CA1155675A - Aqueous herbicidal compositions - Google Patents

Abstract

Z-PHA. 20,919.
ABSTRACT OF THE DISCLOSURE
Improved ultra low volume herbicidal aqueous com-positions containing water soluble herbicides, such as 2,4-D amine salts and aliphatic polyhydric alcohols with 2 to 4 hydroxyl groups attached to the aliphatic chain or a polyalkylene glycol with water as a solvent less than 50 parts by weight. The herbicidal aqueous compositions repre-sent an improvement over the compositions of the prior art by displaying low volatility and significantly enhanced herbicidal activity, requiring a lesser amount of active material. The compositions also permit better penetration of the weed canopy and enhanced penetration and transloca-tion of the active material into leaves of the weed being treated.

Description

; ZPHA. 20,919. 1 ~
1 155~75 '' .......... :
i IMPROVED AQUEOUS HERBICIDAL COMPOSITIONS `
.~
~C~ D O~ ~l3 I-~Y~VION
'I This invention relates to improved aqueous herbicidal Il compositions.
Herbicidal compositions containing such water soluble herbicides as 2,4-D amine salts (2,4-dichlorophenoxy-acetic acid amine salts), Paraquat (l,l',-dimethyl -4,4' bipyridylium ion dichloride salt) in aqueous solutions are well known in the art.
These aqueous compositions may be applied to crops by ¦ -either powered ground equipment or by aerial spraying ! -:
apparatus. In general, however, when large areas are to be ~
covered they are applied by aerial spraying apparatus. I - -=
These aqueous compositions may be applied to crops I -using volumes of from 0.5 to 3.0 gallons per acre, termed Low i, Volume (LV), or in Ultra Low Volume spray (ULV) in volume of 0.5 gallon or less. However, suitable spray applications are .
normally further diluted to reduce the danger of crop damage within a target area and to minimize the danger from --volatility, and drifting spray from harming crops outside the i! target area.
: -. -....- .
The use of 2,4-D amine salt compositions of the prior art in a~ aqueous spray, while favored because of its reduced volatility, has the disadvantage of not being as biologically efficient as the alternative water insoluble 2,4-D esters.
; ! I... i i.. . -r 9 , ,~v .: ~

1 ~ ~567 5 ., !
01 ' It is known from Schmidl U.S. Patent 2,510,839 to 02 employ such glycols as ethylene glycol and propylene glycol in 03 1 place of aliphatic alcohols as solvents for such non-water 04 1l soluble 2,4-D compounds as 2,4, dichlorophenoxyacetic acid and 05 ~I the esters thereof and to include in the herbicidal spray a 06 ¦I corrosion inhibitor, a wetting agent and a hydrocarbon binding 07 1l agent.
OB ll . According to this patent these herbicidal compositions 09 i are diluted with water to form dilute spraying compositions.
l In using such dilute sprays, a greater number of loads need to ~ be carried from the aircraft loading site to the target areas, 12 ,'l resulting in large expenditures of energy and man-hours.
~13 l~ Furthermore the esters employed are more volatile and often 14 i toxic to non-target beneficial plants causing not only undesired damage to crops outside the target area but in many .~ !
16 " cases causing a significant amount of damage to the desired 17 crops within the target area.
l8 In addition, W. Maas, ULV Application and Formulation `L9 ~ Techniques, N.V. Philips Duphar Amsterdam, Netherlands (1971), :: , , pp. 127-128 teach the application of 2,4-D ester solutions in 21 ,; oils and other organic solvents in which 50% formulations of 22 , 2,4-D esters are employed. Although this ULV formulation of !
23 i, the Maas article is useful in destroying unwanted vegetation in 24 1l a target area in a minimum number of applications it has a 1 significant degree of undesireable effect on vegetation outside 26 ., of the target areas because of the inherent volatility of the .. .j .
27 i 2,4-D esters.
~8 I
~9 -2-, .

',PHA 20,919 .
. ~ ~

' .. '-` I~' ,, , Dl It is an object of this invention to provide a new, D2 novel water soluble herbicidal composition that may be suitably 33 applied to target areas utilizing standard airplane apparatus `~4 1l or powered ground equipment. ¦
~5 , In addition, another object of this invention is to ~6 !~ provide a novel herbicidal composition which may be suitably ~7 ~1 applied to target areas in a highly concentrated form.
~8 1ll . Yet another object of this invention is to provide a ~9 ~ highly concentrated 2,4-D amine spray having a low volatility .0 " and a significantly decreased tendency to drift outside the 1 ~I target area.

2 ~ S~ill another object of this invention is to provide a

3 herbicidal composition when applied to target areas provides a

4 I significantly enhanced herbicidal activity as compared to the :5 ' known 2,4-D amine spray compositions, thus requiring the use of 6 ' a lesser amount of the active material.
7 ~, Another object is to provide a herbicidal composition 8 which will effect control of weed species not controlled or 9 marginally controled by the prior art.
O `~ Yet another object is to provide for these results in a manner which brings about a significant decrease in both the 2 ~ energy expended and in the number of man-hours required.
3 ,¦ These and other objects of the invention will be ~4 apparent from the description that follows.
. 5 , BRIEF SUMMARY OF THE INVENTION
Il 6 1l According to the invention new and novel herbicidal r 7 , compositions are prepared by combining in an aqueous solution, ; B 11 a water soluble herbicidal compound in an amount of from about `D 3 ~PHA 2~,919 1 1~55675 01 20 to 80 parts by weight, an aliphatic polyhydric alcohol of up 02 ~ to 4 carbon atoms in the aliphatic chain and from 2 to 4 03 hydroxyl groups attached to the aliphatic chain, or a 04 , polyalkylene glycol in the amount of from 5-25 parts by weight 05 1 and, as the solvent water in a concentration of less than 50 ~6 ,¦ parts and preferably less then 30 parts by weight.
~7 ~¦ It has been unexpectedly found that these novel ~8 I' herbicidal compositions may be applied to target areas without~9 ¦I dilution thus providing a significant saving in energy and man-:0 1 hours particularly when aerial spraying is involved.
It has also been unexpectedly found that these novel .2 lj herbicidal compositions have significantly less tendency to 3 ~1 dri~t than the prior art water insoluble herbicidal or water 4 soluble herbicidal compositions and thus have a significantlylower tendency to cause destruction of desired crops outside of ¦
6 ,~ the target areas. I
.. , "
~7 In addition it has been found that when the novel 8 2,4-D amine compositions of the invention are applied in the , ~
,g field, the activity is significantly enhanced compared to 2,4-D
;j :
0 amine compositions prepared according to the prior art. This 1 enhanced activity is brought about by the better penetration of ;2 the plant canopy obtained with the use of the 2,4-D amine 3 compositions of the invention compared to the application of 4 '' aqueous dilutions. In addition, the compositions of the 11 invention allow for enhanced penetration and translocation of the active ingredient into the plant leaves. This enables the 3 ~4-HA 20,919 1 ~5675 ~1 use of less active material per acre, and in many cases a fewer ~2 number of applications to provide the degree of weed control ~3 desired. - ;
)4 ~ The use of the cheaper amine rather than the more ~5 expensive ester, the use of less active material, and the fewer )6 , number of applications results in a considerable economic )7 l advantage to the user.
18 - Any of the water-soluble herbicidal compounds may be )9 employed. Such herbicides are Paraquat (l,l'-dimethyl '0 -4,4'-bipyridylium ion dichloride salt), 2,4-D amine salts 1 (2,4-dichlorophenoxyacetic acid amine salts), Dicamba amine 2 salts (2,6-dichloro-o-anisic acid amine salts), 2,4-DB salts 3 ' (4-,2-4-dichlorophenoxy butyric acid potassium and amine `4 salts), DNBP amine and sodium salts (2-sec-butyl '`5 4,6-dinitrophenol amine and sodium salts), and Naptalam (sodium 6 N-l-naphthylpathalamate) and MCPA ([4 chloro-0-tolyl) oxy~
7 acetic acid).
~, ;B As examples of the polyhydric alcohols that may be ~9 employed are ethylene glycol, propylene glycol, isobutylene 0 glycol and glycerine.
1 Examples of polyalkylene glycols that may be employed 2 are polyethylene glycol of 400 molecular weight, polyethylene 3 glycol 600, polyethylene glycol 6,000, polypropylene glycol, 4 polybutylene glycol and co-polymers of the above. The polyhydric alcohols and polyalkylene glycols may be employed in 6 1 amounts of 5-25% by weight.

'?HA 20,919 ~ ~567~

,, .

)1 , Wetting agents such as lignosulfonate salts, )2 ; naphthalene sulfonic acid salts and castor oil polyoxyethylene ~3 ' adducts as well as other similar wetting agents and surfactants ~4 1I may be employed in an amount of up to about 2~ by weight.
1l Herbicidal compositions of the invention containing in 16 1l percent by weight, 45-55% of an amine salt of J7 1,' 2,4-dicholorophenoxyacetic acid, preferably the dimethylamine 8 ~ salt, 8-15~ of glycol, preferably ethylene glycol, 37-45% of l9 ' water and up to 2% of wetting agents, surfactants, or similar ;0 ' agents are particularly useful.
1 , In a particularly preferred embodiment 49-51% by 2 weight of the dimethylamine salt of 2,4-dichlorophenoxyacetic 3 acid and about 10 % by weight of ethylene glycol is present.
~4 Among the weeds or other undesired vegetation that may ~j ~ be controlled by the ULV herbicidal compositions of the 6 invention are field bindweed, dandelion, chickweed, stinkweed, , 7 ragweed, Canada thistle, musk thistle, broadleaf weeds in B cereal crops and other undesired vegetation for which the 9 herbicidal compounds utilized in the compositions of the ~D ~ invention are generally employed.
1 These herbicidal compositions may be employed for ~2 selective weed control in crops such as wheat, barley, rye, 3 ~ oats, corn, rice, sugar cane, fallow land, rangelands and others.
j ll DETAILED DESCRIPTION OF THE INVENTION
i The invention will now be described with greater detail with reference to the following examples:

~PHA 2~,919 1~55675 Dl ~ Example 1 ~2 The (ULV) herbicidal composition was prepared by ~3 dissolving in 21.8 ounces of water, 41.9 ounces of 2,4-D acid, ~4 ,, 24.3 ounces of dimethylamine ~40%), 1.0 ounce of a mixture of 1 1 ~5 1' mole of castor oil and 40 moles of ethylene oxide, 1.0 ounce of )6 l, naphthalene sulfonic acid sodium salt and 10 ounces of ethylene ~7 `, glycol.
)8 ,I Example 2 ;)9 , In a similar fashion to Example 1 the following ;0 ' compositions were prepared. All parts of which are glven in 1 percent by weight.

3 Dicamba 41.0%
4 ; Dimethylamine (40%) 24.0%
~~ Water 23.0%
~5 1i 1 Mole of Castor1.0%
7 Oil plus 40 Moles 8 of Ethylene Oxide ~D Naphthalene Sulfonic 1.0%
~1 Acid Sodium Salt ~2 Ethylene glycol10.0%
3 Example 3 4 In a similar fashion to Example 1 the following compositions were prepared. All part of which are given in percent by weight.
7 Dicamba 11.0%
3 2,4-D Acid 21.5%
`3 Water 31.5%
) Ethylene glycol15.0%
L Naphthalene Sulfonic 1.0%
> Acid Sodium Salt I 1 Mole of Castor1.0%
Oil plus 40 Moles -; of Ethylene Oxide Dimethylamine (40~) l9o0 1, 9

5~75 1 Example 4 Field applications using the composition of example 1 3 , were compared with the standard aqueous 2,4-D amine (4 lb.
~4 a.i./gal) formulation of the prior art. Aerial treatments were made to fallow land against the target plant field-bindweed ~6 1l (Convolvulus arvensis), a noxious weed. Treatments were made 7 at recommended dosage comparing the prior art formulation at 3 the rate of 5 gallons of aqueous solution per acre against that 3 ' of the ULV composition applied undiluted in its concentrate ') form. The testing utilized a single aircraft equipped for boom L spraying, flushed and refitted with appropriate nozzling between respective treatments. A11 treatments were applied using a pressure of 40 psi, with the aircraft flying at 80 mph L (125 km/hr) at approximately 4 meters above the ground . .~, . .
i ; surface. The swath width was maintained at 12-1/2 meters ~; (approximately 45 feet).
Treatments were carried out at three locations employing a rate of either three pounds or two pounds, active equivalent, of the composition of Example 1 per acre . These treatments were compared to a program of applying a conventional 2-4-D amine composition in which no glycol is present at the rate of 3 pounds active equivalent in 5 gallons of solution per acre. The results are shown in the following table.
. , ?HA 20,919 ~".

01 Table 1 D2 , volume 03 ~ quarts (quarts 04 lbs.active of applied) ~ weed D6 ; 2,4-D/Acre formul. per acre control 07 Location 1 3 3 3 99 D8 (composition of ~9 ,Example 1) ULV
1lConventional 3 3 20 94 Location 2 ULV 2 2 2 97 ;2 1,Conventional 3 3 20 90 L3 !Location 3 ULV 2 2 2 99 l4 'Conventional 3 3 20 90 ~,L5 Example 5 : i

6 In another application on field bindweed, 3

7 ~ quarts/acre of the ULV 2,4-D amine composition of Example 1 "

8 " were applied and compared with an application of 5 gallons/acre

9 ; of a conventional diluted 2,4-D amine solution described in ~0 Example 4.
1 Three weeks after treatment the weeds in the area 2 treated with the herbicidal composition of Example 1 were 3 completely brown and dry. However 40~ of the weeds in of the 4 area treated with the conventional 2,4-D amine solution of the ~ prior art was still green and limber.
6 Example 6 7 The ULV 2,4-D amine composition of Example 1 was 8 applied to fallow areas containing a broad spectrum of weed 9 1` species. Applications were made by aircraft fitted as 0 described in Example 4. The novel composition was applied 1 undiluted at the rate of 2.6 pounds per acre (2.6 quarts).
2 These were compared to adjacent areas treated with a 3 conventional formulation of the 2,4-D amine using 3 pounds of active ingredient (3 quarts) diluted to 3 gallons of solution per acre, using the same equipment.

.
7 _9_ - ~?j 20,gl5 ~ ~ ~567 ~
., ~. .

... . .
01 ~ Observations made 10 days after application indicated 02 complete knockdown by both formulations of the following weeds:
~03 Tansy mustard Descurainia pinnata 04 Redroot pigweed Amaranthus retroflexus . . ,. i Lambsquarter Chenopodium album 06 ,I Dandelion Taraxacum officinale . Q7 1l Shepherdspurse Capsella bursa-pastoris ; ;D8 1I Ragweed Ambrosia trifida ... .
09 .! However, several species of weeds known to be difficult to , :, , !~ control and resistant to 2,4-D amine formulations of the prior ~11 art were completely controlled using the ULV 2,4-D amine ~12 I formulation of this invention. Examination of the root systems ., .
13 of the perennial weeds indicated not only top kill, but L4 destruction of the roots. The standard 2,4-D amine of the : L5 ; prior art provided partial knockdown and incomplete effect on !6 the root systems. These species included:
~7 Canada thistle Cirsium arvense :.8 Horseweed Erigeron canadensis - 9 Dogfennel Eupatorium capillifolium !0 Horsetail Equisetum arvense `'1 Field bindweed Convolvulus arvensis 2 Pennsylvania Polygonum pennsylvanicum smartweed 4 Russian thistle Salsola kali j Fiddleneck Amsinckia Sp.
6 Henbit Lamium amplexicaule 7 As these test runs demonstrate the ULV herbicidal 8 compositions of the invention provide a means for controlling a ~ PHA 20,919 :

.~ , .

t . . .
115567~
,!
` '' .
01 siqnificantly larger area of undesired vegetation with a given02 payload therefore significantly reducing the energy and 03 man-hours required. .
04 Further as shown in Examples 4, 5 and 6 there is alsoachieved a large increase in the herbicidal activity of the 06 11 2,4-D amine.
07 ,1 Also with the herbicidal compositions of the invention 08 considerably less drift of spray outside the borders of the 09 ' target area was found to exist thereby reducing the possibility of damage to vegetation outside of the target area.
ll While the present invention has been described with 12 references to particular embodiments thereof, it will be 13 understood that numerous modifications can be made by those 1.4 skilled in the art without actually departing from the scope of L5 the invention.

PHA 20,919

Claims (15)

WHAT WE CLAIM IS:

1. A sprayable composition comprising a water soluble herbicidal compound in the amount of 20 to 80 parts by weight, an aliphatic polyhydric alcohol of up to 4 carbon atoms with from 2 to 4 hydroxyls attached to the aliphatic chain or polyalkylene glycol in an amount of from 5 to 25 parts by weight and water in an amount of less than 50 parts by weight.

2. The herbicidal composition of claim 1 wherein the glycol is selected from the group consisting of ethylene glycol, propylene glycol and glycerine.

3. The herbicidal composition of claim 2 wherein the herbicidal compound is an amine salt of 2,4-dichlorophenoxyacetic acid.

4. The herbicidal composition of claim 3 wherein wetting agents in amounts of up to 2% by weight are present.

5. The herbicidal composition of claim 4 wherein the herbicidal compound is the dimethylamine salt of 2,4-dichlorophenoxyacetic acid.

6. A herbicidal composition comprising of 45-55% by weight of the dimethylamine salt of 2,4-dichlorophenoxyacetic acid, 8-15% by weight of ethylene glycol, 37-45% by weight of water and up to about 2% by weight of wetting agents or surfactants.

7. The herbicidal composition of claim 6 wherein about by 49-51% by weight of the dimethylamine salt of 2,4-dichloro-phenoxyacetic acid is present and about 10% by weight of ethylene glycol is present.

,919

8. A method for the control of undesireable vegetation comprising applying to the locus of said undesired vegetation a herbicidally effective amount of the herbicidal composition of claim 1.

9. A method for the control of undesireable vegetation comprising applying to the locus of said undesired vegetation a herbicidally effective amount of the herbicidal composition of claim 2.

10. A method for the control of undesireable vegetation comprising applying to the locus of said undesired vegetation a herbicidally effective amount of the herbicidal composition of claim 3.

11. A method for the control of undesireable vegetation comprising applying to the locus of said undesired vegetation a herbicidally effective amount of the herbicidal composition of claim 4.

12. A method for the control of undesireable vegetation comprising applying to the locus of said undesired vegetation a herbicidally effective amount of the herbicidal composition of claim 5.

13. A method for the control of undesireable vegetation comprising applying to the locus of said undesired vegetation a herbicidally effective amount of the herbicidal composition of claim 6.

0,919

14. A method for the control of undesireable vegetation comprising applying to the locus of said undesired vegetation a herbicidally effective amount of the herbicidal composition of claim 7.

15. The method of claim 14 wherein the undesired vegetation is field bindweed.

PHA 20,919