U.S.D.A. acts to control Karnal bunt wheat fungus after sporadic discoveries

by Teresa Acklin
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   The U.S. Department of Agriculture has declared an “extraordinary emergency” in several U.S. states after the discovery of Karnal bunt, a fungal disease of wheat, in some areas.

   Karnal bunt can affect durum wheat, wheat and triticale. Infected plants produce less grain, and the quality of the grain is lessened, although the fungus does not pose a health threat to humans. Originally discovered in 1931 in India near the town of Karnal, the disease has been prevalent in Mexico for several years.

   The emergency declarations provide statutory authority for the U.S.D.A. to implement a range of actions within states to eradicate the fungus. The declarations also secure funding for what apparently will be a long-term and costly control effort.

   Affected states as of mid-April included Arizona, where the fungus first was detected in early March in durum wheat at a seed dealership; Texas; New Mexico; and California. Reports also indicated some evidence of the fungus in wheat in the states of Montana and Washington.

   None of the outbreaks was thought to be widespread. For example, in Washington, karnal bunt was suspected on only 1.4 hectares, based on contaminated seed planted on 0.04 hectares.

   To prevent the spread of the disease, the U.S.D.A. convened a scientific panel comprising state, federal and industry technical experts and scientists to determine what actions were necessary. Quarantines were instituted on infected properties — seed, farm equipment, planted wheat and soil associated with the infected wheat — as well as on the interstate movement from the quarantined areas of regulated articles such as wheat, conveyances used to move wheat, grain elevators or equipment used to store wheat and milling products and byprod-ucts other than flour.

   Also, a nationwide test of grain elevators and export terminals was under way, and the U.S.D.A. formed an export certification team to deal with trade issues.

   The discovery initially brought U.S. wheat exports to 21 countries to a virtual standstill for a few days; standard contract terms with those customers had specified that U.S. wheat was entirely free of the fungus. Negotiations with each customer resulted in agreements with most to accept phytosanitary certificates stating that the U.S. wheat purchased was “grown in an area where Karnal bunt was not known to occur.”

   Among the 21 countries were several of the world's largest wheat importers, including the former Soviet Union, China, Morocco, Algeria, Turkey, Brazil and Mexico. Japan, Egypt and South Korea, large importers of U.S. wheat, do not have restrictions on Karnal bunt.

   Also affected were North Dakota State University's winter breeding facilities in Arizona, where research on thousands of experimental lines of barley, hard red spring wheat and durum will be disrupted by the quarantine. N.D.S.U. officials said the winter seed nursery would not supply North Dakota wheat and barley breeding programs this spring or summer.