DD153756A5 - FORMULATIONS FOR AGRICULTURAL PURPOSES - Google Patents

Abstract

The invention relates to plant growth-regulating formulations based on phenyliminothiadiazolines. The aim of the invention is to enrich the state of the art with new growth regulators. These are effective in different crops. They contain as active ingredient a compound of the formula I in which the radicals have, for example, the following meaning: R 1 and R 2 are hydrogen or lower alkyl, R 3 is lower alkyl and R 4 is hydrogen, halogen or lower haloalkyl.

Description

 2509

Formulations for agricultural use Field of the invention.

The present invention relates to agricultural formulations containing novel phenyliminothiadiazolines which are effective as plant growth regulators.

Characteristic of the known technical solutions

It has been known that many chemical compounds act on plant growth. Frequently, a change in plant form, leaf curvature and folding, growth inhibition, blotch waste, rooting stimulation in cuttings, and other effects have been observed. It is usually necessary to use the growth-regulating compounds in a relatively small amount in order to obtain very clear growth-regulating effects. At higher levels, one usually obtains selective vegetation destruction, which is greater in some plant species than in others. In fact, growth regulators have been used more as selective herbicides than for other purposes, because in many cases the growth regulating effects achieved by these substances have found no other practical application. Such compounds are described, for example, in Ulimanna Encyklopadie der technischen Chemie / 4th Edition, Volume 12, page 614 »

Object of the invention

57 842 12

 *> 2-

2O

Bs is the object of the invention to enrich the state of the art with new • valuable growth regulators «

Explanation of the essence of the invention

The invention has for its object to provide new growth regulators based on Phenyliminothiadiazolinen.

This class of growth regulating compounds exhibits a number of useful effects which vary from plant species to plant species. For example, some of these compounds promote shoot formation (branching or planting) in oats and certain other grasses and increase fruit set with simultaneous destruction of Digitaria sanguinalis (crab grass).

According to the invention, there is thus provided a formulation for agricultural purposes which contains as active ingredient 0.1 to 95% by weight of a novel phenyliminothiadiazoline of general structural formula I.

(D

R-

contains, in which mean

R is hydrogen or one to four substituents selected from Cl, nitro, lower alkyl and lower alkoxy,

R is hydrogen, lower alkyl, lower alkoxyalkyl, lower alkenyl, lower haloalkyl or an agriculturally acceptable cation,

57 842 12

R- Wasserstof £ _s .niederes _s alkyl lower alkenyl, lower alkynyl lower haloalkyl or benzyl and

IU "is hydrogen or at least one substituent selected from 3 _s 4- ~ _TTimethylen? P, Gl, Br CP ₅ ,,, lower dialkylamino, lower alkylcarbonyl, _Iitro? Lower alkyl.

-ι-. ' 22 2 50 9

and lower alkoxy with the further condition that at least one ortho site is unsubstituted. ',

The terms "lower alkyl", "lower alkoxy", etc., as used above mean C ..- Cg-alkyl, etc.

The method of regulating plant growth, including the eradication of undesired vegetation, is by acting on plants, either by applying to the plants an effective amount of a compound of the aforementioned class of compounds either on the seed, the soil or directly on the plants.

Synthesis of growth regulators

The novel compounds according to the invention can be prepared by procedures based on the following illustrative syntheses. All temperatures are in degrees C.

The thiadiazoline compounds according to the invention are used

i

conveniently prepared by ring closure of a class of thiosemicarbazides which can be prepared by methods which are illustrated below by the specific procedures.

1. Synthesis of methyl hydrogen phthalate

300 ml of methanol are added all at once to 148 g (1.00 mol) of phthalic anhydride and heated the resulting suspension under reflux conditions and stirring for 36 hours; during heating occurs solution. The solvent is removed and the product is recrystallized from a mixture of ethyl acetate and hexane to give 114.6 g of the title compound (lit .: Beilstein, 9.797, F 82.5 °, 84 °).

2. Synthesis of methyl phthaloyl chloride

110.0 g (0.611 mol) of methyl hydrogen phthalate and 77.4 g (0.650 mol) of thionyl chloride are mixed in 200 ml of chloroform, keeping the temperature below 30 °. After stirring for 2 hours at room temperature, the system is refluxed for five hours. The solvent is distilled off under reduced pressure; the crude product (120.9 g) is used without further purification (Lit .: Beilstein, 9., 797, no constants) »

3. Synthesis of 1- (2-C arbome thoxybenzoyl) -2-methyl-4- phe_nyl .l ~ ß-.th ios emi carba zid

A solution of 45.3 g (0.25 mol) of 2-methyl-4-phenyl-3-thiosemicarbazide and 19.8 g (0.25 mol) of pyridine in 800 ml of 1,2-dimethoxyethane is stirred at room temperature and added 49.8 g (0.25 mol) of methyl phthaloyl chloride in 100 ml of 1,2-dimethoxyethane was added dropwise over a period of two hours. The resulting reaction mixture is stirred for 16 hours at room temperature. At the end of this time, pour the contents of the flask into ice-water. The resulting solid is collected to give 73.3 g (85%); F 153.5-154 ° C.

The general procedure for preparing the phenyliminothiadiazolines invention consists in the acid-promoted ring closure dehydration reaction of a compound of general formula II

0 · H

2 2 2 5 0 9

Concentrated sulfuric acid, trifluoroacetic anhydride and thionyl chloride have been found to be effective under the acidic reagents and it appears that the obtained

2

results strongly depend on the nature of the substituents R, - R

4 and R depend.

So far as has been stated, the best general ring closure reaction involves the use of concentrated sulfuric acid in conjunction with chloroform as a diluent, as demonstrated by the following preparation of 5- (2'-carboxyphenyl) -2- (3'-fluorophenylimino) -3- methyl-l, 3,4-thiadiazole-4-one is illustrated.

In a 3-liter three-necked flask equipped with a mechanical stirrer, thermometer, reflux condenser and dropping funnel, immersed in an ice bath, is stirred a solution of 84.3 g (0.243 mol) of 1- (2-carboxybenzoyl ) -4- (3'-fluorophenyl) -2-methyl-3-thiosemicarbazide (F 155-7 ° C) in 1750 ml of chloroform, while slowly adding 4O4 <g of concentrated sulfuric acid over a period of 30 minutes, taking the Temperature keeps below 25 ° C. A clear two-phase solution is obtained after adding about half of the sulfuric acid. Stirring is continued for a further 2 hours at room temperature and the contents are carefully poured into a mixture of 800 ml of concentrated ammonium hydroxide and 2 kg of ice. The resulting two-phase system is stirred for 15 minutes and separated. The organic phase is discarded and the aqueous phase is stirred, cooled to 20 ° C and acidified with 370 ml of glacial acetic acid to a pH of 3, to obtain a solid precipitate. The slurry is stirred for 30 minutes at 10 ° C and filtered. The filter cake is rinsed with two 300 ml portions of cold water, then re-slurried in 750 ml of cold water, filtered and dried in air to give 65 g (81% yield) of a product having a melting point of 207-8 ° C receives.

57 842 12

Two specific procedures are given below which illustrate a small scale laboratory method

To 25 ml of H ₉ SO, is added 5 g (0.015 mol) of 1- (2 ^f ~ Carba2: ybenzoyl) "2" methyl-4 ~ phenyl ~ 3-thiosemicarbazide added "laughing stirring for 30 minutes at room temperature there was crushed ice The resulting acid solution is washed with ethyl acetate and then adjusted to pH 8 with concentrated M ₂₁ OH. The precipitate is collected, washed with aqueous potassium chloride and dried, 1 _s 0 g (F 223 to 225 ⁰ C). ''

Using the same conditions as described above are obtained from 5j0 1 g ^ (2 ^f ~ Carbö.methQxybenzoyl) 2-methyl ^"p 4" Phenyl ~ 3 "thiosemicar'bazid _S 1 3 g of the desired product, P 96 to 98 ⁰ Co

Compounds prepared by the procedures described above are summarized in the following Table I. As can be seen from Formula I, the radicals R ¹ and R ¹ can occupy any free position on the ring; this applies in particular to R in the following compounds Hr "3804 and 4016 *

According to the invention, compounds which are preferably used as the active ingredient include the compounds which are given in Table 1 below.

TABLE I

Compounds of the formula I

Verb no. R ¹ R ² R ³ R ⁴ F ⁰ C Remarks on usability I 'I 2812 H H CH ₃ H 223-225 promotes the sprouting of oats I 31O7 H H\ CH ₃ 3-F 208-209 promotes sprouting i> oi> oats 2 2 2 5 3291 3356 3357 , H H H CH ₃ H CH ₃ CH ₃ CH ₃ H 4-F 4-F 96-98 195-200 60-61 increased fruit set promotes oat sprouting. O 3373 H CH ₃ CH ₃ 4-OCH ₃ oil (D 3498 Ci ₄ CH ₃ CH ₃ H 142-146 3499 Ci ₄ allyl CH ₃ H 90-93 3801 H H CH ₃ 2-CH ₃ 141-143 increased fruit set 3802 H H ti 2-F 201-202 promotes sprouting

oats

TABLE I (continued)

Verb. Wr.

R * F ⁰ C 2-F 119-121 4-CF ₃ 87-88 4-KO ₂ 101-102 3-Cl oil 4-CH ₃ 73-75 3-NO ₂ 178-180 3-CF - 4-Cl 157-158 2-CH, -3-C1- 147-148 2-Cl 194-195 H 194-195 2-CEL · - 6-Cl 183-185 2, 5-dimethyl 164-165 H 83-85 4-COCH-, 197-198

Remarks on usability

3803

33O4 H 384O H 38 41 ' H 3842 H 3902 H

3903 39O4

3961

39 65 4Ol 6

CH,

CH-CH-CH-CH-

 H

3905 H H 3906 3-NO ₂ H 3908 H H

^C 2 ^H 5

CH. increased fruit set and sprout formation in oats increased fruit set increased fruit set increased fruit set increased fruit set

increased oat sprouting

increased fruit set

increased sprouting in oats.

"" with oats

increased fruit set

increased sprouting of oats

TABLE I (continued)

F ⁰ C Comments on usability

4058 H allyl CH ₃ H Oil 4059 H H ; Il 4-N (C ₂ H ₅ J ₂ 175-177 4104 ' H H Il 2,4-dichloro 168-170 4114 ' H H Il 3-CH ₃ 160-162 Alles! H H Il 3-Br 164-165 4175 H H Il 4-CF ₃ 211-213 4177 H CH ₃ M 4- (CH ₂ J ₃ CH ₃ oil 4266 H CH ₃ Il 3-CH ₃ semisolid 4271 H H Il 3,4-trimethylene 180-182

increased fruit set and shoot formation

increased sprouting

increased fruit set and shoot formation

increased sprouting

increased fruit set and shoot formation

increased fruit set and sprouting in oats increased fruit set

O] Ό CO

  Ir

' {Ρ% ί * ^ ΐ ί * ί · F "*

- 3> Q - <£. d, d D

Application of growth regulators

In the case of highly active compounds, phytotoxic effects often occur in Ap.plikati.on before emergence and after emergence. These effects can be demonstrated by the following exemplary methods.

Application before ed on s

About 6.35 cm (2.5 in.) Deep paper cups are filled with soil, sprayed with aqueous spray mixtures at a rate of 5.61 kg of active ingredient per hectare (5 lbs / acre) of the sprayed area, with six species thereof Plant seed is seeded and then covered with about 6.35 mm (1/4 in ») soil.'The spray mixtures are prepared by dissolving the right amount of the wax-tumxsegulator compound in 15 ml of acetone, 4 ml of a solvent / emulsifier Mixture which consists of 60% by weight of a commercially available polyoxyethylated vegetable oil emulsifier (96% by weight of active ingredient, Emulphor EL-719 "), 20% by weight of xylene and 20% by weight of deodorised kerosene, and then the total volume by addition of warm water to 60 ml, 21 days after sowing and treatment the plants are tested and the plant damage is assessed according to the following schedule:

Degree of effect:

0 = no effect

1 = slight effect, plants recovered

2 = moderate effect, damage 26 to 75%

3 = serious effect, damage 76 to 99 %

of the foliage

.4 = maximum effect (all plants enter).

Several types of plants are grown in potting soil within

'- * -:. 22 2 50 9

Polystyrene dishes are grown and tomatoes are grown in 10.16 cm (4 in.) Pots in the greenhouse. Aqueous spray formulations are prepared and the cultured plants are sprayed at a spray volume of 60 gallons / acre and application rate of 5 lbs / acre The spray mixtures are produced in the aforementioned manner. For comparison, plants are further sprayed at 561.3 Ltr / ha with a spray mixture containing no growth regulator. In turn, plant damage is assessed according to the scheme outlined above and the following effects of growth regulation are obtained in trials both before and after emergence:.

effect Abbreviation in the tables Shaping effect on. new growth F epinasty e Turn wax reduction G necrosis N no emergence K Chlorosis C

Table II below reports the observations of pre- and post-emergence herbicidal and growth regulator effects which result from the use of the growth regulators of the invention according to the above procedures.

TABLE II

Effects of compounds on plant species

Verb c no.

2812 3107 3291 3356 3357 3373 3498 3499 3801 3802 3803 3804 3840 3841 3842 3902 3903 3904 3905

Effect before departure

CO

 Ο K>

V) Ott

W V 'r> CJ

05 3 CO

5 δ

K K4 F3G3

K4 '

Fl

K2G1

K

F2G2

Fl

Fl

F2G2

F3G2

FLGL

Fl

Fl

K3G3 F2G2 F2G2

K

Fl

K

K4

FLGL

FLGL

F2G1

F2G1

F2G2

Fl

F

F2

ca · "Co 'τ * * F3G3 F3G3 F3G3 F3G3 F3G3 F3G3 F3G3 F3G2 F2G1 F 2Gl 0 0 F2 Fl F3G3 F3G3 F3G3 F3G3 F3G3 F2G2 K4 F3G2 Fl 0 F3G2 F3G2 K4 F3G2 K4 F3G2 Fl 0 F3G3 F3G2 F3G2 FIGL

n / A

53F1 F3G3 Fl

F3G2

F3G3

F3G3

F2G1

F2G1

F3G2

F3G2

F3G3

F3G2

F2G2

K4

F3G3

FLGL

F3G2

Fl

Fl

F3G2

F3G3

F2G2

F2G1

F2G1

F2G2

F3G2

F2

F2G2

F2G2 effect after leakage

G CS Si ss

CO CO H U.5 ^ u

F2G1 N2G2 FlGl

F 2Gl FlGl 0 0

F2G3

Fl N IG 2

F3G2 F2 F2 F'3G1 F3G2 NLGI NLGI N1G2 N3G3 F2G3 F3G2 Fl NlFl F3G3 F2 F2G3 Fl F2G2 F3G2 F4 F2G1 Fl N1F2 F2G3 F2G1 Fl gl 0 F2G1 Fl Nl F2G2 F2 N1G2 0 N IG 2 GlFl 0 F 2 N1G2 F2G2 F 2 Fl F2 NlFl Fl N4 F2 Fl F2G1 Eq F3G1 F 2 N1G2 N2F1 F3 0 F3G2 0 F2G1 0 Fl C2G2 F2G1 F2G2 Fl F 3Nl F3G1 FLGL FLGL F2G1 F2 F3G3 F2G1 F2G2 F3G3 F2G2 ' F2G1 0 Fl F3G1 F2 F3G3 Fl F2G2 F3.G3 F3G1 F3G2 FLGL FLGL F3G3 F2G1

ir

vs -2 50 9

TABLE II (continued)

Effects of compounds on plant species

Verb.

Effect before leakage effect after leakage

"5

• r »6)

ο o

• v> (O (0

O

to

s to

s>

OO ö)

ca (ο 0 ßa -.j  Ρ Ö ΙΟ • rl O I ⁴ «ο; to O O F2G1 F2 F2G2 F.3G2 Fl 0 F3G3 O gl O. F3G2 K2 F3G3 F3G3 F2G2 F2G2 K4 F3G2 F2G1 F2G2 FLGL F3G3 F3G3 F2G2 F2G2 F2G2 F3G2 F3G3 F3G2 F3G3 Fl F3G3 O O O G2F1 F2 F2G1 F3G1 FLGL F3G2 F3G1 F3G3 F3G3 F3G3 F3G3 F3G3 F2G1 F2G2 Fl F3G3 F3G2 F3G3 F3G3 F3G3 F2G2 F3G3 F2G1 FLGL F2G2 F2G2 F3G3 F3G3 F2G2 F3G3 F3G3 F3G3 F3G2 F3G2 F3G3 F3G3

6a

to

to

o l-§

ν: w et; co

(O

• rl S

Co <i

O Ci. * -> (3 Cd OS

ca

3906 3907 3908 3961

3965 4016 4058 4059 4104 4114 4171 4175 4177 4266 4271

Fl

F2G2 0 F3G2

F2G1

FLGL

F3G2

Fl

F3G1

K4

F2G1

F3G2

FLGL

F3G2

F3G2

F 2 Eq

Fl 0 0 F2G1 Fl Fl FLGL F3G2 N4 F2 0 0 0 N2 0 F3G3 FLGL F2 N4 F3G1 F3G2 Fl F2C1 F3G3 F3 F3G2 F2G2 F2G1 FLGL F3 F3G2 F2G2 F2G1 F3G2 F2 F3G1 FLGL FLGL F2G1 F 2 * FLGL Fl N4 N 4 F2 F3G3 F2G2 N4 N4 F3G2 F3G1 F2 F2G1 F3G3 F3 F3G2 F2 F2G2 F3G2 F3G1 F2 F2 F2 F2 F2 F3G3 F2G2 F2G1 F3G3 F3G1 F3G2 F2G1 FLGL F3G2 F3

The use of numerous growth regulator compounds can be demonstrated by the treatment of soybean (soybean max) increasing the number of seed pods and by the treatment of tomato plants (Lycopersicum esculentum) increasing the fruit set "In an exemplary experiment, soy max (Evans-Abart) and Lycopersicum esculentum (Tiny Tim-Abart) in 10.16 cm (4 in.) Pots (one plant per pot). The pots are planted with greenhouse soil (2 parts good top soil), 1 1/2 parts 'construction sand', 1 1/2 parts peat, fertilized with 2,97 kg (5 lbs.) 12-12-6- Fertilizer and 2.91 kg / m ³ (5 lbs./cu.yd.) Of finely ground limestone). Aqueous spray preparations are prepared and the plants placed in the pots are sprayed at a spray volume of 374.2 ltr./ha (40 gallons / acre) and application levels of 1120, 280 'and 70 g / ha (16, 4 and .1 oz ./acre) sprayed. The spray mixtures are prepared by dissolving the correct quantity of the growth regulator compound in 15 ml of acetone, adding 2 ml of a solvent / emulsifier mixture consisting of 60% by weight of a commercial polyoxyethylated vegetable oil emulsifier (9-6% by weight of active compound, Emulphor EL-719), 20% by weight of xylene and 20% by weight of deodorized kerosene, and then the total volume by adding a 0.155% by weight aqueous solution of a liquid nonionic dispersant (90% by weight of active ingredient Trirnethylnonylpolyäthylenglykoläther, Tergitol TMN-IO) brings to 80 ml. For each application amount, zv / ei specimens are sprayed. "For purposes of comparison, plants are also sprayed at 374.2 ltr./ha (40 gallons / acre) with water. The number of seed pods and fruits as a percentage of the arithmetic mean of the numbers of untreated plants is determined within about 3 weeks after the spray treatment. The results are shown in Table II. The sharpness of growth »

- «2225 0 9

regulatory effect on plants is assessed using a scale ranging from O to IO; the rating numbers are also shown in Table III.

TABLE III

Growth regulation effects against two plant species

Applika Soy max Wachsturns- 5.5 lycopersicum growth tion volume requlier- 2.0 esculentum regulier connects g / ha Number of pates (1), effect (2) 0 fruit effect (2) Droppings (oz / acre). % compared 6.5 number '(1) No. to the unbehan- 2.0 % in comparison 1120 (16) damaged plants 1 to the unbehan- 7.5 28.0 (4) 3.5 damaged plants 4.5 2812 70 (1) 174 ^a 1.0 400 ^b 1 1120 (16) 143 0   255 6 280 (4) 1Ο9 7.5 182 4 ' 31O7 7O (1) 138 ^a 5 136 ^C [1 1120 (16) 112 4 245 5.5   280 (4) 93 7 218 1.5 3291 7O (1st) 143 1.5 136 ^C 0 1120 (16) 115 1 27 4.5 280 (4) 110 109 2 3801 70 (1) 14Ο 700 O 1120 (16) 129 900. 7 280 (4) 136 200 4.5 3802 7O (1) 1Ο5 1100 3.5 136 800 122 800

  TABLE III (cont'd) 3803

3804 3840 3841 3842

'' IO

4266 1120 (16). 114 5.5 175 4.5 CFI

(1) control = 100. * '

(2) Scale rating from 0 (no effect) to 10 (complete kill)

a smaller pods · ·,

b malformed fruit ·

c stimulated growth

1120 280 ¹ 70 (16) (4) (D 119 87 94 5 2 0,5 1120 280 70 (16) (4) (D 143 115 87 8 5.5 3.5 1120 280 7O (16) (4) (D 84 101 105 1.5 O, 5 O 1120 280 70 (16) (4) (D 119 • 108 105 7.5 5.5. 1.5 1120 280 70 (16) (4) ( 133 108 119 7.5 3.5 0.5 1120 280 70 (16) (4) (D 138 121 125 1.5 O 0 1120 280 70 (16) (4) (D 114 114 97 5.5 3 1.5

800 3.5 700 3 400 ( 0.5 900   6.5 700 3 800 1 200 O 200 0 100 0 700 5 800 4 500 1 700 6 800 2 800 1.5 214 3.5 182 2 118 1 175 4.5 225 2 113 • 1

The information given in the tables provided here make it possible for a person skilled in the art to make a selection of the growth regulator compounds according to the invention and to get a certain idea of the application amounts depending on the desired amount. Effect "It can be seen, for example, that complete killings of certain plant species occur at such high application rates as 5.61 to 11.22 kg / ha (5 to 10 lbs./acre), while providing beneficial effects against live plants Application levels of 1.12 kg / ha (1 lb./acre) or less.

The growth regulator compounds are usually applied in combination with inert carriers or diluents, such as in aqueous spray preparations, granules and dusts, in accordance with conventional practice. An aqueous spray preparation is usually prepared by mixing a wettable powder or an emulsifiable concentrate of a growth regulator with a relatively large amount of water to form a dispersion.

Wettable powders are intimate, finely divided mixtures of growth regulator compounds, inert solid supports and surfactants. The inert solid support is usually selected from the group consisting of attapulgite clays, kaolin clays, montmorillonite clays, diatomaceous earths, finely divided silica and purified silicates. Effective surfactants which have wetting, permeation and dispersibility properties are usually in proportions of 0.5 in wettable powder formulations. to about 10 wt .-% present. Surfactants commonly used for this purpose include the sulfonated lignins, naphthalenesulfonates and condensed ones

- «· .- 2 2 2 5 0 9

Naphthalenesulfonates, alkylbenzenesulfonates, alkyl sulfates and nonionic surfactants, such as ethylene oxide condensation products with alkylphenols.

Emulsifiable concentrates of the growth regulator compounds in each case comprise a solution of the growth regulator compound in a liquid carrier which is a mixture of a water-immiscible solvent and surfactants such as emulsifiers. Useful solvents include aromatic hydrocarbons such as xylenes, alkylnaphthalenes, petroleum distillates, terpene solvents, ether alcohols, and organic ester solvents. Suitable emulsifiers, dispersants and wetting agents can be selected from the same classes of products as are used to formulate wettable powders.

In general, the growth regulator formulations conveniently contain from 0.1% to 95% by weight of a compound of formula (I) and from 0.1% to 75% by weight of a carrier or surfactant. However, the direct application to plant seeds prior to planting may in some cases be made by mixing the powdered solid growth regulator with the seed to obtain a substantially uniform coating which is very thin and only 1 or 2% by weight (or less), based on the weight of the seed. In most cases, however, a non-phytotoxic solvent, such as methanol, is used as a carrier to facilitate uniform distribution of the growth regulator on the surface of the seed.

If a compound is to be applied to the soil, as is the case with an application before emergence, granular preparations are sometimes more practical than spraying.

Xi

so - 2 2 2 5

Preparations. A typical granule comprises the growth regulator compound dispersed in an inert carrier, e.g. in coarsely ground clay or clay which has been converted to granules by treating a rolling bed of the powdered material with a small amount of liquid in a granulating drum. In the usual process for the preparation of granules, a solution of the active ingredient is sprayed onto the grains while they are agitated in a suitable mixing device, after which the grains are dried with constant air flow. ,

Claims (1)

57 842 12 zl - # t.- "22 2 50 9 invention claim 1 »Formulation for agricultural purposes, characterized in that it contains as active ingredient 0.1 to 5% by weight of a phenyliminothiadiazoline of the formula IR ¹ (D contains, in which mean R is hydrogen or one to four substituents selected from Cl, nitro, lower alkyl and lower alkoxy, RV / oxygen, lower alkyl, lower alkoxyalkyl, lower alkenyl, lower haloalkyl or an agriculturally acceptable cation _; R- ^ is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, lower haloalkyl or benzyl and R ^ "V or at least one substituent selected from 3i4 ~ Trimethylenj ufitro, Cl, P, Br, CF ,,, never dialkylamino, lower alkylcarbonyl, lower alkyl and lower alkoxy with the further condition that at least one ortho Position is unsubstituted,