CA1212690A - Phosphonium salts of n-phosphonomethylglycine and their use as herbicides and plant growth regulants - Google Patents

Abstract

PHOSPHONIUM SALTS OF N-PHOSPHONOMETHYLGLYCINE
AND THEIR USE AS HERBICIDES AND PLANT GROWTH REGULANTS
Abstact of the Disclosure Novel phosphonium salts of N-phosphonomethylglycine are disclosed herein, having the formula

Description

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PHOSPHONIUM SALTS OF N-PHOSPHONOM~THY~G~YCINE
AND THEIR USE AS HERBICIDES ~ND PLANT GROWTH REGULANTS

This invention is directed to novel chemical conpoords and to ~heir use a~ herbicides and plant grow~h regulan~g~ Speci~icallq, thiB
lnvention relates to phosphonium salts of N-phosphGnomethylglycine.

N-PhosphonomQthylglycine is a well-known chemical agent, sold ocmmercially as the mono-isopropylamune salt ~or herbicide ~pplications and as the sodium salt for the grcwth regulation of sugar cane. The man-ufacturer of the salts is Monsanto Agricultural Products Cbmpany, St.
10 L~:)ui5, Missouri. Various other salts are known, including substituted ammonium salts, aLkali metal salts, and alkallne e~rth metal salts.

A new class of salts of N-phosphonomethylglycLne has now been discoYered to be effec~ive as postemergen oe herbicides and plant gro~kh regulants. ~hether a herbicidal or growth regulant effect will be achieved depends on the crop to which the salts are applied, the method of application, th~ type and extent of weeds present, and the application rate. Determination of the proper combination of such factors is well within the routine skill of those skilled in the art of agriculture.

Herbicidal effects range fran partial control to co~Qlete kill of weeds or gen~rally undesired vegetation. pi~rtial rather than ooTplete contro~ is sometimes preferred for purFoses of economics cr nunimization of æ cc~panying crop mjury (depending on the crop bo be protected).
Plant growth regulant effects are somewhat ~ore varied and include defo-liation and retardation of vege~ati~e growth.
Defoliation can be used to enhance the growth of productive plant parts and to facilitate harvesting. This is particularly use-ful in flax, cotton, and bean crops. Although defoliation kills leaves, it does not harm the rest of the plant and is thus not a herbicidal action. In fact, killing the plant itself is detri-30 mental to defoliation since leaves adhere more strongly to a dead plant.

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~26go The retardation of vegetative growth is useful in a variety ~E
w~ys. In certain pl~nts it causes a diminuticn or elimlna~ion o the norm31 apical doninance, leading to a shorter main stem and increased lateral branching. Smaller, bushier plants wlth increased resistan oe to drought and pest infestation are the result. ~etardation o vegetative growth is also useful in turE gras æ s ~or lessening the vertical growth rate, enhancing root development, and producing a dens~r, sturdier turf.
m e retardation of tur~ grasses also serves to increase the interval ~e-tween mowings of lawns, golf oourses and similar grassy areas. In silage crops, potat oe s, sugar cane, beets, grapes, melons and fruit trees, the retardation of vegetative growth increasss the carbohydrate oontent o~
the plants at harvestO It is believed that growkh retard3tion or sup-pression at the appropriate stage of development decreases the amount of carbbhydrate available for vegetative grow~h and ~hereby enhances st æ ch an2/or sucrose content. Retardation of vegetative growth in fruit trees produces shorter branches and greater fullness o~ shape, and often results in lesser vertical elongation. Ihe æ factors ocntribute to the ease of access to the orchard and simplify the fruit harvesting proce-dure.

Brief ~escription of ~he Invention The present invention resides in a novel class of N-phosphono-methylglycine salts having utility in controlling undesirable vegetation and in regulating the natural growth or development of plants. These novel salts o~npisting essentially of a substituted phosphoniun cation and gylcylmethyl phosphonate anion. m ese salts may be represented as having the formula Rl ~3 0 0 0 R4 ~ P R2 ~ 2NHCH

in which Rl, R2r R3, and R4 are independently æ lected Ero~ the group con-sisting of Cl-Clo alkyl, phenyl, benzyl, substituted benzyl and substituted phenyl whereLn said sub6tituenbs are independently selected fro~ halogen, lower alkoxy and lcwer alkyl.

Z6~ 1 Wi~hin ~he scop~ of the above Pormula, certain enkod1ments are preferred, namely those in which ~1, R2, R3, and R4 are indepenaently S selected frGm the group oonsisting of Cl-C6 alkyl, phenyl, benzyl, substitutecl phenyl wherein ~he subs~ituent is chloro, lower a~kyl or lower alkoxy and ~ubstitut~d benzyl wherein the substituted Ln chloro.
Most prefenred are thos in which Rl, R2, R3, and R4 are identical and are selected from the group oonsisting of Cl-C4 alkyl and phenyl. B~w-ever, n~.x0d substituents are preferred where activity is obtained within thedes~ription hereinab~ve.

By lo~er alkyl and lower alkoxy is meant those groups having 1 to 4 carbon atoms, inclusive, in straight, branched, or ~yclic ~onigura-tion, for example~ me~hyl~ methoxyethyl, ethoxy, pr~pyl, propoxy, butyl, cy d obutylD isobutyl, but~xy and the like.

This ~vention further relates to a nethod of oGntrolling unde-sirabl~ ~eget~tion, oamprising applying bD sudh vegetation in the post-e~ergent state a herbicidally effective amount of a ooTpound having the above formNla.

In ~ddition, this invention relates to a ~2thod of regulating the natural growth cr developmenk of plants, oomprising applying to said plants a regulating~ non~lethal amount of a oompound h~ving the above form~la.

The term ~herbicidally effective amount" designates any amount of the ooTpound~ disclosed herein which will kill a plant or substantial-ly inhibit its growth. By ~plants" is ~eant ge ~ ant seeds, em~rging seedlings, and established vegetation, including r~ots and above-ground portions.

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m e term "natural growth or development" designates the normal life cycle of a plant in accordan oe with its genetics and environment, in the absence of artificial external in1uences. A preerred utility o th~ instant oomeounds is in increasing the sucrose yield d ~ield yrown sugarcane and sorghum. m e term "regulatin~" is used herein to denote the bringing about through chemical means oE any tenporary or permanent %~dification or variation from the normal life cycle short o killing the plant.
Detailed Description of th~ Invention _ _ _ _ _ In accordance with the instant invention, weed cDntrol is achieved m~st effectively by applying the oompounds to the weeds subse-quent to their emergen oe from ~he soil. Regulation of the natural growth or development of crops, on the other hand, is achieved ~y applying the oompounds to the crop plants or to any of their above-yround portions at approximately 4 to 10 weeks prior to harvest. For the latter effect, a growth regulating amoun~ is used withou~ herbicidal results. As under-stood by those skilled in tne æ t, amounts effective for this purpose vary, not only with the particul æ material selected for treatment, but also with the regulatory e~fect to be achieved, the species of plant being treated and its stage of development, and whether a permanent or transient regul~ting effect is sought. Cther factors which determine the appropriate amDunt include the manner of application and weather condi-~ions such as temperature and rainf~ll. m e resulting regulation may arise from the effect of the chemical regulant on either the physiologi-cal processes of the plant or th~ m~rphology of the plant, or from both in oambin~tion or in sequen~eu Mbrphological changes æe generally evidenoed by changes in the size, shape, ~olor or texture of the treated plant or any of i~s parts, as well as in the quantity o fruit or flowers the plant produces.
Physiological changes, on ~he other hand, oc withLn the treated plan~
and are usually hidden rom view. Changes of this type m~st often occur in the production, location, storage or u æ of chemicals naturally occurring in the plant, such as horn~nesO Accompanying changes in mor-phology may be eviden oe o~ such changes, as a~e various analytical pro oe -dures known to those skilled in the art. Regulatory efects occur in a ~2~l21~310 number of diverse ways, varyirg from one plant species t3 the next or from one application rate to the next.

The compounds oE this invention are readily prepared ~r~m N-phosphonomethylglycine by reacting the latter with ~he appropria~ely substituted phosphonium nalide in the presence of propylene ~xide~
N~Phosphonomethylglycine itself can be prepared by the phosphonGmethyla-tion of glycine, the reaction of athyl glycinate with fo~ d~hy~e and die~hylphosphite, c~r the oY.idaticn oF the M-phosphino~ethylglycine. Such methcds are desc~ibed in U.S. Patent No~ 3,799,758 (Franz, i~arch 2~, 1974).

Alternatively, oompounds of this invention æ e prepar~d by oom-bining one equivalent of N-phosphonomethylglycirle and one equivalent of the organic salt in methanol and water while stirring. Silver oxide, in an equivalent a~ount, is ~hen added in sm~ll portions over a period oî
time and the stirri}lg of ~e rea~tion mixture continued for several hours. me ~roduct can ke recovered ky conventional means such as fil-tration followed b~ concentration of the resulting homcgenous solution.

The examples which follcw are intended to be merely illustra-tive, non=limiting de~cnstrations of the preparation of the o~pourds o the instant invention and of their effectiveness in controllil~ undesir~
ablè vegetation and in regula~ing plant growth~

-Preparation of Mbno-tetra-n-butylphosphonium Salt of N-Phosphonomethylglycine A sample of the mono-isopropylamine salt of N-phosphonomethyl-glycine was obtained frcm Monsanto Agricultural Products Co~, St. Louis, Missouri, in the form of an aqueous solution oontaining 41~ active ingre-dient ~y weight. A 51.5 g (0.125 le) portion of this soluticn wasdiluted with 75 ml of water and 10.4 ~1 of 12 N hydrochloric a~id (Oql2i mole) was added. me reaction mixture was stirred for an hour, and the solid product was filtered of. The product was washed successively with water, e~hanol, and acetonel then dried in an oven The yield was 15.8 g (75% of theoretical) of N-phosphonometh~lglycine.

A 3.4 g (0.02 mole) portion of this material was o~mbin~d with 6.8 g (0.02 mole) of tetra-n-butylphosphonium bromide and 20 ml of propy-lene oxide in 100 ml of water~ The mixture was warrned gently at 50~C for thirty minutes, then stripped of water and volatiles to yield 11.0 g o a clear oil with a refractive index Of 3~D3~ - 1.5851. qhe identity of the product was confirrn~d as the rnono-tetra-n-butylphosphoniurn salt o~
N-phosphon~nethylglycine ~y carbon-13 nuclear ~agne~ic resonance and infrared spec~roscopy.

EXA~LE 2 ~, Preparation of Mono-tetrame~hylphosphoni~n Salt ., ~
A 1.4 g (0.0083 mole) portion of the N-phosphonomethylgiycine i~0 prepared in Example 1 was 003nbined with 1.8 g (0.0083 mole) of tetra-m~thylphosphoniun iodide in 100 ml of water~ The mixture was warmed to SOC and stirred for one h~ur. I~ was then oooled to 15C and 6 ~1 of propylene oxide were added. Stirring was oont nued at room temperature for an additional tw~ hours. The reaction mixture was then extracted with 1~0 ml o diethyl ether. m e aqueous phase ~as then stripped to yield 30 g of prcduct ~ch was th~n dissolved and stripped further with tetrahydrofuran and ether to yield 2.3 g of a s~lid product showing decon~o.sition at 80C. The identity was confirmed as the manotetra-methylphosph~niun salt of N-pLosphonomethylglycine ky carbon-13 nuclear magnetic resonance.

P~eparation of Mono-tetr~phenylphosphonium Salt _ _ of N-Phosphoncmethylglycine The procedure of ~xa~ple 2 was followed, using 1.7 g (0.01 mole) of N-phosphonomethylglycine, 4.66 g (0.~1 m~le) of tetraphenylFhos-phonium icdide, and 3 ml of propylene oxide. The yield was 6.2 g o~ a liquid product with a refr~ctive index of nD30 = 1.5768, c~nfirmed by carbon-13 nuclear magne~ic resonan oe bo be the monotetraphenylphosphonium salt of N-phosphonomethylglycine.

~26~0 Preparaticn o~ ~ono-tributyl-2,~-dichlorobenzyl Phosphonium Salt o N-Phosphonomethylglycine ~ . _ , , _ The procedu~e of Example 2 was followed using 2.11 g (0~0125 m~le) of N-phosphonotnethylglycine, 4~97 g (0.0125 Ihole) of tribu~yl-2,4-dichlorobenzylphosphonium chloride, and 1.1 g of propylene o~ide. 'rhere was no reaction a~er tw3 days. The phosphonomethylglycine was still visible (undissolved). Approximately 20 ml o~ the water wa3 removed in v _ to remove the propylene oxide. There was added to the resulting solution 0.5 g (0.0125 m~le) of sGdium hydroxide pellets. After solubi-lizing the N-phosphonom~thylglycine, the solution was ref'uxe~ 1~5 hours.
A~ter strippin~, the solution was titurated with methylen~ chloride,/
toluene maxture. 'ohe solution was stripped in vacuo again and titurated with 20 ml of toluene. Ater filtering, a white solid was received.

~ le yield was 1.6 g, rnelting point >320C. After stripping the toluene filtrate, the residu~ (7.3 g) t~as titurated three times with di-ethyl etheri decanting each time. After stripping the sol~7ent, residue was obtained again. The yield this time w æ 6.6 g of viscous clear oil.
The ~w~ products were combined and the volatile materials removed }n vacuo. There was obtained 7.3 g of crude product. This was redissolved ___ in water to make arl homcgeneous solutionO The total of the aqueous solu-tion was 16.5 g qhe solution was 40% o product with 4.4~ sodi~m ~hlor-ide.

EXAMæ1E 5 Preparation of Mono-~enzyltriphenyl Phosphonium Salt ~C~
m ere w.~s dissolved 3.9 g (0.01 mole) of ~en2yltriphenyl phos-phc~lium chloride in 0.4 g ~0.022 mole) water and methanol; to this solu-tion was added 1.7 g ~0.01 m~le) of ethyl-N-phosphonomethylgly~ine. S'l-ver oxide (2.43 g, 0.0105 mole) was added in small portions over a cne hour period. After the addition was complete the mixture was allowed to stir for an additional two hours. Silver nitrate solution showed no halogen present, nor any other precipit~te with a fe~7 drops of the suFer-natant liquid. The silver chloride and silver oxide were filtered off and the filter cake washed with methanol. m e filtrate was stripped at 25C. 'm ere was ~tained 5.5 g of a white cyrstalline solid, .~elting point 78-82C, which was hydroscopic but soluble in water or chlorofo m .
m e identity ;~as confirmed by carbon-13 nuclear magnetic resonance.

6~0 25C. There was obtained 5.5 g of a ~1ite cyrstalline solid, melting point 78-82C, which was hydroscopic but oluble m water or chloroform.
The identity was confirmRd by carbon-13 nuclear ma~netic resonance.

Preparation of Mono-ethyltriphenyl Phosphonium Salt Of N-Phosphoncme ~
The phosphonium salt, ethyltriphenyl pho~phoniu~ iodide ~4.2 g, 0.01 mo]e) was combined with ethyl-N~phosphono~lethylglycine (1.7 g, 0.01 mole). Mekhanol (150 ml~ was added and the pho~phoniu~ salt dissolved.
Water ~0.4 g, 0.022 mole) was then added. At room temperature silver oxide was added in portions over a one hour period. m e reac~ion mixture was allowed to stir for 2.5 hours at room temperature. The silver iodide and excess silver oxide were filtered off and the filtra~e stripped.
There was o~tained a yield of 4.6 g, havin~ a melting -point of 59-68C.
Identity of ~he pro~uct was confirm~d ~y nucle æ magnetic resonance, inrared spectroscopy, and carbon-13 nucelar magnetic resonance.

EXAMæLE 7 Preparation of Mbno-methyltri-p-tolyl Phosphonium Salt of N-~hosphonomethylglycine In a simil~r procedure as in Example 6, 4.46 g (0.01 m~le) of methyltri-p-tolyl phosphonium iodide W3S combined with 1.7 g (0~0~ le) of N phosphonomethylglycine, followed by the addition of methanol and wa~er. Silver oxide was added over a period of 40 minutes. After the addition was cGmplete7 the reaction nuxture was allowed to stir for 2 hours at room teJqperature. After filtering off the silver oxide and ~ilver iodide the resulting filtrate was s~ripped at 25C at less ~han 1 m~ Hg pressure. lhere was obtained 4.8 g of the title ~ ~pound~ m~lting poLnt of 75-85C. me pr~duct was hydroscopic. Anaiysis was confirm~d by nuclear magnetic re~onance, carbon-l3 nucle æ magnetic resonance, and - infrared analysis.

__ Preperation of Mono-methyltri-(4-methoxyphenyl) Phosphonium Salt of N-Phosphonomethylglycine Using a similar procedur~ as in Example 6, there was ~ombined 5 g ~0.01 mole) of methyltri-(4-methoxyphenyl) iodide and 1.7 g (0.01 . ~lZI~90 mole) of M-phosphonometh~lglycine. Ihe silver oxide was added in por-tions over a period of 30-40 minutes. After stirring fo~ 20 minutes at 20QC the silver iodide and silver oxide were filtered o. The ilt~e was stripped in vacuo at 25C and less than 1 mm Hg pressure. lhere was S obtained a yield of 5.3 9 of white powder, melting point 50-68C, ~hich was hydroscopic. The structure was confirmed by nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and in~rared analysis.

EXAMPL~Preparation of ~no~ethyltri-(4-ch:l.orophenyl) Pho.sphonium 5a't of N-Phos~hon ~thyl~ly~ine Using the same procedure as Example 6, 5.08 g (G.01 m~le) of methyltri-~4-chlorophenyl) iodide was o~mbined with 1.7 g (0.0l moie) of N-p~sphonomethylglycine. Silver oxide was added in Fortions over a 40 minute period. Ater the addition was c~plete, th~ reaction mixture was all~ed ~o stir ~or 2.5 hours at rocm temperature. l~e silver oxide and silve~ iodide were filtered off ~Id the filtrate stripped at 25C at less than 1 mm Pq. m ere was obtained a yi~ld of 5.5 ~ of the title compoun~, -melting point of 85-95~CI which ~s hyd-~oscopic. Structure was o~nfinned by nuclear magnetic re~onance, carbon-13 n~cleal magnetic resonanc~, and infrared analysis.

T~BLE A
_ _ TABLE OF C~OPUNDS

Rl ~3 0 R4--p~9--R2 P-~H2N~ICH2CC~I

Physical Corstant Nb30 or Exarn. ~7.Qltin~
No. Rl R2 R3 R4 E~oint 1 n-C4Hg n-C4H9 n-~4H9 n-C4Hg 1.5g51

2 CH3 CH3 CH3 CH3 80C
d2 ~ ~osed

3 p~enyl phenyl phenyl phenyl 1.5768

4 n-C~Hg n-C4Hg n-C~Hg 2,4-diCl- ~320C
benzyl phenyl p~lenyl phenyl benzyl 78-82C

6 C2H5 phenyl phenyl phenyl 59-68C

7 4-CH3~phenyl 4-CH3_phenyl 4-CH3-phenyl CH3 75-85C

8 4-CH30~phenyl 4-CH30-phenyl 4-CH30-phenyl CH3 60-68C

9 4-C1-phenyl ~-Cl-phenyl 4-C1-phenyl C~3 88-85C

IN~IE 1~
Herbicidal Activity -m is example demonstrates the postemergence herbicidal activi~y of the compounds prepared in the Examples.

Aluminum planting flats measuring 15.2 x 22~9 x 8.9 cm ~re fille~ to a depth of 7.6 ~m with loamy sand soil, oontaining 50 parts per L2~

million (ppm~ each of the comm~rcial fungicide cis-N[(trichlo~Gmethyl)-thio]-4-cyclohexene-1,2-dicarbox~nide (Captan) and 17-17-17 ertillz~r (percentages of N-P20s-K20 on a weight basis). 5even rQws were i~ressed across the width of each flat and a vari~ty o s~eds oE koth grass ar.d broadlea~ we~d species were planted in rows. The weed ~eaies u æ d are listed below:

Broadlea weeds:
A. Annual m~rning glory Ipomcea ~ urea ~ Cocklebur Xanthium sp.
C. Jimsonweed Datura str~noniu~
C.1 Seshania Sesbania exhalta D Velvetleaf Abutilon theophrasti E. Mustard Brassica sp.
F. Nightshade lanum sp.
F.1 Field broadweed Con~olvulus rvensis F.2 Sicklepod Cassia obtusiolra G. Pigweed Amaranthus sp.

Grasses:
_ .
B. Yellow nutsedge ~yperus esculentus I. Downybro~e Bromus tecto~um J. Foxtail Setaria sp.

Grasses:
K. hnnual ryegrass Lolium multifl_rum L. Watergrass Echinochloa crusgalli M. Rox-orange sorghum Sorghum bioolo_ M.1 ~hattercane ~Sorqhum bic3lor N. Wild oat Av fatu The broad leaf species were seeded first, and the grasses were seeded four days later. Ample seeds of each spe~ies were planted to pro-duce 5 to 50-seedlings per row after emergence, depending ~n the si æ o~
~0 each plant~

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Ten days after ~he grasses were seeded, ~he emerged seedlings of all species were sprayed with aqueous solutions o the test co~pound~.
The solutions were prepared to such dilu~ions that a spray rate o~ 80 gallons per acre ~750 liters per hectare) gave ~rom 0.25 ~o 4~0 pounds o~
test compound per acre (0.28 to 4.48 kilograms per hectare) æs desi~ed for each test. Additional flats no~ treated at,all ~er~ us~1 as stan-dards ~or measuring the extent of weed c~ntrol in ~le treat~d flclts.
.. . .
Nineteen days later, the test flats were compar~d to the star.-dard~ and the weeds in e~ch row were rated visually in terms of percent control ranginy 'from 0% to lOC~, ~ith 0~ representing the same de~ree of gra~h as the same row in the standard and 100% representing oo~plete kill of all weeds in the row. All types of plant injuxy were ta~en into consideration. m e results are shown in Tables I and II, each represent-ing an independer.t series of tests.

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~2690 EXA~PLE 11 Herbicidal Activity This example demcnstrates both the pre-emergence and poste~er-gence activity of the same three oompounds on a variety of grasses and broadl~af w~eds at an applicaticn rate of 4 lb/A (4.48 kilograms Fer hec-tare). Many of the same we~d species were used (Table III uses the same notations as Tables I and II) and the procedures were similar to those o~
Example 4, except ~ha~ for the preemergenc~ test, the flats w~re sprayed with the test chemicals the day after seeding~ and injury ra~ings taken thirteen day~ later, and for the postem~rgence ~est, the 1ats were sprayed ten days after sqedil~g and rated thirteen days later. m e re-1~ sults are shown in Table III, where it is clear that the compounds areeffective herbicides only when applied postemergence.

T~BLE III
HE~BICIDE 113ST RESULTS
PRE- AND PO61~R~ENCE AT 4 LB/~
.
Broadleaf We~s Grasses Test CcmpoundApplication A D E G H J L N
Mono-tetra-n-butylpre-emergence 0 0 0 0 0 0 0 0 phosphoniun salt pos~emergen oe 70 80 95 g5 75 100 100 75 Mono-tetra~ethyl-pre-emergence 0 0 0 0 0 0 0 0 ~hosphonium salt pcstemergen oe 85 100 100 100 85 100 100 100 Mono-tetraphenylpre-emergence 0 0 0 0 0 0 0 0 phosphonium salt postemergence 98 85 100 90 65 100 95 ~0 EX~æLE 6 Plant Growth Regulant Activity _ _ _ This example demonstrates the activity of the mono-tetra-n-butylphosphonium and mono-tetrclmethylphosphonium salts of N-phosphono-~thylglycine in regulating the growth of sweet sorghum (~ hum t5 vulgare).

Ihe test procedure was as follows:

A series of fiber pots, 5.0 inches ~12.7 om) in diameter by 5.0 inches (12.7 cm) deep, were filled with sc~ndy loam soil which had been ~2~0 screened and fortified ~7ith suficient 17-17-17 rertilizer to achieve a concentration of 150 ppm each of N, P2Os, and Kz0. A single row of sorghum seeds was planted and the pots were placed in a greenhou æ where the temperature was maintained at 27C during the day and 21C at ni~ht.
Once the small seedlings emerged, they were thinned to one per pot.
Suckers and tillers were r.emoved as they appear~d until th~ plants ~7ere treated. m e pots were fertilized periodically with 17-17-17 fertili æ r.

Nine weeks and four days after æ eding, the ~alk length to the uppermost visible leaf ligule was measured and the plants ~ere sprayed with a solution of the test c~mpol~d dissolved in water further oontain-ing 0.5~ by weight o~ a pol~oxyethylene sorbitan monolaurate surfactant.
The sprayiny system was pressurized by carbon dioxide and mounted on a bicyle-type apparatus. The test soluti~ was sprayed at a rate of 25 gallons per acre (234 liters per hectare3, and the ooncentration of active in~redient was pre-determined t.o produce application rates ran~ing from Or5 to 4.0 poun~s of active ingredient per acre (0.5~ to 4.48 kilo-grams per hectare) at this spray rate.

Ten days later, the plants were harvested by cutting ~he stalks at soil level and re ving all leaves and leaf-sheaths. Ihe length of the stalks to the uppermo.st visible leaf ligule was again measured.
m ese mea~urements and those taken on the spraying date were entered into the following formula to determine the "percent stalk elongation":

Percent ~ ~ength at harvest date Stâ~k ~1 = ~ 0 x 100 Elongation~ len~th at spray date ¦
., m e length o~ the stalks frcm the soil level to the uppermost n~de were then m~asured and recorded as the "stalk length." Ihe seedh~ad and peduncle ~the portion of the staIk extending from the uppermnst node to the base of ~he seedhead) were then removed and the "fresh weight" of each remaini~g stalk was reoorded. Each staIk was then cut into pie oe s of about 1.5 inch (3.8 cm) in length ~d squeezed in a Carver press at 15,000 pounds per square inch (10,340 N/cm2) pressure. m e "quantity"

~JLZ~Z~9~

of the expressed juice fran ea~ st~lk was recorded as w~ll as i~s "total dissolved solids" content in weight percen~, as d~termined by a hand juice refractometer. qhe c~ushed stalks ~re therl dried in a ~orc~ air oven and weighed ~"dry weight'l).

The results are shown in Table IV, including a~eraged n~asur-rnents frcm three untreated check plants for co~rq?arison. '~he ~igures in-dicate a reduction in stalk elonga~lon, fresh weight, and dry ~eight, and an increase in ths peroentage of total dissolved solids in the expressed juice, all due to the ~pplication of the test colrpounds.

~BLE IV
., SUG~R h'NE~A~EMENr 'BT RESULTS ON SWEE~ SORf~ItlM
Percent Stalk Juice Test Application Stalk Length F.W. D.W. T.D.S. Quantitv C~pound P~te (lb/A) ~ ( nn~~g) (9)(96) (~rl) Checlc* 62~3 26542.1 3.364.4 9.0 M~no-tetra- 1.0 4.~ 11010.0 1.227.0 1.8 n-butyl- 2.0 3~4 10510.9 1.237.6 3.0 phosphoniun 4.0 5.3 16016.3 1.803O5 7.D, salt Mono-tetra- 0.5 5. 4 18524.4 3.5212.4 6.6 methyl- 1.0 2.3 25526.2 2.757.0 7.6 phoE~phonium 2. 0 4. 5245 23.92.19 7.4 8.6 salt "F.W." : fresh weight "D.W." : dry weight "T.D.S.": total dissolved solids *A~7erage of three replications.

~Z~i~69~

~ HODS OF APPLICATION

For use at a field site, the compounds o the present invention are gener~lly embodied in suitable ~ormulations containing additional ingredients and dilu~nt carriers ~o aid in their dispersal. Exan~l~s oE
such ingredients or carriers are water, organic solvent~, dust~, gran~
ules, surface active agents, w~ter-in-oil and oil-in~water emulsion~, ~;etting agents, dispersing agents, and emulsiiers. m e fo~nu]atic~s generally take the form of dusts, solutionsl emu}sifiable c~ncentrates, or wettable powder~.

A. W STS
Dusts are dense po~er compositions which c~mbine the active cxxn-pounds with a dense, free-flowing solid carrier. m ey are intended for application in dry form and are designed to settle rapidly to avoid being windborne to areas where their presence is nc~ desired.

The carrier may be of mineral or vegetable origin, and is pre- ~
ferably an organic or inorganic powder of high buIk density, low surface area, and low liq~lid absorptivity. Suitable carriers ~Iclu~e mic~ceous talcs, p~rophyllite, dense kaolin clays, tobacoo dust, and ground calcium phosphate rock.

m e performance of a dust is sometimes aided by t~le inclusion of a liquid or solid wetting agent, of ionic, anionic, or nonionic char-acter. Preferred wetting agents include alXylbenzene and alkylnaphtha-lene sulfonates, sulfated fatty alcohols, amines or acid amides, long chain acid esters of sodiun isothionate, esters of sodium sulfosuccinate, sulfated or sulfonated fatty acid esters, petrolewm sulfonates, sulfon-ated vegetable oils, and ditertiary acetylenic glycols. Dispersants are also useful in the same dust compositions. Typical dispersants include methyl cellulose, polyvinyl alcohol, lignin sulfonates, polymeric alkyl-naphthalene sulfonates, sodium naphthalene sulfonate, polymethylene bis-naphthalenesulfonate, and sodium-N-me~hyl-N-[long chain acid) taurates.

I;n addition~ inert absorptive grinding aids are ~requently included in dust oompositions to aid in the manufacturing of the dust.

;9~

Suitable grinding ~ids include attapulgite clay, diatomaceous silica, synthetic fine silica and synthetic calciu~ and magnesium silicates.

In typical dust comeositions, carriexs are usually present in conc~entrations of from ~bout 30 to 90 weiyht percent o~ ~he total compo-sition. The grinding aid usually constitutes about 5 to 50 w~ight per~
cent, and the wetting agent up to about l.0 weight pe~cent. Dispersan~, when present, constitute up to abou~ 0.5 w~ight percent, and minor amoun~s of anticaking and antistatic agents may als~ ~e present7 'rhe par-ticle ~iæe o~ the entire c~n~osition is us~ally about 30 to 50 microns.

. SOLUTICNS
0 Aqueou5 solutions of the active oompounds are prepared suc'n that applicaLion at the rate o about 1 to about 200 gallons of solution per acre (about 9 to about 1875 liters per hectare) will provide the requir.ed am3unt of aotive ingredient. A small amount of non-phytotoxic surfactant ty~ically b~t~en 0.05% and 0.5% by weight is usually included to impr~ve the wettin~ ability of the solution and thus its distribution cver the plant surface. Anionic, cationic, nonionic, ampholytic, and zwitterionic surfactan~s are all useful in this regard.

Suitable anionic surfactants include alkali metal, ~,~oniu~, and amine salts of fatty alcohol sulfates having from 8-18 carbcn atcms in the fatty chain and sodiurn salts of ~lkyl benzene sulfonates having rom 9 to 15 carbon atoms in the alkyl chain. Suitabl~ c~tionic surfac-tants include dim.ethyl dialkyl quaternary ammorliurn halides with alkyl chains of 8 to 18 carbon atoms. Suitable nonionic surfactants include polyoxyethylene adducts of fatty alcohols ha~ring lO to 18 carbon atoms, pol~ethylene oxide condensates of alkyl phenols with alkyl chains of 6 to 12 carbon atoms and 5 to 25 ~oles of ethylene oxide oondensed onto eac.h m~le of alkyl phenol, and polyethylene oxide condensates of sorbitan esters with 10 to 40 moles of ethylene oxide condensed onto each ro~le of sorbitan ester. Suitable ampholy~ic surfactants include secondary and tertiary aliphatic amine derivatives wi~h cne aliphatic substituent ocn-taining 8 to 18 carbon atoms and another containing an anionic water-solubilizing group such as a sulfate or sulfonate. Sodium-3~dcdec~
aminopropionate ar~ sodium-3-dodecyl amino propane sulfonate are ~Z6~

examples. Suitable ~witterionic surfactan~s include ~erivatives oR ali~
phatic quaternary ~nonium oompounds with one aliphati~ substituent oon-taining 8 to 18 carbon atoms and another containing an anionic water-solubilizing gr.oup. Exa~les of are 3-~N,N-dimethyl-~-hexadecyl2~0nio~-propane-l-sulfonate and 3-(NrN-dimethyl-N-hexadecylammonio)-2-hydroxy propane-l-sulfonate.

C. E.~ULSIFIABLE CONCE~RATES
Emu].sifiable concentrates æ e solutions in which the activ~
materials and an emulsifying agsnt are dissolved in a non-watenniscible solvent.. Prior to U5t~ th~ concentrate is dilut~d with water to form susp~nd~d emulsion of sol.vent droplets.

Typical solvents for use in emulsifiable concentrates include weed O;.lsr chlorinated hydrocarbons, and non-water-miscible ethers, esters, an~ ketones~

Typical emulsifying agents are anionic or nonionic surfactants, lS or mixtures o the two. Examples include long-chain mercaptan polyethoxy alcohols, aIkylaryl polyethoxy alcohols, sorbitan fatty acid es~ers, p~lyoxyethylene ~hers with sorbitan fatty ~cid esters, polyoxyethylene glycol esters with fatty or rosin acids, fatty alkylol amide condensates, calcium and amin~ salts of fatty alcohol sulfates, oil~soluble petroleu~
sulfonates, or preferably mixtures of these emulsifying agents. Such e~.ulsifying agents usually ocmprise about 1 ~o 10 weight percent of ~he tota' oomposition.

Typical emulsifiable ooncentrates oontain akout 15 to 50 weight percent active material, about 40 to ~ weight percent solvent, an~ about 1 tc 1~ weight percent emulsifier. Other additives such as spreading agents and stickers can also be included.

D wE~rA~IE P~WDERS
Wettable powders are water-dispersible oompositions o~ntain-ing the active material, an in~rt solid extender, and one or more surfac-tants to provide rapid wetting and prevent flocculation when suspended in water.

~26~

Suitable solid exkenders include ko~l natural ninerals and materials derived synthetically frcm sucn minerals. Examples include kaolinites, attapulgite clay, montmorillonite clays, ~n'~hetic silicas, synthetic magnesium silicate an~ calcium sulfate dihydra~e~

Suitable surfactants include both nonionic and anionic types, and function as wetting agen~s ar~ dispersants. Usually or~ d each is included. Preferred wetting agents are alkylbenzene and alkylnaph~halene sulf~nates, sulfated fa~ty alcohols, amines or acid amides, lor~ chain acid esters of sodium isothionate, esters of scdium sulfosuccinate, sul-f~te~ or sulfonated fatty acid esters, petroleum sulfonates, sulfonated vegetable oils, and ditertiary acetylenic glycols. Preferred dispersants are methyl oellulGser polyvinyl alcohol, lignin sulfonates, pol~meric alkylnaphthalene sulfonates, sodium naphthalene sul~onate, polyme~hylene bisnaphthalenesulfonate, and sodium-N~nethyliN(long chain acid) taurates.

Typical wettable powders oontain 25 to 90 percent active material, 0.5 to 2.0 percent wetting agent, 0.25 ~o 5.0 percent dispers- ~
ant, ~nd from 9 25 to 74.25 weight percent inert extender. Frequently, 0.1 to 1.~ per oe nt o~ the extender is replaced by a corrosio~ inhibitor andJor an antifoaming agent.

Eo IN GENE~AL
~n g~neral, any oonventional method of 2pplication can be used, including common dusting or spraying equipment. m e amount ~f active ing~dient which is efective in producing the desired result, ke it herbicidal or growth~regulating, depends on the nature of the plant species to be controlled and the prevailing conditions. Herbicidal effects are usually achieved at Ool ~O 5Q pounds active ingredient per acre, preferably 1 to 10, while plant growth regulation is usually achieved at 0.1 to 20 pounds active ingredient per acre, preferably 0~5 to 5. It will be readily aFparent to one skilled in the art that com-pounds of lower activity will require a higher dosage than more active ~o~pounds for the same degree of o~ntrol.

Claims (24)

WHAT IS CLAIMED IS:

1. A compound having the formula in which R1 R2, R3, and R4 are independently selected from the group con-sisting of C1-C10 alkyl, benzyl, phenyl, substituted phenyl and substi-tuted benzyl wherein said substituents are independently selected from halogen, lower alkoxy, and lower alkyl.

2. A compound according to to Claim 1 in which R1, R2, and R3 are independently selected from the group consisting of C1-C6 alkyl and phenyl, and R4 is benzyl, substituted benzyl or substituted phenyl.

3. A compound according to Claim 1 in which R1, R2, and R3 are each n-butyl and R4 is 2,4-dichlorobenzyl.

4. A Compound according to Claim 1 m which R12, R2, and R3, are each phenyl and R4 is benzyl.

5. A compound according to Claim 1 in which R1 is ethyl and R2, R3, and R4 are each phenyl.

6 . A compound according to Claim 1 in which R1, R2, and R3 are each p-tolyl and R4 is methyl.

7. A compound according to Claim 1 in which R1, R2, and R3 are each 4-methoxyphenyl and R4 is methyl.

8. A compound according to Claim 1 in which R1, R3 and R3 are each 4-chlorophenyl and R4 is methyl.

9. A compound having the formula in which R1, R2, R3, and R4 are independently selected from the group con-sisting of C1-C10 alkyl and phenyl.

10. A compound according to Claim 9 in which R1, R2, R3, and R4 are independently selected from the group consisting of C1-C6 alkyl and phenyl.

11. A compound according to Claim 9 in which R1, R2, R3, and R4 are identical and are selected from the group consisting of C1-C4 alkyl and phenyl.

12. A compound according to Claim 9 in which R1, R2, R3, and R4 are each methyl.

13. A compound according to Claim 9 in which R1, R2, R3, and R4 are each n-butyl.

14. A compound according to Claim 9 in which R1, R2, R3 and R are each phenyl

15. A method of controlling undesirable vegetation comprising applying to the vegetation in post-emergent state an herbicidal composi-tion comprising an herbicidally effective amount of a compound having the formula in which R1, R2, R3, and R4 are independently selected from the group con-sisting of C1-C10 alkyl, benzyl, phenyl, substituted phenyl, and substi-tuted benzyl wherein said substituents are independently selected from halogen, lower alkoxy, and lower alkyl, and an inert diluent carrier.

16. A method according to Claim 15 in which R1, R2, and R3 are independently selected from the group consisting of C1-C6 alkyl and phenyl and R4 is benzyl, substituted benzyl or substituted phenyl.

17. A method of controlling undesirable vegetation comprising applying to the vegetation in postemergent state an herbicidal composi-tion comprising an herbicidally effective amount of a compound having the formula in which R1, R2, R3, and R4 are independently selected from the group con-sisting of C1-C10 alkyl and phenyl, and an inert diluent carrier.

18. A method according to Claim 17 in which R1, R2, R3, and R4 are independently selected from the group consisting of C1-C6 alkyl and phenyl.

19. A method according to Claim 17 in which R1, R2, R3, and R4 are identical and are selected from the group consisting of C1-C4 alkyl and phenyl.

20. A method of regulating the natural growth or development of plants which comprise applying to said plants a regulating, non-lethal amount of a compound having the formula in which R1, R2, R3, and R4 are independently selected from the group con-sisting of C1-C10 alkyl, benzyl, phenyl, substituted phenyl, and substi-tuted benzyl wherein said substituents are independently selected from halogen, lower alkoxy, and lower alkyl, and an inert diluent carrier.

21. A method according to Claim 20 in which R1, R2, and R3 are independently selected from the group consisting of C1-C6 alkyl and phenyl and R4 is benzyl, substituted benzyl or substituted phenyl.

22. A method of regulating the natural growth or development of plants which comprises applying to said plants a regulating, non-lethal amount of a compound having the formula in which R1, R2, R3, and R4 are independently selected from the group con-sisting of C1-C10 alkyl and phenyl, and an inert diluent carrier.

23. A method according to Claim 22 in which R1, R2, R3, and R4 are independently C1-C10 alkyl.

24. A method according to Claim 22 in which R1, R2, R3, and R4 are identical and are each C1-C4 alkyl.