1a. Objectives (from AD-416)
The objectives of this cooperative research are to identify, characterize and control soilborne pathogens of wheat and barley, such as Rhizoctonia, Pythium, Gaeumannomyces, Bipolaris and/or Fusarium, which cause root and crown rot diseases; to identify the effects of cropping systems on root pathogen population size and diversity, and on disease epidemiology; and to identify wheat and/or barley germplasm with resistance/tolerance against root diseases.
1b. Approach (from AD-416)
Root and crown rot diseases will be identified and characterized through a combination of laboratory, greenhouse and field studies. The ecology of soilborne pathogens and effects of cropping system on pathogen population size and diversity and disease epidemiology will be determined using plant pathology, microbiology and molecular biology methods. Wheat and barley germplasm will be screened for resistance or tolerance to soilborne pathogens in the field and greenhouse. Practical root disease control will be accomplished through a combination of agronomic practices and biological and chemical treatments. Replacing 58-5348-4-484. Documents SCA with U. of ID.
3. Progress Report
Screening for resistance to dryland foot rot. Seed treatments may reduce some symptoms of soil-borne root and crown disease, but there usually is no yield benefit. There is little genetic resistance available to combat root-infecting fungi such as Fusarium culmorum, the predominant root-infecting Fusarium in southeast Idaho. ARS collaborators at the University of Idaho, Idaho Falls established a foot rot nursery for long term research in which 56 varieties of spring wheat and 48 varieties of barley were screened for resistance. There were significant differences between varieties for yield, and stand, allowing identification varieties that are better adapted to yield under local conditions having substantial disease pressure. Identification of varieties and advance lines showing increased resistance or tolerance (having the ability to yield under high disease pressure and infection levels) to infection assists in the development and recommendation of barley and wheat varieties that perform best under dryland conditions where crown and foot rot prevails, reducing associated yield losses. Seed treatment trials for crown and foot rot diseases in winter wheat. Environmental conditions in high elevation areas of the Pacific Northwest limit some crop production to continuous cereals, exposing crops to high disease pressure. ARS collaborators at the University of Idaho, Idaho Falls investigated the protective capability of several fungicidal seed treatments on wheat. While spring stand varied significantly between seed treatments disease ratings, yield and test weights were not significantly different. As seen in past experiments, seed treatments can improve stand, sometimes reduce disease ratings, maybe improve plant vigor, but often do not significantly improve yield of winter grain. The accomplishments of this project align with Component 3, Problem Statements 3A & B and Component 4, Problem Statements 4A & C of NP 303. Progress on this project is monitored by conversations with the collaborator at meetings and through conference calls.