AU2001256335A1 - Glyphosate compositions and their use - Google Patents

Description

GLYPHOSATE COMPOSITIONS AND THEIR USE

The present invention relates to improved herbicidal glyphosate compositions comprising a glyphosate herbicide and surfactants.

#

Glyphosate is a well known highly effective and commercially important non-selective systemic herbicide for combating a wide variety of unwanted vegetation, including agricultural weeds. Glyphosate is conventionally applied as a formulated product comprising the active ingredient and a surface active component, dissolved in water, to the foliage ofthe plants.

Usually, glyphosate is formulated in commercial compositions in the form of a water-soluble salt. Salts in commercial use include the ammonium salt, alkylamine salts, such as the isopropylamine salt, alkali metal salts, such as the sodium salt, and the trimethylsulfonium salt.

Numerous studies have been made on the effect of surfactants or surfactant combinations on the herbicidal action of glyphosate. Wyrill and Burnside, Weed Science, Vol. 25 (1977), 275-287, studied the effects of many different surfactants including examples from different classes of surfactant. Some classes of surfactant were more effective than others in enhancing the herbicidal effect of glyphosate (used as a solution of the isopropylamine salt) . Wyrill and Burnside concluded that an effective surfactant is an important component of any glyphosate spray formulation.

Monsanto' s well known commercial liquid formulation sold for years under the tradename Roundup^® comprises, per liter of formulated product, 360 g a.e. (acid equivalent) of glyphosate in the form of its isopropylamine salt and 180 g of a tallow amine ethoxylate surfactant .

Efforts have been made in recent years to develop glyphosate compositions that show improved efficacy in general or in certain conditions, and/or which show improved environmental profiles. There also have been developed advantageous solid compositions.

W095/33379 discloses trialkanolamine derivatives and quaternized derivatives thereof for enhancement of the efficacy of agricultural chemicals. It more particularly discloses compounds of the formula (R₅-0)_q-R₂

/ R,-(0-R₄)_p-N \

(R₆-0)_r-R₃ wherein Rl represents inter alia a linear or branched alkyl group or alkenyl group having 5 to 29 carbon atoms,

R₂ and R₃ may be the same or different and each represent hydrogen or a linear or branched alkyl or alkenyl group having from 5 to 29 carbon atoms, p, q, and r may be the same or different and each represent a number of 1 to 30 in the average, and R₄, R₅ and R₆ represent alkylene groups of 2 to 4 carbon atoms, for use with agricultural chemicals. Herbicidal compositions comprising glyphosate are" also disclosed. Example 1, Table 9 suggests herbicidal compositions comprising Roundup^® herbicide and a compound of the above formula wherein R_x and R₂ are alkyl with 18

C-atoms, R₃ is hydrogen, and p, q and r are each 5.

More recently, W096/32839 discloses herbicidal glyphosate compositions comprising an effective herbicidal activity enhancing amount of a surfactant having the chemical formula

(R₃-0)_s-H / R₁-(0-R₂)_m-N \

(R₃-0)_y-H wherein x and y are average numbers such that x+y is in the range from 2 to 60; or

(R₃-0)_x-H /

Rι-(0-R₂)_ra-N⁺-R₄ A^" \ (R₃-0)_y-H wherein x+y is in the range from 0 to 60, and A- is an agriculturally acceptable anion, R₄ is C₁-C₄ alkyl; or

(R₃-0)_x-H / R₁-(0-R₂)_ra-N->0 \ (R₃-0)_y-H wherein x+y is in the range from 2 to 60, and where in all the above formulae, R_x is a straight or branched chain alkyl, aryl, or alkylaryl group having from 6 to 22 carbon atoms, m is an average number from 1 to 10, R₂ and R₃ in each of the m (0-R₂) or (R₃-0) groups is independently alkylene with 1 to 4 carbon atoms. Such compositions may show very high glyphosate concentrations ranging from 450 to 500 g a.e./l while still showing an adequate surfactant concentration. Such compositions are said to show excellent herbicidal performance and a good storage stability under a wide range of temperatures.

An aim of the present invention is to provide improved herbicidal glyphosate compositions.

Another aim of the present invention consists in providing new glyphosate formulations which show an advantageous herbicidal activity together with an acceptable environmental profile.

According to the present invention herbicidal compositions comprise

(a) glyphosate acid or an agriculturally acceptable salt or derivative thereof, and

(b) a surface active component having the formula (R₃-0)_x-Rι

/ R-N (I)

\

(R₃-0)_y-R₂ or a quaternized form thereof

(R₃-0)_x- ι / RR'-N⁺ A^" (II) \ (R₃-0)_y-R₂ or the amine oxide derivative thereof

(R₃-0)_x-R₁ / R-N->0 (III) \

(R₃-0)_y-R₂ wherein R and R' represent hydrogen or alkyl having 1 to 3 carbon atoms, Rl and R2 each independently represent a straight or branched chain alkyl or alkenyl group having from 4 to 24 C-atoms, R₃ in each (R₃-0) -group may be the same or different and represents alkylene having from 2 to 4 carbon atoms, A^" is an agriculturally acceptable anion, and x and y are average numbers such that x+y is in the range from 2 to 160.

Such compositions show a surprisingly high degree of herbicidal efficacy compared to prior art compositions, in the sense that, at typical glyphosate/surfactant ratios, the efficacy is at least similar to, but at increased glyphosate/surfactant ratios is drastically improved over, conventional surfactant (s) containing compositions. Invention compositions show similar performance or biological effect to prior art compositions, with the advantage of using higher glyphosate/surfactant ratios. As a result, compositions of the invention may contain higher concentrations of glyphosate and be economically more interesting.

As used herein, "glyphosate" means N-phosphono- methylglycine in its acid form as well as in any salt form or derivative of glyphosate which in aqueous solution provides glyphosate anions along with suitable cation. Glyphosate includes the isopropylamine salt of glyphosate and other agriculturally acceptable salts of glyphosate such as those disclosed in US Patent 3,799,758.

Surfactants as defined hereabove are known to the person skilled in the art and may be prepared by amnaonolysis of the corresponding alcohol (alkoxylated or not) with ammonia and a suitable catalyst. According to that method of preparation, the relevant alcohol or an alcohol mixture is heated in the presence of a suitable catalyst, such as for example a nickel catalyst, to a temperature ranging from 130 to 220 degrees C, preferably to about 190 degrees G, while flushing with nitrogen. Ammonia and hydrogen are then added continuously at a proportion of 5 to 1 to 1 to 2 by volume, preferably around 3 to 1. The pressure of the reaction medium can be varied from normal pressure to medium pressure conditions of approximately 20 bar. The resultant surfactant is obtained after 9 to 20 hours, after distillation of the reaction water. After the reaction is completed, the product is cooled to room temperature, the catalyst is filtered off and the product is degassed in an evaporator. The product obtained may the further be reacted according to standard procedures in view of desirable alkoxylation, methylation, oxidation or quaternization.

In the compositions of the invention, the weight ratio of glyphosate (expressed as glyphosate acid equivalent) to the total surface active component can vary over a considerable range, for example from 1:5 to 20:1. The optimum ratio will vary according to the manner and conditions in which the herbicidal composition is applied, the weed species to be treated, and the particular surfactant used, but is normally higher than 1:1, preferably higher than 2:1, more particularly higher than 5:1. Compositions of the invention are so advantageously effective that compositions with unexpectedly high glyphosate a. e . /surfactant ratios of the order of 20:1 or 15:1 still give good results . Compositions having a glyphosate a.e. to surfactant ratio of 8:1, 10:1 or 12:1 are particularly preferred. Such compositions show an acceptable commercial control of undesired plants similar to current commercial and prior art compositions while containing a reduced surfactant level.

A composition of the invention can be a liquid concentrate intended to be diluted with water to form a spray solution for the herbicidal application. A liquid concentrate will normally contain at least 50 grams glyphosate acid equivalent per litre, and preferably at least 200 g/1, up to 600 g/1 bur in certain cases, more diluted ready to use formulations may contain glyphosate concentrations of about 2 to 20 g/1. Compositions containing 300 to 600 g/1 or 400 to 550 g/1 are preferred.

In another form, a composition of the invention is a solid, for example a free-flowing particulate, granular solid or compressed into tablets or briquettes of any desired size and shape. Such compositions will usually contain not more than 5% and preferably not more than 1% by weight of water. Solid compositions may be formulated to include a water-soluble inert carrier, and for this purpose ammonium salts such as ammonium sulphate may be particularly suitable (see below) . The weight ratio of glyphosate (expressed as glyphosate acid equivalent) to surface active component in such compositions will be within the general range mentioned above. The amount of water-soluble inert carrier is not critical, and in the case of ammonium sulphate, the amount may, for example, range from 0% to 80% of the total weight of the composition. A dry composition normally contains at least 5 - 80 % w/w glyphosate acid equivalent. Solid compositions can be made, for example by spray drying an aqueous solution of the components, by dry-blending the ingredients in conventional granulating apparatus, or by extrusion blending whereby a granular product is obtained in an essentially single operation.

Compositions of the invention also include spray solutions. In these solutions, the concentration of glyphosate is selected according to the volume per unit area of spray solution to be used and the desired rate of application of glyphosate per unit ^'area. For example, conventional spraying is done at 50-800 litres of spray solution per hectare, and the rate of application of gly- phosate is typically 0.125 to 4 kg of glyphosate acid equivalent per hectare. In controlled drop spraying, the rate of application of glyphosate per hectare will normally be within the same range, but the volume of spray solution per hectare will be considerably less, perhaps 15-50 litres per hectare. Spray solutions for controlled drop spraying are therefore more concentrated than those used in conventional spraying.

Spray solution compositions can be prepared by diluting liquid concentrates or dissolving solid compositions of this invention as described above, or by tank mixing the separate components of the claimed compositions .

Compositions of the invention may include a significant amount of an agriculturally-acceptable inorganic ammonium salt such as ammonium nitrate, ammonium thiocyanate, ammonium thiosulfate, ammonium phosphate, ammonium chloride, preferably ammonium sulphate, in addition to the glyphosate herbicide and surface active component.

Compositions of the invention, more particularly formulated concentrate compositions of the invention may further contain other adjuvants like formulation aids, such as extrusion aids, dyes, thickeners, defoamers, such as silicon based defoamers, stabilizers, anti-freeze agents such as ethylene glycol and other surfactants, or even other pesticidal actives, as may be determined by the person skilled in the art.

Preferably Rl and R2 each independently represent a straight or branched chain alkyl or alkenyl group having from 8 to 18 carbon atoms.

Surfactants corresponding to formula (I) are preferred. Most preferred are surfactants of formula (I) wherein Rl and R2 each independently are a straight or branched chain alkyl or alkenyl group having 12 to 18 carbon atoms .

x+y may range from 2 to 160 or even more while maintaining the good efficacy of the surfactant in the invention compositions. An advantageous alkoxylation degree ranges from x+y = 4 to 100, preferably 6 to 50. In certain instances, depending on the actual chemical structure of the surfactant, an alkoxylation degree of x+y comprised between 8 and 20, or 10 to 20 or preferably 12 to 20 has shown particularly advantageous.

Another embodiment pertaining to the present invention includes an adjuvant for agricultural compositions, more particularly herbicidal glyphosate compositions, which comprises a surface active component as per formulae (I) to (III) •

Adjuvant compositions of the invention, similarly to the herbicidal compositions of the invention as described above can optionally contain other components .

The concentrates and solutions of the invention may also be mixed with other pesticides. Preferably though not required such other herbicides, insecticides or fungicides have low irritancy and toxicity.

Yet another aspect of the present invention is a method of use of compositions described above for the control of unwanted vegetation.

The invention will be described in more detail hereafter with reference to examples.

EXAMPLE 1

A solid composition (cmps 1) according to the invention was prepared as follows: A monium salt of glyphosate (MON8750 powder) , surfactant of formula C_12.18H₂₅_₃₇- (OCH₂CH₂) ₅-NH- (CH₂CH₂0) ₅-C₁₂.₁₈H₂₅.₃₇ (surfactant 1) and Rhodorsil 432 (tradename) antifoa were blended in that order at room temperature in a Hobart 5 planetary mixer. Water was then added and mixing continued until a dough is formed with a consistency suitable for extrusion. The dough mixture was charged into a Fuji Paudal EXDS-60 extruder fitted with a 0.7 mm radial screen. The extruded granules were dried using an

10 Aeromatic Strea-1 fluid bed dryer controlled at approx 50 degrees C for approx 30 minutes, and sieved on an Endecotts EFL MK3 sieve shaker. Fines of <0.3mm and oversize >2.0mm in size were removed by the sieving process and discarded. The final product was comprised of

15 _. free flowing, non-dusty off white coloured granules.

Final composition was as follows: ammonium glyphosate (MON8750 powder) 89.81 %w/w surfactant N. 1 9.70

20 Rhodorsil 432 0.49

The product had an initial residual moisture content of < 1 % w/w.

25.

Details of storage stability test results can be seen in the table below. Assay of the formulation indicated no loss of glyphosate active ingredient after one month at 54 degrees C compared to a sample stored at --18 degrees C for

30 the same period. The formulation was found not to foam on dilution when tested according to method CIPAC MT47.2 at a concentration of 6.4g product in 230ml of water. The dissolution and solution stability was tested according to CIPAC method MT179 at a concentration of 6.9g of

35 formulation in 250ml of water; both initially and after storage for two weeks at 54 degrees C the formulation was found to dissolve within the specified 5 minutes and the solution thus formed exhibited no precipitation or phase separation after 18 hours.

EXAMPLE 2

The herbicidal efficacy of the composition of

Example 1 was evaluated in a greenhouse test, in comparison with prior art compositions:

■ cmps a, commercial Roundup^® comprising 360 g/1 glyphosate a.e. and 180 g/1 tallow amine ethoxylate (15 EO) based surfactant;

■ cmps b, commercial glyphosate composition sold under the tradename Roundup^® Bioforce^® in France, comprising 360 g/1 glyphosate a.e. and 180 g/1 of a surfactant composition comprising a propoxylated quaternary ammonium surfactant as per Example 6 of EP-0 441 764;

■ cmps c, a soluble liquid comprising 81.80% w/w isopropylamine salt of glyphosate (grade 205 - 46 %w/w of glyphosate acid equivalent) and 7.53 %w/w surfactant as per W096/32839 (having the amine structure wherein Rl is a branched alkyl chain having 11 - 14 C-atoms, R2 is isopropyl, m is 1, R3 is ethylene oxide and x+y is 5. The rates of application of this test were equivalent to 240, 480, 720 and 960 g a.e. /ha.

Agropyron repens (AGRRE - narrow leaf) and

Raphanus sativus (RAPSA - broadleaf) plants were grown from seed in 10 cm pots containing a natural sandy loam soil. The pots were placed in a growth-room until the spraying with a precise relative humidity as well as temperature control. After spraying plants were transferred to a greenhouse where light and temperature were also well controlled. Plants remained in this greenhouse for the remainder of the experiment. Both in growth-room and in the greenhouse, the water was supplied from below the pots by an automatic irrigation system.

Plants reached the appropriate growth stage for spraying around 3-4 weeks after sowing. Before spraying, pots were selected for uniformity as far as possible and atypical pots were discarded.

Glyphosate compositions were applied post- emergence with a precision laboratory sprayer (IMAG-DMLO) , delivering a volume of 200 1/ha solution through "Flat Even" nozzles (11003) in a single pass. All compositions were diluted in water. All replicate pots (4 pots per treatment) were sprayed with one pass of the sprayer.

Pots were distributed randomly in the growth room after treatment. Untreated control pots were placed at random among treated pots.

Assessment of per cent phytotoxicity was made by comparison with untreated control pots on an arbitrary scale from 0 to 100%, where 0 means no visible effect and 100 means death of all plants. The results are presented as average values of four replicates and three assessments at 24 days after treatment .

TABLE 1A : Efficacy on RAPSA

Rate (g a.e. /ha) 240 480 720 960

Composition a 55 89 75 85 b 53 70 80 81 c 63 73 81 89

1 65 83 92 87

TABLE IB: Efficacy on AGRRE

Rate (g a.e. /ha) 240 480 720 960

Composition a 25 69 85 92 b 23 54 84 91 c 28 73 91 97

1 26 64 85 91

As can easily be seen from the above, all compositions provide similar performance, with no significant statistical difference between them, although the invention composition comprises far less surfactant than the prior art compositions.

EXAMPLE 3

In this Example, the following surfactants were used: R_{1 =}=R₂= (R₃ -0) =E0 R surf actant x+y= N . sat . , branched C13 16 H 2

( i sotridecyl ) 30 H 3 sat . , linear C16/ 18 16 H 5

( tallow) 16 CH3 6

40 H 8 unsat., linear, C16/18 16 H 9

(oleyi) 40 H 10 sat., C24 40 H 11 (guerbet)

Surfactant N.4 corresponds to the formula RN[ (EO)_x, (P0)_X„R ₂ wherein x' =3 and x"=3, R is H and R_x is isotridecyl.

Surfactant N.7 corresponds to a quaternized compound according to formula (II) wherein R is CH₃ , R' is CH₃, R₃ is ethylene, x + y is 16, and R_x is a saturated, linear alkyl chain from tallow.

The tested compositions were tank mixed compositions comprising isopropylamine salt of glyphosate and the relevant surfactant in a ratio of 5:1.

Glyphosate was applied at dose rates of 360, 720 and 1080 g a.e. /ha following essentially the procedure as detailed in Example 2. Plant species tested were Elyτnus repens (narrowleaf) , Raphanus sativus (broadleaf ) , Ipomea purpurea (broadleaf) . Phytotoxicity was evaluated and recorded at 6 , 18, and 25 days after treatment (DAT) .

The results are presented as average values of four replicates at the dose rates and DAT as indicated. Table III

Glyphosate RAPSA AGRRE IPOPU RAPSA AGRRE IPOPU rate 6 DAT 6 DAT 6 DAT 15 DAT 18 DAT 18 DAT

IPA-G sur 1

360 18.8 10.0 32.5 60.0 76.3 57.5

720 23.8 20.0 47.5 70.0 90.0 85.0

1080 25.0 20.0 36.3 61.3 93.8 ^'75.0

IPA-G sur 2

360 17.5 18.8 27.5 42.5 76.3 52.5

720 22.5 23.8 31.7 60.0 82.5 80.0

1080 27.5 26.3 53.8 72.5 94.0 88.8

IPA-G sur 3

360 17.5 15.0 30.0 43.8 65.0 60.0

720 27.5 25.0 46.7 63.8 91.5 90.0

1080 27.5 20.0 51.3 67.5 91.3 90.0

IPA-G sur 4

360 16.3 26.3 20.0 40.0 90.3 61.3

720 20.0 25.0 26.3 52.5 91.5 72.5

1080 21.3 27.5 31.3 56.3 94.5 85.0 TABLE III con'^'t

Glyphosate RAPSA AGRRE IPOPU RAPSA AGRRE IPOPU rate 6 DAT 6 DAT 6 DAT 15 DAT 18 DAT 18 DAT

IPA-G sur 5

360 25.0 20.0 30.0 51.7 73.8 71.3

720 21.3 21.3 27.5 68.8 85.0 78.8

1080 21.3 37.5 50.0 76.3 97.3 91.3

IPA-G sur 6

360 07.5 17.5 36.3 47.5 70.0 61.3

720_. 20.0 32.5 47.5 61.3 92.8 86.3

1080 21.3 22.5 41.3 58.8 92.0 91.3

IPA-G sur 7

360 16.3 10.0 20.0 43.8 58.8 58.8

720 20.0 12.5 35.0 61.3 72.5 87.5

1080 22.5 32.5 35.0 65.0 93.3 90.0

IPA-G sur 8

360 16.3 13.8 40.0 46.3 75.0 77.5

720 18.8 12.5 40.0 51.3 80.0 81.3

1080 26.3 13.8 41.3 81.3 86.3 92.5

IPA-G sur 9

360 18.8 17.5 31.3 48.8 77.5 72.5

720 23.8 17.5 37.5 57.5 83.8 85.8

1080 27.5 21.3 36.3 77.5 90.8 92.5 TABLE III con' t

Glyphci— sate RAPSA AGRRE IPOPU RAPSA AGRRE IPOPU rate 6 DAT 6 DAT 6 DAT 15 DAT 18 DAT 18 DAT

IPA-G sur 10

360 17.5 13.8 35.0 51.3 77.5 77.5

10 720 20.0 25.0 42.5 67.5 92.8 92.0

1080 21.3 22.5 45.0 60 . 0 92.0 93.8

IPA-G sur 11

15 360 17.5 10.0 33.8 58.8 65.0 72.5

720 28.8 17.5 33.8 72.5 91.3 85.0

1080 27.5 17.5 35.0 71.3 91.3 83.8

IPA-G

20 sur 1

360 70.0 86.3 56.7

720 77.5 97.8 93.3

1080 75.0 100.0 87.5

25 IPA-G sur 2

360 55.0 82.5 60.0

720 80.0 93.8 87.7

1080 84.5 99".5 97.0

30

J TABLE III con'^'t

Glyphosate RAPSA AGRRE IPOPU rate 25 DAT 25 DAT 25 DAT

IPA-G sur 3

360 55.0 75.0 70.0

720 76.3 98.0 98.3

1080 81.3 98.8 96.5

IPA-G sur 4

360 52.5 93.3 72.5

720 63.8 95.8 83.8

1080 72.5 99.5 90.8

IPA-G sur 5

360 60.0 80.0 77.0

720 86.3 97.0 87.0

1080 87.5 99.0 97.0

IPA-G sur 6

360 60.0 75.0 73.8

720 75.0 96.5 95.8

1080 89.5 98.3 97.3

IPA-G sur 7

360 61.3 71.3 68.8

720 78.8 82.5 95.8

1080 81.3 98.3 97.3 TABLE III con' ' t

Glyphc )- sate RAPSA AGRRE IPOPU rate 25 DAT 25 DAT 25 DAT

IPA-G sur 8

360 61.3 83.3 83.8

720 70.0 93.8 92.0

1080 91.3 97.0 96.5

IPA-G sur 9

360 62.5 83.8 76.3

720 72.5 93.3 96.5

1080 93.3 98.8 96.5

IPA-G sur 10

360 60.0 81.3 86.3

720 85.0 98.3 95.8

1080 78.8 99.5 95.0

IPA-G sur 11

360 75.0 70.0 81.3

720 86.5 97.8 94.5

1080 90.8 98.5 92.0

IPA-G: means isopropyl amine salt of glyphosate; sur: means surfactant followed by the number of the surfactant as referred to earlier;

360, 720 and 1080 mean grams acid equivalent per hectare.

This Example shows that, at glyphosate a . e . /surfactant ratios of 5/1, all these invention compositions perform very well and to a similar extent.

EXAMPLE 4

A similar test was performed according to essentially the same protocol, except that evaluations were made as indicated (DAT) .

Compositions tested were as follows:

■ composition a, as defined in Example 2;

■ composition b, as defined in Example 2; M composition c, as defined in Example 2;

H a tank mix comprising a 10/1 ratio of glyphosate isopropylamine salt and surfactant 1;

■ a tank mix comprising a 10/1 ratio of glyphosate isopropylamine salt and surfactant 3; ■ a tank mix comprising a 10/1 ratio of glyphosate isopropylamine salt and surfactant 4;

■ a tank mix comprising a 10/1 ratio of glyphosate isopropylamine salt and surfactant 5;

■ a tank mix comprising a 10/1 ratio of glyphosate isopropylamine salt and surfactant 9;

■ a tank mix comprising a 10/1 ratio of glyphosate isopropylamine salt and surfactant 11.

■ a tank mix composition comprising isopropylamine salt of glyphosate and surfactant N. 12 (R1=R2= C2 guerbet, (R3-0) is EO, x+y=160, and R=H) in a ratio of 10:1;

The test results are summarized in Table IV below. TABLE IV

Glyphosate RAPSA IPOPU AGRRE RAPSA AGRRE IPOPU rate 11 DAT 11 DAT 18 DAT 26 DAT 26 DAT 27 DAT

cps a

360 35.0 21.3 37.5 65.0 52.5 38.8

720 56.3 41.3 60.0 82.5 73.8 63.8

1080 62.5 38.8 75.0 85.0 80.0 67.5

cps b

360 28.8 30.0 41.3 52.5 51.3 50^".0

720 37.5 17.5 71.3 70.0 77.5 57.5

1080 43.8 55.0 85.0 76.3 83.8 73.8

cps c

360 27.5 13.8 42.5 42.5 50.0 35.0

720 43.8 37.5 72.5 73.8 81.3 53.8

1080 52.5 40.0 82.5 82.5 86.3 73.8

IPA-G sur 12

360 41.3 16.3 31.3 63.8 37.5 41.3

720 45.0 51.3 45.0 83.8 53.8 61.3

1080 56.3 33.8 53.8 80.0 70.0 65.0

IPA-G sur 1

360 33.8 17.5 36.3 58.8 42.5 38.8

720 48.8 35.0 52.5 72.5 71.3 60.0

1080 50.0 55.0 73.8 78.8 83.8 68.8 Glyphosate RAPSA IPOPU AGRRE RAPSA AGRRE IPOPU rate 11 DAT 11 DAT 18 DAT 26 DAT 26 DAT 27 DAT

IPA-G sur 3

360 33.8 25.0 30.0 53.8 53.0 41.3

720 46.3 36.3 46.3 72.5 61.3 57.5

1080 55.0 42.5 68.8 82.5 78.8 65.0

IPA-G sur 4

360 30.0 17.5 30.0 43.8 31.3 31.3

720 40.0 27.5 38.8 65.0 50.0 40.0

1080 50_..0 41.3 60.0 78.8 71.3 58.8

IPA-G sur 5

360 37.5 16.3 31.3 65.0 33.8 30.0

720 47.5 25.0 48.8 76.3 62.5 41.3

1080 55.0 38.8 42.5 85.0 56.3 62.5

IPA-G sur 9

360 37.5 37.5 33.8 66.3 46.3 56.3

720 43.8 36.3 48.8 72.5 58.8 67.5

1080 61.3 48.8 76.3 83.8 82.5 73.8

IPA-G - sur 11

360 46.3 17.5 35.0 73.8 45.0 33.8

720 50.0 20.0 48.8 81.3 62.5 45.0

1080 45.0 33.8 48.8 76.3 62.5 58.8

IPA-G means isopropylamine salt of glyphosate; sur means surfactant followed by the surfactant number which refers to the corresponding surfactant definition; 360, 720 and 1080 are the glyphosate acid equivalent dose rates applied, expressed in grams/ha.

This example shows that at glyphosate a. e . /surfactant ratios as high as 10:1 the compositions of the invention perform unexpectedly well, and as good as prior art compositions with ratios of 5:1 or 2:1.

EXAMPLE 5

A similar test was performed according to essentially the same protocol.

The tested compositions were prior art compositions a, b and c, and tank mixed compositions comprising isopropylamine salt of glyphosate and the relevant surfactant in a ratio of 5:1.

The surfactants used in this test are as follows :

R_X=R₂= (R₃-0)=EO R surfactant x+y= N. sat., linear C8/10 16 H 13

2 0 H 14 sat., linear C12/18 20 - H 15

16 H 16 sa . , linear C8/10 10 H 17

Glyphosate was applied at dose rates of 360, 720 and 1080 g a . e . /ha following essentially the procedure as detailed in Example 2. Plant species tested were Elymus repens (narrowleaf ) , Raphanus sativus (broadleaf) , Ipomea purpurea (broadleaf) . Phytotoxicity was evaluated and recorded at 6, 17, and 25 days after treatment (DAT) .

The results are presented as average values of four replicates at the dose rates and DAT as indicated on each Table.

Table V

Glyphosate RAPSA AGRRE IPOPU RAPSA AGRRE IPOPU rate 6 DAT 6 DAT 6 DAT 17 DAT 17 DAT 17 DAT

cps a

360 55.0 16.3 20.0 83.3 61.3 42.5

720 63.8 43.8 23.8 90.8 86.3 63.8

1080 72.5 47.5 31.3 95.8 96.3 79.5

cps b

360 43.3 16.3 25.0 65.0 55.0 60.0

720 50.0 50.0 27.5 87.5 95.3 70.0

1080 55.0 58.8 37.5 92.0 97.5 72.5

cps c

360 36.7 35.0 20.0 78.3 61.3 48.8

720 58.8 53.8 27.5 91.3 95.8 65.0

1080 66.3 43.8 30.0 95.0 93.8 84.5

IPA-G sur 1

360 28.3 23.8 20.0 61.7 61.3 51.3

720 62.5 31.3 30.0 88.3 87.5 73.8

1080 76.3 32.5 26.3 99.5 99.5 73.8 TABLE V con't

Glyphosate RAPSA AGRRE IPOPU RAPSA AGRRE IPOPU rate 6 DAT 6 DAT 6 DAT 17 DAT 17 DAT 17 DAT

IPA-G sur 13

360 45.0 27.5 15.0 77.7 81.3 37.5

720 56.3 40.0 33.8 87.5 98.8 68.8

1080 56.3 41.3 35.0 88.3 99.5 78.8

IPA-G sur 14

360 48.3 17.5 26.3 76.0 63.8 41.3

720 68.3 30.0 28.8 97.5 94.5 52.5

1080 62.5 46.3 31.3 86.3 97.5 68.8

IPA-G sur 15

360 40 . 0 16.3 22.5 61.7 48.8 45.0

720 55.0 26.3 33.8 92.0 90.8 70.0

1080 65.0 21.3 35.0 94.5 95.8 78.8

IPA-G sur 16

360 45.0 15.0 22.5 75.0 43.8 47.5

720 55.0 27.5 22.5 96.3 87.5 5O.0

1080 77.5 25.0 33.8 100.0 93.8 73.8

IPA-G sur 17

360 35.0 15.0 21.3 60.0 65.0 42.5

720 63.8 20.0 31.3 87.5 81.3 57.5

1080 70.0 18.8 37.5 93.3 93.8 71.3 TABLE V con't

Glyphosate RAPSA AGRRE IPOPU rate 25 DAT 25 DAT 25 DAT

cps a

360 89.3 67.5 51.3

720 95.0 92.5 67.5

1080 96.3 98.5 83.3

cps b

360 68.3 61.3 65.0 ^'

720 93.3 98.8 76.3

1080 97.5 99.0 80.0

cps c

360 76.7 71.3 57.5

720 93.8 98.5 72.5

1080 97.5 96.3 93.8

IPA-G sur 1

360 68.3 68.8 61.3

720 91.3 96.0 82.5

1080 100.0 100.0 82.5

IPA-G sur 13

360 83.3 89.5 46.3

720 93.8 99.5 75.0

1080 95.8 100.0 90.0 TABLE V con't

Glyphosate RAPSA AGRRE IPOPU rate 25 DAT 25 DAT 25 DAT

IPA-G sur 14

360 81.7 70.0 56.3

720 98.8 97.8 61.3

1080 92.0 99.5 78.8

IPA-G sur 15

360 68.0 57.5 56.3

720 93.8 95.3 76.3

1080 96.3 99.0 85.8

IPA-G sur 16

360 76.7 51.3 61.3

720 98.3 90.0 63.8

1080 100.0 99.0 80.0

IPA-G sur 17

360 61.7 70.0 58.8

720 91.3 87.5 63.8

1080 95.0 97.8 79.0

IPA-G means isopropylamine salt of glyphosate; sur means surfactant followed by the surfactant number which refers to the corresponding surfactant definition; 360, 720 and 1080 are the glyphosate acid equivalent dose rates applied, expressed in grams/ha.

This example shows that at glyphosate a . e . /surfactant ratios of 5:1 the compositions of the invention perform unexpectedly well compared to prior art compositions with ratios of 5:1 or 2:1.

Claims (10)

1. Herbicidal composition comprising:

(a) glyphosate acid or an agriculturally acceptable salt or derivative thereof, and

(b) a surface active component having the formula

(R₃-0)_x-R₁ / R-N (I) \

(R₃-0)_y-R₂ or a quaternized form thereof

(R₃-0)_x-Rι / RR'-N⁺ A^" (II)

\ (R₃-0)_y-R₂ or the amine oxide derivative thereof

(R₃-0)_x-R₁ /

R-N->0 (III)

\ (R₃-0)_y-R₂ wherein R and R' represent hydrogen or alkyl having 1 to 3 carbon atoms, Rl and R2 each independently represent a straight or branched chain alkyl or alkenyl group having from 4 to 24 C-atoms, R₃ in each (R₃-0) -group may be the same or different and represents alkylene having from 2 to 4 carbon atoms, A^" is an agriculturally acceptable anion, and x and y are average numbers such that x+y is in the range from 2 to 160.

2. Composition according to Claim 1 wherein Rl and R2 represent a straight or branched chain alkyl or alkenyl group having from 8 to 18 C-atoms.

3. Composition according to Claim 1 or 2 wherein the surfactant is a surfactant according to formula (I) .

4. Composition according to Claim 3 where in the surfactant formula Rl and R2 each independently represent a straight or branched chain alkyl or alkenyl group having from 12 to 18 C-atoms.

5. Composition according to any preceding Claim where in the surfactant formula x+y ranges from 4 to 100, preferably from 6 to 50.

6. Composition according to any preceding Claim where the weight, ratio of glyphosate (expressed as glyphosate acid equivalent) to the total surface active component ranges from 1:5 to 20:1.

7. Composition according to Claim 6 wherein the weight ratio of glyphosate (expressed as glyphosate acid equivalent) to the total surface active component is higher than 1:1, preferably higher than 2:1, more particularly higher than 5:1.

8. Composition according to Claim 7 wherein the glyphosate a. e. /surfactant ratio is as high as 15:1.

9. Composition according to any of claims 6 to 8 wherein the weight ratio of glyphosate (expressed as glyphosate acid equivalent) to the total surface active component is about 8:1, 10:1 or 12:1.

10. Adjuvant composition comprising a surfactant as defined in any of Claims 1 to 5, possibly together with other adjuvants, like solvent or diluent such as water or a lower alcohol, such as isopropanol or glycol, inorganic ammonium salt, dyes, thickeners, stabilizers and/or other MISSING AT THE TIME OF PUBLICATION