ISDA Major Plant Disease Surveys and Projects
Sudden Oak Death: Sudden Oak Death is a forest disease caused by the quarantine plant pathogen Phytophthora ramorum. This pathogen has caused widespread dieback of tanoak and several oak species (coast live oak, California black oak, and others) in California ‘s central and northern coastal counties and in Southwest Oregon . It has also been found to infect the leaves and twigs of numerous other plants species. While many of these “foliar hosts”, such as camellias and rhododendrons do not die from the disease, they do play a key role in the spread of P. ramorum, acting as breeding ground for innoculum, which may then be spread through wind-driven rain, water, plant material, or human activity. For more information see: https://www.suddenoakdeath.org.
Karnal Bunt: Karnal Bunt is a cereal disease caused by the quarantine plant pathogen Tilletia indica. This fungal pathogen invades growing wheat kernels and replaces the wheat tissue with fungal spores. The spores are not toxic to humans or animals, but do cause poor quality. This pathogen has been discovered and quarantined in CA, NM, AZ, and TX. Further spread has been prevented by yearly surveys for the presence of the pathogen. Grain growers and processors in Idaho have always participated in these yearly surveys. For more information visit USDA Animal Plant and Health Inspection Service.
Plum Pox: Plum pox is a virus disease of stone fruit (peaches, plums etc.) caused by the quarantine plant pathogen Plum Pox Potyvirus. The disease occurs throughout parts of Europe and was first found and quarantined in Pennsylvania in 1999. The disease causes discolored and misshapen fruit, and yellowing of the leaves. Surveys for the disease were conducted in Idaho orchards and nurseries in 2000, 2001, and 2002, with no virus detected. No further spread of the pathogen in the U.S. has been found to date. For more information visit USDA Animal Plant and Health Inspection Service.
Brown Rot / Geranium Wilt: Brown Rot / Geranium wilt is a bacterial disease of potatoes, tomatoes, eggplants and geraniums, among others, caused by the quarantine plant pathogen Ralstonia solanacearum race 3 biovar 2. This bacterium has been introduced in the past few years into the U.S. through infected geranium stock, but has been eradicated after each introduction. Efforts to monitor nurseries that may have received infected stock at one time are continuing as part of Idaho’s nursery certification program (insert link). For more information about this pathogen visit USDA Animal Plant and Health Inspection Service.
Mop-top: Mop-top is a virus disease of potatoes caused by the plant pathogen Potato Mop-top Furovirus. Mop-top caused necrotic rings in potato tubers and is spread by the fungus Spongospora subterranean the causal agent of powdery scab of potatoes. Canadian officials had detected this pathogen in shipments of commercial tubers originating from several U.S. states, including Idaho . A survey was conducted in potato seed lots from both the U.S. and Canada for this pathogen in the fall and winter of 2002. No signs of this virus were found in Idaho seed lots, but there were detections of this pathogen in the country. There is no continued federal quarantine of this pathogen.
For additional ISDA survey, see Plant Diseases and Other Pests