifoam agents, colorants, thickeners and other additives as necessary for improved storage, handling and application properties. Suitable application improving agents include, but are not limited to, non-ionic surfactants, silicone oils, crop oil concentrates, organosilicones, or vegetable oil concentrates. Preferred application improving agents include non-ionic surfactants (e.g., Surf-Ac® 820) or methylated soybean oil. These application improving agents would typically be used in a range of 0.1 % to 1 %, with 0.25% to 0.5% preferred, in the final spray mixture. These agents may be built-in the formulated compositions, but in practice may also be added as a tank mix component. Additional pesticide ingredients such as fungicides, insecticides, and plant growth regulators may also be included for control of other undesirable pests or reduction of plant growth in the locus of application. The above described agents may be built-in the formulated composition or added as a tank mix component.

The above description is provided by way of summary only, and more detailed descriptions along with examples demonstrating the surprising efficacy of applicant’s invention are provided below.

Description of Exemplary Embodiments

It has now been discovered that aqueous compositions comprising trialkylbenzyl ammonium salts of the formula:

CeH₅-CH2-N(+)Ri R₂R3 X(-) wherein, Ri and R are each independently Ci to C alkyl; R is Cs to Cis alkyl or alkenyl; and X is chloride or another agriculturally acceptable anion, in concentrations between 0.1 % and 1 .4%, exhibit surprising herbicidal activity on annual bluegrass and rough bluegrass, while showing minimal negative effects on desirable turf species. A first embodiment provides a selective postemergence herbicidal composition for control of annual bluegrass and rough bluegrass when applied to the locus of the undesired bluegrass weeds, said composition comprising: a trialkylbenzyl ammonium salt of the chemical formula below

CeH₅-CH2-N(+)RiR₂R3 X(-) wherein, Ri and R₂ are each independently Ci to CA alkyl; R3 is Cs to Cis alkyl or alkenyl; and X is chloride or another agriculturally acceptable anion, and the concentration of the trialkylbenzyl ammonium salt is in the range of 0.1 % to 1.4%. This composition may further comprise agents for improvement of application properties and/or one or more selective herbicides. The locus of the weeds includes the leaves and stems of the weeds as well as any desirable plants in the application area.

The preferred forms of the trialkylbenzyl ammonium salts have both R1 and R₂ as methyl, R3 as an alkyl chain ranging from Csto Cis, and X as chloride. The most preferred forms include CAS # 68424- 85-1 having Re with an alkyl chain range of Ci₂ to C- and CAS # 68391-01 -5 having R3 with an alkyl chain range of Ci₂ to Cis. However, other R3 alkyl chain length ranges, as well as mixtures of any of these variants, may also be suitable for the compositions. The preferred concentration of the trialkylbenzyl ammonium salt is in the range of 0.1 % to 1 .0%. The most preferred concentration of the trialkylbenzyl ammonium salt is in the range of 0.15% to 0.5%. In some embodiments, the concentration of trialkylbenzyl ammonium salt is 1 .0% to less than 1 .5%.

The triaikyia!kyibenzyiammonium sail active ingredients are commercially available from a number of suppliers as aqueous solutions in concentrations ranging up to 80%. These concentrates may contain up to about 20% of ethanol as a stabilizer. Examples of commercially available products include the BTC® series from Stepan Company, The Barquat® series from Lonza Group Ltd. or AquaChem® Algaecide concentrates from Chemtura Corporation. The inventive compositions may be prepared by dilution of the aqueous concentrate to the desired concentration with water and stirring vigorously to ensure complete mixing.

A second embodiment provides a selective herbicide composition of the first embodiment further comprising one or more postemergence or preemergence selective herbicides.

Another embodiment provides methods of controlling annual bluegrass and rough bluegrass weeds comprising the application of the above described trialkylbenzyl ammonium salt compositions to the locus of the undesired bluegrass weeds. In any of the embodiments of the present invention the composition for application can be a ready-to- use composition or prepared as a tank mix of components.

EXAMPLES

The following examples illustrate the herbicidal properties and methods of use of the inventive compositions but should not be considered limitative of the scope of the invention.

The outdoor tests described below were conducted in North Carolina. The reported average daily max air temperature was 81 .9 °F, with a monthly average daily temperature of 72.1 °F. These tests used a“spray to wet” application rate directly on the plants (both annual bluegrass and desired turf) which, based on sprayer calibration, would correspond to a broadcast spray rate of about 140 gallons per acre (1300 L/ha). At the most preferred ADBAC concentration range of 0.15% to 0.5%, this broadcast spray volume would result in ADBAC application rates of about 1 .7 to 5.8 pounds per acre (1.9 to 6.5 kg/ha). Using larger scale broadcast spraying, lower spray volumes may be suitable. The tests on potted plants utilized mature plants collected from the field without disturbing the roots. The plants were transferred to 4”x4” pots and allowed to adjust to conditions before testing. Control plants harvested and transplanted in the same manner showed good vigor throughout the testing period.

The indoor tests were conducted under controlled conditions, with indirect sunlight and temperatures ranging from 50 to 60 °F.

Example 1

Test solution 1 (1 .0% ADBAC): A quantity (10 grams) of 50% concentrate of alkyl dimethyl benzyl ammonium chloride (ADBAC), with the alkyl group distribution of 67% C , 25% Cu, 7% Cie, 1 % C (CAS # 68391 -01-5), was mixed with water (490 grams) while stirring vigorously until completely mixed.

Test solution 2 (0.75% ADBAC): A quantity (7.5 grams) of 50% concentrate of alkyl dimethyl benzyl ammonium chloride (ADBAC), with the alkyl group distribution of 67% C , 25% Cu, 7% Cie_, 1 % C (CAS # 68391 -01-5), was mixed with water (492.5 grams) while stirring vigorously until completely mixed.

Test solution 3 (0.5% ADBAC): A quantity (5 grams) of 50% concentrate of alkyl dimethyl benzyl ammonium chloride (ADBAC), with the alkyl group distribution of 67% C , 25% Cu, 7% Cie_, 1 % C (CAS # 68391 -01-5), was mixed with water (495 grams) while stirring vigorously until completely mixed.

Test solution 4 (0.25% ADBAC): A quantity (2.5 grams) of 50% concentrate of alkyl dimethyl benzyl ammonium chloride (ADBAC), with the alkyl group distribution of 67% C , 25% Cu, 7% Cie_, 1 % C (CAS # 68391 -01-5), was mixed with water (497.5 grams) while stirring vigorously until completely mixed. Test solution 5 (0.25% ADBAC plus non-ionic surfactant): A quantity (2.5 grams) of 50% concentrate of alkyl dimethyl benzyl ammonium chloride (ADBAC), with the alkyl group distribution

(CAS # 68424-85-1), was mixed with water 496 grams and 1 .5 grams of Surf-Ac® 820 non-ionic surfactant (80% Alcohol ethoxylate/Alkylphenol ethoxylate) was added with good mixing.

Test solution 6 (0.25% ADBAC plus vegetable oil concentrate/organosilicone): A quantity (2.5 grams) of 50% concentrate of alkyl dimethyl benzyl ammonium chloride (ADBAC), with the alkyl group distribution of 40% C12, 50% C14, 10% C16 (CAS # 68424-85-1), was mixed with water 496.25 grams and 1.25 grams of Cardinal MSO Plus vegetable oil concentrate (methylated seed oil and organosilicone blend) was added with good mixing.

Test solution 7 (0.5% ADBAC plus quinclorac herbicide): A quantity (4 grams) of 50% concentrate of alkyl dimethyl benzyl ammonium chloride (ADBAC), with the alkyl group distribution of 67% C12, 25% C14, 7% C16, 1 % C18 (CAS # 68391-01 -5), was mixed with water (391 .5 grams) and 4.5 grams of Drive® XLR8 (quinclorac) herbicide was added with good mixing.

Test solution 8 (1 .25% ADBAC): A quantity (12.5 grams) of 50% concentrate of alkyl dimethyl benzyl ammonium chloride (ADBAC), with the alkyl group distribution of 40% C12, 50% C14, 10% C16 (CAS # 68424-85-1), was mixed with water (487.5 grams) while stirring vigorously until completely mixed.

Example 2

Test solution 1 (of Example 1) above (1 .0% ADBAC) was applied to thoroughly wet the leaf surfaces of vigorously growing annual bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (three separate tests in field turf). Percentage of herbicidal effects, determined by visual assessment of the leaf surfaces of the plants, are presented in the table below. Tall fescue plants also treated in the test remained bright green showing minimal effect of the treatment after 9 days.

Example 3

Test solution 1 (of Example 1) above (1 .0 % ADBAC) was applied to thoroughly wet the leaf surfaces of vigorously growing rough bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (one indoor test using potted plants). Percentage of herbicidal effects, determined by visual assessment of the leaf surfaces of the plants, are presented in the table below. The plants were resprayed with test solution 1 after 14 days.

Example 4

Test solution 2 (of Example 1) above (0.75% ADBAC) was applied to thoroughly wet the leaf surfaces of vigorously growing annual bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (2 separate tests in field turf). Percentage of herbicidal effects, determined by visual assessment of the leaf surfaces of the plants, are presented in the table below. Several tall fescue plants also treated in the test area remain bright green showing minimal effect of the treatment after 9 days.

Example 5

Test solution 3 (of Example 1) above (0.5% ADBAC) was applied to thoroughly wet the leaf surfaces of vigorously growing annual bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (2 separate tests in field turf). Percentage of herbicidal effects, determined by visual assessment of the leaf surfaces of the plants, are presented in the table below. Several tall fescue plants also treated in the test area remain bright green showing minimal effect of the treatment after 8 days.

Example 6

Test solution 4 (of Example 1) above (0.25% ADBAC) was applied to thoroughly wet the leaf surfaces of vigorously growing annual bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (2 separate tests in field turf). Percentage of herbicidal effects, determined by visual assessment of the leaf surfaces of the plants, are presented in the table below. Several tall fescue plants also treated in the test area remain bright green showing minimal effect of the treatment after 11 days.

Example 7

Test solution 5 (of Example 1) above (0.25% ADBAC plus non-ionic surfactant) was applied to thoroughly wet the leaf surfaces of vigorously growing annual bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (one indoor test using potted plants). Percentage of herbicidal effects, determined by visual assessment of the leaf surfaces of the plants, are presented in the table below.

Example 8

Test solution 6 (of Example 1) above (0.25% ADBAC plus vegetable oil concentrate/organosilicone) was applied to thoroughly wet the leaf surfaces of vigorously growing annual bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (one indoor test using potted plants). Percentage of herbicidal effects, judged by examination of the leaf surfaces of the plants, are presented in the table below. One tall fescue plant and an unidentified broadleaf plant in the treated sample showed only limited phytotoxicity effects from the treatment after 1 1 days.

Example 9

Test solution 7 (of Example 1) above (0.5% ADBAC plus quinclorac herbicide) was applied to thoroughly wet the leaf surfaces of one vigorously growing annual bluegrass plant, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (one test in field turf).

Percentage of herbicidal effects, judged by examination of the leaf surfaces of the plants, are presented in the table below.

Example 10

Test solution 7 (of Example 1) above (0.5% ADBAC plus quinclorac herbicide) was applied to thoroughly wet the leaf surfaces of vigorously growing rough bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (one indoor test using potted plants). Percentage of herbicidal effects, judged by examination of the leaf surfaces of the plants, are presented in the table below.

Example 11

Test solution 8 (of Example 1) above (1 .25% ADBAC) was applied to thoroughly wet the leaf surfaces of vigorously growing annual bluegrass plants, and the herbicidal effects (chlorosis and necrosis of plant tissue) were observed over time (one indoor test using potted plants). Percentage of herbicidal effects, determined by visual assessment of the leaf surfaces of the plants, are presented in the table below.

Example 12

Test solution 2 (of Example 1) above (0.75% ADBAC) was applied to thoroughly wet an area of vigorously growing Bermuda grass, and phytotoxicity effects were monitored over a period of 12 days. While some discoloration of the turf was observed over this time, the effects remained at acceptable levels (less than 20%).

Claims

1. A method for effective control of annual bluegrass (Poa annua) and rough bluegrass (Poa trivialis) weeds, the method comprising:

identifying annual bluegrass and rough blue grass weeds; and

applying to locus of the weeds a composition comprising:

a trialkylbenzyl ammonium salt of the chemical formula

CeH₅-CH₂-N(+)Ri R R X(-) wherein, Ri and R are each independently C to C alkyl; R is Cs to C-is alkyl or alkenyl; and

X is chloride or another agriculturally acceptable anion;

wherein the composition is a selective herbicidal composition.

2. The method of claim 1 , wherein the trialkylbenzyl ammonium salt is present at a concentration between 0.1 % and 1 .4%.

3. The method of claim 1 , wherein the selective herbicidal composition further comprises a nonionic surfactant comprising 80% alcohol ethoxylate/alkylphenol ethoxylate.

4. The method of claim 1 , wherein R and R are methyl; R is Cs to Cis alkyl or alkenyl; and X is chloride.

5. The method of claim 2, wherein the composition further comprises one or more

postemergence or preemergence selective herbicides. The method of claim 5, wherein the postemergence and/or preemergence herbicides include auxinic herbicides, aryloxyphenoxypropionic herbicides, sulfonylureas, triazines, flumioxazin, amicarbazone, methiozolin, metribuzin, ethofumesate, bispyribac, indaziflam, prodiamine, metolachlor, s-metolachlor, dimethenamide, pronamide, dithiopyr, oryzalin, oxadiazon, mesotrione, bensulide, benefin and pendimethalin.

7. The method of claim 5, wherein the composition further comprises additional agents for improvement of storage, handling and application properties. The method of claim 7, wherein the additional agents include one or more of non-ionic surfactant, vegetable oil concentrate, crop oil concentrate or silicone oil.

9. The method of claim 1 , wherein the locus of the annual bluegrass (Poa annua) and rough bluegrass (Poa trivialis) weeds is on turf.

10. The method of claim 1 , wherein the turf is residential and institutional lawns, athletic fields, parks, sod farms, golf course fairways, roughs, tees and greens.

1 1 . A selective herbicidal composition for control of annual bluegrass (Poa annua) and rough bluegrass (Poa trivialis) weeds when applied to the locus of the weeds, said composition comprising: a trialkylbenzyl ammonium salt of the chemical formula below

CeH₅-CH2-N(+)Ri R₂R3 X(-) wherein, R1 and R₂ are each independently C1 to C4 alkyl; R3 is Cs to Cis alkyl or alkenyl; and X is chloride or another agriculturally acceptable anion, and the concentration of the trialkylbenzyl ammonium salt is in the range of 0.1 % to 1 .4%.

12. The selective herbicidal composition of claim 1 1 , wherein R1 and R₂ are methyl; R3 is Cs to Cis alkyl or alkenyl; and X is chloride.

13. The selective herbicidal composition of claim 12, further comprising one or more postemergence or preemergence selective herbicides.

14. The selective herbicidal composition of claim 13, wherein said composition consists essentially of the trialkylbenzyl ammonium salt.

15. The selective herbicidal composition of claim 1 1 , further comprising an additional agent comprising non-ionic surfactant comprising 80% alcohol ethoxylate/alkylphenol ethoxylate.

16. A method for effective control of annual bluegrass (Poa annua) and rough bluegrass (Poa trivialis) weeds, the method comprising applying to locus of the weeds a composition comprising: a trialkylbenzyl ammonium salt of the chemical formula

CeH₅-CH2-N(+)Ri R₂R3 X(-) wherein, Ri and R₂ are each independently Ci to C4 alkyl; R3 is Cs to Cis alkyl or alkenyl; and X is chloride or another agriculturally acceptable anion;

wherein the trialkylbenzyl ammonium salt is present at a concentration between 0.1 % and 1 .4%.