Karnal Bunt

Karnal bunt is the disease of wheat, durum wheat, and triticale that is caused by Tilletia indica. Plant pathologists generally consider Tilletia indica to be a weak pathogen that causes a disease of minor production importance. Measurable yield loss is uncommon. The most severe adverse economic impacts are associated with the current domestic and the more than 50 foreign quarantines which have disrupted the traditional marketing of wheat produced in the United States. The presence of Tilletia indica-like teliospores jeopardizes wheat shipments in the marketplace.

There is a consensus, among the majority of the plant regulatory officials of the United States and plant pathologists, who work with smut diseases, that Tilletia indica can be effectively managed and controlled with normal crop management practices. Since Karnal bunt is a pathogen of minor significance, the USDA should emphasize and promote the successful management of Karnal bunt in the United States in discussions with our trading partners.

The USDA should call for deregulation of Karnal bunt as a quarantine pest by our trading partners and individual states immediately. Any revisions to domestic restrictions should include provisions for the shipment of seed from a potentially infected area if that seed is tested free of teliospores and treated with a fungicide. NASDA encourages USDA to immediately work with the National Plant Board to revise the federal domestic quarantine regulating grain to allow its movement while minimizing the spread of the disease. To this end, NASDA encourages USDA and the National Plant Board to analyze and review the pest risk posed by allowing movement based upon tests for bunted kernels versus teliospores. USDA also should revise the federal foreign quarantine to be consistent with the revised federal domestic quarantine.

Recognizing that, in the meantime, quarantine requirements will be established by importing countries, the USDA should continue efforts to prevent additional quarantine restrictions and to negotiate with trading partners for reasonable phytosanitary requirements. The national survey should continue to validate the pest-free status of all United States production areas, serve as the basis for further regulation on an annual basis and be the validation for Federal Phytosanitary Certificates.

Consistent with the Principles of Plant Quarantine, USDA should work with the scientific community to identify, prioritize, and facilitate the accomplishment of research objectives. Further, NASDA encourages the international scientific community to develop a scientific position statement on Karnal bunt and other smut diseases for the global community.