Corn is one of the United States most valuable crops. In 1997 the United States produced 247,943 million metric tons of corn of which 51,889 million metric tons were exported. The value of the 1997 crop was $22 billion. The introduction of corn diseases to the United States would be devastating to the US economy and producers.
Corn and its relatives are regulated to prevent the entry of exotic plant diseases including Peronospora maydis, Sclerospora sacchari, and other downy mildews, also Physoderma zeae-maydis, and P. maydis. Millets, close relatives of corn, include such species as Echinochloa spp., Eleusine, spp., Panicum spp., Setaria spp., and Pennisetum. Other relative of corn include Chionachne spp., Coix spp., Euchleana spp., Miscanthus spp., Polytoca spp., Sclerachne spp., Sorghum spp., Trilobachne spp., and Tripsacum spp.
Decorative craft items made with corn and corn-related products with unprocessed seeds are restricted entry to the United States. In recent years, a number of these items have been found in retail outlets resulting in national recalls of these products. Importers and manufactures of these items need to be aware of the materials their items are made of to prevent problems with importing their articles. For more information on corn and corn relatives permits, please contact USDA APHIS' Permit Unit.