GB2153226A - Selective herbicidal agents containing a triazinone - Google Patents

Abstract

Selective herbicidal compositions containing 4-amino-6-tert.-butyl-3-ethylthio-1,2,4-triazin-5(4H)- one of the formula <IMAGE> are used for selectively combating monocotyledon and dicotyledon weeds in crops of cereal and leguminosae. The compositions may contain at least one other active herbicide suitable for the same field of use.

Description

SPECIFICATION Selective herbicidal agents based on triazinone The present invention relates to the use of a known 1,2,4-triazin-5-one for selectively combating weeds, and to new herbicidal agents which contain this triazinone derivative in combination with certain other known herbicidal active compounds.

It has already been disclosed that certain 3,6-disubstituted 4-amino-l ,2,4-triazin-5-(4H)-ones can be used as herbicides (compare, for example, U.S. patent Specifications 3,671,523 and 3,905,801). However, these triazinones are not always satisfactory when they are employed for selectively combating weeds. Thus, in practice, most triazinones present difficulties when they are used for selectively combating dicotyledon weeds and graminaceous weeds in cereals. Of the group of triazinones described, 4-amino-6-tert.-butyl-3-methylthio-1 ,2,4-triazin-5(4H)-one (A) has found acceptance in practice, and is used for selectively combating weeds in soya beans, potatoes, tomatoes and Lucerne and, with severe limitations, in cereals. Its use in cereals is based chiefly on post-emergence treatment.It is not possible to use it in cereals by the preemergence method for tolerance reasons. In addition, for reasons of phytotoxicity towards the cereal, its use is recommended only with certain varieties of cereal, and even in this case only in a limited area.

It is furthermore already known that 4-amino-6-tert.-butyl-3-ethylthio-1,2,4-triazin-5(4H)-one (B) has general herbicidal properties (compare U.S. Patent Specification 3,671,523). However, particular properties of this compound, in particular possibilities for selective use of this triazinone derivative in crops of useful plants, have not been disclosed.

It has now been found, surprisingly, that 4-amino-6-tert.-butyl-3-ethylthio-1,2,4-triazin-5(4H)- one of the formula

which is known, is particularly suitable for selectively combating monocotyledon and dicotyledon weeds in cereal crops and leguminosae crops before and after emergence of the plants. The use of active compound (B) as a selective herbicide for cereals, chiefly in barley and wheat, is of particular importance.

It is particularly surprising that, in the case of the active compound (B) to be used according to the invention-in contrast to the closely related active compound (A)-the difference between the effective herbicidal dose and the dose still tolerated by cereals and leguminosae is relatively large, so that the danger of phytotoxic damage to the crop plants is very slight. In the case of use in cereals, it is furthermore surprising that the active compound (B), again in contrast to active compound (A), can be employed not only by the post-emergence method but also by the pre-emergence method; moreover, active compound (B) can also be successfully used by the so-called pre-sowing incorporation method.

These particular properties of active compound (B) enable weeds to be combated in cereals using a herbicidally active triazinone which, at the same time, is well tolerated by the crop plants. The active compound (B) which can be used according to the invention thus represents a great enrichment of selective herbicides in the cultivation of cereals and leguminosae.

By weeds, in the broadest sense, there are to be understood all plants which usually occur as contaminants of cereal crops or leguminosae crops. Examples which may be mentioned of weeds which are destroyed by the triazinone (B) to be used according to the invention and frequently occur in cereal crops and leguminosae crops are: Dicotyledon weeds of the genera: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis, Papaver and Centaurea.

Monocotyledon weeds of the genera: Echinochloa, Setaria, Panicum, Digitaria, Phleum, Poa, Festuca, Eleusine, Brbchiaria, Lolium, Bromus, Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis, Sagittaria, Eleochris, Scirups, Paspalum, Ischaemum, Saphenoclea, Dactyloctenium, Agrostis, Alopecurus and Apera.

However, the use of the active compound (B) according to the invention is in no way restricted to these genera, but also extends in the same manner to other plants.

Active compound (B) is particularly suitable for combating weeds in the wheat, barley and maize varieties of cereal and in the pea and soya bean varieties of leguminosae, the action being directed equally towards dicotyledon weeds (dicotyledoneae) and towards graminaceous weeds (monocotyledoneae), in particular Avena fatua, Bromus, Alopecurus and Setaria.

It has also been found that new active compounds combinations consisting of 4-amino-6-tert. butyl-3-ethylthio-1 ,2,4-triazin-5(4H)-one (B) and certain other known herbicidal active compounds have a particularly high herbicidal activity and areoutstandingly suitable for broadening the action spectrum and for extending the application range of the triazinone (B).

Thus, active compound combinations consisting of the triazinone (B) on theone hand and at least one of the following compounds mentioned: (a) S-2,3,3-trichloroallyl diisopropylethiolcarbamate (triallate), (b) S-2,3-dichloroallyl diisopropylthiolcarbamate (diallate) or (c) 1-amino-6 ethylthio-3-(2,2-dimethylpropyl)-l ,3,5-triazine-2,4(1 H,3H)-dione (ametridione), on the other hand, can be particularly successfully used by the pre-sowing incorporation method or by the pre-emergence method.

In the case of post-emergence treatment, active compound combinations which consist of the triazinone (B) on the one hand at least one of the following compounds mentioned: (c) 1-amino 6-ethylthio-3-(2, 2-dimethylpropyl)-1, 3, 5-triazin-2,4(1 H, 3 H)-dione (ametridione), (d) 4-amino-6tert.-butyl-3-methylthio- 1, 2,4-triazin-5-(4H)-one (A) (metribuzin), (e) 1, ,2-dimethyl-3,5-diphenyl- pyrazolium methyl-sulphate (difenzoquat), (f) ethyl N-benzoyl-N-(3,4-dichlorophenyl)-2-aminopropionate (benzoyl-prop-ethyl), (g) isopropyl N-benzoyl-N-(3-chloro-4-fluoro-phenyl)-2-am inopropionate (flampropisopropyl), (h) methyl N-benzoyl-N-(3-chloro-4-fiuorophenyl)-2-aminopropionate (flamprop-methyl), (i) methyl 2-[4-(2,4-dichlbrnphenoxy)phenoxy]-prnpionate (dichlofop-methyl), (k) methyl-2-chloro-3-(4-chlorophenyl)-propionate (chlorofenprop-methyl), (I) 3,5-dibromo-4-hydroxy-benzonitrile (bromoxynil), (m) 3,5-diiodo-4-hydroxy-benzonitrile (ioxynil), (n) 2,4-dichlorophenoxyacetic acid (2,4-D), (o) 2-(2,4-dichlorophenoxy)-propionic acid (2,4-DP), (p) 4-chloro-2methylphenoxyacetic acid (MCPA), (q) 2-(2-methyl-4-chlorophenoxy)-propionic acid (MCPP), (r) 1 -(2-benzothiazolyl)-1 , 3-dimethylurea (methabenzthiazuron), (s) 3-(4-isopropylphenyl)-1 ,1-dimethylurea (isoproturon), (t) 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea (chlorotoluron) or (u) 3 isopropyl-2, 1 ,3-benzo-thiadiazin-4-one 2,2-dioxide (bentazon), on the other hand, are preferred.

The active compound combination consisting of the triazinones (B) + (A) is particularly preferred for post-emergence treatment (that is to say by the post-emergence method).

Surprisingly, the herbicidal activity of the active compound combinations mentioned is greater than the sum of the actions of the individual components, that is to say the active compound combinations exhibit a synergistic effect. The new active compound combinations thus likewise represent a valuable enrichment of the art.

The weight ratios of the active compounds in the active compound combinations can vary within relatively wide limits. In general, 0.02 to 10 parts by weight of the mixing partner mentioned, preferably 0.05 to 4 parts by weight, are present per part by weight of the triazinone (B).

The active compound combinations according to the invention can be used for the same plants as the active compound (B).

The triazinone (B) and the new active compound combinations mentioned can be converted to the customary formulations, such as solutions, emulsions, wettable powders, suspensions, powders, dusting agents, pastes, soluble powders, granules, suspension-emulsion concentrates, natural and synthetic materials impregnated with active compound, and very fine capsules in polymeric substances.

These formulations are produced in known manner, for example by mixing the active compounds with extenders, that is, liquid solvents and/or solid carriers, optionally with the use of surface-active agents, that is, emulsifying agents and/or dispersing agents, and/or foamforming agents. In the case of the use of water as an extender, organic solvents can, for example, also be used as auxiliary solvents.As liquid solvents, there are suitable in the main: aromatics, such as xylene, toluene or alkyl naphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chloroethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, for example mineral oil fractions, alcohols, such as butanol or glycol as well as their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents, such as dimethylformamide and dimethylsulphoxide, as well as water.

As solid carriers there are suitable: for example ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals, such as highly-dispersed silicic acid, alumina and silicates; as solide carriers for granules there are suitable: for example crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite and dolomite, as well as synthetic granules of inorganic and organic meals, and granules of organic material such as sawdust, coconut shells, maize cobs and tobacco stalks; as emulsifying and/or foam-forming agents there are suitable: for example non-ionic and anionic emulsifiers, such as poly-oxyethylene-fatty acid esters, polyoxyethylenefatty alcohol ethers, for example alkylaryl polyglycol ethers, alkylsulphonates, alkylsulphates, arylsulphonates as well as albumin hydrolysation products; as dispersing agents there are suitable: for example lignin-sulphite waste liquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and synthetic polymers in the form of powders, granules or latices, such as gum arabic, polyvinyl alcohol and polyvinyl acetate, can be used in the formulations.

It is possible to use colorants such as inorganic pigments, for example iron oxide, titanium oxide and Prussian Blue, and organic dyestuffs, such as alizarin dyestuffs, azo dyestuffs and metal phthalocyanine dyestuffs, and furthermore trace nutrients such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc, as further additives in the formulations.

The formulations in general contain between 0.1 and 95 per cent by weight of active compound or active compound combination, preferably between 0.5 and 90%.

The active compound combinations according to the invention are in general used in the form of finished formulations. However, the active compounds contained in the active compound combinations can also be mixed as individual formulations when used, that is to say they can be used in the form of tank mixtures.

The active compound (B) and the new active compound combinations, as such or in the form of their formulations, can also be used as mixtures with other known herbicides for cereals and leguminosae, finished formulations or tank mixing again being possible. Mixtures with other known active compounds, such as fungicides, insecticides, acaricides, nematicides, bird repellents, growth factors, plants nutrients and agents which improve soil structure, are also possible.

The active compound (B) and the new active compound combinations can be used as such, in the form of their formulations or in the use forms prepared therefrom by further dilution, such as ready-to-use solutions, suspensions, emulsions, powders, pastes and granules. The are used in the customary manner, for example by watering, spraying, atomising, dusting or scattering.

Whilst the triazinone (A) can be applied to cereals only by the "post-emergence" method, and even then only with the further limitations mentioned, it is possible to apply the triazinone (B) and the above-mentioned new active compound combinations to cereals both by the "postemergence" method and by the "pre-emergence" method. The triazinone (B) and the new active compound combinations can also be incorporated into the soil before sowing.

The amount of active compound applied can vary within a substantial range, and depends, inter alia, on the weather and on soil factors. In general, the amounts applied are between 0.01 and 5 kg of active compound (B) or active compound combinations per ha, preferably between 0.1 and 3 kg/ha.

The following examples serve to further illustrate the invention.

Preparation Examples 1. 4-Amino-6-tert.-butyl-3-ethylthio-1 ,2,4-triazin-5(4H)-one (B) 5 ml of an alkylaryl polyglycol either, as an emulsifier, and 572 g (5.25 mols) of ethyl bromide are added to a solution of 1,000 g (5 mols) of 4-amino-6-tert.-butyl-3-mercapto-1 ,2,4- triazin-5(4H)-one (compare U.S. Patent Specification 3,671,523) in 5,250 ml of 1 N sodium hydroxide solution. The mixture is stirred vigorously at 50"C until the pH value of the aqueous phase has fallen to 7-8 (10-12 hours). After cooling the mixture to 20do, the reaction product which has crystallised out is filtered off, washed several times with water and dried at 50"C.

1,050 g (92% of theory) of an isomer mixture which has a melting point of 77-82"C and the following composition, determined by gas chromatography, are obtained: 81X of

4-amino-6-tert .-butyl-3- ethylthio-1,2,4-triazin- 5(4H)-one (B) 19X of

,-amino-6-tcrt.-butyl-2- ethyl-1,2,4-triazin-5(4H)- one-3(2H)-thione (C) The pure 3-ethylthio derivative (B) with a melting point of 95"C can easily be separated off by recrystallising the isomer mixture from cyclohexane.

If, instead of ethyl bromide, the equivalent amount of ethyl iodide is used, the two isomers (B) and (C) are formed in a ratio of 90:10.

2. Formulation Example: A 60% strength wettable powder is prepared by the following procedure: 60 parts by weight of the triazinone (B), consisting of technical grade active compound, 3 parts by weight of an arylalkylsulphonate, 3 parts by weight of sulphite waste liquor (spray-dried), 5 parts by weight of a formaldehyde/cyclohexanone/Na bisulphite condensate, 10 parts by weight of highly dispersed silicic acid and alumina (as the remainder to make up to 100 parts by weight) are mixed in a Lödiger mixer and the mixture is then ground via an 8 inch jet mill.

The formulation thus prepared can be suspended in water and is used for the preparation of a ready-to-use spray formulation.

Use Examples In all the examples: (A) = 4-amino-6-tert.-butyl-3-methylthio- 1 , 2, 4-triazin-5(4H)-one (B) = 4-amino-6-tert.-butyl-3-ethylthio-1 , 2, 4-triazin-5(4H )-one Explanation of the abbreviations: I PAN MY = Panicum miliaceum SINAL = Sinapis alba GASPA = Galinsoga parviflora STEME = Stellaria media CHEAL = Chenopodium album LAMSS = Lamium spec.

POLCO = Polygonum convolvulus POLLA = Polygonum lapathifolium VIOTR = Viola tricolor RAPRA = Raphanus raphanistrum GALAP = Galium aparine POLAV = Polygonum aviculare Example A Post-emergence test/greenhouse Solvent: 5 arts by weight of actone Emulsifier: 1 part by weight of alkylaryl polyglycol ether To produce a suitable preparation of active compound, 1 part by weight of active compound is mixed with the stated amount of solvent, the stated amount of emulsifier is added and the concentrate is diluted with water to the desired concentration.

Test plants which have a height of 5-1 5 cm are sprayed with the preparation of the active compound in such a way as to apply the amounts of active compound per unit area which are indicated in the table. The concentration of the spray liquor is so chosen that the amounts of active compound shown in the table are applied in 2,000 litres of water/ha. After three weeks, the degree of damage to the plants is rated in % damage in comparison with the development of the untreated control.The figures denote: 0% = no action (like untreated control) 100% = total destruction The active compounds, amounts applied and results can be seen from the following Table A: Table A Post-emergence test / greenhouse Active Amount of PANMI SINAL GASPA STEME Wheat Maize compound active compound applied kg/ha (A) 1,0 100 100 100 100 100 90 0,5 100 100 100 100 90 90 0,25 100 100 100 100 90 70 (B) 1,0 100 100 100 100 20 80 0,5 100 100 100 100 0 20 0,25 95 100 100 90 0 0 Example B Post-emergence test/open air In a multi-variety test, summer wheat, summer barley and peas were sown on sandy loam with a medium humus content. Sowing took place on the 8th May. Treatment with the herbicide was carried out after 33 days, on the 10th June, that is to say by the post-emergence method.At the time of treatment, the weeds were in the 4-6 leaf stage. The amounts of active compound indicated were applied in 500 liters of water/ha. The active compounds were triazinone (A), formulated as a 70% strength wettable powder, and triazinone (B), formulated as a 60% strength wettable powder. The plot size was 10 m2. The herbicidal action was measured on the naturally occurring weed population.The action on the weeds and crops was determined in percentage damage in comparison with the untreated control and is summarised in the following Table B: Table B Post-emergence test / open air Amount of active Active compound CHEAL RAPRA GALAP POLCO POLAV Summer Summer Peas compound applied barley wheat kg/ha (A) 2.0 100 100 90 100 100 95 70 70 1.5 100 100 85 100 100 90 50 50 1.0 100 100 80 100 100 85 30 30 0.5 100 100 75 100 100 30 10 10 (B) 2.0 100 100 100 100 100 10 0 15 1.5 100 100 95 100 100 5 0 10 1.0 100 100 90 100 100 0 0 5 0.5 100 100 80 100 100 0 0 0 Example C Pre-emergence test/greenhouse In a greenhouse test, the reaction of various varieties of cereal towards herbicides was examined in seed dishes. Seed dishes (20 X 20 cm in size) were filled with sandy loam with a humus content of 2.2%.After sowing the various varieties of cereal, spraying took place in a spray booth on the same day, that is to say by the pre-emergence method. The amount of active compound was applied in 420 litres of water/ha. Evaluation took place 4 weeks after sowing.

The action was rated as percentage damage in comparison with the untreated control and is summarised in the following Table C.

Table C Pre-emergence test / greenhouse

Amount of active Wheat Barley Active compound Neepawa Triumph Wascana Larker Bonanza Galt compound applied kg/ha (A) 0.5 87 100 100 100 97 100 0.25 17 60 63 25 10 17 0.125 0 2 10 3 2 8 (B) 0.5 0 2 18 3 8 12 0.25 0 0 10 0 0 10 0.125 0 0 2 0 0 0 Example D Pre-emergence test/open-air In a multi-variety test, summer wheat, summer barley and peas were sown on sandy loam with a medium humus content.Sowing took place on 8th May. Treatment with the herbicide took place the same day, that is to say by the pre-emergence method. The amounts of active compound indicated were applied in 500 litres of water/ha. The active compounds were triazinone (A), formulated as a 70% strength wettable powder, and triazinone (B), formulated as a 60% strength wettable powder. The plot size was 10 m2. The herbicidal action was measured on the naturally occurring weed population.The action on weeds and crops was determined in percentage damage in comparison with the untreated control and is summarised in the following Table D: Table D Pre-emergence test / open-air Amount of active Active compound CHEAL LAMSS POLCO Summer Summer Peas compound applied barley wheat kg/ha (A) 2,0 100 100 100 50 30 70 1,5 100 100 100 30 10 50 1,0 100 95 100 20 5 30 0,5 95 90 95 10 0 10 (B) 2,0 95 100 100 10 10 10 1,5 90 100 100 0 0 0 1,0 85 95 95 0 0 0 0,5 75 80 90 0 0 0 Example E Pre-emergence test/open-air In a multi-variety test, summar wheat, summer barley and peas were sown on sandy loam with a medium humus content. Sowing took place on 20th May and treatment with the herbicide was carried out on the following day, that is to say by the pre-emergence method.The amounts of active compound indicated were applied in 500 litres of water/ha. The active compounds were triazinone (A), formulted as 70% strength wettable powder, and triazinone (B), formulated as a 60% strength wettable powder. The plot size was 10 m2. The herbicidal action was measured on the naturally occurring weed population.The action on weeds and crops was determined in percentage damage in comparison with the untreated control and is summarised in the following Table E: Table E Pre-emergence test / open-air Amount of active Active compound POLLA VIOTR LAMSS POLCO Summer Summer Peas compound applied barley wheat kg/ha (A) 2,0 100 100 100 100 50 50 5 1,5 98 100 100 95 20 30 0 1,0 95 98 95 90 10 20 0 0,5 85 95 90 85 5 10 0 (B) 2,0 100 100 100 100 0 0 0 1,5 100 95 100 95 0 0 0 1,0 95 90 95 90 0 0 0 0,5 85 70 85 80 0 0 0 Example F Pre-sowing incorporation/greenhouse In a greenhouse test, the reaction of various varieties of cereal towards herbicides was examined in seed dishes. Seed dishes (20 X 20 cm in size) were filled with sandy loam with a humus content of 2.2%. Spraying took place in a spray booth.The amounts of active compound were applied in 420 litres of water/ha. After the spraying, the active compound was incorporated into the soil and the varius varieties of cereal were then sown. Application thus took place by the pre-sowing incorporation method. Evaluation took place 4 weeks after sowing.

The action was rated as percentage damage in comparison with the untreated control and is summarised in the following Table F: Table F Pre-sowing incorporation / greenhouse

Amount of Active active Wheat Barley compound compound Neepawa Triumph Wascana Larker Bonanza Galt applied kg/ha (A) 0,5 100 100 100 100 100 100 0,25 25 57 90 75 63 17 0,125 3 15 27 12 17 8 (B) 0,5 8 15 8 3 8 12 0,25 3 5 0 0 0 10 0,125 0 0 0 0 0 0 Example G Individual field plots were tested with the herbicides (A) and (B), respectively, 4-amino-6-tert. butyl-3-methylthio-1 ,2,4-triazin-5(4H)-one and its 3-ethylthio homologue, by applying them broadcasting over the soil surface at various kg/hectare rates and immediately rototilling them in to a depth of approximately 4 inches. On the same day, wheat and barley were planted rowwise into the plots.

Abbreviation Botanical Name Common Name AMARE Amaranthus retroflexus Red Root Pig Weed AMBEL Ambrosia artemisiifolia Rag Weed AVEFA Avena fatua Wild Oat BRAPI Brachiaria piligera None CHEAL Chenopodium album Lambs Quarters DATST Datura stramonium Jimson Weed DIGSA Digitaria sanguinalis Large Crab Grass ECHCG Echinochloa crus-galli Barnyardgrass GAETE Galeopsis tetrahit Hemp nettle HE WE Helianthus annuus Sunflower POLPE Polygonum persicaria Redshank POLSC Polygonum scabrum Green Smartweed moench SETVI Setaria viridis Green Foxtail Four weeks later evaluations were made visually in comparison to adjacent untreated CHECK plots with respect to the amount of damage. Each weed evaluation was based on four combined plots receiving the same concentration of herbicide.For each crop there was determined that concentration of herbicide which produced at most 15% damage. For each weed there was determined that concentration of herbicide which produced at least 80% control.

Tables G and H present the results for each herbicide with respect to both crops and weeds.

The vertical lines represents the acceptable concentration for each crop and "X' to the right of such line for any given weed means the weed is not controlled at a concentration suitable for that crop. If "X" is to the left of the vertical, it means the weed is controlled.

The longer the horizontal line is to the left of the vertical line, the greater is the margin of safety in using the particular herbicide.

These tables show that the 3-ethylthio homologue with these crops is superior to the 3methylthio homologue.

Table G Wheat Rate of Herbicide (B) at pre-emergent application (kg/ha)

Weed Herbicide (B) .. o., QS I 0.t 1 n 0 ' l2SI 1.51 0n has L AVEFA v AMARE X OIEAL Y AVEFA X .

AMARE QIFAL X POISE (CAETE) . . I > AVEFA XI BRAPI . . ~ (DICTA) . .. I (EACG) . . t . . . ~ AMARE . .v .. ~ AMBEL -. - - - AEAL ... ~~ . Y ......

FLATS ...

}{ElAN AVEFA SFNI X I SETVI , CHEAL ~~. z '.'----- x AVEFA X AMARE X (xEAL POBC Tw AVA X POLPE P()UE X, , I EVEFA X sEnrl > POLEE . . y Table G - Continued Wheat / Comparison Test Rate of Herbicide (A) at pre-emergent application (kg/ha)

Weed I Herbicide (A) oA OA O. O.2 102slf sIo.s IQl o 12S ttS . ~ ~ ~ . .~. ~ . ..~. ~. ..~ .~~~~ AVEFA > . .~ ~.~ ~ z SEM - -. - - . - - -.-- - - - -. - - A^ARE .~ .. ... ~ .~ ~ ~ aBL .... ~ ~. o ~ .7.7 AVEFA . .Y . ~ ..

AMARE .. - . --- --.-.-. --- CHEAL , ,,,-D... ---.--- -------- ~ ~~ ~~ POLSC .,.,... ... . . ... - -------- (GAMETE) . .x .-.. .X. ~. ~~ ~.~,.

AVP'A . .~. x AVEFA ..~.. X BRAPI - ----7j:rrx.:.- -. (DIGSA) ,.,., . -- x.

(Ea;) ~ -.

AMARE ...... . . -- -.- - --'- . - AMBEZ --- --. ~ ~ ~~ X;~~~~ zsm .~ .~ X HELEN .. -- ,, .. ~.- ~ ,X,.

AVEFA X . ~.~ szrvl ---------LS OEAL X .... ~. ~ .~ ~ ~ AVEFA . . - .-- . .- - AMARE XAL .

PLLLSC d AVEFA I X I. - - - ~ JXSE X EVEFA .. . X. .

jFNI.

PoL Remarks on Table G: The vertical line indicates the rate at which damage to the crops was within acceptable limits, i.e. no more than 10-15%.

"X" indicates the rate at which each individual weed was controlled to a commercially acceptable degree, i.e. about 80%.

If the letter "X" is on the vertical line, commercial control of that weed was achieved at the highest, still tolerable rate. If the letter "X" appears to the left of the vertical line, weed control was achieved at a lower rate than the crop tolerance limit. The horizontal connecting line between "X" and the vertical indicates selective weed control, and the length of the line reflects the margin of safety.

Table H Barley Rate of Herbicide (B) at pre-emergent application (kg/ha)

Weed Herbicide (B) o. .os o.s 1D 0 .s I zo s wo 1 vs AVEFA X SFIVI - X AMARE X OZEAL AVEFA ~X I,,, AMARE~ Y ~ .POISC -X GAFI1E- (AMFA) X (sEnn) x MEAL OEAL AVEFA .

AMARE X QIAL POLSC . x I AVEFA PUE X I AVEFA (SETVI) X ? POLPE Table H - Continued Barley / Comparison Test Rate of Herbicide (A) at pre-emergent application (kg/ha)

Herbicide (A) Weed ar los Icz Ics lanslo.s Icrl?e Irs Ilr AV3A X"' ' SEIVI PMARE - ---r CEAL .7C AVEFA ~ ~ ~ PJRE I CHEAL ' ' -X ~ . s ~ ~ ~ , (AVEFA) (SFNI) I (SErE) .. z x WEAl-' . X, ,, ~L::P , ~ ~.~~ AVEFA - -. - .--.- . ~ ^ ~ ~ AWARE . F ... - BL. -- z ---- ----- ....-..- ~~ poLsC. -- . ~ .~ ~ ,.

.

AVEFA - X - .' ----= I AVA AVEFA x. -.-. - - - . --. .

(ssran) . -. - . . -- - POLPE .. ...

Remarks on Table H: The vertical line indicates the rate at which damage to the crop was within acceptable limits (no more than 10-15%).

"X" indicates the rates at which each individual weed was controlled to a commercially acceptable degree (about 80%).

If the letter "X" is on the vertical line, commercial control of that weed was achieved at the highest, still tolerable rate. If the letter "X" appears to the left of the vertical line, weed control was achieved at a lower rate than the tolerance limit. The horizontal connecting line between "X" and the vertical is then indicative for selective weed control, and the length of the line reflects the margin of safety.

Claims (14)

1. A method of selectively combating monocotyledon and/or dicotlydon weeds in cereal crop or leguminosae crops, comprising applying to said weeds or to a habitat thereof, an active compound 4-amino-6-tert.-butyl-3-ethylthio-1,2,4-triazin-5(4H)-one of the formula

alone or in admixture with a diluent or carrier.

2. A method according to claim 1 in which the active compound of formula (B) is applied to an area of agriculture in an amount of 0.01 to 5 kg per hectare.

3. A method according to claim 2, in which the active compound of formula (B) is applied to an area of agriculture in an amount of 0.1 to 3 kg per hectare.

4. A method according to any of claims 1 to 3 in which the active compound of formula (B) is applied before and/or after emergence of said crops.

5. A method according to any of claims 1 to 4, in which the compound of formula (B) is applied by the pre-sowing incorporation method.

6. A method according to any of claims 1 to 5, in which the said weeds are combated in cereal crops.

7. A method according to claim 6 in which the cereal crops are barely or wheat.

8. Cereal crops or leguminosae crops characterised by being protected from damage by monocotyledon or dicotyledon weeds by being grown in areas in which immediately prior to and/or during the time of the growing an active compound of formula (B), as defined in claim 1, was applied, alone or in admixture with a diluent or carrier.

9. A selective herbicidal agent for use by the pre-emergence method and for pre-sowing incorporation, containing an active compound combination consisting of (1) 4-amino-6-tert.-butyl-3-ethylthio-1 ,2, 4-triazin-5(4H)-one and (2) at least one compound selected from: (a) S-2,3,3-trichloroallyl diisopropyl-thiolcarbamate (triallate); (b) S-2, 3-dichloroallyl diisopropylthiolcarbamate (diallate) and (c) 1 -amino-6-ethylthio 3-(2, 2-dimethylpropyl)- 1 '3, 5-triazine-2,4( 1 H,3H)-dione (ametridione).

10. A selective hebicidal agent for use by the post-emergence method, containing an active compound combination consisting of (1) 4-amino-6-tert.-butyl-3-ethylthio-1,2,4-triazin-5(4H)-one and (2) at least one compound selected from: (c) 1 -amino-6-ethylthio-3-(2,2-dimethylpropyl ,3,5- triazin-2,4(1 H,3H)-dione (ametridione), (d) 4-amino-6-tert.-butyl-3-methylthio- 1 ,2,4-triazin-5(4H)- one (A) (metribuzin), (e) 1 ,2-dimethyl-3, 5-diphenylpyrazolium methylsulphate (difenzoquat), (f) ethyl N-benzoyl-N-(3,4-dichlorophenyl)-2-amino-propionate (benzoylprop-ethyl), (g) isopropyl Nbenzoyl-N-(3-chloro-4-fluorophenyl)-2-amino-propionate (flamprop-isopropyl), (h) methyl N-ben zoyl-N-(3-chloro-4-fluorophenyl)-2-amino-propionate (flamprop-methyl), (i) methyl 2-[4-(2,4-di chlorophenoxy)-phenoxy-propionate (dichlofopmethyl), (k) methyl 2-chloro-3-(4-chlorophenyl)propionate (chlorprop-methyl), (1) 3, 5-dibromo-4-hydroxy-benzonitrile (bromoxynil), (m) 3,5diiodo-4-hydroxy-benzonitrile (ioxynil), (n) 2,4-dichlorophenoxyacetic acid (2,4-D), (o) 2-(2,4dichlorophenoxy)-propionic acid (2,4-DP), (p) 4-chloro-2-methylphenoxyacetic acid (MCPA), (q) 2-(2-methyl-4-chlorophenoxy)-propionic acid (MCPP), (r) 1 -(2-benzothiazolyl)-1 ,3-dimethylurea (methabenzthiazuron), (s) 3-(4-isopropylphenyl)- 1 , 1 -dimethylurea (isoproturon), (t) 3-(3-chloro-4 methylphenyl)- 1 1 -di-methylurea (chlortoluron) and (u) 3-isopropyl-2, 1, 3-benzo-thiadiazin-4-one 2,2-dioxide (bentazon).

11. A selective herbicidal agent for combating weeds in cereal crops and leguminosae crops, containing an active compound combination consisting of (1) 4-amino-6-tert.-butyl-3-ethyltho-1 ,2,4-triazin-5(4H)-one and (2) 4-amino-6-tert.-butyl-3-methylthio-1 .2,4-triazin-5(4H)-one.

1 2. A selective herbicidal agent according to any of claims 9 to 11 in which the weight ratio of component (1) to component (2) in the active compound combination is between 1:0.02 and 1:10.

1 3. A selective herbicidal agent according to Claim 12, in which the weight ratio of component (1) to component (2) in the active compound combination is between 1:0.05 and 1:4.

14. A selective herbicidal agent according to any of claims 9 to 1 3 containing the active compound combination in admixture with a solid dilutent or carrier or in admixture with a liquid diluent or carrier containing a surface active agent.

1 5. Use of a selective herbicidal agent according to any of claims 9 to 14 for selectively combating weeds in cereal crops and leguminosae crops.

1 6. A process for the preparation of a selective herbicidal agent, in which an active compound combination as defined in any of claims 9 to 1 3 is mixed with one of more extenders and/or one or more surface-active agents.