Granular pesticide composition

Abstract

A granular pesticide composition is prepared by reacting polyvinyl alcohol, pesticide, a borate, and optional filler(s) in water until a gel is formed, drying the gel, and then grinding the product to the desired particle size. The product is then applied to the soil for controlling pests.

What is claimed: 
     
       1. A granular slow release soil pesticide composition .Iadd.comprising by weight based on the total composition of from about 5 to about 90% of polyvinyl alcohol, from about 1 to about 20% of a borate, from about 2 to about 50% of a compatible pesticide, and 0 to about 80% of filler(s) .Iaddend.prepared by mixing .[.from about 5 to about 90% by weight of.]. (.Iadd.a) .Iaddend.an aqueous solution of polyvinyl alcohol .Iadd.wherein the solids concentration of polyvinyl alcohol is about 10% .Iaddend.and .[.from about 2 to about 50% of.]. a compatible pesticide .[.plus 0 to about 80% of.]. .Iadd.and optionally .Iaddend.at least one filler selected from the class consisting of diatomites, attapulgites, bentonites, talcs, montmorillonites, perlites, vermiculites, calcium carbonates, corn cob grits, wood flour, lignin sulfonates, and mixtures thereof with .[.from about 1 to about 20% of.].  (.Iadd.b) .Iaddend.a borate until .[.said.]. ingredients (.Iadd.a) and (b) .Iaddend.react to form a gel, drying the gel, and grinding the dried product to the desired particle size. 
     
     
       2. The composition of claim 1 wherein the pesticide is selected from the group consisting of chlorpyrifos, chlorpyrifos-methyl, diazinon, fonofos, parathion, fensulfothion, methyl parathion, phorate, and trifluralin. 
     
     
       3. The composition of claim 1 wherein the product is ground to pass through a number 14 mesh screen but is retained on a number 40 mesh screen. 
     
     
       4. A method of controlling pests comprising applying an effective amount of the composition of claim 1 to soil. .Iadd.5. A method of encapsulating a pesticide comprising the steps of: a. preparing a solution or dispersion of such pesticide in a matrix-forming material comprising an aqueous solution of a gel-forming polyvinyl alcohol wherein said aqueous solution has a solids concentration of said polyvinyl alcohol of about 10%, wherein the relative amount of said polyvinyl alcohol with respect to said pesticide is sufficient to entrap said pesticide within a matrix of said polyvinyl alcohol;   b. reacting said polyvinyl alcohol with a borate to form a continuous insolubilized matrix gel having entrapped therein uniformly dispersed, discontinuous domains of said pesticide; and   c. recovering free-flowing particles of said entrapped pesticide. .Iaddend. .Iadd.6. A composition of matter produced by the process of claim 5. .Iaddend.