Urea pellets coated with starch that contains entrapped herbicides

Abstract Urea pellets were combined with herbicides entrapped in starch to reduce herbicide volatility and to increase safety of handling. One method involved coating the pellets with a dispersion of herbicide in gelatinized starch to render the herbicide immediately available upon dissolution of urea. In another, a solution of polystyrene containing suspended encapsulated herbicide was used. This mixture was applied to urea pellets to provide a product with rate of release of herbicide proportional to the square root of time.