Method for regulating plant growth

Abstract

A process for increasing the rate of plant growth. Plants are treated with one or more acids, which are condensation products of glycolic and/or L-lactic acid. These acids also increase the concentration of chlorophyll, increase the rate of new plant formation when plants are propagated by tissue culture, decrease the amount of added nutrients required for plant growth, and protect plants against the toxic effects of salts. Certain of the acids are useful for increasing the rate of root formation in the plant. The questions raised in reexamination request Nos. 90/002,306, filed Mar. 26, 1991 and 90/003,035 filed Apr. 27, 1993, have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e).

What is claimed is: .[.1. A process for increasing the rate of growth of a plant which comprises supplying to the roots, stems and foliage of the plant an effective amount of one or more acids having the structural formula: ##STR3## where n is a whole number from 1 to 10; the Rs are the same or different and denote H or CH 3  ; and if at least one R is CH 3 , at least 
     
        some of the asymmetric centers are in the L-configuration..]..[.2.  The process of claim 1 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 1 and about 1000 parts per million on a weight/volume basis..]..[.3. The process of claim 1 wherein the plant is Lemna minor L..]..[.4. The process of claim 1 wherein th plant is selected from the group: lettuce, spinach, and corn..]..[.5. The process of claim 4 wherein the plant is grown in hydroponic culture..]..[.6. A process for increasing the concentration of chlorophyll in a plant which comprises supplying to the roots, stems and foliage of the plant an effective amount of one or more acids having the structural formula: ##STR4## where n is a whole number from 1 to 10; the Rs are the same or different and denote H or CH 3  ; and if at least one R is CH 3 , at least 
     
     
        some of the asymmetric centers are in the L-configuration..]..[.7.  The process of claim 6 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 100 and about 1000 parts per million on a weight/volume basis..]..[.8. The process of claim 6 wherein the plant is selected from the group: Lemna minor L. and Chlorella vulgaris..]..[.9. A process for increasing the rate of root formation in a plant which comprises supplying to the roots, stems and foliage of the plant an effective amount of one or more acids having the structural formula: ##STR5## where n is a whole number from 1 to 10, and at least some of the 
     
     
        asymmetric centers are in the L-configuration..]..[.10.  The process of claim 9 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 1 and about 1000 parts per million on a weight/volume basis..]..[.11. The process of claim 9 wherein the plant is selected from the group: Lemna minor L., lettuce, and corn..]..[.12. A process for decreasing the concentration of the basic nutrient medium required for growth of a plant which comprises supplying to the roots, stems or foliage of the plant an effective amount of one or more acids having the structural formula: ##STR6## where n is a whole number from 1 to 10; the Rs are the same or different and denote H or CH 3  ; and if at least one R is CH 3 , at least 
     
     
        some of the asymmetric centers are in the L-configuration..]..[.13.  The process of claim 12 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 1 and about 1,000 parts per million on a weight/volume basis..]..[.14. The process of claim 12 wherein the plant is Lemna minor L..]..[.15. A process for protecting a plant against the toxic effects of salts which comprises supplying to the roots, stems and foliage of the plant an effective amount of one or more acids having the structural formula: ##STR7## where n is a whole number from 1 to 10; the Rs are the same or different and denote H or CH 3  ; and if at least one R is CH 3 , at least 
     
     
        some of the asymmetric centers are in the L-configuration..]..[.16.  The process of claim 15 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 1 and about 1000 parts per million on a weight/volume basis..]..[.17. The process of claim 15 wherein the plant is selected from the group: Lemna minor L. and 
     
     
        Chlorella vulgaris..]..Iadd.18.  A process for increasing the rate of growth of a plant which comprises supplying to the roots and stems and foliage an effective amount of a condensation product of glycolic acid having from two to eleven acid units per molecule. .Iaddend..Iadd.19. The process of claim 18 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 1 and about 1000 parts per million on a weight/volume basis. .Iaddend..Iadd.20. A process for increasing the concentration of chlorophyll in a plant which comprises supplying to the roots, stems and foliage of a plant an effective amount of a condensation product of glycolic acid having from two to eleven acid units per molecule. .Iaddend..Iadd.21. The process of claim 20 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 100 and about 1000 parts per million on a weight/volume basis. .Iaddend..Iadd.22. A process for decreasing the concentration of the basic nutrient medium required for growth of a plant which comprises supplying to the roots, stems and foliage of the plant an effective amount of a condensation product of glycolic acid having from two to eleven acid units per molecule. .Iaddend..Iadd.23. The process of claim 22 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 1 and about 1000 parts per million on a weight/volume basis. 
     
     
        .Iaddend..Iadd.24.  A process for protecting a plant against toxic effects of salts which comprises supplying to the roots, stems and foliage of a plant an effective amount of a condensation product of glycolic acid having from two to eleven acid units per molecule. .Iaddend..Iadd.25. The process of claim 24 wherein the acid is supplied to the plant in an aqueous solution at a concentration of between about 1 and about 1000 parts per million on a weight/volume basis. .Iaddend.