Use of derivatives of (1-cyanocyclopropyl)phenylphosphinic acid, esters thereof and/or salts thereof for enhancing tolerance in plants to abiotic stress

1. A method for increasing tolerance in plants to abiotic stress, comprising:

applying an effective amount of a derivative of (1-cyanocyclopropyl)phenylphosphinic acid of the formula (I), or an ester or salt thereof, to the plants;

wherein formula (I) is:

where:

R 1 is:

halogen; or

a branched or unbranched alkyl, cycloalkyl, alkenyl, alkynyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkoxyalkyl, hydroxyalkyl, alkoxyalkenyl, alkylthio, haloalkylthio, alkylsulfinyl, alkylsulfonyl, haloalkyl, alkoxy, haloalkoxy, carboxyl, alkoxycarbonyl, aminocarbonyl which is optionally mono- or disubstituted; or

cyano, amino, or nitro;

R 2 is hydrogen, or a branched or unbranched alkyl, cycloalkyl, cycloalkylalkyl, alkenyl, alkenylalkyl, alkynyl, alkynylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkoxyalkyl, hydroxyalkyl, alkoxyalkenyl, hydroxyalkenyl, alkylthioalkyl, haloalkyl, alkylaminoalkyl, bisalkylaminoallyl, or cycloalkylaminoalkyl; and

n is 0, 1, 2, 3, 4, or 5.

2. The method of claim 1 , wherein:

R 1 is a halogen, or a branched or unbranched alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxyalkyl, alkylthio, haloalkyl, alkoxy, carboxyl, or alkoxycarbonyl;

R 2 is hydrogen, or a branched or unbranched alkyl, cycloalkyl, alkenyl, alkynyl, arylalkyl, heteroaryl, heteroarylalkyl, alkoxyalkyl, hydroxyalkyl, hydroxyalkenyl, or haloalkyl; and

n is 0, 1, 2, 3, 4, 5.

3. The method of claim 1 , wherein:

R 1 is a halogen, or a branched or unbranched (C 1 -C 6 )-alkyl, (C 3 -C 7 )-cycloalkyl, (C 2 -C 4 )-alkenyl, (C 1 -C 4 )-alkynyl, (C 1 -C 4 )-alkoxy-(C 1 -C 4 )-alkyl, (C 1 -C 4 )-alkylthio, halo-(C 2 -C 4 )-alkyl, (C 1 -C 4 )-alkoxy, carboxyl, or (C 1 -C 4 )-alkoxycarbonyl;

R 2 is hydrogen, or a branched or unbranched (C 1 -C 6 )-alkyl, (C 3 -C 7 )-cycloalkyl, (C 2 -C 6 )-alkenyl, (C 2 -C 6 )-alkynyl, (C 1 -C 4 )-alkoxy-(C 1 -C 4 )-alkyl, or halo-(C 1 -C 6 )-alkyl; and

n is 0, 1, 2 or 3.

4. The method of claim 1 ;

wherein an effective amount of a salt of formula (II), of the derivative of formula (I), is applied to the plants;

wherein formula (II) is:

where:

the cation (M) is:

(a) an ion of an alkali metal; or

(b) an ion of an alkaline earth metal; or

(c) an ion of an transition metal; or

(d) an ammonium ion in which one, two, three or all four hydrogen atoms are optionally replaced by identical or different radicals from the group of (C 1 -C 4 )-alkyl, hydroxy-(C 1 -C 4 )-alkyl, (C 3 -C 6 )-cycloalkyl, (C 1 -C 4 )-alkoxy-(C 1 -C 4 )-alkyl, hydroxy-(C 1 -C 4 )-alkoxy-(C 1 -C 4 )-alkyl, (C 1 -C 6 )-mercaptoalkyl, phenyl or benzyl, where the aforementioned radicals are optionally substituted by one or more identical or different radicals from the group consisting of halogen, nitro, cyano, azido, (C 1 -C 6 )-alkyl, (C 1 -C 6 )-haloalkyl, (C 3 -C 6 )-cycloalkyl, (C 1 -C 6 )-alkoxy, (C 1 -C 6 )-haloalkoxy and phenyl, and where in each case two substituents on the nitrogen atom together optionally form an unsubstituted or substituted ring; or

(e) a phosphonium ion; or

(f) a sulfonium ion or sulfoxonium ion; or

(g) an oxonium ion; or

(h) an optionally singly or multiply fused, and/or (C 1 -C 4 )-alkyl-substituted, saturated or unsaturated or aromatic, N-containing heterocyclic ionic compound having 1-10 carbon atoms in the ring system; and

z is 1, 2, or 3.

5. The method of claim 1 ;

wherein an effective amount of a salt of formula (II), of the derivative of formula (I), is applied to the plants;

wherein formula (II) is:

where:

the cation (M) is

(a) an ion of an alkali metal; or

(b) an ion of an alkaline earth metal; or

(c) an ion of an transition metal; or

(d) an ammonium ion in which one, two, three or all four hydrogen atoms are optionally replaced by identical or different radicals from the group of (C 1 -C 4 )-alkyl, hydroxy-(C 1 -C 4 )-alkyl, (C 3 -C 4 )-cycloalkyl, (C 1 -C 2 )-alkoxy-(C 1 -C 2 )-alkyl, hydroxy-(C 1 -C 2 )-alkoxy-(C 1 -C 2 )-alkyl, (C 1 -C 2 )-mercaptoalkyl, phenyl or benzyl, where the aforementioned radicals are optionally substituted by one or more identical or different radicals from the group consisting of halogen, nitro, cyano, azido, (C 1 -C 2 )-alkyl, (C 1 -C 2 )-haloakl, (C 3 -C 4 )-cycloalkyl, (C r C 2 )-alkoxy, (C 1 -C 2 )-haloalkoxy and phenyl, and where in each case two substituents on the nitrogen atom together optionally form an unsubstituted or substituted ring; or

(e) a quaternary phosphonium ion; or

(f) a tertiary sulfonium ion or sulfoxonium ion; or

(g) a tertiary oxonium ion; or

(h) a cation selected from the group consisting of pyridine, quinoline, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2,4-dimethylpyridine, 2,5-dimethylpyridine, 2,6-dimethylpyridine, 5-ethyl-2-methylpyridine, piperidine, pyrrolidine, morpholine, thiomorpholine, pyrrole, imidazole, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU); and

z is 1, 2 or 3.

6. The method of claim 1 ;

wherein the abiotic stress conditions correspond to one or more conditions selected from the group consisting of drought, aridity and lack of water, cold and hot conditions, osmotic stress, waterlogging, elevated soil salinity, elevated exposure to minerals, ozone conditions, strong light conditions, limited availability of nitrogen nutrients, limited availability of phosphorus nutrients, and shade avoidance.

7. The method of claim 1 ;

wherein the plants are selected from the group consisting of useful plants, ornamental plants, turfgrass types, and trees; and

wherein the application is to the plants, to the seed thereof, or to the area on which the plants grow.

8. The method as claimed in claim 1 ;

wherein the resistance of the plants thus treated to abiotic stress is increased by at least 3% compared to untreated plants under otherwise identical physiological conditions.

9. The method of claim 4 , wherein:

(a) the ion of the alkali metal is lithium, sodium, or potassium;

(b) the ion of the alkaline earth metal is calcium or magnesium;

(c) the ion of the transition metal is manganese, copper, zinc, or iron;

(f) the sulfonium ion or sulfoxonium ion is tri-((C 1 -C 4 )-alkyl)sulfonium or tri-((C 1 -C 4 )-alkyl)sulfoxonium; and

(g) the oxonium ion is tri-((C 1 -C 4 )-alkyl)oxonium.

10. The method of claim 5 , wherein:

(a) the ion of the alkali metal is lithium, sodium, or potassium;

(b) the ion of the alkaline earth metal is calcium or magnesium;

(c) the ion of the transition metal is manganese, copper, zinc, or iron;

(e) the quaternary phosphonium ion is a tetra-((C 1 -C 4 )-alkyl)phosphonium or tetraphenylphosphonium, where the (C 1 -C 4 )-alkyl radicals and the phenyl radicals are optionally mono- or polysubstituted by identical or different radicals selected from the group consisting of halogen, (C 1 -C 2 )-alkyl, (C 1 -C 2 )-haloalkyl, (C 3 -C 4 )-cycloalkyl, (C 1 -C 2 )-alkoxy and (C 1 -C 2 )-haloalkoxy;

(f) the tertiary sulfonium ion or sulfoxonium ion is a tri-((C 1 -C 4 )-alkyl)sulfonium or triphenylsulfonium, where the (C 1 -C 4 )-alkyl radicals and the phenyl radicals are optionally mono- or polysubstituted by identical or different radicals selected from the group consisting of halogen, (C 1 -C 2 )-alkyl, (C 1 -C 2 )-haloalkyl, (C 3 -C 4 )-cycloalkyl, (C 1 -C 2 )-alkoxy and (C 1 -C 2 )-haloalkoxy, or tri-((C 1 -C 4 )-alkyl)sulfoxonium; and

(g) the tertiary oxonium ion is a tri-((C 1 -C 4 )-alkyl)oxonium, where the (C 1 -C 4 )-alkyl radicals are optionally mono- or polysubstituted by identical or different radicals selected from the group consisting of halogen, (C 1 -C 2 )-alkyl, (C 1 -C 2 )-haloalkyl, (C 3 -C 4 )-cycloakl, (C 1 -C 2 )-alkoxy and (C 1 -C 2 )-haloalkoxy.

11. A method for increasing tolerance of genetically modified cultivars to abiotic stress, comprising:

applying an effective amount of a derivative of (1-cyanocyclopropyl)phenylphosphinic acid of the formula (I), and/or of one or more esters or salts thereof, to the genetically modified cultivars, to seed of the genetically modified cultivars, or to cultivation areas on which these cultivars grow;

wherein formula (I) is:

where:

R 1 is:

halogen; or

a branched or unbranched alkyl, cycloalkyl, alkenyl, alkynyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkoxyalkyl, hydroxyalkyl, alkoxyalkenyl, alkylthio, haloalkylthio, alkylsulfonyl, haloalkyl, alkoxy, haloalkoxy, carboxyl, alkoxycarbonyl, aminocarbonyl which is optionally mono- or disubstituted; or

cyano, amino, or nitro;

R 2 is hydrogen, or a branched or unbranched alkyl, cycloalkyl, cycloalkylalkyl, alkenyl, alkenylalkyl, alkynyl, alkynylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkoxyalkyl, hydroxyalkyl, alkoxyalkenyl, hydroxyalkenyl, alkylthioalkyl, haloalkyl, alkylaminoalkyl, bisalkylaminoalkyl, or cycloalkylaminoalkyl; and

n is 0, 1, 2, 3, 4, or 5.