NO145215B - DEVICE FOR AA MUTE TYPING AND TRANSMISSION OF THE FLYING VESSEL CONTROL SYSTEM - Google Patents

Description

Herbicide mixture.

This invention relates to a herbicidal mixture containing 3',4'-dichloro-2,2-dimethylpropionanilide, 3',4'-dichloro-2,2-dimethylvaleranilide or 3'-chloro-2,2,4'-trimethylval -eranilide or a mixture thereof, as active compounds. These substances are extremely active as selective herbicides for sprouted plants (post-emergence).

Throughout the twentieth century, chemicals have been used to counteract the growth of weeds. However, the chemicals that were first used had a very limited degree of effectiveness. In recent times, the scientific regulation of weeds among agricultural and horticultural products first began with the discoveries in the 1940s of the selective action of the phenoxyacetic acids. This discovery came at a time when the supply of labor was decreasing and there was a need for increased mechanization in the agricultural industry. The search for new and better plant growth regulating chemicals has continued with ever greater intensity. There is still a need to obtain such agents, which have greater activity and which exhibit different selectivities.

When trying to find an effective, selective emergency herbicide, it is necessary to take two important biological factors into account. Firstly, in order to have any practical value as a selective herbicide, a compound must be able to be used in economically reasonable quantities when they are to give a good result. Secondly, the beneficial plants must be able to withstand the addition of the weed regulators

the funds in a reasonable amount. Both of these be-

circumstances must therefore be taken into account when assessing a chemical's usability as an anti-weed agent.

It is well known that the selective effect of such chemicals cannot be predicted in advance. For example, in the class of phenoxy fatty acids, phenyl-0-(CH2)nCOOH, the core unsubstituted compounds in this series have only little herbicidal activity, while the parachloro derivatives are somewhat more effective, the 2,4,6-trichloro derivatives are mostly inactive and the greatest effect is found with the 2,4-dichloro and 2,4,5-trichloro derivatives. Furthermore, the side nuclei of the acid are of great importance, and the active substances are those where n in the above formula is an odd number. This is because beta-oxidation takes place along the entire acid chain and possibly culminates in the respective phenoxy-acetic acid, which then acts as a plant growth-regulating chemical.

The inventors have studied anilides which have the general formula:

and have found that there are many variations in herbicidal activity and plant selectivity in these anilids. It can e.g. active compounds are produced where n in the formula denotes 0 or 2, but if n denotes 3 or more, the compounds are herbicidally ineffective. More specifically exhibits

the compounds, if n = 0 or 2, significant post-emergent activity and also pre-emergent activity. If n = 1, the compound has almost no pre-emergent activity and their post-emergent activity is less than that of the compounds where n is equal to 0 or 2. The exact mechanism by which the anilides act as herbicides is not known.

In the formula

X denotes chlorine or a methyl group, which provides maximum herbicidal activity. When X denotes chlorine, maximum herbicidal activity is obtained when n = 2, and if n = 0, a significant pre-emergent herbicidal activity is obtained. If X is hydrogen, the compound has activity, but it was found, for example, that application rates of C,,H7(CH3)-CCONHCfiH3Cl2-3.4 in amounts that provide complete post-emergence control of such weeds as finger millet, brush millet and acid, are completely ineffective for C.^H^CH,);,-CCONHC(;HjCl-3, which to give equivalent control had to be used in at least a four times larger amount, i.e. an economically unusable amount, and which would also reduce the selectivity of useful products. The compounds 2,2-dimethylvaleranilide and 2,2-dimethylpropionanilide, which have no substituents in the phenyl nucleus, are inactive as herbicides. If you replace additional hydrogen atoms in the anilide chain with methyl groups in the 2,2-dimethylvaleric acid moiety, the activity decreases to practically zero.

Furthermore, it has been shown that for a given anilide series, in which the aniline from which the anilide is derived is kept constant, and the acid proportion is varied, for each different acid there will be a difference in the selective effect that cannot be determined in advance on different products. For example, barley, lima beans, broccoli, peas, ryegrass, sorghum and wheat tolerate 3,4-Cl2CGH:!-NHCOR if R denotes (CH3)3C- but not if R denotes (CH3)2CH-, while snap beans show exactly the opposite tolerance to these two compounds. Similarly, lima beans, maize, potatoes and sweet potatoes tolerate the substances where R is C3H7(CH3)2C-, but not anilides in which R is C3H7(CH.,)-CH-. On the other hand, iin and rice tolerate 3' ,4'-dichloropropionanilide (where R in the above formula is C2H5-) but not 3',4'-dichloro-2,2-dimethylpropionanilide (where R is (CH3)3C-) or 3',4'-dichloro- 2,2-Dimethylvaleranilide (where R is C3H7(CH3)2C-).

The above-mentioned indications show that herbicidal activity and plant selectivity cannot be predicted with certainty for chemical compounds, even for those that lie within a small group of substances of the kind known to have herbicidal properties. These compounds are surprisingly different from one another, and their usefulness for weed control cannot be predicted in any way.

The purpose of the invention is to provide selective post-emergence herbicides which are effective when used in small quantities and which can control a large number of harmful plants and which, by appropriate selection of application quantity, time or application method, can be used for selective limitation of weed growth among useful plants.

The inventors have prepared anilides from 2,2-dimethylpropionic acid and 2,2-dimethylvaleric acid, and have found that the completely new compounds 3',4'-dichloro-2,2-dimethylpropion-anilide, 3',4'-dichloro -2,2-dimethylvaleranilide, as well as 3'-chloro-2,2,4-trimethylvaleranilide, are particularly advantageous as selective post-emergence herbicides and provide very good control of a number of monocotyledonous and dicotyledonous weeds, at small application quantities, while at the same time they have practically no harmful effect on many useful plants, in the quantities used.

The present invention thus consists of a herbicidal mixture which is characterized in that it contains as active ingredient at least one chlorine-substituted anilide with the formula

in which n = 0 or 2 and X is a chlorine atom or a methyl group, X being a chlorine atom when n = 0. The new active chlorine-substituted anilides used in the herbicidal mixtures according to the invention can be prepared by a carboxylic acid having the formula where n denotes 0 or 2, is reacted with a substituted aniline which has the general formula in which X denotes a chlorine atom or a methyl group and Y denotes H or the radical -P(O-alkyl)2, or the radical in which X has the above meaning, and where — if Y is equal to H in the formula II — an acid halide, anhydride, ester or amide derivative of the relevant carboxylic acid having the formula (I) can be used, whereby a chlorine-substituted anilide having the formula is obtained

in which X and n have the above meanings.

A preferred method for the production of the new active compounds used in the herbicidal mixtures according to the invention consists in reacting the suitably substituted aniline with 2,2-dimethylpropionic acid or with 2,2-dimethylvaleric acid or with their halide or acid anhydride. This usually takes place in the presence of a volatile, inert, organic solvent, but can also be carried out without the presence of any solvent. If an acid halide is used, an acid scavenger is usually used at the same time to neutralize the hydrogen halide formed. If you use acid itself, the reaction is promoted by heating with reflux cooling and removing water, e.g. in the form of an azeotropic liquid.

The new active compounds used in herbicidal mixtures according to the invention

nelsen, have been isolated in yields as high as 95 per cent.

3',4'-dichloro-2,2-dimethylvaleranilide was found after recrystallization from benzene and melted at 104°-105°C.

3'-chloro-2,2,4'-trimethylvaleranilide was recrystallized from a benzene-hexane mixture and melted at 107°-108°C.

3',4'-dichloro-2,2-dimethylpropionanilide melted after recrystallization from alcohol at 148°-150°C and was found by infrared analysis to have a purity of 95 per cent.

The mixtures according to the invention can be used in the form of different kinds of preparations, e.g. as wettable powders, emulsion concentrates, powders in the form of dust or granules, and can be added to the plants to be treated in different ways, e.g. in an air stream or as a watery shower when sprinkled in powder form. They are usually supplied in an amount of 0.06-2.25 kg, preferably 0.1-0.7 kg per goal. Solid preparations containing 1-20 per cent or liquid showers containing 0.1-5 per cent can be advantageously used. The selected concentrations and amounts are chosen in each case depending on many factors, such as e.g. the plant's growth stage, the type of preparation used and the way in which the preparation is applied.

The preparations can be prepared with the addition of agriculturally economically active carriers, surfactants, etc., if desired. With the expression "agriculturally economically active carrier" is meant here any substance that can be used to dissolve, disperse or distribute the chemical without reducing its toxic effect and which does not have a permanent harmful effect on the solid substance in any chemical or physical manner. It may also be desired that the carrier used is non-phytocidal just above the beneficial products to be protected.

The wettable powder-type preparations can be concentrates containing, for example, 10-80 wt. 2,2-dimethylprop-ionanilide or 2,2-dimethylvaleranilide. As solid carriers, which can be used as diluents, mention can be made of natural substances that have been finely ground, sieved and possibly purified, e.g. kaolin clay, fuller's earth, bentonite clay, talc, pyrophyllite, diatomaceous earth, hydrated silica, aluminum silicates or calcium and magnesium silicates or

-carbonates. As a rule, it is desirable to add 1-10% by weight. of a surface-active agent or of a combination thereof. For example, dispersing agents can be added to wettable powder preparations

agents such as the sodium salt of the copolymer of maleic anhydride and an olefin, e.g. e.g. diisobutylene, or sodium lignin sulphonate, or adhesives or spreading agents such as e.g. glycerin-mannltan laureate or a condensate of polyglycerin and oleic acid which has been modified with phthalic anhydride, or wetting or emulsifying agents of e.g. non-ionic type, e.g. condensation products of ethylene oxide and fatty alcohols, alkylphenols, mercaptans, or fatty acids, of anionic type such as e.g. calcium benzene sulphonates, or of the cationic type such as, for example stearyldimethyl-benzylammonium chloride.

Typical wettable powder preparations are those which consist of (1) 25 parts by weight of an anilide used according to the invention, 70 parts by weight of magnesium carbonate and 5 parts by weight of a solid surface-active agent containing 40 per cent octylphenoxy-polyethoxyethanol and 60 per cent magnesium carbonate, and (2) 50 parts by weight of 3',4'-dichloro-2,2-dimethylvaleranilide, 45 parts by weight of fuller's earth, 2.5 parts by weight of sodium formaldehyde-hydronaphthalene sulfonate, 2.5 parts by weight of a 3:1 mixture of dinoyl-phenoxy- polyethoxyethanol and calcium dodecylbenzenesulfonate.

The preparations according to the invention can be dust concentrates containing a finely divided mixture of one or more carriers. The carrier material is preferably of the kind that is normally used in such preparations, e.g. finely powdered clay, talc, silica and magnetic silicates, e.g. two-bay dust or walnut shell flour. Concentrates are usually produced which contain from 20 to 80 per cent of the active substance, but these are preferably diluted for use to a content of 5-20 per cent of the active substance. Dust concentrates can be suitably prepared by adding a finely divided carrier material of the type normally used in such preparations to a wettable powder of the kind described above. A typical dust concentrate is, for example, one made from 33% by weight. of an anilide and 67 wt. talc.

Typically granular herbicidal mixtures are prepared by incorporating these into granular or pelletized carrier material, e.g. of granular clay, vermiculite, charcoal, ground corncobs, etc. in size 16-64 mesh (U.S. standard sieve size). A typical preparation is one that contains 5-10% by weight. anilide and the rest 30-60 mesh vermiculite.

A particularly suitable method for the preparation of a solid preparation consists in dissolving the 2,2-dimethylpropion-i anilide or the 2,2-dimethylvaleranilide in a volatile solvent, e.g. acetone, mix this solution thoroughly with the solid diluent, with or without additives, and remove the solvent by evaporation.

The herbicidal mixtures according to the invention can advantageously be used as an aqueous shower, which is produced from emulsion concentrates. The concentration of the active substance can vary from 10 to 80 per cent, but is preferably in the range 25-50 per cent. Suitable solvents for the anilides include hydrocarbons, chlorinated hydrocarbons, ketones, esters, alcohols and amides, e.g. xylene, naphthas, ethylene dichloride, cyclohexanone, methylhexyl ketone, isophorone, methyl hexanoate or dimethylformamide, the preferred solvents being ketones and mixtures of ketones and hydrocarbons. A typical emulsion concentrate consists of 25 parts by weight of anilide according to the invention, 47 parts by weight of isophorone, 23 parts by weight of xylene and 5 parts by weight of an emulsifier soluble in the solvents, which has been produced by mixing the following substances, stated in parts by weight: 38 parts of octylphenoxypolyethoxyethanol, 42 parts calcium dodecylbenzene sulfonate and 20 percent solvent for these.

A standard method for valuing the post-emergence herbicidal properties consists of sowing seeds and representative crops and weeds in a solid medium in which the seeds can develop and grow, allowing the seeds to germinate and — when the sprouts are approx. 2 weeks old — they are treated with the preparation to be tested. The test plants' phytotoxic reaction and growth condition must be read approx. 2 weeks thereafter. Solid preparations are usually supplied in a quantity of 0.1-2.25 kg per measure and shower are usually in an amount of approx. 50 liters per measure, but larger or smaller amounts can also be used. The main factor for determining the beneficial effect is the amount used per surface area.

In this way, the impact on monocotyledonous plants has been studied, including finger millet, Sorghum vulgare, Sorghum halepense, Cynodon dactylon, turf grass, chicken millet, big bush millet, millet, field oats, barley, field and garden maize, wheat, rice, ryegrass, sorghum and wheat.

Among dicotyledonous plants, mention may be made of watercress, sorrel, mullein, cat cheese, late turnip, perumelde, purslane, sorrel, wild yellow roots, alfalfa, broccoli, carrots, clover, cotton, cucumbers, flax, lima beans, peas, spinach, snap beans and soybeans, peanuts.

Comparisons were made between the effectiveness of many anilides, all of which contained 2,2-dimethyl substituents in

the fatty acid proportion. The results are indicated in

table I for typical monocot weeds and in table II for typical dicot weeds.

The herbicidal compounds that stand out in these tables are C,jH7C(CH3)2-CONHC(iH3Cl2-3,4 (compound A); C^C-(CH3)2CONHC0H3Cl-3-CH3-4 (compound B ) and CH3C(CH3j2CONHCBH3Cl2-3,4 (compound C).

It can be seen that in many of the cases where these compounds were used, complete control of both grass-like and broad-leaved weeds was achieved using as little as 0.35 kg/measure.

It has previously been found that 2,2-dimethyl-

valeranilide itself had no practical value as a herbicide, and showed no activity against noxious weeds when used in the above, or greater, amount.

The three most active compounds (referred to above as compounds A, B and C respectively) were assessed in a dosing test series with different typical weed species. The percentage phytotoxicities found two weeks after the treatment are given in Table III, and show the great ability of these particular anilides to counteract weeds.

An open field experiment was carried out where 3',4'-dichloro-2,2-dimethylvaleranilide (compound A) and 3',4'-dichloro-2-methylvaleranilide (compound D) were compared with regard to beneficial growth tolerance and weed control in the open field. In this experiment, selected crops were planted in a field which was known to produce a large development of both monocot and dicot weeds. After planting, irrigation was carried out, and a suitable level of humidity together with a relatively high temperature resulted in a strong germination of both useful crops and weeds. After approx.

Over the course of 3 weeks, the planted field was thoroughly sprayed with watery showers, which were

prepared from 25% emulsion concentrates of the compounds A resp. B. Both of these were used in an amount of 0.225 resp. 0.35 kg/measure in a carrying volume of approx. 50 litres/measure. The beneficial growth tolerance was expressed as a phytotoxicity index where:

1 = small amount of burnt leaves 2 = moderate damage 3 = heavy damage but not killed 4 = most plants killed, and the impact on weeds was expressed as percent weed control. Table IV shows the results obtained.

It appears from table IV that the two compounds, which differ chemically from each other only by the number of methyl groups, which are connected to the 2-carbon atom in the acid side chain, have very different effects as far as beneficial growth tolerance is concerned. Compound A is far better tolerated by the above-mentioned outdoor crops and at the same time provides sufficient control of weeds.

A similar post-emergence test was carried out, using 0.22 resp. 0.35 kg/measure, for a larger number of useful crops. When 3',4'-dichloro-2,2-dimethylvaleranilide (compound A) was used, it was found to be tolerated by carrots, field and garden maize, peanuts, pears, lima beans, snap beans, soybeans, sorghum, sweet and common potatoes, while cereal plants, including rice, flax, cotton, and further broccoli, beets, alfalfa, clover, tomatoes, spinach, muskmelon and pumpkin could not tolerate it.

3'-chloro-2,2,4'-trimethylvaleranilide (compound B) was tolerated by beans, carrots, corn, cotton, oats, sweet and regular potatoes, rice, rye, sorghum, pumpkins, tomatoes and wheat, but cannot be tolerated by alfalfa, barley, beetroot, broccoli, cabbage, flax muskmelon, ryegrass and spinach. Compound C, i.e. 3',4'-dichloro-2,2-dimethylpropionanilide, was tolerated by barley, broccoli, carrots, lima beans, snap beans, soybeans, field and

field corn, cotton, oats, peanuts, pears, sweet and regular potatoes, rye, ryegrass, sorghum and wheat, while alfalfa, clover, beets, flax, lettuce spinach, tomatoes, rice and certain pumpkin species only tolerated the compound to varying degrees. It was also found that, among the above-mentioned crops, only carrots, pears and sorghum could tolerate 3',4'-dichloro-2-methylvaleranilide (compound D) in such quantities that had to be used to achieve weed control.

It appears from the above that to counteract unwanted plants among useful crops are 3'-chloro-2,2,4'-trimethylvaleranilide, 3',4'-dichloro-2,2-dimethylvaleranilide and 3',4'-dichloro- 2,2-dimethylpropionanilide particularly effective. They kill both monocot and dicot weeds when used in small quantities. They are highly selective in relation to useful crops that tolerate them. In some cases, when used outdoors, these anilids can cause a little damage if they are used on young crops in the recommended treatment quantities, but the plants recover after a few days, without having suffered lasting damage.

Claims (1)

Herbicidal mixture, characterized in that it contains as active ingredient at least one chlorine-substituted anilide with the formula wherein n = 0 or 2, and X is a chlorine atom or a methyl group, X being a chlorine atom when n = 0.