Substituted Tetrazolinones and Herbicidal Compositions Thereof

1. Field of the Invention

The instant invention is directed to a new class of substituted tetrazolinone compounds. More specifically, the instant invention relates to a new class of substituted tetrazolinone compounds which are useful as preemergence herbicides, post-emergence herbicides, and/or as plant growth regulators.

2. Background of the Prior Art

The synthesis of certain substituted tetrazolinones is known in the art. Thus, Horwitz, et al, JACS, 81 3076 (1959) and Tsuge et al, J. Org. Chem., 45 5130 (1980) provide methods for synthesizing tetrazolinones. These disclosures provide no utility for the classes of substituted tetrazolinones synthesized.

The need for effective herbicides, both preemergence and post-emergence needs no special emphasis. The control of weeds and undesirable vegetation is of great economic importance since weed competition inhibits the production of foliage, fruit or seed of agricultural crops. The presence of weeds can reduce harvesting efficiency and the quality of the harvested crop. Weed control is essential for maximum production of many agronomic and horticultural crops including corn, (Zea mays L.), cotton (Gossypium SP), sunflower (Helianthus annus L.) and soybeans (Glycine max (L.) Merr.). Weeds on noncropped areas may cause a fire hazard, undesirable drifting of sand or snow, and/or irritation to persons with allergies. Thus, suppression of undesirable weed growth is very advantageous.

Moreover, the need for agricultural chemicals having significant effects on the growth and development of crop plant species is similarly well known. Thus, for many crops, it is highly desirable that certain plant growth regulatory effects by accomplished. In general, these growth regulatory effects include one or more of the following: dwarfing, cessation of terminal growth, inhibition or stimulation of axillary and intercalary growth, retardation or stimulation of internode elongation, inhibition or stimulation of flowering or reproductive development, and the like.

It has now been found that a new class of substituted tetrazolinones unexpectedly provides excellent pre-emergence and post-emergence herbicidal properties and/or plant growth regulatory effects.

In accordance with the instant invention, a compound having the formula: ##STR1## wherein R is:

C.sub.1 -C.sub.12 alkyl,

C.sub.2 -C.sub.13 alkoxyalkyl,

C.sub.7 -C.sub.9 aralkyl,

C.sub.5 -C.sub.6 cycloalkyl,

C.sub.3 -C.sub.12 alkenyl,

naphthyl,

phenyl,

phenyl substituted with at least one member selected from the group consisting of:

fluorine,

chlorine,

bromine,

iodine,

C.sub.1 -C.sub.4 alkyl,

C.sub.1 -C.sub.4 alkoxy,

methylenedioxy,

NR.sup.3 R.sup.4 wherein R.sup.3 and R.sup.4 are the same or different and are hydrogen or C.sub.1 -C.sub.6 alkyl,

C.sub.2 -C.sub.5 alkoxycarbonyl,

carboxy,

phenoxy,

nitro,

cyano,

trihalomethyl wherein halo is fluorine, chlorine or bromine,

trihalomethoxy wherein halo is fluorine, chlorine or bromine,

C.sub.1 -C.sub.6 alkylthio, and

C.sub.1 -C.sub.6 fluoroalkylthio; or benzyl substituted with at least one member selected from the group consisting of:

fluorine,

chlorine,

bromine,

iodine,

C.sub.1 -C.sub.4 alkyl,

C.sub.1 -C.sub.4 alkoxy,

methylenedioxy,

C.sub.2 -C.sub.5 alkoxycarbonyl,

phenoxy,

nitro,

cyano,

trihalomethyl wherein halo is fluorine, chlorine or bromine,

trihalomethoxy wherein halo is fluorine, chlorine or bromine,

C.sub.1 -C.sub.6 alkylthio, and

C.sub.1 -C.sub.6 fluoroalkylthio;

R.sup.1 and R.sup.2 are the same or different and are:

C.sub.1 -C.sub.6 alkyl,

C.sub.3 -C.sub.6 alkenyl,

C.sub.5 -C.sub.6 cycloalkyl,

C.sub.7 -C.sub.9 aralkyl,

C.sub.7 -C.sub.9 aralkyl substituted with at least one member selected from the group consisting of:

fluorine,

chlorine,

bromine,

iodine,

C.sub.1 -C.sub.6 alkyl,

C.sub.1 -C.sub.2 haloalkyl wherein halo is fluorine, chlorine or bromine,

halomethoxy wherein halo is fluorine, chlorine or bromine,

C.sub.1 -C.sub.6 alkoxy,

C.sub.1 -C.sub.6 alkylthio,

C.sub.1 -C.sub.6 fluoroalkylthio,

phenoxy,

phenylthio,

carboxy,

C.sub.2 -C.sub.5 alkoxycarbonyl,

nitro,

cyano, and

NR.sup.7 R.sup.8 wherein R.sup.7 and R.sup.8 are the same or different and are hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.4 -C.sub.8 alkylene or C.sub.4 -C.sub.8 oxydialkylene; or

naphthyl,

phenyl, or

phenyl substituted with at least one member selected from the group consisting of:

fluorine,

chlorine,

bromine,

iodine,

C.sub.1 -C.sub.6 alkyl,

C.sub.1 -C.sub.2 haloalkyl wherein halo is fluorine, chlorine or bromine:

halomethoxy wherein halo is fluorine, chlorine or bromine,

C.sub.1 -C.sub.6 alkoxy,

C.sub.1 -C.sub.6 alkylthio,

C.sub.1 -C.sub.6 fluoroalkylthio,

phenoxy,

phenyl,

phenylthio,

carboxy,

C.sub.2 -C.sub.5 alkoxycarbonyl,

nitro,

cyano, and

NR.sup.7 R.sup.8 wherein R.sup.7 and R.sup.8 are the same or different and are hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.4 -C.sub.8 alkylene or C.sub.4 -C.sub.8 oxydialkylene; or

R.sup.1 and R.sup.2 together are C.sub.4 -C.sub.8 alkylene or C.sub.4 -C.sub.8 oxydialkylene, is disclosed.

In further accordance with the instant invention a composition is provided comprising the compound of this invention with a carrier.

In still further accordance with the present invention a method for controlling weeds and undesirable vegetation employing the composition of this invention is taught.

In yet further accordance with the present invention, a method for regulating the growth of plants employing the composition of this invention is taught.

The present invention is directed to a compound having the structural formula: ##STR2## wherein R is:

C.sub.1 -C.sub.12 alkyl,

C.sub.2 -C.sub.13 alkoxyalkyl,

C.sub.7 -C.sub.9 aralkyl,

C.sub.5 -C.sub.6 cycloalkyl,

C.sub.3 -C.sub.12 alkenyl,

naphthyl,

phenyl,

phenyl substituted with at least one member selected from the group consisting of:

fluorine,

chlorine,

bromine,

iodine,

C.sub.1 -C.sub.4 alkyl,

C.sub.1 -C.sub.4 alkoxy,

methylenedioxy,

NR.sup.3 R.sup.4 wherein R.sup.3 and R.sup.4 are the same or different and are hydrogen or C.sub.1 -C.sub.6 alkyl,

C.sub.2 -C.sub.5 alkoxycarbonyl,

carboxy,

phenoxy,

nitro,

cyano,

trihalomethyl wherein halo is fluorine, chlorine or bromine,

trihalomethoxy wherein halo is fluorine, chlorine or bromine,

C.sub.1 -C.sub.6 alkylthio, and

C.sub.1 -C.sub.6 fluoroalkylthio; or benzyl substituted with at least one member selected from the group consisting of:

fluorine,

chlorine,

bromine,

iodine,

C.sub.1 -C.sub.4 alkyl,

C.sub.1 -C.sub.4 alkoxy,

methylenedioxy,

C.sub.2 -C.sub.5 alkoxycarbonyl,

phenoxy,

nitro,

cyano,

trihalomethyl wherein halo is fluorine, chlorine or bromine,

trihalomethoxy wherein halo is fluorine, chlorine or bromine,

C.sub.1 -C.sub.6 alkylthio, and

C.sub.1 -C.sub.6 fluoroalkylthio;

R.sup.1 R.sup.2 are the same or different and are:

C.sub.1 -C.sub.6 alkyl,

C.sub.3 -C.sub.6 alkenyl,

C.sub.5 -C.sub.6 cycloalkyl,

C.sub.7 -C.sub.9 aralkyl,

C.sub.7 -C.sub.9 aralkyl substituted with at least one member selected from the group consisting of:

fluorine,

chlorine,

bromine,

iodine,

C.sub.1 -C.sub.6 alkyl,

C.sub.1 -C.sub.2 haloalkyl wherein halo is fluorine, chlorine or bromine;

halomethoxy wherein halo is fluorine, chlorine or bromine,

C.sub.1 -C.sub.6 alkoxy,

C.sub.1 -C.sub.6 alkylthio,

C.sub.1 -C.sub.6 fluoroalkylthio,

phenoxy,

phenylthio,

carboxy,

C.sub.2 -C.sub.5 alkoxycarbonyl,

nitro,

cyano, and

NR.sup.7 R.sup.8 wherein R.sup.7 and R.sup.8 are the same or different and are hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.4 -C.sub.8 alkylene or C.sub.4 -C.sub.8 oxydialkylene; or

naphthyl,

phenyl,

phenyl substituted with at least one member selected from the group consisting of:

fluorine,

chlorine,

bromine,

iodine,

C.sub.1 -C.sub.6 alkyl,

C.sub.1 -C.sub.2 haloalkyl wherein halo is fluorine, chlorine or bromine:

halomethoxy wherein halo is fluorine, chlorine or bromine,

C.sub.1 -C.sub.6 alkoxy,

C.sub.1 -C.sub.6 alkylthio,

C.sub.1 -C.sub.6 fluoroalkylthio,

phenoxy,

phenyl,

phenylthio,

carboxy,

C.sub.2 -C.sub.5 alkoxycarbonyl,

nitro,

cyano, and

NR.sup.7 R.sup.8 wherein R.sup.7 and R.sup.8 are the same or different and are hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.4 -C.sub.8 alkylene or C.sub.4 -C.sub.8 oxydialkylene: or

R.sup.1 and R.sup.2 together are C.sub.4 -C.sub.8 alkylene or C.sub.4 -C.sub.8 oxydialkylene.

Among the more preferred compounds of this invention are those wherein:

R is C.sub.1 -C.sub.4 alkyl, phenyl, or phenyl substituted with at least one member of the group consisting of:

C.sub.1 -C.sub.3 alkyl and

C.sub.1 -C.sub.3 alkoxy:

R.sub.1 is C.sub.1 -C.sub.4 alkyl: and

R.sub.2 is phenyl or

phenyl substituted with at least one member of the group consisting of:

C.sub.1 -C.sub.3 alkyl,

C.sub.1 -C.sub.3 alkoxy,

chlorine, and

trihalomethyl.

Particularly preferred compounds include:

1-methyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-ethyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-n-propyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-n-butyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-phenyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-phenyl-4-[(N-isopropyl,N-[2-methyl]phenyl)carbamyl]-5(4H)-tetrazolinone,

1-phenyl-4-[(N-isopropyl,N-[4-chloro]phenyl)carbamyl]-5(4H)-tetrazolinone,

1-(2-methyl)phenyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-(2-methoxy)phenyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone, and

1-(2,6-dimethyl)phenyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolino ne.

More preferably, when the compound of this invention is to be employed as a plant growth regulator, the invention is directed to a compound having the structural formula given above wherein R is:

C.sub.1 -C.sub.4 alkyl,

C.sub.7 -C.sub.9 aralkyl,

naphthyl,

phenyl, or

phenyl substituted with one or more members of the group consisting of:

fluorine,

chlorine,

bromine,

C.sub.1 -C.sub.3 alkyl,

C.sub.1 -C.sub.2 alkoxy,

trifluoromethyl, and

thiomethyl;

R.sup.1 and R.sup.2 are the same or different and are:

C.sub.1 -C.sub.4 alkyl,

cyclohexyl,

C.sub.7 -C.sub.9 aralkyl,

phenyl, or

phenyl substituted with one or more members of the group consisting of:

chlorine,

methoxy,

methyl, and

trifluoromethyl; or

R.sup.1 and R.sup.2 together are C.sub.4 -C.sub.7 alkylene or C.sub.4 -C.sub.6 oxydialkylene.

Most preferred compounds for plant growth regulatory purposes include:

1-methyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-ethyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-n-propyl-4-(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-n-butyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-phenyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolinone,

1-phenyl-4-[(N-isopropyl,N-[2-methyl]phenyl)carbamyl]-5(4H)-tetrazolinone,

1-phenyl-4-[(N-isopropyl,N-[4-chloro]phenyl)carbamyl]5(4H)-tetrazolnone,

1-(2-methyl)phenyl-4-(N-isopropyl,N-phenyl)carbamyl]5(4H)-tetrazolinone,

1-(2-methoxy)phenyl-4-[(N-isopropyl,N-phenyl)carbamyl]5(4H)-tetrazolinone,

1-(2,6-dimethyl)phenyl-4-[(N-isopropyl,N-phenyl)carbamyl]-5(4H)-tetrazolino ne,

1-(2-trifluoromethyl)phenyl-4-[(N-propyl,N-isopropyl)carbamyl]-5(4H)-tetraz olinone,

1-(2-methyl)phenyl-4-[(N,N-diisopropyl)carbamyl]-5(4H)-tetrazolinone,

1-(2-ethyl)phenyl-4-[(N,N-diethyl)carbamyl]-5(4H)-tetrazolinone,

1-(2-methoxy)phenyl-4-[(N,N-diisobutyl)carbamyl]-5(4H)-tetrazolinone,

1-phenyl-4-[(N-isobutyl,N-isopropyl)carbamyl]-5(4H)tetrazolinone, and

1-phenyl-4-[(N-ethyl,N-hexyl)carbamyl]-5(4H)-tetrazolinone.

The compounds of this invention are prepared by reacting a tetrazolinone compound having the formula: ##STR3## wherein M is hydrogen or alkali metal (such as Li, Na or K) and R is as defined above with a carbamoyl halide having the formula XCONR.sup.1 R.sup.2, wherein X is chlorine or bromine and R.sup.1 and R.sup.2 have the meanings above.

When M is hydrogen, the reaction is preferably conducted in the presence of a suitable acid acceptor such as pyridine or a tertiary amine (e.g., triethylamine). It is noted that this tetrazolinone compound may be synthesized by the methods disclosed in the Horwitz et al and Tsuge et al references mentioned above. The equivalent ratio of X/M (as representative of the above reactants) may vary from about 0.75/1 to about 2/1, preferably from about 0.9/1 to about 1.5/1. Excess of M may be advantageous in the purification of product since the M-type tetrazolinone is soluble in base. The reaction temperature may range from about 40.degree. C. to the boiling point of the solvent used. Typically, the reaction is conducted under reflux conditions. Suitable solvents are those which are inert to the reactant, such as acetone, acetonitrile, toluene, chloroform and the like. The reaction time may vary from several minutes or less to several hours or more depending on factors such as reaction batch size, reaction temperature, and the like.

The instant invention is also directed to a composition comprising the substituted tetrazolinone compound of this invention and a carrier therefor. The carrier employed in one preferred embodiment of this invention is a finely-divided or granular inorganic or organic material such as attapulgite clay, sand, vermiculite, ground corn cobs, activated carbon and the like. The compound of this invention may be impregnated on the finely-divided or granular material.

The carrier may also be an inert powder. Preferably, the inert powder is one of the mineral silicates, e.g., mica, talc, pyrophyllite and clays. In this case, the composition is formed by grinding the compound of this invention into a fine powder and mixing it with the inert powder to which a surface active dispersing agent has been added.

A third carrier is the combination of the above inert powder and water. This carrier employs the wettable powder dispersed in water.

Yet another carrier is a solvent and water. In this embodiment the compound of this invention is dissolved in a solvent such as benzene, toluene or other aliphatic or aromatic hydrocarbon. An emulsifiable concentrate is formed with the addition of a surface active and/or dispersing agent. The emulsifiable concentrate is then dispersed in water. In this composition water solubility may be increased using a cosolvent system involving acetone, dimethyl sulfoxide or other water miscible solvent.

It is noted that the surface active agents preferred for use in the composition of this invention are well known to those skilled in the art. In addition, suitable surface active agents for use in the composition of this invention are provided in McCutcheon's Detergents and Emulsifiers, 1970, Allured Publishing Corp., Ridgewood, N.J.: U.S. Pat. No. 2,614,916, columns 2 to 4; and U.S. Pat. No. 2,547,727, columns 3 and 4.

The present invention is furthermore directed to a method of controlling weeds, both pre-emergence and post-emergence, by application of a herbicidally effective amount of the composition of this invention.

In the case where the composition comprises impregnated granules of the compound of this invention, application, to control weeds, is by spreading on the soil. The wettable powder may be similarly applied. In the case where the wettable powder is dispersed in water, this composition controls weeds by spraying the dispersion on weeds or unwanted vegetation or onto the soil surface. Where an emulsion is formed that emulsion is likewise sprayed onto the weeds or onto the soil surface.

When employed as a herbicide, the concentration of the compound of this invention in the composition of this invention may vary widely, e.g. from 1 to 95%. The concentration of active compound in dispersions applied to the soil or foliage is generally from 0.002% to about 75%.

For use as a pre-emergence herbicide the compound of this invention is typically applied at rates of from about 0.05 to about 25 pounds per acre (from about 0.056 to about 28 kg/ha) to soil which contains weed and crop seed, namely either to the surface of the soil or incorporated into the upper one to three inches (2.5 to 7.5 cm.) of soil. As a post-emergence herbicide, the compound is typically applied at rates of from about 0.05 to about 25 pounds per acre (from about 0.056 to about 28 kg/ha) to the foliage of weeds. The compound may be employed singly or as a mixture of two or more chemicals.

When employed as a herbicide, the most suitable rate of application in any given case will depend on such factors as soil type, soil pH, soil organic matter content, the quantity and intensity of rainfall before and after treatment, the air and soil temperature, light intensity and light duration per day. All of these factors can have an influence on the efficacy of the chemicals for a given weed control use.

The herbicide use may include control of vegetation at industrial sites or selective weed control in crop fields.

In addition, the present invention is directed to a method of regulating the growth of plants by the application of a plant growth regulatory effective amount of the composition of this invention. It will be understood that the term plant, as used herein, includes plant parts such as foliage, roots, flower stems and seeds. Depending on the crop variety, dosage, time of application and certain cultural practices, the growth regulating effects which may be obtained include one or more of the following: dwarfing, cessation of terminal growth, inhibition of axillary and intercalary growth, retardation of internode elongation, inhibition of flowering or reproductive development, and the like.

Compounds of this invention may be used alone, or in combination with one or more pesticidal compositions, or in combination with one or more spray adjuvants (e.g. surface active agents, stickers, spreaders, emulsifiers, suspending agents, or extenders). The amount of active compound employed follows conventional practice for plant growth regulatory uses, and the chemicals are suitable applied as a formulation in accordance with conventional agricultural chemical practice.

The most suitable dosage of application of the active ingredient(s) for plant growth regulatory effects and the type and amount of adjuvant substances to be added to the spray solution will depend on a number of factors, including the plant species; the stage of plant development; the mode of application; the specific biological effect desired; the air and soil temperature; the quantity and intensity of rainfall before and after treatment; the soil type, pH, fertility and moisture and organic matter content; the physiological condition and vigor of the target plants; the relative humidity and wind velocity of the air around the crop; the extent and density of the foliar canopy of the target plant; the light quality, intensity and duration each day; the type and interval of previous and subsequent crop protectant chemical applications. All of these factors may have an influence on the efficacy of chemicals applied as plant growth regulators. However, one skilled in the art can, by routine experimentation, readily determine optimum conditions for the employment of any particular compound of this invention.

The following examples are given to illustrate the invention. Since these examples are illustrative of the invention, the invention should not be deemed to be limited thereto.

Preparation of 1-(2-ethoxyphenyl)-5(4H)-tetrazolinone

Aluminum chloride (15.0 grams, 0.11 mole) was added in small portions while stirring to 75 ml of tetrahydrofuran (THF, tested for absence of peroxide), keeping the temperature of the solution below 30.degree. C. 2-Ethoxyphenyl isocyanate (16.2 grams, 0.1 mole), 50 ml THF and 19.5 grams, (0.3 mole) of sodium azide were combined in a separate flask, equipped with a condenser and thermometer. The aluminum chloride solution was added to the flask and the mixture was refluxed at 70.degree. to 80.degree. C. for 16 hours. The mixture was cooled to room temperature, and 10 ml of concentrated hydrochloric acid and 10 ml of water were added in one portion to the stirred mixture. The mixture was warmed slightly, and nitrogen was swept over the surface to remove unreacted hydrazoic acid. The mixture was stirred for 20 minutes and filtered. The salt was washed twice with 50 ml portions of THF. The THF layers were combined and after concentration under reduced pressure the product crystallized. After recrystallization from ethanol, 10.0 grams (50%) of white crystals were obtained, mp 115.degree.-116.degree. C. The structure was confirmed by infrared (IR) and nuclear magnetic resonance (NMR) analyses.

This compound was subsequently reacted with N,N-dimethylcarbamyl chloride resulting in Compound No. 20 of Table I.

Potassium carbonate (6.6 grams, 0.048 mole), 50 ml of acetonitrile and 4.4 grams (0.02 mole) of 1-(2,5-di- methoxyphenyl)-5(4H)-tetrazolinone were combined and refluxed at 85.degree. C. for 15 minutes. The mixture was cooled to room temperature, and 3.2 grams (0.3 mole) of dimethylcarbamyl chloride was added in one portion. The mixture was refluxed at 80.degree.-85.degree. C. for one hour, cooled and the salt removed by filtration. After the removal of the solvent under reduced pressure, the product crystallized. The product was recrystallized from ethanol, giving 4.0 grams (69% yield) of white crystals, m.p. 125.degree.-6.degree. C.

The structure was confirmed by IR and NMR spectra.

1-Phenyl-5(4H)-tetrazolinone (4.8 grams, 0.03 mole), 5.4 grams (0.04 mole) of potassium carbonate and 50 ml of acetonitrile were combined and refluxed at 80.degree. C. for 10 minutes. The mixture was cooled to room temperature, and 5.4 grams (0.04 mole) of diethylcarbamyl chloride was added in one portion. The reaction mixture was refluxed at 80.degree.-90.degree. C. for 16 hours, cooled, and salt removed by filtration. The filtrate was poured into 75 ml of H.sub.2 O, and a white preciptate was formed. The product was recrystallized from 25 ml of ethanol and 5 ml of hexane, giving 4.5 grams (57% yield) of white crystals, m.p. 66.degree.-8.degree. C. The structure was confirmed by IR and NMR-spectra.

As essentially described above, a series of chemicals of this invention was prepared as summarized in Table I.

Following essentially the procedures outlined above additional compounds within the scope of this invention are prepared. These compounds, compounds 25-46, are defined in Table II.

To illustrate the effectiveness of the previously described substituted tetrazolinones of this invention as pre-emergence herbicides, 300 mg chemical was dissolved in a composition comprising 10 ml acetone to which 30 mg emulsifying agent, ethoxylated sorbitan monolaurate, was added. The solution was diluted to 100 ml with distilled water. Ten milliliters of this 3000 ppm solution was diluted to 250 ppm with distilled water. The chemical was applied at the rate of 10 pounds/acre (11.2 kg/ha) by drenching 46 ml of the 250 ppm solution on the surface of soil in 41/2 inch (11.25 cm) plastic pots wherein seeds of the following weeds had been planted: velvetleaf (Abutilon theophrasti medic) (VL), jimsonweed (Datura stramonium L.) (JW), tall morning glory (Ipomea purpurea L. Roth) (TM), switchgrass (Panicum virgatum L.) (SG), barnyardgrass (Echinochloa crusgalli (L.) Beauv.) (BG), green foxtail (Setria viridis (L.), Beauv.) (GF). The percent control of the weeds compared to untreated checks was determined two weeks after treatment. TABLE III summarizes the results achieved with compounds formulated as indicated above, and the data clearly indicate the good to excellent herbicidal efficacy of compounds of this invention.

To illustrate effectiveness of the described substituted tetrazolinones as post-emergence herbicides, the 3000 ppm solution described under Example 4 was atomized with a conventional DeVilbiss [.TM.]sprayer, wetting the foliage to the drip point. The weeds, which were the same species as described under Example 4, were treated six days after emergence. The percent weed control was evaluated two weeks after treatment. Table IV illustrates the postemergence herbicidal efficacy of chemicals of this invention.

Similar pre- and post-emergence herbicidal results are achieved with Compound Numbers 25-46 when applied to weeds in a manner indicated in Examples 4 and 5.

To illustrate the effectiveness of the described compounds as plant growth regulants, 600 mg of chemical were dissolved in a 10 ml organic solvent comprising acetone to which 30 mg of an emulsifying agent, "Tween 20" (.TM.) (an ethoxylated sorbitan monolaurate), was added. This solution was diluted to 200 ml with distilled water, producing a 3000 ppm solution/suspension. By appropriate dilutions with distilled water, 1000 and 500 ppm solution/suspensions were prepared. The spray solution/suspensions were atomized with a DeVilbiss (trademark) No. 152 sprayer and wetted the foliage to the drip point of soybean plants (Glycine max (L.) Merr., cv. Williams, 2 weeks old), cotton plants (Gossypium hirsutum L. cv. Stoneville 213, 3-4 weeks old), bean plants (Phaseolus vulgaris L. cv. Pinto III, 2 weeks old), barley plants (Hordeum vulgare L. cv. Herta, 1 week old) and rice plants (Oryza sativa L. cv. Nato, 1 week old). After 1 to 3 weeks (depending on plant species) in a greenhouse, the plants were evaluated for retardation of vegetative growth. A summary of growth retardation data appears in Table V.

Pinto bean plants were grown in the greenhouse until they had 1 to 3 trifoliate leaves. The stem was cut off at 2 or 3 cm above the primary leaves, and the branches in those leaf axils were removed. Spray solution/suspensions were prepared and applied in a manner similar to that described in Example 6. After 10-12 days in the greenhouse, any axillary branch growth was removed and weighted, and the percentage of growth control was calculated. A summary of these results appear in Table VI.

The above embodiments and examples illustrate the scope and spirit of the instant invention. These embodiments and examples will make apparent to those skilled in the art, other embodiments and examples within the scope of the present invention. Therefore, the instant invention should be limited only by the appended claims.