Plant growth regulation compositions and methods using gibberellin biosynthesis inhibitor combinations
Described are plant growth regulation compositions and methods utilizing combinations of Class A and Class B gibberellin biosynthesis inhibitors. Preferred methods and compositions involve the combination of trinexapac-ethyl with either or both of flurprimidol and paclobutrazol, in particular to provide a synergistic effect in the regulation of the growth of turfgrass.
1 . A method for regulating plant growth, comprising:
applying to a plant a Class A gibberellin biosynthesis inhibitor; and
applying to the plant a Class B gibberellin biosynthesis inhibitor;
wherein said Class A and Class. B gibberellin synthesis inhibitors exhibit synergism in regulating growth of the plant.
2 . A method according to claim 1 , wherein:
said Class A gibberellin synthesis inhibitor-is encompassed by the formula:
wherein
A is an —OR 2 or —NR 3 R 4 radical,
R is C 3 -C 6 cycloalkyl,
R 2 R 3 and R 4 are each independently hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 10 alkoxyalkyl, C 2 -C 10 alkylthioalkyl, C 3 -C 6 alkenyl, which is unsubstituted or substituted by halogen, C 1 -C 4 alkoxy or C 1 -C 4 alkylthio; C 3 -C 6 alkynyl; phenyl or C 1 -C 6 aralkyl, wherein the phenyl nucleus is unsubstituted or substituted by halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy,
C 1 -C 4 haloalkyl, nitro or cyano; one of R 3 and R 4 is methoxy; or
R 3 and R 4 , together with the nitrogen atom to which they are attached, form a 5- or 6- membered heterocyclic ring system which may contain an additional oxygen or sulfur atom in the ring; and the metal or ammonium salts thereof.
3 . A method according to claim 2 , wherein the Class A gibberellin synthesis inhibitor is trinexapac-ethyl.
4 . A method according to claim 1 , wherein the Class B gibberellin synthesis inhibitor is encompassed by the formula:
wherein
R 5 is alkenyl, alkynyl or optionally substituted aralkyl;
Y is ═N— or ═CH—;
R 6 is cycloalkyl, alkyl or haloalkyl; and
R 7 is hydrogen, methyl or alkenyl, or an ester, an ether, an acid addition salt or a metal complex thereof.
5 . A method according to claim 4 , wherein the Class B gibberellin synthesis inhibitor is paclobutrazol.
6 . A method according to claim 1 , wherein:
the Class B gibberellin synthesis inhibitor is encompassed by the formula:
wherein
R 8 is 2-pyrazinyl, 3-pyridyl, or 5-pyrimidinyl;
R 9 is phenyl, pyridyl, C 1 -C 12 alkyl, or C 3 -C 8 cycloalkyl;
R 10 is trifluoromethoxy phenyl, tetrafluoroethoxyphenyl, pentafluoroethoxyphenyl, 3,4-(difluoromethylenedioxy)phenyl, or 2,2,4,4-tetrafluoro-1,3-benzodioxanyl;
X is hydrogen, hydroxy, lower alkoxy, lower alkylthio, or lower alkanoyloxy;
or an acid addition salt thereof.
7 . A method according to claim 6 , wherein the Class B gibberellin synthesis inhibitor is flurprimidol.
8 . A method according to claim 1 , wherein the Class A and Class B gibberellin biosynthesis inhibitors are applied together.
9 . A method according to claim 1 , wherein the Class A and Class B gibberellin biosynthesis inhibitors are applied separately.
10 . A method according to claim 1 , wherein the plant is turfgrass.
11 . A method according to claim 10 , wherein the Class A gibberellin biosynthesis inhibitor is trinexepac-ethyl, and wherein the trinexepac-ethyl is applied at a level of about 0.02 to about 0.7 pounds of active ingredient per acre.
12 . A method according to claim 11 , wherein the Class B gibberellin biosynthesis inhibitor is flurprimidol, and wherein the flurprimidol is applied at a level of about 0.05 to about 1.5 pounds of active ingredient per acre.
13 . A method according to claim 11 , wherein the Class B gibberellin biosynthesis inhibitor is paclobutrazol, and wherein the paclobutrazol is applied at a level of about 0.05 to 1.0 pounds of active ingredient per acre.
14 . A method according to claim 10 , wherein the Class A and Class B gibberellin biosynthesis inhibitors are applied together.
15 . A method according to claim 10 , wherein the Class A and Class B gibberellin biosynthesis inhibitors are applied separately.
16 . A method according to claim 14 , wherein the turfgrass comprises one or more grasses selected from as Bahiagrass ( Paspalum notatum ); Bermudagrass ( Cynodon dactylon ); Buffalograss ( Buchloe dactyloides ); Carpetgrass ( Axonopus affinis ); Centipedegrass ( Eremochloa ophiuroides ); Kikuyugrass ( Pennisetum cladestinum ); Seashore paspalum ( Paspalum vaginatum ); St. Augustinegrass ( Stenotaphrum secundatum ); Zoysiagrass ( Zoysia matrella ( japonica )); Annual ryegrass ( Lolium multiflorum ); Bentgrass ( Agrostis spp.); Fescue ( Festuca spp.); Kentucky bluegrass ( Poa pratensis ); Perennial ryegrass ( Lolium perenne ); and Poa annua.
17 . A method according to claim 14 , wherein the turfgrass comprises one or more grasses selected from Bermudagrass ( Cynodon dactylon ); Annual ryegrass ( Lolium multiflorum ); Bentgrass ( Agrostis spp.); Kentucky bluegrass ( Poa pratensis ); and Perennial ryegrass ( Lolium perenne ).
18 . A composition for regulating plant growth, comprising:
a Class A gibberellin biosynthesis inhibitor; and
a Class B gibberellin biosynthesis inhibitor;
wherein said biosynthesis inhibitors exhibit synergism in the regulation of plant growth.
19 . A composition according to claim 18 , wherein:
said Class A gibberellin synthesis inhibitor is encompassed by the formula:
wherein
A is an —OR 2 or —NR 3 R 4 radical,
R is C 3 -C 6 cycloalkyl,
R 2 R 3 and R 4 are each independently hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 10 alkoxyalkyl, C 2 -C 1 o alkylthioalkyl, C 3 -C 6 alkenyl, which is unsubstituted or substituted by halogen, C 1 -C 4 alkoxy or C 1 -C 4 alkylthio; C 3 -C 6 alkynyl; phenyl or C 1 -C 6 aralkyl, wherein the phenyl nucleus is unsubstituted or substituted by halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy,
C 1 -C 4 haloalkyl, nitro or cyano; one of R 3 and R 4 is methoxy; or
R 3 and R 4 , together with the nitrogen atom to which they are attached, form a 5- or 6-membered heterocyclic ring system which may contain an additional oxygen or sulfur atom in the ring; and the metal or ammonium salts thereof.
20 . A composition according to claim 18 , wherein the Class A gibberellin synthesis inhibitor is trinexapac-ethyl.
21 . A composition according to claim 18 , wherein the Class B gibberellin synthesis inhibitor is encompassed by the formula:
wherein
R 5 is alkenyl, alkynyl or optionally substituted aralkyl;
Y is ═N— or ═CH—;
R 6 is cycloalkyl, alkyl or haloalkyl; and
R 7 is hydrogen, methyl or alkenyl, or an ester, an ether, an acid addition salt or a metal complex thereof.
22 . A composition according to claim 21 , wherein the Class B gibberellin synthesis inhibitor is paclobutrazol.
23 . A composition according to claim 18 , wherein:
the Class B gibberellin synthesis inhibitor is encompassed by the formula:
wherein
R 8 is 2-pyrazinyl, 3-pyridyl, or 5-pyrimidinyl;
R 9 is phenyl, pyridyl, C 1 -C 12 alkyl, or C 3 -C 8 cycloalkyl;
R 10 is trifluoromethoxyphenyl, tetrafluoroethoxyphenyl, pentafluoroethoxyphenyl, 3,4-(difluoromethylenedioxy)phenyl, or 2,2,4,4-tetrafluoro-1,3-benzodioxanyl;
X is hydrogen, hydroxy, lower alkoxy, lower alkylthio, or lower alkanoyloxy;
or an acid addition salt thereof.
24 . A composition according to claim 23 , wherein the Class B gibberellin synthesis inhibitor is flurprimidol.
25 . A composition according to claim 18 , wherein:
the Class A gibberellin biosynthesis inhibitor is trinexepac-ethyl, and wherein the trinexepac-ethyl is present in the composition at a concentration of about 0.5 to about 3 pounds per gallon.
26 . A composition according to claim 18 , wherein:
the Class B gibberellin biosynthesis inhibitor is flurprimidol, and wherein the flurprimidol is present in the composition at a concentration of about 0.5 to about 3 pounds per gallon.
27 . A composition according to claim 18 , wherein:
the Class B gibberellin biosynthesis inhibitor is. paclobutrazol, and wherein the paclobutrazol is present in the composition at a level of about 0.5 to about 3 pounds per gallon.
28 . A composition according to claim 26 , adapted for application to turfgrass.
29 . A composition according to claim 27 , adapted for application to turfgrass.
30 . A method according to claim 28 , wherein the turfgrass comprises one or more grasses selected from Bermudagrass ( Cynodon dactylon ); Annual ryegrass ( Lolium multiflorum ); Bentgrass ( Agrostis spp.); Kentucky bluegrass ( Poa pratensis ); and Perennial ryegrass ( Lolium perenne ).
31 . A composition according to claim 18 , which comprises an aqueous carrier.
32 . A composition according to claim 18 , wherein the Class A and Class B gibberellin biosynthesis inhibitors are present in a molar ratio of about 1:0.625 to about 1:5.