A Wide Variety of annual weeds in commercial vineyards have been controlled in recent years with chemical herbicides. Although very effective on these annuals, the use of such herbicides has actually increased difficulties with perennial weeds in many plantings. An active research program has been under way at the University to develop means of controlling these persistent pests. A number of foliar-contact and hormone-type herbicides have been recommended for use against them. However, there remains an urgent need for an effective soil-residual herbicide that would be effective against perennial weeds.