CA1300393C - Herbicidal products on the basis of oxynil esters - Google Patents

Abstract

ABSTRACT

Herbicidal product with improved effectiveness on the basis of an oxynil ester, comprising a mixture of n-heptanoic and n-butyric esters of bromoxynil and/or ioxynil associated preferably with one or several phenoxy-alkanoic acids particularly in the ester or salt form.
No figure.

Description

~l3V~3~3 HERBICIDAL PRODIJCTS ON THE BASIS OF OXYNIL ESTER~

BACKGROUND OF THE INVENTION
The inveniton relates to herbicidal products on the basis of oxynil esters.
It is also directed at the association of oxynil esters with phenoxy-alkanoic acid esters.
These herbicidal products constitute selective weed-killers used principally in cereal cultivation in order to destroy or control alien wideleaved plants, particulary dicotyledons.
The generic term "oxynil" denotes :
- 3,5-dibromo-4-hydroxy-benzonitrile or "brom-oxynil"
lS - 3,~ diiodo-4-hydroxy-benzonitrile or "ioxynil"
which are known selctive herbicides and which are used generally in the form of their n-octanoic acid esters.
The phenoxy-alkanoic acids which are part of the abovesaid association are generally those known under 0 the names 2 , 4 - D
2,4-DP
2, 4-MCPA and Mecoprop 25 and they are used for the most part in the form of their isooctyl or butylglycol esters.
The abovesaid associations may be either con-stituted by a single and unique concentrated formulation comprising the one o~ more oxynils and the one or more phenoxy-alkanoic acids, or be constituted by two separ-ate concentrated formulations of which the mixing is carried out at the time of use by dispersion in water in the desired proportions.
In associations of the type concerned which are 35 already known, the active principles are formulated in solution in hYdrocarbon solvents and in proportion such ~,~

:IL3~J~3~33 that there is, on use, for one part of oxynil, between 1 and 6 parts and mostly between 1 and ~ parts of phenoxy-alkanoic acid.
These commercial products o~ten contain, besides the active herbicidal principles and the solvent, a mixture of surface active agents designed to make them dispersable in water in the form o~ an emulsion stable at leas~ for one hour; in that case they are denoted as "emulsifiable concentrates".
It has been indicated above that the oxynil esters are mostly those of octanoic acid.
It is pointed out however that there have already been proposed in the trade mixtures of n-oc-tanoic and n-butyric esters of bromoxynil, associated with a phenoxy alkanoic acid ester, particularly the butylglycol ester of 2,4-MCPA.
GENERAL DESCRIPTI~N OF THE INVENTION
Within the scope of its constant efforts seeking to widen the arsenal of selective herbicides for cere-als, Applicants have observed at present that, surpris-ingly, a herbicidal product comprising n-heptanoate and n-butyrate of oxynil possibly in association with one or several phenoxy alkanoic acids has a particularly improved herbicidal efficiency with respect to that of the prior art products.
Consequently, the herbicidal product on the basis of oxynil esters according to the invention comprise a mixture of n-heptanoic and n-butyric esters of bromoxynil and/or ioxynil associated preferably with one or several phenoxy-alkanoic acids in ~he form of a salt, or in the form of an ester.
These herbicidal products according to the invention may be used especially in selective weeding of winter or spring cereals either with better destruction of the alien flora at the doses customarily used for such products or with an overall equivalent result of 130~ 3 destruction of the alien flora, at dos~s less than those custumarily used.
The overall activity spectrum is not fundament-ally changed, but plants which were sensitive only at certain periods of their growth or under certain conditions, become sensitive within wider circumstances.
Plants which are resistant under certain circumstances are found to be moderately sensitive due to the products according to the invention. Overall, the total her-bicidal effectiveness level increases over a largenumber of plants and the failure level diminishes.
The bromoxynil n-heptanoate or 3,5-dibromo 4-n-heptanoyloxy benzonitrile is a waxy solid of cream colour and melting point about 45C when it is pure and about 39DC when ,it is of technical grade. It has herbicidal properties similar to those of bromoxynil n-octanoate.
Ioxynil n-heptanoate or 3,5-diiodo-4-n-heptanoy-loxy benzonytrile is a waxy solid of cream to chestnut 20 co lour and melting point of about 68C. This substance has not, until now, been widely used as a weed-killer.
Bromoxynil n-butyrate or ~,5-dibromo-4-n-butan-oyloxy benzonitrile is a waxy solid of cream colour and of melting point about 82C. Due to its relatively low 25 solubility in the solvents customarily used in weed killer formulations, it has not until now been used alone but in association with bromoxynil n-octanoate and possibly phenoxy alkanoic acid esters. Under these conditions, formulations containing up to 480 gllitre of 30 bromoxynil or 360 g/liter of bromoxynil and 360 g/liter of 2,4-MCPA are produced industrially.
Ioxynil n-butyrate or 3,5 diiodo-4-n-butanoyloxy benzonitrile is a waxy solid cream to chestnut in colour and of melting point about 118C. ~ue to the fact, as 35 for bromoxynil, of its relatively low solubility in the solvents customarily used in weed-killer formulations it ~3~ 3 is not recommend~d to use it alone and associations of ioxynil in the form of mixtrues of the n-butyric and n-octanoic esters are found. Such associations are not however used in practice.
A mixture containing two moles of bromoxynil n-heptanoate and one mole of bromoxynil n-butyrate has a melting point of about 26C and a mixture containing one mole of bromoxynil n~heptanoate and one mole of bromoxynil n-buty,ate has a melting point of about 40 -50C. These two mixtures are at least as soluble as bromoxynil n-octanoate in the solven~s for herbicidal formulations; associations with phenoxy alkanoic acid esters like mecoprop or 2,4-MCPA may be produced as.with bromoxynil n-octanoate.
In the same way as for bromoxynil, a mixture containing two moles of ioxynil n-heptanoate and one mole of ioxynil n-butyrate has a melting point of about 49C and a mixture containing one mole of.ioxynil n-heptanoate and one mole of ioxynil n-butyrate has a melting point of about 72'C. These two mixtures are substantially as soluble as ioxynil n-octanoate in the solvents for weed-killer formulations; associations with phenoxy-alkanoic acid esters like mecoprop or 2,4-MCPA
may be formed as with ioxynil n-octanoate.
The mixture in a definite molar ratio of bromo-xynil n-heptanoate and bromoxynil n-butyrate according to the invention, may be prepared according to the invention by the reaction of bromoxynil with a mixture in suitable proportions of reactive derivatives of n-heptanoic and n-butyric acids, for example their anhydrides or their acid chlorides, or by mixing suit-able amounts of bromoxynil n-heptanoate and n-butyrate, or again by mixing in suitable amounts a mixture already formed, in another molar ratio of bromoxynil n-hept-anoatè and n-butyrate, with either bromoxynil n-hept-anoate or bromoxynil n-butyrate~

~3t~393 The mixture in a definite molar ratio of ioxynil n-heptanoate and ioxynil n-butyrate according to the invention may be prepared by the three processes des-cribed above for bromoxynil, adapted to ioxynil.
In the herbicidal products according to the invention, bromoxynil, (or ioxynil) n-heptanoate and bromoxynil (or ioxynil) n-butyrate are in a molar ratio of bromoxynil (or ioxynil) n-heptanoate to bromoxynil (or ioxynil) n-butyrate comprised between 0.25 and 10, preferably between 0.65 and 4; more especially, the following two ratios are selected 1.0 and 2Ø
In the event that the mixture of oxynil(s) with the one or more phenoxy-alkanoic acid(s) is to be prepared only at the time of use, concentrated form-ulations may be prepared, con~aining as active materialonly bromoxynil and/or ioxynil in ~he form of a mixture of n-heptanoic and n-butyric esters. These formulations constitute emulsifiable concentrates which are dispersed in distribution water simultaneously with the formula-tions of the phenoxy-alkanoic acids in the form of ester or salt and possibly also with formulations of any other active substance.
To concentrate to the maximum the for~ulations containing the oxynil portion, the molar ratio of n-heptanoic to n-butyrate esters is selected in order to provide a point of crystallisation as low as possible, thus ratio being 2Ø
When the concentrated formulation contains, in addition to ~he oxynil(s) portion, the phenoxy-alkanoic acid ester portion, the latter is always present in large proportions and, consequently, it will not be possible to increase significantly the total content of bioactive weed-killer materials. In this case, it is preferred to use a molar ratio of n-heptanoic to n-butyric esters close to 1.0 which provides in the formulation a higher amount of oxynil equivalent, with a 13V5)3~33 constant amount of esters (due to the fact that the proportion of oxynil ls greater in the butyrate ~han in the heptanoate) whilst providlng a behavior under cold condition identical to that of the formulation formed on S the basis of octanoic ester.
The liquid herbicidal products according to the invention which by way of dispersion in water constitute spraying fluids suitable for applica~ion to plants comprise, besides the bromoxynil and/or ioxynil ester mixtures and the phenoxy-alkanoic acid esters previously defined, one or several solvents and suitable ionic or non-ionic emulsifiers.
As solvents, petroleum hydrocarbons may be used, particularly the aromatic and paraffin constituents. It is als~ possible to use other solvents such as animal, vegetable or synthetic oils.
Preferably, mineral oils with a high content of aromatic substances are used and more particularly those having a weight content of aromatic substances of at least 70X and a flash point higher than 50-C.
A preferred solvent for a formulation without phenoxy-alkanoic acid ester is that with 99% of aromatic substances marketed by ESSO under the trade mark ~SOL-~ESSO 200". In the case of formulations containing a phenoxy-alkanoic acid ester, it is possible also to use the solvent marketed by SHELL under the trade mark ~SHELL SOL R~ and which only contains 74% of aromatic substances. It is also possible to use alcohols having a linear, branched or cyclic hydrocarbon chain, composed of at least 6 carbon atoms, polyols like for example ethyleneglycol, ~utylglycol or products of the DOWANOL~ -series marketed by DOW.
As emulsifiers, there may be used sulforici-noleates, quaternary ammonium derivatives, products based on ethylene oxide condensates with propylene oxide or with alkylphenols, for example nonyl or octyl or 13~)Q393 polyarylphenols, or with vegetable oils which may be saponified or not, or also with straight or branched alcohols, for example lauryl alcohol. It is also possible to use carboxylic esters of anhydrosorbitols possibly polyethoxylated, alkaline salts, alkaline earth or ammonium salts of sulphuric esters, sulfonic deriv-ati~es of high molecular weight such as lignosulphonates or alkylbenzene-sulphonates of sodium and of calcium.
Finally, it is possible to use alkali, alkaline-earth or amminium salts or amines of carboxylic acids.
These emulsifiers are used preferably in the ratio of 0.1 to 20% weight/weight, or in hydrocarbons as for example a mineral oil having a flash point higher than 50C and a weight content of aromatic substances of at least 70%, or in short alcohols, like methanol, isopropanol or isobutanol.
The herbicidal products according to the inven-tion contain from 100 - 600 g/l of ioxynil and or brom-oxynil equivalent, in the form of a mixture of n-heptan-oic and n-butyrate esters. They are intended for use conjointly with concentrated formulations of phenoxy-alkanoic acids.
These herbicidal products according to the in-vention may comprise only from 50 to 400 g per liter of ioxynil and/or bromoxynil equivalent, in the form of a mixture of n-heptanoic and n-butyric esters, but they then contain also between 100 and 650 g per liter of one or several phenoxy alkanoic acids, in the form of esters, especially of butylglycol or iso-octanol, or in salt form.
The products according to the invention may also contain other herbicides having good solubility in the solvents mentioned, like for example the biphenyl-ether family among which are bifenox (that is to say 2,4-dichloro-5-phenoxy-2-nitro~benzoate of methyl), benzoic acid derivates among which are dicamba, (3,6-d~

~13~)~3g3 chloro-2-methoxy-benzoic acid), ~erivatives of picolinic acid among which are 3,6-dichloro-pico1inic acid, der-ivatives of triazines among which are cyanazine [2(4-chloro-ethyl-6-amino-1,3.5-triazin-2-yl-amino)-2-methYl-propionitrile].
These other herbicides are present in the liquid herbicidal products according to the invention in an amount which depends on their weed-killing effective-ness.
The spraying fluids for the destruction of alien plants, obtained by the dispersion in water of the liquid herbicidal products according to the invention, as well as a method of destroying these alien plants by means of these spraying fluids are also objects of the invention.
The spraying fluids contain from 0.05 to 5%
weight/volume of a mixture of n-heptanoic and n-butyric e'sters of bromoxynil and/or ioxynil and from 0.1 to 10%
weight/volume of phenoxy alkanoic acid esters; they are used at weed killer application doses of 50g to lkg per hectare of bromoxynil and/or ioxynil equivalent and from 100g to 3kg per hectare of phenoxy alkanoic acid equiv-alent, this according to the culture and the complement-ary associations contemplated.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will be better understood by means of the examples which ~ollow and which, without being limiting, relate on the one hand, to advantageous em-bodiments of the invention and on the other hand two '30 comparative tests demonstrating the activity of the herbicidal products according to the invention.

This example relates to herbicidal products ac-cording to the invention without phenoxy alkanoic acid.
Solvented solutions suitable to be used as emulsifiable concentrates and containing 480g/l of ~30(~3~33 g oxynil equivalent are prepared by dissolving different bromoxynil and/or ioxynil esters, specified below, in an essentially aromatic mineral oil (Solvesso 200). The proportions of the different esters in each solution are given in molar percentages.
These solutions are shaken until they are homo-geneous and of clear liquid appearance. Then there is added, with stirring, a mixture of anionic and nonionic emulsifiers, some of which are marketed by Applicants' Company under the trade mark GALORYL, the others being polyethoxylated castor oils. In this way emulsifiable concentrates are obtained leading, by disperion at 1% in water, to emulsions stable for at least 2 hours.
Table 1 shows the constituents of three corres-ponding emulsifiable concentrates, denoted by a,b and c.
<~ , TABLE

Constituants of the eaulsifiable Proportions 2 0 concentrates a b c Holar proportions of o~ynil esters 50 Zô
Broeoxynil-n-heptanoate 67 33 Ioxynil-n-hcptanoate 50 22 8ro-oxynil-n-butyrate 33 17 2 5 loxynil-n-butgrate Content of oxynil equivalent (g/l) loxynil ~ôO ¦ 2~0 Proportion of enulsifiers in the 3 0 e-ulsifiable concentrate (~ 7-bt) 6aloryl EH Sl~ 3,5 6aloryl EH ~039 5,5 5,0 Condensate of lO eoles EO to castor oil 1,5 Condensat~ of 20 xoles EO to castor oil 6,5 3,0 5,0 (EO - ethylene oxide) 3 5 Solvent : _ OLYESSO 200 ,qsp 100 Z Ip/p1 ~ .

~L3~C~3~3 The three emulsifiable concentrates so prepared, whose densities at 20C are respectively 1.24Z (a) 1.283 (b) and 1.265 (c), are homogeneous and liquid. They are physically and chemically stable at ordinary tempera-ture, on storing with accelerated aging for 14 days at54~C, and at the temperature of -5C.

This example relates to herbicidal products according to the invention comprising a phenoxy alkanoic acid.
The solvented solutions suitable to be used as emulsifiable concentrates and containing 160 g/l of oxynil equivalent are prepared by dissolving different bromoxyinl or ioxyinl esters, hereinafter specified, in an essentially mineral oil (Solvesso 200).
The proportions of the esters in each solution are established in molar percentages. To these solutions is added a liquid phenoxy-alkanoic acid ester in an amount corresponding to 480 g/l of acid equivalent.
The solutions so prepared are stirred until homogeneity and clear liquid appearance. Then with stirring a mixture of anionic and non-ionic emuslifiers, as in example 1, as added. The emulsifiable concentrates so obtained provide, when they are dispersed at the 25 proportion of 1% in water, emulsions which are stable over at least two hours.
In Table II, are indicated the constituents of these two emulsifiable concentrates, denoted respective-ly by d and e. For the purpose of comparison, there are also indicated in Table II the constituents of three emulsifiable concentrates according to the prior art, denoted respectively by f, g and h, whose contents of active materials are not always indicated.
In Table II there are also indicated the proportions of emulsifiers and of solvent.

', . I

35~3 ~L I I
- 1 'I
Constituents of the ~-ulsifiabl~ Proportions concentrates d e f 9 h Holar proportions of oxynil esters 50 Bro-oxynil-n-heptanoat& 50 loxynil-n-heptanoate 50 50 Sro~oxynil-n-~utyrate SO
Ir,xynil n-b~tyrate 1ûO 50 ~romoxynil-n-octanoate 100 `1 O loxynil-n-octanoate Content of oxynil equivalent (9/1) ûrosoxynil 360 2ûO 360 loxynil 160 120 Content of phenoxy-alkanoic acid equivalent (g/l) 1 5 In the for~ of ùutylglycol ester of 480 360 Proportions of erulsifiers in the euulsifiable concentrat- (X ~t/~t) 2 7 Galoryl EH 514 6 ~ Galoryl EH 4036 6,5 5,0 5,û
2 0 ( Galoryl EH 4039 ~,15 2,0 9 3 Condensate of 10 aoles EO to castor oil 2 35 3 O 2 ~ 7 Condensate of 20 uoles EO to castor oil , (EO . ethylene oxide) Solvent (wt/wt~ : SOLVESSO 200 qsp 100Z lOOZ
SHELL SOL R qsp lOOZ .

The density of these five products is:
product d: 1.168 product e: 1.175 product f: 1.091 product g: 1.090 prod:uct h: 1.178 The five emulsifiable concentrates so prepared are homogeneous and liquid. They are physically and chemically stable at ordinary tempera~ure, on 35 storage in accelerated aging for 14 days at 54-C and on storage at -5-C.

~3~0~3 EXAMPLE ~
This example relates to comparative tests, in the field between products according to the invention and prior art products.
In a test conducted in 7 different fields dispersed so as to obtain vegetation conditions and hence plant reactions which were different, there were compared:
- a herbicidal product according to the prior art (product f, table II) on the basis of ioxynil n-octanoate and mecoprop, this product comprising 120 g/l of ioxynil and 360 g/l of mecoprop, - a herbicidal product according to the invention on the basis of ioxynil n-heptanoate and n-butyrate, this product comprising 160 g/l of ioxynil and 480 g/l of mecoprop (product d of Table II).
These products were tested on winter cereals on plots or parcels of about 15 to 22 m2. The treatments were duplicated and control plots, untreated, were 20 provided always after two treated plots. The herbicides were applied at a moment situated between the beginning of tilling and full tilling of the cereals, in the form of emulsion in water at the rate of 500 liters of dilute liquid per hectare.
The two products were used at two doses, namely:
- 300 g/ha of ioxynil plus 900 g/ha of mecaprop, i.e. 2500 l/ha of product f, Table II or 1870 l/ha of product d, table II, - 360 g/ha of ioxynil plus 1080 g/ha of 30 mecaprop, i.e. 3000 l/ha of product f, Table II or 2250 l/ha of product d Table II.
The plots were observed about 45 days after treatment and the percentage o~ destruction of the alien plants present on each plot was measured.
`~ 35 To the extent that weeds occur at a different plant stage from one field to another, thus rendering .

~31~3~3 them more or less resistant to the weed-killers, it was not tried to calculate an overall mean effectiveness, neither per field nor per plant which would not have brought out the strong points and the weak points of each product, on the contrary, there are reported per plant and then overall, on the one har,d the percentage of observations corresponding to cases where the weeds were almost destroyed (effectiveness of at least 95%) and, on the other hand, the percentage of observations corresponding to cases where the weeds were insuf-ficiently or not at all mastered (effectiveness less than 70%).
Such a method enables to find easily on a graph of the tested spectrum, the respective sensitivity of the plants under various conditions of use, i.e.
geographic and climatic conditions and different plant stages of the various alien plants. By superposikion of the graphs, it is possible to compare various products.
In Table III. are collected all the results of effectiveness at 45 days, per plant, field, plot and rate of product. Then, in Table IV, there are merged the two doses of each product, which is possible in view of their proximity, in order to establish per plant the percentages of observations of satisfaction and non-satisfaction for each product, over a sufficient number of observations.
The overall percentages of the cases of satisfactory and unsatisfactory results are indicated as well as the deviations from these averages which give in fact a view over the regularity of action of the prod-ucts, over the spectum of plants tested.
There is shown, in the graph of Figure I, the comparative spectrum of the degree of satisfaction and non-satisfaction of the products.
35In this graph there are shown, both for the product according to the prior art (f, Tables III and IV) and for the product according to the invention (d, ~30~13~3 Table III and IV), as positive ordinate Y+ and negative ordinate Y , respectively the percentage of satisfactory results (herbicidal effectiveness~ 95%) and the percentage of unsatisfactory results (herbicidal effectiveness < 70%) which corresponds successively to each of the plants tested plotted at A to P on the abscissae X, i.e.
A = Aphanes arvensis B = Cardamine hirsuta C = Cerastium glomeratum D - Galium aparine E = Lamium purpureum F = Legousia speculum-veneris G = Matricaria chamomilla H = Matricaria inodora I = Papaver rhoeas J - Polygonum convolvulus K = Ranunculus sardous L = Raphanus raphanistrum M = Rumex acetosa N = Veronica hederifolia P - Veronica persica the group of satisfactory results forming curves Cf+ and Cd for the positive percentages relating to products f and d, all of the unsatisfactory results formlng curves Cf and Cd for the negative percentages relatin~ to products f and d.
In this graph there also appear the arithmetic means relating to curves Cf . Cd and Cf , Cd .

.

~ 35 ?

~`

~3V(:~3~3 .
_ Products tested (f) (d) ioxynil n~ ioxynil octanoate I n-heptanoate/
~ecoprop n-butyrate butylglycol ~ ~ecoprop ester butylglycol ester r I _ Dose loxynil~mecoprol ) (g/ha) 300~900 ¦ 360f1080¦ 300+900 360~1080 PLANT Field Results obtained L ._ _ Aphanes arvensisfield 2 10ûl10û 100/100 1001100 1001100 field 53D130 100/100 1001100 1001100 field 670130 70/70 95/70 95/70 __________________ __________ ____ _____ _________ ________ Cardamine hirsuta field S100/100 100/100 100/95 100/100 field 795/70 95t70 95170 100195 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - .. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ~ _ Cerastium glomeratum fi!eld 470/70 95195 100195 1OO/95 field 51001100 1001100 1001100 1001100 field 770130 95195 95/95 100/100 _____________ ____ . ____ _ _ _________ _____ __ __ ______ Galium aparine field 3100/95 100/95 100/95 100195 _____ _________ ____ . ______ _________ _________ __ ______ Lamium purpureum field S 100/95 100/70 100/100 1001100 __________ __~_____ field 7 ¦ 70/30 70/30 9S/70 95/70 Legousia speculum- field 6 70130 70170 95/95 95/70 vener~s ________ __________ . . _ _______________ ________ _________ Matricaria field 5 70/70 95/70 95/70 95/70 chamomilla . . ' _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ Matricaria inodQra I field I 30130 1001100 30130 1001100 field 4 1001100 100/100 1001100 1001100 field 5 1001100 1001100 1001100 1001100 _________ __________ . ________ _________ _________ _________ Papaver rhoea~s field 470130 70170 95170 95/95 field 670/30 70/70 95170 95195 _________________ __. ________ _________ _______ _ ___ _____ vulus iield ~95/70 70170 100195 1 dO/70 ~3V~33~
`

TA8LE III ( contd ) , .___ _ ` Products testsd (f) (d) ioxynil n- ioxynil octanoate + n-heptanoate/
aecoprop n-butyrate butylglycol + aecoprop ester butylglycol ester Dose ioxynil~mecoprol l ~g/ha~ 300~900 360-1080 300~900 360~10 PLANT Fie.ld Results obt~ined .
Ranunculus sardous field 7 100/95 100/95 __________ 100l95 trum field 5 100/ l O0 100/ 100 100/ 100 l oo/ 100 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Rumex acetosa field 5 515 5/5 100/100 30/5 ____________________ _________ _________ __________ _______ I
Veronica field 2 100/100 95/70 100170 95/70 hederifoliafield ~ 5/5 30/5 70/5 30/5 field 5 95/70 lO0/95 95/95 lO0/95 . .
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ \/eronica persica field 6~ 70/30 70/70 95/70 95/70 field 7 95/95 lO0/95 95/95 100/100 ~. I

~L3~)~)3~3 TABLE ~V
i' ' -¦ Products tested ., _ (f) (d) ioxynil n- ioxynil octanoate ~ n-heptanoate/
mecoprop n-butyrate ; butylglycol + ~ecoprop ester butylglycol estsr Nusber ¦ % of results X ofresults PLANT of obser- satis- unsatis- satis- unsatis-vations factory factory factory fartory Aphanes arvensis .____ __ . _ __ 25 _ , _ ___ _ ___ Cardamine hirsuta 8 75 0 û7 0 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Cerastium glomsratum 12 67 8 lO0 0 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ I _ . Galium aparine 4 100 0 100 û
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . Lamium purpureum 8 37 25 75 0 ___________ __ ____ ______ _ _.. ______ ______ _ ____ _ __ ____ ___ Legousia speculum- 4 0 25 75 0 veneris l--_ ________ _________ ____ ___ _______ _____ ___ ____ __ _ _______ Matricaria ~ 25 0 50 0 chamomilla ___________ ________ ________ ________ __________ ________ ____ _____ . Matricaria inodora12 83 17 a3 17 ____ __ ___ __ ___ __ _ _ __ _ _ __ __ _ _ _ _ ___ _ _ __ __ _ ___ _______ _ __ _ __ __ _ Papaver rhoeas 8 0 25 75 0 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Polygonum convolvulus __ _____ 25 __________ _ ______ ___ _ _____ Ranunculus sardous 4 100 _ ____ ___ lOû ___________¦
Raphanus raphanistrum 4 100 0 100 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Rumex acetosa 4 0 lO0 S0 50 ________________ ____ ____ __ __ _____ _______ __ ________ ___________ Veronica hederifolia 12 50 33 50 2S
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Veronica persica 8 50 12 75 0 .
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ General oeanl b 8 51 18 7û 6 deviation aith 108 36 26 18 14 respect to the sean _ .

.

-~L~3U~3 It results from Table IV that, per plant the formulation according to the invention provides an im-provement on the level of the percentage of cases of successful weed-killing (on lamium purpureum, Legousia speculum-veneris, Raphanus raphanistrum, Ploygonum convolvulus and Rumex acetosa), with respect to the percentage of cases of failure ~on Aphanes arvensis, Lamium purpureum, legousia speculum-veneris, Raphanus raphanistrum and Rumex acetosa).In the case of the four last plants mentioned, the improvement is on two scores.
The arithmetic mean concerning all the plants indexed are also in favour of the formulation according to the invention and in Figure 1, the hatched areas show very explicitely the improvement provided by the form-ulation according to the invention with respect to thepreviously known formulation. It is to be noted that, in no plant was the formulation according to the invention found to be inferior to the comparison formulation and that the plants for which the percentages of satisfac-tion or non-satisfac~ion become equivalent for the two products, correspond in fact to the cases in which the comparison formulation gives total satis~action.
It is also to be noted that, for none of the products, at none of the tested doses, the winter cereals were affected.

In the comparative tests carried out on five different dispersed fields, there were compared the two emulsifiable concentrates of example 3 on winter csreals at a different stage of growth: during the period of end of tilling to the beginning of sap ascent.
The utilisation doses per hectare, the method-ology of testing and of exploitation of the results are the same as in example 3. In Table V are recorded all the results of effectiveness at 45 days per plant, field, plot and product dose, and in Table VI, there are .

~3(3C~3~3 merged the two doses of each product in order to estab-lish per plant, the percentage of observations of satisfaction (herbicidal effectiveness greater than or equal to 95%) and of unsatisfaction (herbicidal effectiveness less than 70%) for each product over a sufficient number of observations. The overall per-centages of the cases of satisfaction and of non-satis~
faction as well as the typical deviations ~rom these arithmetic means are given.
There is shown in the graph of Figure 2, the comparative spectrum of the levels of satisfaction and non-satisfaction of the tested products.
The details provided above with respect to Figure 1 apply in the same way to Figure 2, the plants tested being:
A = Aphanes arvensis B = Cardamine hirsuta C = Cerastium glomeratum E = Lamium purpureum F = Legousia speculum-veneris G = Matricaria chamomilla H = Matricaria inodora I = Papaver rhoeas J = Polygonum convolvulus K = Ranunculus sardous L = Raphanus raphanistrum M = Rumex acetosa N = Veronica hederifolia P = Veronica persica.
C+f1 ~ Cd1 and Cf1 , Cd1 Corresponding to curves Cf , Cd , Cf , Cd of Figure 1.
Finally there are also indicated the arithmetic means concerning the curves Cf1+, Cd1+, Cf1-, Cd1~.

13V~;~g3 , .. ..
TABLE V

Products testsd . ~f) (d) ioxynil n- ioxynil octanoate ~ n-heptanoate/
oecoprop n-butyrate butylglycol +oecoprop ester butylglycol ester l I
Dose ioxynil~mecoprop lg/ha) 300-900¦ 360~1080 300~900 ¦360t1080 _ l _ PLANT Field Results obtained ~ _ Aphanes arvensis field I lûû/100 1001100 100/1ûO 100/100 field 4 70/7n 95/70 95/9S 9S/95 ~______ ___ _ _ . _ _ __ __ ____ ._ _____ Cardamine hirsuta field 3 9S/70 95/70 95/95 95/70 field S 95/70 9S/70 9S/70 9S/70 _______________~ ___ _ __ _~ _________ _ __ ___ __ ,_____ _ Cerastium glomeratum field 2lO0/lO0 100/lO0100/lO0 lO0/95 field 3 lO0/95 95t95 lO0/95100/9S
field S 9S/70 95/70 95/70 95/9S
____ _ _ __ _ _____ ____ __ _______ _ ______ .________ Lamium purpureum field 5¦70/30 70/30 70/70 70/70 ____ ________ _ _ _ ~__------ ----------_____ ________ ______ Legousia speculum- field 4 ¦70/7095/30 70/709S/70 veneris ___________________ ___ _ _ _ ______ _ _ _______ ,______ _ Ma~ricaria field 495/10 95i70 100195 95/70 chamomilla .
____________ __ _ _________ _ ________ _________ ~__ _____ l~latricaria inodora field 2 5/5 30/5 5/5 100/100 : field 3 30/3095/5 70/30 95/70 ___ ________ _ _ _ __ __ _ ___ _____ . _ _ _ Papaver rhoeas field 2 1 100/100 100/lO0 100j100 100/100 .

field 4 ¦~oO/95 100/70 100/100 100/100 ? ___________ _ _ I ~_ _____ ________ _ ______ ___ _ _ Polygonum convol- field 2:l ioo/loo lO0/100 95i95 95/9S
.` ~_ ~ I I l I I

!

`:

~3()~3~i3 : TAOLE. V ~ contd) _ , Products tested ~f) (d) ioxyn;l n- ioxynil . octanoate f n-heptanoate/
; ~ecoprop n-butyrate butylglycol ~ mecoprop ester butylglycol ester Dose ioxynil~mecoprop ~g/ha) 300~9ûO 360~10aO 3UO~900 360~1060 , , _ PLANT Field Results obtained _. _ _ Ranunculus sardous field S 95/30 9S/70 95/70 95/70 _________ _ _ _____ _ ___ ____ ___ _____ __________ _______ Raphanus raphanistrum field 3 100/100 9S/95 100/100 95/95 _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Rumex acetosa field 2 100/70 100/70 100/70 100/95 . field 3 lOO/lOO lOO/100 lOOtlOO 95/70 _____ _ __ _ _____ ______ _ ____ --I--_________ __ _____ Veronica hederifolia field 1 1on/7o 70/70 ¦ 70/70 95/70 field 2 70/30 70/30 1 95/30 100/30 field 3 100/95 100/95 100/100 100/100 .
___________ ________ _______ __ __ __ _ _____ ____ _____ __ Veronira persica fiold ~ 70/30 ¦ 70/30 70/70 95/70 . field 5 95/70 ¦ 95/70 9S/70 95l95 l I

~ . ;

~30~13~3 T A 8 L E . V 1 Products tested , (f) (d) ioxynil n- ioxynil octanoate + n-heptanoate/
~ecoprop n-butyrate butylglycol + recoprop ester butylglycol PLANT nuaber % of results X Of results of obser- satis- unsatis- satis- unsatis- -vations factory factory factory factory Aphanes arvensis 8 62 O 100 O
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ Cardamine hirsuta a so O 62 O
___________________ _ __ ___ ___ ____ ____ _____ _____ __ . ______ Cerastium g1om~ratum 12 83 O 92 O
______________ _ _ __ ________ ________ ________ _ ___ _ ___ _____ ____ Lamium purpureum ~ O 50 O O
______________ __ __ ________ ________ ___ ____ _ ___ _____ .__________ Legousia speculum- 4 25 25 25 O
veneri s _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ Matricaria ~ 50 O 75 O
chamomilla ______________ ___ __ ________ ________ __________ _________ .____ __ llatricaria inodora 8 12 as 37 37 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ Papaver rhoeas 8 88 O 100 O
________ ____________ ________ _________________ _________ ._ ______ Polygonum convolvulus 4 100 O 100 O
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ _ Ranunculus sardous ~ 50 25 50 û
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ Raphanus raphanistrum ~ 100 O 1011 O
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ _ _ Rumex acetosa 8 75 . O 75 O
_____________________ ________ __________________ _______. ._ ________ Veronica hederifo~ia 12 ~2 17 58 17 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ _ Veronica persica 8 25 25 50 O
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ _ _ _ General aean 96 5~ 16 66 devi ation l~ith 9 6 3 2 2 6 3 2 10 . respect to the llean _ . _ _ __ i ~3V~3~3 As in example 3, when examining Table Vl, it ap~ears that the formulation according to the invention provides an improvement as far as the percentage of cases of satisfactory herbicidal results (on Aphenes arvensis, Matricaria chamomilla and inodora and on Veronica persica), with respect to the percentage of cases of unsatisfactory results (on Lamium perpureum, Legousia speculum-veneris, Matricaria inodora, ~anun-culus sardous and Veronica persica) is concerned. In the 0 case of Matricaria inodora and Veronica persica, the improvement concerns the two planes.
The arithmetic means over all plants tested are also in favour of the formulation according to the invention and in Figure 2, the hatched areas show very explicitly the improvement provided by the inventi,on.
As in example 3, on no plant the formulation according to the invention is inferior to the formulation previously known.
It is also to be noted that, for no product, at none of the doses tested, winter cereals were affected.

.

Claims (11)

1. Herbicidal product with improved efficiency comprising in admixture - at least one n-butyric ester selected from the group con-sisting of bromoxynil n-butyrate and ioxynil n-butyrate, - at least one n-heptanoic ester selected from the group consisting of bromoxynil n-heptanoate and ioxynil n-heptanoate and - at least one phenoxy-alkanoic acid selected from the group consisting of mecoprop, 2,4-MCPA, 2,4-D and 2,4-DP
in ester form, the said product comprising from 50 to 400 g/l of ioxynil and-or bromoxynil equivalent and from 100 to 650 g/l of at least one phenoxy-alkanoic acid, the molar ratio of n-heptanoate to n-butyrate being comprised between 0.25 and 10.

2. Herbicidal product according to claim 1, wherein the phenoxy-alkanoic acid is in the form of butylglycol or iso-octanol ester.

3. Herbicidal product according to claim 1, wherein the molar ratio of n-heptanoate to n-butyrate is comprised between 0.65 and 4.

4. Herbicidal product according to claim 1, wherein the molar ratio of n-heptanoate to n-butyrate is 1.

5. Herbicidal product according to claim 1, wherein the molar ratio of n-heptanoate to n-butyrate is 2.

6. Herbicidal product according to claim 1, compris-ing a solvent selected from the group consisting of petroleum hydrocarbons, particularly their aromatic and paraffinic cons-tituents, and animal, vegetable and synthetic oils.

7. Herbicidal product according to claim 1, compris-ing a solvent constituted by a mineral oil having a weight content of aromatic product of at least 70% and a flash point higher than 50°C.

8. Herbicidal product according to claim 1, compris-ing an emulsifier selected from the group consisting of sulpho-ricinoleates, quaternary ammonium derivatives, products based on condensates of ethylene oxide with propylene oxide or with alkylphenols, carboxylic esters of anhydrosorbitols possibly polyethoxylated, alkaline, alkaline-earth or ammonium salts of sulphuric esters, sulphonic derivatives with high molecular weights selected from among lignosulphonates and sodium and calcium alkylbenzene-sulfonates.

9. Herbicidal product according to claim 1, compris-ing an emulsifier selected from the group consisting of sulpho-ricinoleates, quaternary ammonium derivatives, products based on condensates of ethylene oxide with propylene oxide or with alkylphenols, carboxylic esters of anhydrosorbitols possibly polyethoxylated, alkaline, alkaline-earth or ammonium salts of sulphuric esters, sulphonic derivatives with high molecular weights selected from among lignosulphonates and sodium and calcium alkylbenzene-sulfonates, that emulsifier being used in the proportion of 0.1 to 20% weight/weight in hydrocarbons or in short alcohols.

10. Spraying fluids for the destruction of alien plants obtained by dispersion in water of herbicidal products according to claim 1, said spraying fluids containing from 0.05 to 5% by weight/volume of a mixture of bromoxynil and/or ioxynil n-heptanoic and n-butyric esters and from 0.1 to 10% by weight/volume of phenoxy-alkanoic acid esters.

11. Method of destroying alien plants comprising the use of a herbicidal product according to claim 1 at a dose of 50g to 1 kg/ha of bromoxynil and/or ioxynil equivalent.