Composition and process for promoting the growth of crop plants

Compounds of the formula EQU Ar--X--C.sub.n H.sub.2n --R wherein Ar is (substituted) phenyl or naphthyl, X is oxygen, sulfur, SO or SO.sub.2, n is 1-3 and R is CN or C(NH.sub.2)NOR.sub.1, (wherein R.sub.1 is preferably hydrogen) are useful as safeners in crop protection.

The present invention provides compositions having activity as safeners and 
containing a compound of the formula I 
EQU Ar--X--C.sub.n H.sub.2n --R (I) 
in which 
Ar is phenyl optionally mono- or trisubstituted with chlorine or bromine, 
and/or monosubstituted with CF.sub.3, (C.sub.1 -C.sub.4)-alkyl, (C.sub.1 
-C.sub.4)-alkoxy, CN, NO.sub.2, phenyl, benzyl or phenoxy in 
para-position; or is benzyl or phenoxy which in turn are optionally mono- 
or disubstituted in the phenyl nucleus with chlorine, bromine, CN,NO.sub.2 
or CF.sub.3 ; or is naphthyl optionally mono- or disubstituted with 
chlorine, bromine, (C.sub.1 -C.sub.4)-alkyl, CN, NO.sub.2 or CF.sub.3 ; 
X is oxygen, sulfur, SO or SO.sub.2 ; 
n is 1, 2 or 3; 
R is CN or C(NH.sub.2)NOR.sub.1 ; 
R.sub.1 is H, (C.sub.1 -C.sub.4)-alkyl optionally substituted with 
chlorine, bromine, 
##STR1## 
R.sub.2 and R.sub.3 each are H or (C.sub.1 -C.sub.18)-alkyl or, together 
with the nitrogen atom, form a piperidino, pyrrolidino or morpholino 
radical; 
R.sub.4 is (C.sub.1 -C.sub.3)-alkyl, phenyl or benzyl; the latter two 
optionally being mono- or disubstituted in the phenyl nucleus with 
chlorine, bromine, CN, NO.sub.2, CF.sub.3 or (C.sub.1 -C.sub.3)-alkyl; 
R.sub.5 is (C.sub.1 -C.sub.4)-alkyl, phenyl or tolyl; and 
R.sub.6 is (C.sub.1 -C.sub.4)-alkyl. 
The compounds of the formula I in which R is C(NH.sub.2)--NOH can be used 
alternatively in the form of their metal salts or acid addition products. 
Preferred compositions are those which contain compounds of the formula I 
in which Ar is halophenyl, substituted phenoxyphenyl or naphthyl; X is 
oxygen; and 
##STR2## 
Examples of preferred individual compounds of the formula I are the 
following: 
4-chlorophenoxyacetonitrile and -acetamidoxime, 
.alpha.-(4-chlorophenoxy)propionitrile and -propionamidoxime, 
2,4-dichlorophenoxyacetonitrile and -acetamidoxime, 
3,4-dichlorophenoxyacetonitrile and -acetamidoxime, 
4-bromo-2-chlorophenoxyacetonitrile and -acetamidoxime, 
2,4,5-trichlorophenoxyacetamidoxime, 
.alpha.-(4-bromo-2-chloro)phenoxypropionitrile and -propionamidoxime, 
4-chloro-2-methylphenoxyacetonitrile and -acetamidoxime, 
2-chloro-4-methylphenoxyacetonitrile and -acetamidoxime, 
2,3-dichlorophenoxyacetonitrile and -acetamidoxime, 
2-naphthyloxy-acetonitrile and -acetamidoxime, 
.alpha.-(2,4-dichlorophenoxy)-propionitrile and -propionamidoxime, 
4-chloro-phenylthioacetonitrile and -acetamidoxime, 
3,4-dichlorophenylthio-acetonitrile and -acetamidoxime, 
3,4-dichlorophenylsulfinyl-acetonitrile and -acetamidoxime, 
3,4-dichlorophenylsulfonyl-acetonitrile and -acetamidoxime, 
O-acetyl-4-chlorophenoxy-acetamidoxime, 
O-(N-methyl-carbamoyl)-2,4-dichlorophenoxyacetamidoxime, 
O-(N-octadecyl-carbamoyl)-2,4-dichlorophenoxyacetamidoxime, 
O-(N,N-dimethyl-carbamoyl)-2,4-dichlorophenoxyacetamidoxime, 
O-p-toluenesulfonyl-2,4-dichlorophenoxyacetamidoxime. 
The compounds of the formula I as such are known and can be prepared 
according to methods known per se, or in an analogous manner; [J. Am. 
Chem. Soc. 69, 1690 (1947); Rocz. Chem. 45, 345 (1971); U.S. Pat. Nos. 
3,139,455; 3,547,621 and 3,644,523; French Pat. No. 1,572,961; Japanese 
Pat. Nos. 42-9944 and 72,37,5407. Some of them have been proposed for 
herbicidal application. 
Surprisingly, it has been observed that the compounds of the formula I, at 
low dosage, have growth-promoting and safening properties. Thus, they 
stimulate the growth of sprouting seeds and young plants, which becomes 
manifest by an enlarged root system, increased photosynthesis and faster 
development of the overground parts of the plants. Application of the 
compounds in a later stage of plant development results in increased 
fructification, earlier maturity and improved crop yield. Treatment of the 
seeds or seedlings with compounds of the formula I enables them to compete 
better with the non-stimulated weed flora. Furthermore, this treatment 
increases the chances of crop plants to grow under unfavorable conditions, 
for example on soils of low nutrient content. 
A further important application field for the compounds of the formula I 
resides in their property of reducing or suppressing phytotoxic side 
effects of pesticides, especially herbicides, on selective use in crop 
plants, thus extending considerably the application scope of usual 
pesticides. Compounds having the property of protecting crop plants from 
phytotoxic damage by pesticides without adversely affecting their 
pesticidal action are called antidots or saferners. 
Only a few example of herbicide antidots are hitherto known, e.g. 
N,N-diallyl-2,2-dichloroacetamide, [Can. J. Pl. Sci. 52, 707 (1972); 
German Pat. No. 2,218,097] or naphthalic anhydride [Weed. Sci. 19, 565 
(1971); U.S. Pat. No. 3,131,509], and some oxime ethers and esters (German 
Offenlegungsschrift No. 2,808,317), especially in combination with 
thiocarbamate herbicides [see also F. M. Pallos and J. E. Cassida, 
"Chemistry and Action of Herbicide Antidots", Academic Press, New 
York/London, 1978]. 
Among the herbicides the phythotoxic side effects of which can be reduced 
by means of compounds of the formula I are phenyl ureas, triazines, 
carbamates, thiolcarbamates, halo-acetanilides, substituted phenoxy- and 
phenoxyphenoxy-carboxylic acid esters, pyridyloxy-, benzoxazyloxy- or 
benzothiazolyloxy-phenoxycarboxylic acid esters, furthermore benzoic acid 
derivatives, dimedonoxime derivatives and dinitro-aniline derivatives. 
The following herbicides may be cited as examples: 
(A) Herbicides of the phenoxycarboxylic ester type such as 
.alpha.-[4-(2,4-dichlorophenoxy)-phenoxy]-propionic acid methyl ester, 
.alpha.-[4-(4-bromo-2-chlorophenoxy)-phenoxy]-propionic acid methyl ester, 
.alpha.-[4-(trifluoromethylphenoxy)-phenoxy]-propionic acid methyl ester. 
.alpha.-[4-(2-chloro-4-trifluoromethylphenoxy)-phenoxy]-propionic acid 
methyl ester, 
.alpha.-[4-(2,4-dichlorobenzyl)-phenoxy]-propionic acid methyl ester, 
.alpha.-[4-(4-trifluoromethylphenoxy)-phenoxy]-2-pentene-1-carboxylic acid 
ethyl ester, 
.alpha.-[4-(3,5-dichloropyridyl-2-oxy)-phenoxy]-propionic acid ethyl ester, 
.alpha.-[4-(6-chlorobenzoxazol-2-yl-oxy)-phenoxy]-propionic acid ethyl 
ester or 
.alpha.-[4-(6-chlorobenzothiazol-2-yl-oxy)-phenoxy]-propionic acid methyl 
ester. 
(B) Chloroacetanilide herbicides such as 
N-Methoxymethyl-2,6-diethyl-chloroacetanilide, 
N-[3'-methoxyprop-(2')-yl]-2-methyl-6-ethyl-chloroacetanilide, 
N-(3-methyl-1,2,4-oxdiazol-5-ylmethyl)-chloroacetic 
acid-2,6-dimethylanilide. 
(C) Thiocarbamates such as 
S-ethyl-N,N-dipropylthiocarbamate or 
S-ethyl-N,N-diisobutylthiocarbamate. 
(D) Dimedon Derivatives such as 
2-(N-ethoxybutyrimidoyl)-5-(2-ethylthiopropyl)-3-hydroxy-2-cyclohexene-1-on 
e or 
2-(1-allyloxyiminobutyl)-4-methoxycarbonyl-5,5-dimethyl-3-oxocyclohexenol. 
(E) Herbicides of the dinitroaniline type such as 
N,N-di-n-propyl-2,6-dinitro-4-trifluoromethylaniline. 
For application, the compounds of the formula I can be formulated with 
usual auxiliaries to give dusts, wettable powders, dispersions, 
emulsifiable concentrates etc., which contain from 2 to 80% of active 
substance, and which are used as such (dusting agents, pellets) or 
dissolved or dispersed before use in a solvent (water). 
The quantitative ratio of antidot to herbicide may vary within wide limits 
of from 0.01 to 10 parts of antidots per part of herbicide. The optimum 
herbicide/antidot proportion depends on the particular type of herbicide 
and antidot and the kind of plant population to be treated, and can be 
determined according to the circumstances by corresponding tests. 
Main application fields for the antidots of the invention are grain farming 
(wheat, rye, barley, oats, rice, corn, sorghum), furthermore crop farming 
of cotton, sugar beets, cane sugar, soybeans and the like. 
Depending on their properties, the compounds of the invention can be used 
for pretreating (disinfecting) the seeds or cuttings of the crop plants, 
they may be applied to the furrows before sowing or pre- or post-emergent 
in the form of tank mixtures (the pre-emergence process including 
treatment of the area under cultivation before and after sowing). In 
principle, the antidot can be used before, after or simultaneous with the 
herbicide; preferred, however, is simultaneous application in the form of 
tank mixtures or ready-for-use formulations. 
The following examples illustrate the invention.