Method and composition for protecting pavement structure from growth of seeds and roots in splits of the structure

A method and device are used for controlling growth of plants in pavement splits by preventing seeds from germinating and by preventing growth of plants from existing roots in the vicinity of the splits. The growth of plants is controlled for extended periods of time (2 to 20 years). A pre-emergence herbicide and a systemic herbicide are incorporated into a polymeric matrices. The polymeric matrices are formed into shaped objects, such as, bands or cords which are then inserted into splits. The split is then filled with a sealer which permits easy migration of the herbicides therethrough. The herbicides gradually released from the shaped objects at a rate sufficient to maintain a minimal effective level of herbicide outside said sealer for a predetermined period of time.