A herbicide composition comprising clomazone encapsulated within microcapsules having a polymer wall comprising a cross-linked polyacetylenecarbamide-polyurea. The composition is prepared by providing a water immiscible organic phase comprising clomazone, one or more polyfunctional isocyanates and a cross-linking resin, such as alkoxylated glycoluril resins providing an aqueous phase comprising one or more polyfunctional amines dispersing the organic phase in the aqueous phase to form a dispersion of droplets of the organic phase in the aqueous and allowing theformation of a polyacetylene carbamide-polyurea polymer at the interface of the dispersed organic phase and the aqueous phase. The composition is useful in the control of plant growth.
