Patent EP-0199699-A2 (EP)
Inventor: OLIN JOHN F
IPC: A01N37/26
Filed: 1986-04-11
Abstract: A method for retarding the growth of turf grass comprises applying to said turf grass an effective growth retarding amount of a compound of the formula:
     wherein R, is C 1 -C 4  alkyl; R 2  is hydrogen, C 1-4  alkyl, alkenyl, alkoxy, haloalkyl; C 1-2  alkylamino, C 1-2  alkylthio, C 3-4  cycloalkyl, C 2-6  alkoxyalkyl, C 2-6  alkyl- 'thiomethyl, amino, phenoxy, phenamino, or furan; and R, is phenyl, or phenyl substituted with one or more C 1-4  alkyl or alkoxy. wherein R, is C,-C, alkyl; R, is hydrogen, C 1-4  alkyl, alkenyl, alkoxy, haloalkyl; C  1 . 2  alkylamino, C l .  2 alkylthio. C 3-4 cycloalkyl, C 2 . 6  alkoxyalkyl, C 2-6 alky-Ithiomethyl, amino, phenoxy, phenamino, or furan; and R, is phenyl, or phenyl substituted with one or more C 1-4  alkyl or alkoxy. 
     As used herein, the term "alkyl" refers to both straight chain and branched chain alkyl radicals. 
     The term "alkenyl" refers to both straight chain and branched chain alkenyl groups of the type 
     
       
         
       
     
     The term "alkoxy" refers to both straight chain and branched chain alkoxy radicals containing alkyl or alkenyl groups as defined above. 
     The term "alkylthiomethyl" refers to a methyl group substituted by an alkthio group. 
     The term "haloalkyl" refers to an alkyl group substituted by one or more halogen atoms. Preferably, trichloromethyl is avoided. 
     The term "phenoxy" refers to both substituted and unsubstituted radicals of the formula phenyl-0-. 
     The term " p henamino" refers to both substituted and unsubstituted radicals of the formula phenyl-NR C  where R c  is hydrogen or alkyl. 
     In general, the selection of other types of substituents for R 2  is not critical to the method of the present invention and it is contemplated that other substituents such as aryl, carboxy, carboalkoxy, heteroaryl and the like would be equivalent to the compounds used in the method of the present invention. 
     The method of the present invention involves application of an effective plant-regulating, non- lethal amount of the compounds to the plant locus of the turf grass. Regulating the growth of turf grass involves altering the natural growth of the turf grass to enhance various horticultural features of the grass. As employed herein, the term "natural growth" designates the normal life cycle of the grass in accordance with its genetics and environment in the absence of artificial, external influences. Regulation of the growth of turf grass can include retarding the amount of natural vegetative growth of the grass and/or retarding or reducing the natural formation of seedheads in turf grass. The regulation of natural growth of turf grass does not include killing or herbicidal action. By application to the "plant locus" is meant application to the plant's growing medium, such as the soil, as well as to the plant parts. such as roots, stems, and leaves. Preferably, the compounds are applied to establish turf grass. Application of the compounds to emerging seedlings may result in injury. 
     It is believed that the compounds are absorbed into the plant through the roots. Therefore, it is desirable after application of the compounds to the turf to water the turf to thereby wash the compounds into the soil. Watering of the turf is conveniently done within a short period of time after applying the compounds, e.g., within from about 3 hours to about 48 hours. A sufficient amount of water should be utilized to transport the compounds to the root zone. Depending upon the type and composition of the soil, conveniently about  1   4  inch to about 1 inch of water is utilized. 
     In selecting an appropriate regulating amount of the compound for use in the method of the present invention, it will be recognized that the effective regulating amount will vary with the plant species being treated, its stage of development, the specific compound being utilized, and the type of regulating effect being sought. The degree of regulating effect will vary with each species depending upon the absorption, translocation, and biological activity of the compound towards the species. An effective regulating amount will normally vary from about 0.1 to about 10 Ibs. per acre. Conveniently a rate of from about 0.5 to about 5 lbs. per acre will be utilized. However, those skilled in the art will be able to determine an effective regulating amount of the compound for each species of turf grass and each specific compound. 
     In order to maximize the amount of regulation of the growth of turf grass, it is advantageous to apply the compounds to the turf grass during the period beginning with green-up and prior to initiation of seedheads. "Green-up" is the transition of turf grass from dormancy (winter phase) to the active growth phase. "Initiation of seedheads" in the turf grass is defined as the physical appearance of seedheads at the base of the turf grass stem. Generally, it is preferred to apply the compounds to the turf grass at about 75% -100°a green-up. Application of the compounds to the turf grass prior to initiation of green-up may result in retarding the green-up of the grass. Application of the compounds after initiation of seedheads will