IE48774B1

IE48774B1 - Herbicides

Info

Publication number: IE48774B1
Application number: IE1325/79A
Authority: IE
Original assignee: Lilly Industries Ltd
Priority date: 1978-07-15
Filing date: 1979-08-08
Publication date: 1985-05-15
Also published as: SU860674A3; PL217116A1; EG13945A; ATA483979A; AR225418A1; DD144858A5; KR830002045B1; FR2430723A1; FI792193A; IL57767A; FR2430723B1; IE791325L; AT364572B; IT7949754A0; HU180832B; RO78004A; GR69817B; DK160967C; DE2927908A1; AU527751B2

Abstract

The mixing rate of compd. I (Bigenox) and compd. II[M.C. P.A., when X=CH2-.; M.C.P.B., when X=-(CH2)3-.; Mecoprop, When x=-CH(CH3)-, as herbicides is described. Thus, wt% of bifenox and mecoprop was faborable at the rate of 1:3˜1.5:1. The mixt. of bifenox 20, nicoprop (K-salt) 40, Na-lauryl-sulfate 3, Na-lignin-sulfate 3, precipritated silica 8 wt%, and caolin 26 inhibited the growth of Anethum Graveolens, caspella Bursa-pastorsm Centaruea Cyanusm Fumaria officinalis, Lamium amplexicaulem Papaver rhoeasm Silene, and Syerallia Media by 80%

Description

The invention relates to a method of combating weeds in cereal crops and to herbicidal formulations for use in such method.

Heretofore, the broadleaf weed species Matricaria spp has proved particularly resistant to conventional herbicides, causing much damage to winter and spring cereal crops such as wheat, barley, oats and rye. We have now found that by using a combination of particular known herbicides this weed species is controlled to a surprisingly high level, synergism, in accordance with the well-known Colby Equation (Weeds, 15, 20-22, 1967), being observed. Additionally, control of other problematic weed species has been found to be very satisfactory when using the combination, synergism again being observed in several cases.

Thus, according to the present invention a method of combating weeds in a cereal crop locus comprises applying to said locus, post emergence the crap, a compound of formula I, and one or more compounds of formula 11, O-X-COOH (IX) 8 7 7 4 wherein X is -CH(CHg)-, -CHg- or -(CHgJg-, and wherein when a compound of formula II, in which X is -CH(CHg)-, is employed, the compound of formula I is applied at a rate of 0.25 to 3.0 kg/ha and the compound of formula IX is applied at a rate of 0.5 to 3.0 kg/ha; and when a compound of formula II, in which X is -CH.,-, is employed, the compound of formula I is applied at a rate of 0.7 to 2.0 kg/ha and the compound of formula II is applied at a rate of 0.7 to 3.0 kg/ha, and when a compound of formula II, in which X is -(CH2)3-, is employed, the compound of formula I is applied at a rate of 0.25 to 3.0 kg/ha and the compound of formula II is applied at a rate of 0.1 to 3.5 kg/ha, the crop being other than spring wheat when a compound of formula I and a single compound of formula II, wherein X is -CH(CHg)-, is employed, wherein the crop is sprayed with spray application liquor formed by addition of water to an aqueous suspension or wettable powder formulation containing the compounds of formulae.

I and IX.

In general, the compound of formula I is applied at a rate of from 0.7 to 2.0 kg/ha and the compound (s) of formula II at a rate of from 0.7 to 3.0 kg/ha.

The compound of formula I is known as bifenox, the preparation thereof being described in United Kingdom Patent Specification No. 1,232,368 and its use as a herbicide being described in Proc.N.E.Weed Sci Conf. 1973,27,31.

The compound of formula II, wherein X is -CH(CH3)-, is known as mecoprop.

The compound of formula ll, where X is -CHg-, is known as M.C.P.A.

The compound of formula II, wherein X is -(CHg)^-, is known as M.C.P.B.

Mecoprop, M.C.P .A., M.C.P.B., their salts and esters, their manufacture and their herbicidal properties are well documented in the literature.

The compounds of formula II may be employed in free acid form or in a salt or ester form which is non-phytotoxic to cereals. As examples of salts forms may be given the alkalimetal , τ 4 8 7 7 4 -4e.g. sodium and potassium, salt forms and the ammonium, alkylammonium and alkanolammonium salt forms, e.g. the ethanolammonium salt form. As examples of eS+°r forms may be given the lower, e.g. C|_g, alkyl ester forms, e.g. the methyl and octyl ester forms. The use of such salts and ester forms is embraced by the present invention.

In the method of the present invention, the compound of formula 1 (bifenox) is preferably employed at an application rate of from 0.7 to 1.5 kg/ha and more preferably at a rate of about 0.75 to 1.0 kg/ha. The compound of formula II, wherein X is -CHfCH^)- or -(Ch^g-, i.e. mecoprop or M.C.P.B., is preferably employed at an application rate of from 1.0 to 2.0 kg/ha. The compound of formula II, wherein X is -Ck^-, i.e. M.C.P.A., is preferably employed at an application rate of from 0.7 to 1.5 kg/ha and more preferably at a rate of about 0.75 to I.Okg/ha.

The weight ratio of the compound of formula I to fhe compound^) of 15 formula II is generally in the range of from 1:4 to 3:1. Where the bifenox is employed together with mecoprop or M.C.P.B., the weight ratio of the former to the latter is preferably in the range of from 1:3 to 1.5:1, more preferably about 1:2. Where the bifenox is employed together with M.C.P.A., the weight ratio of the former to the latter is preferably In the range of from 1:2 to 2:1, more preferably about I:I, In the case of the compounds of formula II, the above weights and ratios are based on the acid equivalent thereof if a salt or ester is employed.

The method of the present invention is preferably carried out when the crop is between fhe one leaf stage and appearance of the second node The preferred crops for treatment by the method of the present invention are winter wheat, spring barley and winter barley. 8 7 7 4 -5The compound of formula I and the compound(s) of formula II may be applied together or separately. If the latter, the time period between applications is preferahiv short, say one day or less. If is by far preferred, however, for the compounds to be applied simultaneously as a single formulation. In order to simplify manufacture, storage and transport, herbicidal formulations will normally be produced in concentrate form intended for dilution in water to the degree necessary to enable the above application rates to be achieved. Such concentrate formulations may contain from I to 90%, preferably 15 to 85%, by weight of active ingredients associated with one or more inert, nonphytotoxic, carriers therefor. Such formulations will usually be in the form of a wettable powder, an emulsifiable concentrate or an aqueous suspension or solution.

Herbicidal formulations form a further aspect of the present invention. Thus, there is provided a herbicidal formulation to be used in the method of the invention, after dilution if appropriate, and comprising a compound of formula I and one or more compounds of formula II, or a salt or ester thereof, in a weight ratio range of from 1:4 to 3:1 (based on the acid equivalent of the compound(s) of formula II) together with a non-phytotoxic diluent or carrier. The preferred weight ratio ranges are as given above.

As a further separate aspect of the present invention, there is provided a herbicidal formulation comprising a compound of formula (,stated above, together with a compound of formula II, in which X is -(Oy^-, or a salt or ester thereof, in a wei^it ratio raige of from 1:4 to 3:1 (based on the acid equivalent of the compound of formula II), together with a non-phytotoxic diluent or carrier. Again, the preferred weight ratio rtnges are as given above.

The herbicidal formulations of the present invention are intended to embrace not only the so-called concentrate formulation forms, but also ready-to-use dilute formulations such as tank mixes and application spray liquors. 487 7 4 -6Such dilute formulations are generally produced by dilution down to the appropriate degree of concentrate formulations but, if desired, may be produced by t^e separate nd^iticn of appropriate cmounts cr the ind'viduai components to an appropriate diluent or carrier. ς Turning, however, to the concentrate formulations, wettable powders comprise an intimate mixture of the active ingredients, one or more inert carriers and one or more appropriate surfactants. The inert carrier may be chosen from the attapulgite clays, the montmorillonite clays, the diatomaceous earths, kaolins, micas, talcs and purified silicates. Effective surfactants may be found amcng the sulphonated lignins, the naphthalene sulphonates and condensed naphthalene sulphonates, the alkyl succinotes, the alkylbenzene sulphonates, the alkyl sulphates and non-ionic surfactants such as ethylene oxide adducts of phenol. Illustrative wettable powders are those having the following composition: WETTABLE POWDERS % by weight.

Compound of formula I I to 73 Compound of formula II* I to 79 Surfactantis) I to IO Dispersing Agent 0 to IO Anticaking Agent Oto IO Inert carrier(s) to I00 * based on acid equivalent Emulsifiable concentrates comprise the active ingredients dissolved in one or more suitable solvents, together with a surfactant. As examples of solvents may be given alkyl substituted benzenes, o-chlorotoluene, heavy aromatic naphthalenes, glycol ethers and cyclic ketones. Illustrative emulsifiable concentrates are those having the following composition : 8 7 7 4 -7EMULSIFIABLE CONCENTRATES % weight/volume Compound of formula I ! to Compound of formula II* I to 60 Surfactant(s) 2 to 10 Co-solvent 0 to 40 Solvent to 100 * Based on acid equivalent Aqueous suspensions and solutions comprise the active ingredients suspended or dissolved in water together with any desired surfactants, thickening agents, antifreezing agents or preservatives. Suitable surfactants may be chosen from those mentioned above in connection with wettable powders. Thickening agents, if used, are normally chosen from appropriate cellulose materials and natural gums,whilst glycols will generally be used when an antifreezing agent is required. Preservatives may be chosen from a wide range of materials such as the various paraben antibacterials, phenol, o-chlorocresol, phenyl mercuric nitrate aid formaldehyde. Illustrative aqueous suspensions are those having the following composition : AQUEOUS SUSPENSIONS % weight/volume Compound of formula 4 to 59 Compound of formula 11* 5 to 65 Wetting Agent 0 to 10 Dispersing Agent 0 to 6 Thickening/Suspending Agent 0 to 5 Antifreeze Agent Oto 15 Preservative 0 to 2 Water to 100 8 7 7 4 -8* Based cn acid equivalent The aqueous suspension and wettable powder formulations are preferred for use in the method of t^e present invention, g'v’ng signif'cantiy lower phytotoxicity to the cereal crop than the emulsifiable concentrate formulations.

The following Examples further illustrate the inventions. In all Examples, the amount of mecoprop, M.C.P.A and M.C.P.B used is based on the acid equivalent.

EXAMPLES I TO 5 The following wettable powders ingredients shown : (1) Bifenox Mecoprop (potassium salt) Sodium iauryi sulphate Sodium lignin sulphonate Precipitated silica Kaolin (2) Bifenox Mecoprop (Sodium salt) Ethoxyiated alkyl phenol Lignosulphonate Fumed Silica Attapulgite (3) Bifenox Mecoprop (diethanolamine salt) Sodium salt of condensed naphthalene sulphonic acids Precipitated silica Sodium alumino silicate were prepared, in each case having the % by weight to I00 % by weight ( to I00 % by weight I0 ( I0 to I00 -9% by weight (4) Bifenox 30 M.C.P.P. ^so^ium sc't' 45 Sodium lauryl sulphate 2 Sodium lignin sulphonate 3 Precipitated silica 5 Montmorilionite to 100 % by weight (5) Bifenox 30 M.C.P.A. (sodium salt) 30 Sodium lauryl sulphate 2 Sodium lignin sulphonate 3 Precipitated silica 5 Montmorilionite to 100 In each Example, the active ingredients were carefully blended with the specified exipients in conventional mixing equipment. The blend was then further milled in a fluid energy mill to a size rcnge of from I to iO microns EXAMPLES 6 TO 10 The following emulsifiable concentrates were prepared having the constituents shown below : % by weight/ by volume (6) Bifenox 15 Mecoprop 30 Calcium dodecylbenzone sulphonate 3 Alkyl phenoxypolyoxyethylene ethanols 3 Isophorone 20 Xylene to 100 -10- % by weight/ by volume Bifenox 15 Mecoprop ester 20 Alkyl aryl sulphonate 4 Polyoxyethylene triglyceride 4 Cyclohexanone 20 Orthoch loroto luene to I00 % by weight/ by volume Bifenox IO Mecoprop Amine salt of dodecylbenzene 25 sulphonic acid Polyoxyethylene sorbitol 3 fatty esters 4 Isophorone I5 Heavy aromatic naphtha to I00 % by weight/ by volume Bifenox 20 M.C.P.B. (mixed butyl esters) 30 Calcium dodecylbenzene sulphonate Alkyl phenoxypolyoxyethylene 3 ethanols 4 Isophorone 30 Orthochlorotoluene to I00 8 7 7 4 (IO) Bifenox % by weight/ by volume ?n M.C.P.A 20 Calcium dodecylbenzene sulphonate 3 Alky Iphenoxypoiyoxy ethylene ethanols 4 Isophorone 30 Orthochlorotoluene to 100 The active ingredients were added to the appropriate solvents) with stirring and optional heating to facilitate dissolution of the active materials. The surfactants were then added. The solutions were then filtered to remove insoluble impurities EXAMPLES I i TO 13 The following aqueous suspensions were prepared having the constituents shown below : (Ii) % by weiqht Bifenox 30 M.C.P.A (amine salt) 30 (Ethyl)hydroxyethyl cellulose 0.2 Lignin sulphonate 3 Propylene glycol 2 Water to 100 (i2) Bifenox % by weight 20 M.C.P.B (amine salt) 35 Hydroxyefhyl cellulose 0.2 Amine ethoxylate 3 Water to 100 .. 4 8 7 7 4 % by weight 0.5 to 100 -12(I3) Bifenox Mecoprop (amine salt) Hydroxyethyl cellulose Phosphate ester Ethylene glycol Water ig The following Examples serve to illustrate the synergistic effect demonstrated by the method of the invention EXAMPLE 14 Several field trials were carried out on winter wheat and one on spring 15 barley on sandy and clay loam soils. Applications was made as tank mixtures with a knapsack sprayer at a volume of 300-800 l/ha. The crop stage at application varied from the start of tillering to the stage at which the second node was visible. Visual assessments of herbicidal activity were made from 2 to weeks after application using the Barratt and Horsfall (1945) rating system.

In the following table is set out the average of' the results obtained in terms of percent control of the weed species Matricaria spp for the individual herbicides Bifenox, mecoprop and M.C.P.A.and for the tank mix combinations of Bifenox + mecoprop and Bifenox + M.C.P.A., there also being given the control value estimated by the Colby formula for additive effect..The concentrates from which the aqueous spray liquors were formed were Bifenox 80% wettable power, mecoprop 55% aqueous solution and M.C.P.A 40% aqueous solution. 8 7 7 4 -13TABLE Dosage Rate Kg/kn % Control Observedro'by formula Bifenox I.O 16.1 N/A Bifenox I.5 25.5 N/A Bifenox 2.0 40.3 N/A M.C.P.A (amine salt) 0.8 38.5 N/A M.C.P.A.(amine salt) 1.6 64.8 N/A | Mecoprop (amine salt) 2.0 54.8 N/A 1 Bifenox + M.C.P.A. (amine salt) 1.0 + 0.8 85.1 48.4 It 1.5 + 0.8 93.4 54.2 II 2.0+ 1.6 95.3 79.0 Bifenox + mecoprop (amine salt) 1.0 + 2.0 86.0 62.1 M 1.5+2.0 89.0 66.3 Thus, from the above it can be seen that a genuine synergistic effect is observed when employing the method of the present invention.

Slight scorching of the crop was noted, which was subsequently out-grown.

As well as excellent control of the Matricaria spp, the following weed species were well controlled (greater than 80%) employing, in separate tests, the above combined tank mixes : Anethum graveolens, Capsella bursa-pastoris, Centourea cyanus, Fumaria officinalis, Lcmium amplexicaule, Papaver rhoeas, Si lene spp and Stellaria media.

The Bifenox + M.C.P.A. combination additionally gave good control (greater then 80%) of the following weed species. Anagallis arvensis, Chenopodium album, Polygonum aviculare Ranunculus arvensis, 8 7 7 4 -14Rgnuncules repens. Raphanus raphanistrum, Rumex crispus, Sinapis arvensis, Sonchus arvensis and Veronica hederifolia The Bifenox * mecoorop combination ad-fitHna'1/ gave good ccnt-o1 (greater than 80%) of Galium aparine EXAMPLE 15 The following greenhouse test was carried out to asses the efficacy of bifenox combined with M.C.P.B.

METHOD Seeds; Galium aparine Matricaria recutita Veronica persica Planting : 0.5cm depth.(Matricaria sg light covering) Temperature/liqhtinq : Greenhouse (cool) Watering : when required Fertilisation; none Experiment design ; randomised block (4 replicates) Plot size treated; 10 x 10cm pots Soil texture; loam 2o Application equipment; single nozzle microsprayer, 50cm band width, volume rate per area 50 ml per sq metre.

Weed Stage at Application : 3-5 true leaves.

In the following table is set out the average of the results obtained in terms of per cent control of the weed species, together with the control value estimated by the Colby formula. For the Veronica persica a visual control rating was made. For the other two species fresh weight of shoots was obtained. 8 7 7 4 -15The bifenox from which the spray liguor was formed was an 80% wettable powder, the M.C.P.B. was a 48% aqueous solution, the combination being a tank mix.

Rate kg/ha WEED SPECIES,% CONTROL Matricaria Sp Galium marine Veronica persica uoservea uoioy uoservea Colby uoservea uoioy Bifenox 0.75 56.5 N/A 62.5 N/A 77.0 N/A M.C.P.B I.O 7.5 N/A 0.0 N/A 73.0 N/A M.C.P.B I.5 2.4 N/A 0.0 N/A 78.0 N/A Bifenox + MCPB 0.75+I.O 73.0 60.0 72.1 62.5 100.0 94.0 It 0.75+1.5 82.0 57.5 78.3 62.5 100.0 96.0 Thus, from the above, it can be seen that a genuine synergistic effect is observed when employing the method of the present invention.

EXAMPLE I6 This example further illustrates the synergistic effect demonstrated by the combination of bifenox + mecoprop when used for control of the broadleaf weed Matricaria spp.

Winter wheat was sown in France in October at a depth of 3 cm. and at a rate of I50 kg/hectare. The crop was allowed to grow without treatment until the following March, at which time the crop was at growth stage 4-5 (see Plant Pathol., 3 128-9, (1954)).

Bifenox and mecoprop were then applied separately and combined together as a tank mix and sprayed onto the area in which the crop was growing using a knapsack sprayer at a volume rate per hectare of 300 litres. Assessments, as weed control ratings, were made between 2 and 5 weeks after application. 8 7 7 4 -16TABLE Dosage rate g/HectareMat':ccir:a spp % control Bifenox 1000 6 Bifenox 1500 I5 Bifenox + Mecoprop 1000 + 2000 87 Bifenox + Mecoprop 1500 + 2000 88 Mecoprop 2000 50 8 7 7 4

Claims

CLAIMS:I. A method of combating weeds in a cereal crop locus comprising applying to said locus, post emergence the crop, a compound of formula I,

1.5 kg/ha. 25

2. A method according to claim 1, wherein the compound of 20 formula I is applied at a rate of 0.7 to 2.0 kg/ha and the compound(s) of formula IX at a rate of 0.7 to 3.0 kg/ha.

3. A method according to claim 1 or claim 2, wherein the compound of formula I is applied at a rate of from 0.7 to

4. A method according to any one of claims 1 to 3, wherein, in the compound of formula II, X is -CH(CH 3 )~. 4 8 7 7 4 5. Emulsifiable concentrate.

5. A method of any one of claims 1 to 3, wherein, in the compound of formula II, X is-(CHg) 5 at a rate of 0.5 to 3.0 kg/ha; and when a compound of formula II, in which X is -CHg- is employed, the compound of formula I is applied at a rate of 0.7 to 2.0 kg/ha and the compound of formula II is applied at a rate of 0.7 to 3.0 kg/ha, and when a compound of formula II, wherein X is 5 and one or more compounds of formula II (ID

6. A method according to claim 4 or 5, wherein the com30 pound of formula 11 is applied at a rate of 1.0 to 2.0 kg/ha. - 19

7. A method according to any one of claims 1 to 3, wherein, in the compound of formula IX, X is -CHg-.

8. A method according to claim 7, wherein the compound of formula II is applied at a rate of from 0.7 to 1.5 kg/ha. 5

9. A method according to claim 8, wherein the compound of formula II i.s applied at a rate of from 0.75 to 1.0 kg/ha.

10. A method according to claim 4 or 5, wherein the weight ratio of the compound of formula I to the compound of formula II is in the range of 1:3 to 1.5:1. 10 10 -(CHg) 3 -, is employed the compound of formula I is applied at a rate of 0.25 to 3.0 kg/ha and the compound of formula II is applied at a rate of 0.1 to 3.5 kg/ha, the crop being other than spring wheat when a compound of formula I and a single compound of formula II, wherein X is -CHfCHg)-, is

11. A method according to claim 8, wherein the weight ratio of the compound of formula I to the compound of formula II is in the range of 1:2 to 2:1.

12. A method according to any preceding claim, wherein the crop is a winter wheat spring barley or winter barley crop. 15

13. A method according to any preceding claim, wherein the treatment of the crop takes place when the crop is at a stage between the one leaf stage and the appearance of the second node.

14. A method according to any preceding claim, wherein the 20 compound of formula II is in a salt or ester form non-phytotoxic to cereal crops.

15. A method according to claim 1, substantially as hereinbefore described. 15 employed; wherein the crop is sprayed with spray application liquor formed by addition of water to an aqueous suspension or wettable powder formulation containing the compounds of formulae I and II.

16. A herbicidal composition comprising a compound of 25 formula I, stated in claim 1, and a compound of formula II, stated in claim 1, for use at the rates and in the crops stated in claiiii 1, the weight ratio of the compound of formula I to - 20 the compound of formula II being in the range of 1:4 to 3:1, together with a non-phytotoxic diluent or carrier, with the proviso that the composition is not an emulsifiable concentrate or a spray liquor obtained by dilution of an

17. A composition according to claim 16, wherein, in the compound of formula II, X is -CH(CH^)-.

18. A composition according to claim 16, wherein, in the compound of formula II, X is -CHg-. 10 - 18 wherein X is -CHtCHg)-, “CHg- or -(CHg)and wherein when a compound of formula II, in which X is -CH(CHg)-, is employed, the compound of formula I is applied at a rate of 0.25 to 3.0 kg/ha and the compound of formula II is applied

19. A composition according to claim 16, wherein, in the compound of formula II, X is -(CHg) ^-. 20. A composition according to any one of claims 16 to 19 in the form of an aqueous suspension or a wettable powder. 21. A herbicidal composition comprising a compound of 15 formula I, stated in claim 1, together with a compound of formula II, stated in claim 1, in which X is -(CHg) 3 ~. 22. A composition according to any one of claims 16 to 23, wherein the compound of formula II is in a salt or ester form non-phytotoxic to cereal crops.

20. 23. A composition according to claim 16 to 21, substantially as hereinbefore described.