acetolactate synthase inhibitors , such as imazapyr and pyrithiobac and mixtures thereof , prepared as slow - release formulations are useful for the preparation of seed dressing , seed priming , seed or particle - substrate coating herbicidal compositions for control of parasitic weeds such as orobanche spp ., striga spp . and alectra spp . the use of agrochemicals can be rendered more efficient when coated or bound as a slow release formulation . particles used as the substrateto be coated may be plant seeds or particles made of a strong or weak ionic resin or a biodegradable carbohydrate natural polymer , a modified polymer , or artificially lignified cellulose . the herbicidal formulation may be covalently linked or adsorbed to the surface of the particle . the same slow release formulations are invaluable for preventing rapid herbicide leaching in agricultural as well as non - agricultural weed control situations .