Control of Weeds Harmful to Water Uses in the West

An extensive program of controlling aquatic and ditchbank weeds in irrigation and drainage canals in seventeen western states prevented weed losses of $15,860,026 in one typical year, an annual saving of $7,746,729 over control costs. The improved methods used were developed in a research program conducted since 1947 by the United States Agricultural Research Service in cooperation with the Bureau of Reclamation and several state agricultural experiment stations. Expansion of the cooperative research program in 1961 resulted in the development of several effective and other promising chemical methods of controlling submersed weeds in ponds, lakes, and reservoirs; also of the most troublesome water-wasting phreatophytes growing on river flood plains, along small streams, and around reservoirs. However, moost of these methods are expensive and are not used extensively in the West. Investigations are being continued to discover more effective, less expensive, and safer chemical, mechanical, biological, and ecological methods of controlling weeds harmful to water uses in the West.