Defoliant composition and method

Abstract

An aqueous suspension or slurry (suspension concentrate) contains a synergistic amount of thidiazuron, diuron and surfactants. The aqueous suspension contains surfactants in amounts to obtain a stable suspension or slurry without the use of organic solvents.

1 . A composition for controlling vegetation comprising an aqueous suspension or slurry of thidiazuron, diuron, and at least one surfactant in an amount sufficient to maintain thidiazuron and diuron in suspension in an aqueous matrix. 
     
     
         2 . The composition of  claim 1 , wherein said thidiazuron and diuron are present in a ratio of about 5:1 by weight. 
     
     
         3 . The composition of  claim 1 , wherein said diuron is present in a synergistic amount to enhance the efficacy of the thidiazuron. 
     
     
         4 . The composition of  claim 1 , wherein the composition further includes at least one component selected from the group consisting of emulsifiers, wetting agents, thickening agents, dispersing agents, and mixtures thereof. 
     
     
         5 . (canceled) 
     
     
         6 . The composition of  claim 1 , wherein the composition is a suspension concentrate. 
     
     
         7 . The composition of  claim 6 , wherein the concentrate includes about 10 wt % to about 40 wt % thidiazuron and about 5 wt % to about 20 wt % diuron based on the total weight of the concentrate. 
     
     
         8 . The composition of  claim 6 , wherein the concentrate includes about 35 wt % to about 40 wt % thidiazuron and about 15 wt % to about 20 wt % diuron based on the total weight of the concentrate. 
     
     
         9 . The composition of  claim 6 , further comprising a dispersing agent. 
     
     
         10 . The composition of  claim 9 , wherein the thidiazuron and diuron have a median particle diameter of not greater than about 5 μm. 
     
     
         11 . The composition of  claim 9 , wherein the concentrate comprises about 10 wt % to about 40 wt % thidiazuron, about 5 wt % to about 20 wt % diuron, a surfactant, a dispersing agent and the balance water, where the percentages are based on the total weight of the concentrate. 
     
     
         12 . The composition of  claim 1 , wherein the composition is in the absence of 1-octyl-2-pyrrolidone and 1-dodecyl-2-pyrrolidone. 
     
     
         13 . A method of controlling vegetation comprising the step of applying an aqueous mixture to vegetation in an amount effective to treat the vegetation, wherein the mixture is obtained from an aqueous suspension or slurry comprising thidiazuron, diuron and a surfactant. 
     
     
         14 . The method of  claim 13 , wherein the diuron is included in a synergistic amount to enhance the efficacy of the thidiazuron. 
     
     
         15 . The method of  claim 13 , wherein the aqueous suspension or slurry comprises thidiazuron and diuron in a ratio of about 1:1 to about 5:1 by weight. 
     
     
         16 . The method of  claim 13 , wherein the aqueous suspension or slurry comprises thidiazuron and diuron in a ratio of about 2:1 by weight. 
     
     
         17 . The method of  claim 13 , comprising applying the aqueous mixture in an amount of about 0.02 to 0.20 lbs total actives per acre. 
     
     
         18 . (canceled) 
     
     
         19 . The method of  claim 13 , wherein the aqueous suspension or slurry is in the absence of an organic solvent. 
     
     
         20 . The method of  claim 13 , wherein the aqueous suspension or slurry is in the absence of 1-octyl-pyrrolidone and 1-dodecyl-2-pyrrolidone. 
     
     
         21 . A method of defoliating vegetation comprising applying a mixture to the vegetation in an amount effective to defoliate the vegetation, wherein the mixture is obtained from an aqueous suspension or slurry comprising thidiazuron, a synergistic amount of diuron to enhance the efficacy of the thidiazuron, and a surfactant. 
     
     
         22 . The method of  claim 21 , wherein the composition comprises thidiazuron and diuron in a ratio of about 1:1 to 5:1 and where the composition is applied at a rate of about 0.02 to 0.20 lbs total actives per acre. 
     
     
         23 . The method of  claim 21 , wherein said vegetation is cotton plants. 
     
     
         24 .- 25 . (canceled) 
     
     
         26 . The method of claim  24 , wherein the aqueous suspension or slurry is in the absence of 1-octyl-2-pyrrolidone and 1-dodecyl-2-pyrrolidone.