IL45303A - Plant growth regulant compositions containing carboxyphosphonates and certain novel cargoxyphosphonates - Google Patents

Description

45303/2 ,o»nas ¾7 >ιτ»ιη 'ΓΙΟΙΛΒ o»n»w3n Plant growth regplant compositions containing carboxyphosphonates and certain novel carboxyphosphonates B.I. DU PONT NEMOURS A D COMPANY C. 43239 BACKGROUND OF THE INVENTION This invention relates to carboxyphosphonates and their use as brush control agents. The use of various carbamoylphosphonates for control of plant growth is known in the art. For example, U.S. '3, ?7, 07 and Offenlegung-sschrift 2,0^0,367 relate to the use of carbamoylphosphonates for plant grov;th control. However, neither of these references suggest the carboxyphosphonates of this invention. Berichte 57_, 1023 (1Q2'I) describes trisodium carboxyphosphonate as well as the zinc, manganese, copper, lead and silver salts. However, this reference does not describe any utility for these salts. U.S. 3,033,891 discloses esters and salts of (alkylthio)carbonylphosphonic acid, but the reference does not suggest the plant growth regulant activity of these compounds.

SUMMARY OF THE INVENTION Plant growth can be regulated by application to the plants of compounds having one of the following formulae: 0 0 0 Y + „ R0-P-C-0M or RO-P-C-XR, OM OM I II wherein M is selected from sodium, lithium, potassium, calcium, magnesium, zinc, manganese, barium or R is M, alkyl of 1 to 8 carbons, optionally substituted with a chlorine, a bromine, a fluorine, iodine atom; alkenyl of 3 to 8 carbon at where X is oxygen or sulfur; Y is oxygen or sulfur, provided that when Y is sulfur, X is sulfur and when X is sulfur, R is not hydrogen; A is cHlorine or methyl, D is chlorine or methyl, n is 0 or 1, and m i s 0 or 1; is hydrogen, alkyl of 1 to k carbon atoms, or hydroxyalkyl of 2 to Ί carbon atoms; is hydrogen, alkyl of 1 to Ί carbon atoms, or hydroxyalkyl of 2 to Ί carbon atoms; is hydrogen, alkyl of 1 to Ί carbon atoms, or hydroxyalkyl of 2 to Ί carbon atoms; and is hydrogen or alkyl of 1 to 12 carbon atoms, provided that the total number of carbon atoms in R^, R2> R^ and R^ is less than 16; is alkyl of 1 to 6 carbon atoms, alkenyl of 3 to Ί carbon atoms, or benzyl.

Of the compounds in Formula I, those wherein R I alkyl of 1 to ¾ carbon atoms or M where M is sodium or potassium are preferred. Within this group preferred compounds are trisodium carboxyphosphonate, disodlum ethyl carboxy-phosphonate, and disodlum methyl carboxyphosphonate. 45303/2 The active compounds described above can be applied to plants to regulate plant growth. The phrase "applied to plants" as used herein includes both direct application to the plants and also application to the soil in which the plants grow.

Of the compounds described above, those having the formula 0 Z ♦ " R'O-P-C-ZRc OM* wherein ' Is hydrogen, sodium, lithium, potassium, calcium, barium or ammonium; Z is oxygen or sulfur; R' is M* , alkyl of 1 to 8 carbons, alkenyl of 3 to 8 carbon atoms or benzyl; Rg is M' or R'5 where R'5 is alkyl of 1 to 6 carbon atoms or benzyl; provided that: (a) when Z is S then R1 cannot be hydrogen and g cannot be ' ; (b). when Rg is M1 then R' or M' cannot be hydrogen; and (c) when both R1 and Rg are M* and Z is O, ' cannot be hydrogen or sodium, are novel. 45303/2 I ■ Preferred compounds of this invention also include those coT.po.unds of Formula II where R is alkyl of 1 to Ί carbons, benzyl or M; is hydrogen, sodium, potassium or ammonium; .c is alkyl of 1 to 3 carbons; X is oxygen or sulfur, provided that when X is sulfur, R is not hydrogen; and Y is oxygen.

Among the most preferred compounds of this invention are methoxycarbonylphosphonic acid, diammonium methoxycarbonyl- phosphonate, ethyl sodium methoxycarbonylphosphonate , and methyl sodium methoxycarbonylphosphonate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The compounds of formula I are formed by alkaline hydrolysis of the appropriately substituted alkyl car- boxyphosphonate . The hydrolysis is conducted by refluxing the starting material in aqueous solutions having 2 or 3 equivalents of alkali metal hydroxide. Once an alkali metal salt is formed, other salts can be formed by reaction with metal salts of other acids or by conventional ion exchange. It should be noted that the activity of the compounds useful in this inven- tion resides in the carboxyphosphonate anion. The exact identity of the cations with which it is associated is of little signi ficance .

For Formula II where R and M are hydrogen, the alkoxycarbony Iphosphonic acids and (alkylthio)carbonylphos-phonic acids of Formula II are readily prepared by the interaction of dialkyl alkoxycarbonylphosphonates or (alkylthio)carbonylphosphonates with hydrogen iodide. Salts of these acids are prepared by reacting the acids with one or two equivalents of a base having the appropriate cation.

The dialkyl alkoxycarbonylphosphonates and (alkyl-thio)carbonylphosphonates which are precursors to the compounds of this invention can be prepared by a variety of methods available in the literature, such as Nylen, Chem. Ber . 57, 1023 (192*1), and Reetz et al . , JACS 77, 3813 (1955). The method comprises treating an appropriate trialkyl phosphite with a chloroformate or thiolchloroformate .

The following Examples further illustrate the preparation of the compounds of this invention.

Example 1 Using the method of Nylen, Ber. , 57B, 1023 (192*1), a solution of 21 parts ot triethyl carboxyphosphonate in 60 parts of water containing 2*1 parts of 50% sodium hydroxide was re- fluxed for 2 hrs. The solution was allowed to cool overnight. Filtration of the reaction mixture gave 4.7 parts of the product, trisodium carboxyphosphonate hexahydrate, mp >250°; vKBr c 1560 » 1530 cm"1« In a similar manner, by using the appropriate metal hydroxide, the following compounds can be prepared: 0 0 f 0-P-C-0M OM (R Is M) M Li K Ca Mg Zn Mn Ba The triammonium salts cannot be prepared directly by hydrolysis of the trialkyl esters. They must be obtained by passage of a solution containing trisodium carboxyphosphonate through an ion exchange column previously treated with the appropriate ammonium cation.

In such a manner, the following compounds can be prepared: 0 0 MO-P-C-0-M OM M (CH3)NH3 (C12H25)NH3 (CH3)2 H2 (CH3)NH2(C1 (CH3)3 H (Ο^Η9)3ΝΗ (CH3)„N (CH3)3N(CilH9) (CH3)3N(C12H25) (C2H1|OH)NH3 (HOCH2CH2CH2CH2)NH (CH3)NH2(CH2CH2OH) (CH3)N(CH2CH2OH)3 Example 2 · Λ solution of- 15.5 parts of ammonium ethyl car-bamoylphosphcnatR and lG parts of 50% sodium hydroxide in 50 parts of water was refluxed for ? hours. The solution cooled and evaporated under vacuum to dryness to give the disodlum ethyl carboxyphosphonate , m.p. >300°, v . = 1580 Example 3 To a solution of 8.5 parts of trimethyl carboxyphosphonate in 50 parts of water was added slowly 8.0 parts of 50% sodium hydroxide. The solution was refluxed for 1 hour, cooled and the solvent removed under vacuum to give 10.6 parts of disodium methyl carboxyphosphonate, m.p. >250°, vneat = 1580, 1080 (P-0~), 1050 ( P-0CH3) cm"1.

In a similar manner, by using the appropriate metal hydroxide and phosphonate ester, the following compounds can be prepared: 0 0 RO-P-CO-M OM CH2=CHCH2 30 CH3CH2CH2CH2 30 C6H5CH2 30 CH3CH2CH2CH2CH2CH CH3CH2CH2CH2CH2CH CH2=CHCH2 CH5=CHCH= CH3 C1CH2CH2 CH3CH2CH2CH2CHCH2 CH.

CH2=CHCH2CH2 CH3CH2CH2CH2 BrCH2CH2- Na FCH2CH2- Na ICH2CH2- Na CH3CH2CH2CH2GH2-CH=CH-CH2- Na By passage of a solution of an appropriate disod.lum alkyl carboxyphosphonate through an appropriate ion exchange column; pretreated with the appropriate ammonium cation, the following conpounds can be prepared: 0 0 I t " R_0-P-COM t OM CH3 NH¾ CH3CH2- CH2=CHCH2 (CilHg) H3 CH3CH2 (C12H25)NH3 CH2=CHCH (CH3)2 H2 CH3 ( C1CH2CH2 (CH3)NH2(CH2CH2OH) CH =CCH_ (0ήΗ9)2ΝΗ2 CH3CH2CH2CH (^Η9)3 Η CH3CH2 (HOCH2CH2CH2CH2)3NH CH3CH2 (CH^ CH2«=CHCH2CH (CH3)3 (C12H25) CH3CH2CH2CH2CH2CH2 H^ CH3CH2CH2CH2CH2CH2CH2CH2 (CH^NH.

Exam le Into a stirred solution comprised of l'J.8 parts of dimethyl nethoxycarbony lphosphonate and 100 parts of methylene chloride at (-)5 - (+)5°C was added 30 parts of anhydrous hydrogen iodide. The reaction was then allowed to warm to room temperature v/hereupon it was stirred overnight. The bottom layer which formed was separated and evaporated under reduced pressure to afford 6.7 parts of methoxycarbonylphos-phonic acid. The nmr spectrum (dmso-d^) exhibited none of the P-0-CH_ doublet, but retained the C00CH_ 9 -1 — -signal. The ir showed the C-OCH^ at WO cm' ~ and the P-0 at 1100 cm""1.

By replacing the dimethyl methoxycarbonvl-phosphonate of Example 1 with the appropriate dimethyl alkoxycarbonyl- or (alky lthio )carbony lphosphonate , the following compounds can be prepared.

OH CH2=CHCH2CH2 CH2=CHCH2 CH3CH2 ( CH^ ) 2CHCH2 CH3CH2CH2CH2CH2CH C6H5CH2 CH,CH CH CH CH Examnle 5 To 50 parts of ammonium hydroxide containing a few pieces of ice was added with stirring 3 parts of methoxy-carbonylphosphonic acid, the product of Example 1. The cooled solution was allowed to stir for 15 minutes and was then evaporated under reduced pressure to afford the desired diammonium methoxycarbonylphosphonate , m.p. 157°d.

By replacing the ammonium hydroxide of Example 2 with one or two equivalents of the appropriate . base or by routine cation exchange procedures, the following salts could similarly be prepared: OM R M CH3 Na H CH3 Na Na CH3 H^ H CH CH2 Ca Ca CH3CH2CH2CH2CH2CH2 Li Li CH3 1/2 Mn 1/2- Mn CH3CH2CH2 1/2 Zn 1/2 Zn C6H5CH2 1/2 Ba 1/2 Ba CH3 1/2 Mg 1/2 MR CH3 (CH2CH2OH)3NH H CH3 (CH3)2NH2 (CH3)2NH2 CH3 (Ci2H25) H3 H CH3 (CH3)3N(Cl2H25) H CH2=CHCH2- Na Na Example 6 A mixture of 15.0 parts of sodium iodide and 8.4 parts of dimethyl methoxycarbonylphosphanate on 20 parts of 2-butanone was heated to 60° for 1 hour. The mixture was cooled and filtered to provide 8.0 parts of the desired methyl sodium methoxycarbonylphosphonate , mp l83°d.

Example Ethyl Sodium Methoxycarbonylphosphonate A solution of 5.9 parts of diethyl methoxycarbonyl phosphonate and 4.5 parts of sodium iodide was stirred at room temperature in 50 parts of tetrahydrofuran for 60 hours The resultlnp; mixture was filtered to give 3.5 parts of the desired ethyl sodium methoxycarbonylphosphonate, .p. 123°d.

In a similar manner, the following salts can be prepared from the dialkyl alkoxycarbonylphosphonates .

OM R , M M.P. , °C CH3- Na 198-204 CH2=CHCH2 CH3- Na >300 CH3CH2CH2CH2 CH3CH2 Na 248 d CH3CH2CH2CH2 CH3CH2CH2CH2CH2CH2 Na Wax CH3 CH3CH2C1I2CH2CH2CH2 Na 73-8 CH3 (CH3)2CHCH2 Na 154-6 CH3CH2 C6H5CH2 Na >300 C1CH2CH2 CH3- Na —— OM R M M.P., °C.

CH [2, CH Na CH3CH2CH2CH2CH2CH2 CH3CH2 Na DrCH2CH2- CH3- Na Example 8 Passage of an aqueous solution of ethyl sodium methoxycarbonylphosphonate through an appropriate acid ion exchange column gives ethyl hydrogen methoxycarbonylphosphonate .

In a similar manner, the following hydrogen phosphonates can be prepared from the appropriate salts. 0 0 /Ml ROP-C- OH Rr CH CH^CHg 0Η30Η20Η20Η2 CH CH2 CH CH0CH CH~CHCH CH. CH CH: CH2=CHCH2 CH3CH2 C1CH2CH2 CH CH2 CH3CH2 CH2=CHCH2 CH2=CCH2 » CH CH3 CH2CH2CH2CH CH.

CH3CH2 C6H5CH2 CH3- CH3CH2CH2CH2CH2CH2- CH3- —CH2—CH=CH2 Example 9 Careful neutralization of an aqueous solution of methyl hydropen methoxycarbonylphosphonate with one equivalent of ammonium hydroxide p;ives the methyl ammonium methoxycarbonylphosphonate .

In a similar manner, the following phosphonate salts can be prepared from the appropriate hydrogen phosphonate and the appropriate base.

OM R R, M CH3CH2 CH K CH2CH2CH2CHCH2 CH2 CH Na CH3- CH3CH2CH2CH2 1/2 Ba C1CH2CH2 CH3CH2CH2 NHj, CH2CH2CH2CH2CH2 CH2=CHCH2 (HOCH2CH2)3NH CH3- C6H5CH2 (C12H25) H3 CH2=CH-CH2 CH0- Na Alternately, these salts can be prepared directly from the sodium salts by conventional ion exchange methods.

Example 10 Uslnp; the procedure described in U.S. 3,033,891, the following sodium salts can be prepared.

OM CH3CH2CH2CH2 CH3- Na Wax C6H5CH2 CH3CH2 Na 3CH2CH2CH2CH2CH2 CH3- Na CH3- CH2C6H5 Na (CH3)2CHCH2 CH3CH2CH2CH2CH2CH2 Na Example 11 Ethyl Hydrogen (Methylthio)carbonylphosphonate Passage of an aqueous solution of ethyl sodium (methylthio)carbonylphosphonate prepared as described in U.S. 3,033s891 through an appropriate acid ion exchange resin gives ethyl hydrogen (methylthio)carbonylphosphonate .

In a similar manner, the following hydrogen phosphonates can be prepared from the appropriate salts.

RO OH R R 5 CH2=CHCH2 CH3CH2CH2CH2CH2CH2 ClCH CH CH3CH2 Example 12 Methyl potassium (benzylthio)carbonylphosphonate Careful neutralization of an aqueous solution of methyl hydrogen (benzylthlo) carbonylphosphonate with one equivalent of potassium hydroxide gives methyl potassium (benzylthlo) carbonylphosphonate .

In a similar manner, the following salts can prepared from the appropriate hydrogen phosphonate and the appropriate base.

OM R Si M CH3CH2 CH2BCHCH2 NH, (CH3)2CHCH2 CH3- (H0CH2CH2) CH2CH2CH2CH2CH2CH2 CH3CH2 1/2 Ba CH2=CHCH2 CH3- (CH3)3NH Alternately, these compounds can be prepared by conventional ion exchange methods directly from the sodium salts .

Example 13 Ethyl sodium (methylthio)thiocarbonylnhosnhonate To a solution of 2.3 parts of diethyl (methylthio)-thiocarbonylphosphonate in 50 parts of dry tetrahydrofuran was added 1.5 parts of sodium iodide. The solution was stirred for l8 hours at room temperature, then warmed on a steam bath for one-half hour. The desired oranpe ethyl sodium (methylthio) thiocarbonylphosphonate was then filtered, m.p. 288°d.

Example l^ Ethyl hydrogen (methylthio)thiocarbonylnhosnhona.te Passage of an aqueous solution of ethyl sodium (methylthio) thiocarbonylphosphonate throuprh an appropriate acid ion exchange column rives ethyl hydroren (methylthio) thiocarbonylphosphonate .

In a similar manner by use of the appropriate phosphonate salt, the following compounds can be prepared.

OH R CH3CH2CH2CH2CHCH2 CH3- CH? f Example 15 Methyl barium (methylthio)thiocarbonylphosphonate Careful neutralization of methyl hydrogen (methylthio) thiocarbonylphosphonate with one-half equivalent of barium carbonate Rives methyl barium (methylthlo) thiocar-bonylphosphonate .

In a similar manner, the following phosphonate salts can be prepared from the appropriate hydrogen phosphonate and the appropriate base. 0 S OM R R5 M (CH3)2CHCH2 CH3- NH, CH3- CH3CH2CH2CH2 1/2 Zn CH3- (CH3)2CHCH2 (HOCH2CH2)3NH C6H5CH2 CH3- Li CH2CH2CH2CH2CH2 CH3CH2 K Alternately, these salts can be prepared directly from the sodium salts by conventional ion exchange methods.

The compounds and salts of the invention are useful for modifying the growth of plants. The compounds and salts of this invention are particularly useful for preventing bud break and retarding the growth of woody plants. Thus, the compounds and salts of this invention can be applied in areas such as power line rights-of-way where low-growing and slow-growing vegetation is especially desirable.

The compounds of this invention are useful for controlling the growth of plants. The compounds of this invention are particularly useful for preventing bud break and retarding the growth of woody plants. Thus, the compounds of this invention can be applied in areas such as power line rights-of-way where low-growing and slow-growing vegetation is especially desirable.

In addition to their value as plant growth retardants, the compounds of this invention can also be used to control flowering, fruit set, and coloration on apples and other fruits. They are useful in controlling the growth and flowering of ornamental species such as chrysanthemum and azalea.

The compounds of this invention can also be used to prolong the dormancy of perennial plants, and thereby protect the unsprouted buds from frost damage. This can be especially important in the protection of flower buds, which in some years may sprout early and be killed by cold temperatures. Application to plants in the sta^e where the next year's buds are being initiated, or are developing gives marked retardation of bud break the following spring and greatly reduced growth.

To illustrate the growth-retardant activity of the compounds and salts of this case, cne following uata are presenteu.

In one test, the test compound was applied in a solvent with a wetting agent and a humectant to cotton plants (five-leaf stage Including cotyledons), bush bean (second trifoliate leaf expanding), morningglory (four-leaf stage including cotyledons), cocklebur (Xanthlum 3p. , four-leaf . stage including cotyledons), Cassia tora (three leaves including cotyledons), nutsedge (Cyperus rotundus, three to five-leaf stage), crabgrass (Digitarla sp. , two-leaf stage), fcarnyardgrass (Echinochloa sp. , two- leaf stage), wild oats (Avena fatua, one-leaf stage), wheat (two- leaf stage), corn (three-leaf stage), soybean (two cotyledons), rice (two- leaf stage), and sorghum (three-leaf stage).

Treated plants, and controls were maintained in a greenhouse for sixteen days, then all species were compared with controls and visually rated for response to treatment. - 92 - O 0 Nutsedge C- Cassia Nutsedge ro ro In another test, the test compound was applied a similar solvent to pots of privet (Ligustrum sp.), willow (Salix sp.), forsythla (Forsythla sp.), Arbor Vitae (Thuja sp.), and apple ( alus sp.). The plants were maintained in a greenhouse. Plant response ratings were taken one week and four weeks after application.

In another test, the test compound was applied in a similar solvent to pots of Black Valentine bean (Phaseolus vulgaris cv. Black Valentine), apple (Malus sp.) and willow (Salix sp.). The plants were maintained in a greenhouse, and plant response ratings were taken after application as indicated.

Rate IN § Κκ/Ha B.V. Bean Apple Wi — 1 1 1 week weeks week weeks we 00 H-C0PC0" "Na+ 1 9G IOC 0 6G 7 i » 0 3X — + Na 90 IOC 0 10G 1 Rate , On kft/ha We • 00 tf II HOPCOCH 1 0 OH 4 0 1 vJi H3 1 H3 Ma 1 H3 CH Rate, kg/ha Week Weeks We The plant response ratings (above) are composed of a number and a letter. The number describes the extent of the response and ranges from zero to ten with zero representing no response, and ten representing lOO!S response. The letter describes the type of the response, as follows: C, chlorosis-necrosis H, formative effect (Malformation) D, defoliation U, unusual pigmentation G, growth retarded I, increased chlorophyll P, terminal bud injury 8Q* , increased fruit size X, axillary stimulation 8Y* , Abscised buds or flowers « Note: With the "8Q" and "6Y" , the number does not refer to extent of response (any percent HTcrease in fruit size is represented by an 8Q.

Test Procedure Seeds of crabgrass (Digitaria spp.), barnyardgrass (Echinochloa crusftalli') , wild oats (Avena f tua) , Cassia tora, roomingglory (Ipomoe spp.), cocklebur (Xan thium spp.), sorghum, corn, soybean, rice, wheat and nutsedge tubers were planted in a growth raediura and treated preemergence with the chemicals dissolved in a non-ph'y otoxic solvent. At the same time, cotton having five leaves (including cotyledonary ones), bush beans with the third trifoliate leaf expanding, crabgrass with two leaves, barnyardgrass with two leaves, wild oats with one leaf, cassia with three leaves (including cotyledonary ones), morningglory with four leaves (including the cotyledonary ones), cocklebur with four leaves (including the cotyledonary ones), sorghum with three leaves, corn with three leaves, soybean with two cotyledonary leaves, rice with two leaves, wheat with one leaf, and.nutsedge with three-five leaves were sprayed. Treated plants and controls were maintained in a greenhouse for sixteen days, then all species were compared to controls and visually rated for response to treatment. A quantitative rating was made on a scale of 0 to 10; a rating of 10 means complete kill, a rating of 0 means no injury. A qualitative rating for type of injury was also made: ... - ' c Chlorosis/necrosis E Emergence inhibited' G Growth retarded H Formative effect 6Y Abscised buds or flowers U = Unusual pigmentation (other than dark green color) The term "plant growth retardant" as used In thir. disclosure is to be understood to mean an agent which, when applied to a plant or its environs, will slow the growth of the plant. This also includes a delaying response on bud sprouting or prolonging of the dormancy period.

The compounds and salts of this invention can be applied as foliar sprays or as soil applications to retard the growth rate of such plants or to affect flowering and fruit set .

Preferably, the compounds of this invention are applied as foliar or dormant wood sprays to the point of runoff although lower-volume application can also be effective.

The compounds and salts of the invention are very versatile and may be applied at one of many different time periods to suit the convenience of the applicator. For example they may be applied in Spring a short time prior to the period when maximum plant growth is anticipated, to effect growth retardation. They may be applied later in the growing season just after trimming, to effect growth retardation. Or they may b'e applied when the year's growth has ceased (late Summer., Fall, or Winter) with the result that treated plants will remain dormant the following Spring, whereas untreated plants will sprout and grow. If flowering and fruit set are to be modified, the treatment is applied before, during, or shortly after flowering.

It will be recognized that the application rate is dependent upon the species to be treated and the results desired. In general, rates of from 0.25 to 20 kilograms per hectare are used although higher or lower rates can achieve the desired effect in some instances.

Useful formulations of the compounds and salts of this invention can be prepared in conventional ways. They include dusts, granules, pellets, solutions, suspensions, emulsions, wetting powders, emulsifiable concentrates and the like. Many of these may be applied directly.

Sprayable formulations can be extended in suitable media and used at spray volumes of from a few pints to several hundred gallons per acre. Hir,h strength compositions are primarily used as intermediates for further formulation. The formulations, broadly, contain about 1% to 99$ by weight of active ingredient (s ) and at least one of a) about 0.1% to 20% surfactant (s ) and b) about 5% to 99% solid or liquid diluent (s).

More specifically, they will contain these ingredients in the following approximate proportions: Percen Active Ingredient Diluent (s) Wettable Powders 20-90 0-7^ Oil Suspensions 5-50 40-95 and Emulsions Aqueous Solutions 10-50 50-90 Dusts 1-25 70-99 Granules and 1-95 5-99 Pellets High Strength 90-99 0-10 Compositions Lower or higher levels of active ingredient can, of course, be present depending on the intended use and the physical properties of the compound.

Higher ratios of surfactant to active ingredient are sometimes desirable, and are achieved by incorporation into the formulation or by tank nixing. Likewise, high levels of oils or humectants can be incorporated either in the formulation or by tank-mixing.

Typical solid diluents are described in Watkins, et al. , "Handbook of Insecticide Dust Diluents and Carriers", 2nd. Rdn., Dorland Books, Caldwell, M.J.

The more absorptive diluents are preferred for wettable powders and the denser ones for dusts. Typical liquid diluents and solvents are described in Marsden, "Solvents Guide", 2nd. Edn. , Interscience , New York, 1950. Solubility under 0.1* is preferred for suspension concentrates; solution concentrates are preferably stable against phase separation at 0°C. "McCut cheon ' s Detergents and Emulsifiers Annual", Allured Publ. Corp., Ridgewood, New Jersey, as well as Sisely and Wood, "Encyclopedia of Surface Active Agents", Chemical Publ. Co., Inc., New York, 1964, list surfactants and recommended uses. All formulations can contain minor amounts of additives to reduce foam, caking, corrosion, microbiological growth, etc. Preferably, ingredients should be approved by the U.S. Environmental Protection Agency for the use intended.

The methods of making such compositions are well known. Solutions are prepared by simply mixing- · blending, and, usually, grinding as in a hammer or fluid energy mill. Suspensions are prepared by wet milling (see, for example, Littler, U.S. Patent 3,θ6θ,θ8Ό. Granules and pellets may be made by spraying the active material upon preformed granular carriers or by agglomeration techniques. See J. E.

Browning, "Agglomeration", Chemical Engineering, Dec. 4, I967, pp. l*)7ff. and "Perry's Chemical Engineer's Handbook", *!th. Edn., McGraw-Hill, M . Y . I963, PP. 8-5 ff.

For further information regarding the art of formulation, see for example: H. . Loux, U.S. Patent 3,235,361, Feb. 15, 1966, Col. 6, Line 16 through Col. 7, Line 19 and Examoles 10 through W. P. Langsdorf, U.S. Patent 3,627.507, Dec. 1*1, I97I. col. 8, line 1 through col. 11, linel2 and Examples 6Ο-65.

G. C. Klingman, V/eed Control as a Science" John V/lley & Sons, Inc., New York, 1961 pp. 8I-96.

J. D. Fryer and S. A. Evans, "Weed Control Handbook", 5th Edn. Blackwell Scientific Publications, Oxford, 1968, pp. 101-103.

The following Examples further illustrate the formulation and application, of the compounds of this invention.

Example 16 Wettable Pov.'der disodium methyl carboxyphosphonate '10J6 dioctyl sodium sulfosuccinate 1.5% sodium ligninsulfonate 3% low viscosity methyl cellulose 1.5% attapulgite 5H The ingredients are thoroughly blended, passed through an air mill, to produce an average particle size under 15 microns, reblended, and sifted through a U.S.S. Mo. 50 sieve (0.3 mm openin?) before packaging.

All compounds of this invention may be formulated in the same manner.

Fifteen kilograms of this formulation are mixed with 600 liters of water in a sprayer fitted with an agitator. The mixture is sprayed on a one hectare area of newly trimmed hedgerow in the spring after the leaves have expanded. (The spray may be either directly on the plants or. to the locus of the plants.) This treatment greatly reduces the growth of plants growing in the hedgerow, but does not seriously in ure them.

Thus, the hedgerow is kept neat with a minimum of labor expended for trimming it.

Example 1J Water-Soluble Powder disodium ethyl carboxyphosphonate 95.0% dioctyl sodium sulfosuccinate 0.5% sodium ligninsulfonate 1.0% synthetic fine silica . 3.5% The ingredients are blended and coarsely ground in a har.mer mill so that only a few percent of the active exceeds 250 microns (U.S.S. No. 60 sieve) in size. When added to water with stirring, the coarse powder initially disperses and then the active ingredient dissolves so that no further stirring is needed during application.

Ten kilograms of this formulation are dissolved in 800 liters of water containing 0.5% of a non-phytotoxic wetting agent. This formulation is sprayed from a helicopter to a one hectare area under an electric power line in which the brush and trees have been freshly trimmed. This treatment retards the growth of black willow (.ciali nif-ra) , black cherry ( Prunus serotina) , and many other woody species.

Example 18 Solution trisodium carboxyphosphonate 12.5% octylphenox polyethoxyethanol 0.5% water 87.5 The ingredients are combined and stirred to produce a solution which can be applied directly or after dilution with additional water.

Fifteen liters of this solution are mixed with 200 liters of water and sprayed in late summer on a one hectare area of woody plants growing on a power line right-of-way. The treated plants continue to appear like untreated plants. However, the following year the treated plants remain dormant for an extremely long period of time, whereas untreated ones sprout and grow normally. Thus, the treatment" greatly reduces the amount of labor required to maintain the plants at a desirable height.

Example 19 Oil Suspension * trisodium carboxyphosphonate 25% polyoxyethylene sorbitol hexaoleate 5% highly aliphatic hydrocarbon oil 70% The ingredients are ground together in a sand mill until the solid particles have been reduced to under about 5 microns. The resulting thick suspension nay be applied directly, but preferably after being extended with oils or emulsified in water.

One part of this suspension is mixed with one part of water in a sprayer fitted with an agitator, and applied in winter to the point of runoff on the bark of dormant woody plants growing under a power line. The treated plants remain dormant for an extremely long period of time, thus greatly reducing plant growth and also the labor required for pruning.

- U - Example 20 Water-soluble Powder diammonlum methoxycarbonylphosphonate 95.0% dioctyl sodium sulfosuccinate 0.5% sodium ligninsulfonate 1.0% synthetic fine silica 3.5% The ingredients are blended and coarsely ground in a hammer mill so that only a small percent of the active exceeds 250 microns (U.S.S. #60 sieve) in size. When added to water with stirring, the coarse powder initially disperses and then the active ingredient dissolves so that no further stirring is needed during application.

Ten kilograms of this formulation are dissolved in 800 liters of water containing 0.5% of a nonphytotoxic wetting agent. This formulation is sprayed from a helicopter to a one-hectare area under an electric power line in which the brush and trees have been freshly trimmed. This treatment retards the growth of black willow (Sallx nigra) , black cherry (Prunus serotina) , and many other woody species.

The following can be formulated and applied in similar manner with similar results. ethyl sodium methoxycarbonylphosphonate methyl sodium methoxycarbonylphosphonate methyl sodium ethoxycarbonylphosphonate ethyl sodium ethoxycarbonylphosphonate ethyl sodium (methylthio)carbonylphosphonat methyl sodium (ethylthio)carbonylphosphonat Example 21 Wet able Powder diammonium methoxycarbon lphosphonate dioctyl sodium sulfosuccinate sodium ligninsulfonate low viscosity methyl cellulose attapulgite The ingredients are thoroughly blended, passed through an air mill, to produce an average particle size under 15 microns, reblended, and sifted through a U.S.S. No. 50 sieve (0.3 mm opening) before packaging.

All solid compounds of the invention may be formulated in the same manner.

Fifteen kilograms of this formulation are mixed with 600 liters of water in a sorayer fitted with an agitator. The mixture is sprayed on" a one hectare area of newly trimmed hedgerow in the spring after the leaves have expanded. (The spray may be either directly on the plants. or to the locus of the plants.) This treatment greatly reduces the growth of plants growing in the hednerow but does not seriously injure them. Thus, the hedperow is kept neat with a minimum of labor expended for trimminp; it.

Example 22 Solution methoxycarbonylphosphonic acid 20.02 oct lphenoxypolyethoxyethanol 0.5 water 79.52 The ingredients are combined and stirred produce a solution which can be applied directly or after dilution with additional water. All sufficiently soluble compounds of the invention may be formulated in similar fashion.

Fifteen liters of this solution are mixed with 200 liters of water and sprayed in late Summer on a one hectare area of woody plants growing on a power line right-of-way. The treated plants continue to appear like untreated plants. However, the following year the treated plants remain dormant for an extremely Ions period of time, whereas untreated ones sprout and grow normally. Thus the treatment greatly reduces- the amount of labor required to maintain the plants at a desirable height.

Claims (8)

1. CLAIMS: 1. A method of controlling the growth of plants consisting essentially of applying to the plant an effective amount of at least a compound selected from compounds having the following formulae: 0 0 0 Y + » † " RO-P-C-OM or ROP-C-XRt- OM OM I II wherein M is chosen from hydrogen, sodium, lithium, potassium, calcium, magnesium, zinc, manganese, barium or N R ^ ^ R R is M, alkyl of 1 to 8 carbons, optionally substituted with a chlorine, a bromine, a fluorine, or an iodine; alkenyl of 3 to 8 carbon atoms, where A s ch or ne or methyl, B is chlorine or methyl, n is 0 or 1, m is 0 or 1; is hydrogen, alkyl of 1 to Ί carbon atoms, or hydroxyalkyl of 2 to Ί carbon atoms; R2 is hydrogen, alkyl of 1 to Ί carbon atoms, or hydroxyalkyl of 2 to Ί carbon atoms; R^ is hydrogen, alkyl of 1 to Ί carbon atoms, or hydroxyalkyl of 2 to Ί carbon atoms; and is hydrogen or alkyl of 1 to 12 carbon atoms, provided that the total number of carbon atoms in R1, R2, R3 and R¾ is less than 16. Hi- is alkyl of 1 to 6 carbon atoms, alkenyl of 3 to H carbon atoms, or benzyl; provided that when the compound is selected from Formula I, M may not be hydrogen; X is oxygen or sulfur; Y is oxygen or sulfur, provided that when Y is sulfur, X is sulfur; and when X is sulfur, R is not hydrogen.

2. The method of Claim 1 wherein a compound of Formula I is utilized and R is methyl, ethyl, sodium, lithium or potassium and M is independent y sodium, lithium or potassium. 3· The method of Claim 1 wherein the compound of Formula II is utilized and R is M, alkyl of 1 to 4 carbon atoms , or benzyl ; Re is alkyl of 1 to 3 carbon atoms; M is hydrogen, sodium, potassium, or ammonium; X is oxygen or sulfur, provided that when X is sulfur, R is not hydrogen; and Y is oxygen. The method of Claim 3 wherein X is oxygen. 5. The method of Claim 1 wherein the compound is trisodium carboxyphosphonate. 7. The method of Claim 1 wherein the compound is disodium ethyl carboxyphosphonate . 8- The method of Claim 1 wherein the compound is ethyl sodium methoxycarbonylphosphonate . 9. The method of Claim 1 wherein the compound is methyl sodium methoxycarbonylphosphonate . 10. The method of Claim 1 wherein the compound is diamrnonium methoxycarbony lphosphonate . 11. The method of Claim 1 wherein the compound is methyl sodium (methy lthio) carbony lphosphonate . 12. The method of Claim 1 wherein the compound is methoxycarbony lphosphonic acid. 1

3. Compounds of the formula 0 Z R'O-P-C-ZR,- » b ONI' wherein M' is hydrogen, sodium, lithium, potassium, calcium, barium or ammonium; Z is oxygen or sulfur; R' is " , alkyl of 1 to 8 carbons, alkenyl of 3 to 8 carbon atoms or benzyl; - 51 - Rg is ' or R'5 where R'5 is alkyl Of 1 to 6 carbon atoms or benzyl provided that: (a) when Z is S then R* cannot be hydrogen and Rg cannot be M'j (b) when Rg is M' then R' or M' cannot be hydrogen; and (c) when both R' and Rg are M' and Z is O, M* cannot be hydrogen or sodium. 1

4. A compound of Claim 13 wherein Z is oxygen, Rg is alkyl of 1 to 3 carbon atoms, R;is Ml alkyl of 1 to 4 carbon atoms, or benzyl, and 'IS hydrogen, sodium, potassium, or ammonium. 1

5. The compound of Claim 13, ethyl sodium methoxycarbonylphosphonate. 1

6. The compound of Claim 13, methyl sodium methoxycarbonylphosphonate· 17· The compound of Claim 13, diammonium methoxycarbonylphosphonate. 18. The compound of Claim 13, methoxycarbonyl-phosphonic acid. 19. A plant growth regulant composition consisting essentially of an inert diluent and a compound of formula I or II in Claim 1. 20. A plant growth regulant composition consisting 45303/2 21. A composition of Claim 20 wherein in the active compound Z is oxygen Rg is alkyl of 1 to 3 carbon atoms R is hydrogen, alkyl of 1 to 4 carbon atoms, or benzyl; and M' is hydrogen, sodium, potassium, or ammonia. 22. A composition of Claim 20 wherei the active compound is ethyl sodium methoxycarbonylphosphonate. 23. A composition of Claim 20 wherein the active compound is methyl sodium methoxycarbonylphosphonate. 24. A composition of Claim 20 wherein the active compound is diammonium methoxycarbonylphosphonate. 25. A composition of Claim 20 wherein the active compound is methoxycarbonylphosphonic acid. 26. A compound according to Claim 13 of the formula wherein * is sodium, lithium, potassium, calcium, barium or ammonium;, and R' is M* , alkyl of 1 to 8 carbons, alkenyl of 3 to 8 carbon atoms or benzyl; with the proviso that when M' is sodium R' is not ' . 2

7. The compound of Claim 26, disodium methyl carbpxyphosphonate. 2

8. A plant growth regulant composition consisting essentially of an inert diluent and a compound of Claim 26.