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,
McKnight Foundation Collaborative Crop Research Program toward conservation of agricultural biodiversity, breeding and variety selection, seed systems, integrated crop and pest management, risk management and climate variability, nutrition, soil fertility management, and market development. East & Horn of Africa CoP (Ethiopia, Kenya, and Uganda) The E&HAf CoP aims to improve performance of farming systems primarily through support for crop diversification, for crop improvement and diversification, and an emphasis on management strategies that enhance crop access to scarce soil nutrients and water resources and reduce pest and disease losses. The CoP is also turning attention to post-harvest issues such as consumption, storage, transformation, and markets to increase