(S)-abscisic acid derivatives for enhanced grape coloration
The present invention is directed to the treatment of grapes with 3′-methyl-(S)-abscisic acid, 3′-propargyl-(S)-abscisic acid, and/or salts thereof in order to enhance the color of the grapes.
1. A method of enhancing red grape coloration comprising applying from about 20 to about 400 parts per million of (2Z,4E)-5-((S)-1-hydroxy-2,3,6,6-tetramethyl-4-oxocyclohex-2-en-1-yl)-3-methylpenta-2,4-dienoic acid (3′-methyl-(S)-abscisic acid) or a salt thereof to the plant.
2. The method of claim 1 wherein the abscisic acid derivative is 3′-methyl-(S)-abscisic acid.
3. The method of claim 2 wherein the 3′-methyl-(S)-abscisic acid is applied at a rate of from about 0.3 to about 8 mg per cluster.
4. The method of claim 3 wherein the 3′-methyl-(S)-abscisic acid is applied at a rate of from about 6 to about 160 grams per acre.
5. The method of claim 2 wherein the 3′-methyl-(S)-abscisic acid is applied to the vine during the period beginning when the fruit is about 3 weeks before veraison and ending when the fruit is about 4 weeks after the onset of veraison.
6. The method of claim 5 wherein the 3′-methyl-(S)-abscisic acid is applied to the vine during the period beginning when the fruit is about 1 week before veraison and ending when the fruit is about 3 weeks after the onset of veraison.
7. The method of claim 2 wherein the 3′-methyl-(S)-abscisic acid is applied to Vitis vinifera grapes.
8. The method of claim 2 wherein the 3′-methyl-(S)-abscisic acid is applied with a plant growth regulator selected from the group consisting of cytokinins, gibberellins, auxins, and ethylene precursors.
9. The method of claim 8 wherein the ethylene precursor is ethephon.