(a) The fact has been determined by the Secretary of Agriculture, and notice is hereby given, thatmaize or Indian corn (Zea mays L.) and closely related plants are subject to certain injurious diseases, especially Peronospora maydis Raciborski, Sclerospora sacchari Miyake and other downy mildews; also the Physoderma diseases of maize, Physoderma zeae-maydis Shaw, and Physoderma maydis Miyake, new to and not heretofore widely prevalent or distributed within and throughout the United States, and that these diseases occur in southeastern Asia (including India, Siam, Indo-China and China), Malayan Archipelago, Australia, Oceania, Philippine Islands, Formosa, Japan, and adjacent islands.