Crop diversity fruit trees and banana plants) are cloned. A single pest or disease could threaten a whole crop due to this uniformity ("genetic erosion"). A well-known historic case was the Irish Potato Famine of 1845-1847, where a vital crop with low diversity was destroyed by a single fungus. Another example is when a disease caused by a fungus affected the monocultured 1970 US corn crop, causing a loss of over one billion dollars in production. A danger to agriculture is wheat rust, a pathogenic fungus causing reddish patches, coloured by its spores. A virulent form of the wheat disease, stem rust,
Canada–Panama Free Trade Agreement 99% of its tariffs on goods from Panama. Canada will keep tariffs on some imports of sugar, poultry, eggs and dairy products. Panama will end its ban on beef from Canada which was initiated after cases of mad cow disease were found in Canada in 2003. In 2008, bilateral merchandise trade between Canada and Panama totaled $149.1 million. Trade has increased by 48 percent from 2007. Canada made up $127.9 million of total trade between the two countries, while Panama made up the remaining $21.2 million. Both countries parliament needed to approve the agreement before it could come into force.