2007 Annual Report 1a.Objectives (from AD-416) Discover, identify, and evaluate the efficacy of exotic pathogens as classical biological control agents. Conduct risk analyses to determine the agricultural and ecological safety for the release of pathogens a classical biological control agents. Release, monitor, and evaluate impact of pathogens on weed populations and non-target effects in the field. 1b.Approach (from AD-416) Exotic pathogens will be collected from symptomatic target weeds in countries where they are native, evaluated for their potential using standard plant pathology methods, and identified using both classical morphological characters and molecular sequence data. Molecular signatures will be developed for unambiguous identification and detection. Pathogens will be evaluated for the risk associated with intended release into ecosystems containing economically and ecologically important North American plant species. Proposals for release of the pathogen into the environment will be developed for review by the Technical Advisory Group for Biological Control Agents of Weeds, and subsequent development of an Environmental Assessment, declaration of Finding Of No Significant Impact and issuance of federal and state permits for release. Inoculum will be prepared in sufficient quantity for release, hosts will be inoculated in the field and provided conditions that favor infection and establishment. Weather and baseline weed population density data will be collected at each release site. The establishment and spread of pathogens will be monitored in the field by recording disease symptoms on the target weed and verifying identification of the pathogen using classical morphology and molecular diagnostic assays. Damage to target weed populations and environmental factors important in pathogen establishment, efficacy and spread, will be measured. Regional collaborations will be established to restore sites where biological control has proven efficacious toward more stable and sustainable ecosystems. 3.Progress Report 1920-22000-031-01S - Specific Cooperative Agreement - Pennsylvania State Univ: The main objectives of this agreement are to fund a graduate student at PSU to develop a protocol for the generation of Canada thistle propagules infected with the fungal biocontrol agent Puccinia punctiformis, to use as sources of fungal inoculum for field infestations. Over the past year we have produced large quantities of inoculum for field trials. This project was monitored by site visits in 2007, as well as numerous calls and e-mails to the cooperator over the course of the year. For a complete report on the progress of this agreement, see the report for 1920-22000-031-01S. 1920-22000-031-02S - Specific Cooperative Agreement - American Farm School: This agreement was established to place scientific expertise at this USDA-ARS European Biological Control Laboratory satellite location for collaborative research measuring the efficacy of promising fungal pathogen biocontrol candidates on target invasive weeds in the field. During the course of the past year, we continued replicated field tests for host-range testing of non-target plants with several promising fungal biocontrol agents. This project was monitored by an extensive site visit in 2007, as well as, numerous calls and e-mails to the cooperator over the course of the year. For a complete report on the progress of this agreement, see the report for 1920-22000-031-02S 1920-22000-031-03S - Specific Cooperative Agreement - California Dept. of Food and Agriculture: The objective of this cooperative research is to achieve successful establishment of the rust fungus, Puccinia jaceae var. solstitialis as a biological control agent on yellow starthistle (YST) in California and determine its effectiveness in controlling field populations of YST. Cooperators at CDFA Biological Control Program have released P. jaceae on yellow starthistle populations in 41 counties in California. The fungus established and survived into a second season at more than 30 locations. This project was monitored by a site visit in 2007, as well as numerous calls and emails to the cooperator over the course of the year. For a complete report on the progress of this agreement, see the report for 1920-22000-031-03S 1920-22000-031-04N – Non-Funded Cooperative Agreement - Ondokuz Mayis University: The objective of this cooperative research is to develop isolates of weed pathogens collected in Turkey for biological control agents for invasive weeds in the U.S. and Turkey. The goals are to: (1) collect, in Turkey, new pathogens of invasive weeds that are important in the U.S. and Turkey. (2) determine the efficacy of the pathogens in infecting and damaging these weeds in the field in Turkey and (3) determine the host range of the pathogens among related non-target species. Ondokuz Mayis University has not, at this time, approved the agreement, so there is no progress to report at this time. For a complete report on this agreement, see the report for1920-22000-031-04N. 4.Accomplishments a. Canada thistle is perhaps the most important invasive weed in the U.S. based on the number of states that have declared it noxious. Biological control of Canada thistle using the rust fungus Puccinia punctiformis has been largely unsuccessful in part due to a low incidence of systemically infected shoots and heterogeneous distribution of teliospores in the soil. In field studies with cooperators at Penn State University, we investigated the feasibility of strategic mowing to improve incidence of systemically infected shoots, and enhance disease development in two unused pastures. Mowing treatments significantly increased the proportion of systemically infected shoots compared to no mowing. This indicates that mowing followed by re-growth of systemically infected shoots may help enhance severity of this disease and control Canada thistle, particularly in rangelands, pastures, and natural ecosystems. This research falls within ARS National Program 304, Crop Protection & Quarantine, specifically addressing Component IX (Biological Control of Weeds). The project relates directly to NP 304 Action Plan Component IX.2C (Field Evaluation). This research falls within ARS National Program 304, Crop Protection & Quarantine, specifically addressing Component IX (Biological Control of Weeds). The project relates directly to NP 304 Action Plan Component IX.2C (Field Evaluation). b. Yellow starthistle (YST) is a serious pest of Western rangelands, infesting over 10,000 hectares in the state of California (CA) alone. Cooperators at the CA Department of Food and Agriculture (CDFA) Biological Control Program have released P. jaceae on yellow starthistle populations in 41 counties (approx. 70 releases in 2006; 178 sites since 2003) in CA. The fungus established and survived into a second season at more than 30 locations, and substantial spread (more than 30 meters) has been noted at some release sites. Field monitoring has established that field-inoculated plants are damaged by the infections. The potential for Puccinia jaceae to reduce YST populations in concert with established natural enemies and integrated management practices is still under investigation. This research falls within ARS National Program 304, Crop Protection & Quarantine, specifically addressing Component IX (Biological Control of Weeds). The project relates directly to NP 304 Action Plan Components IX.2A (Agent Discovery and Selection and Risk Assessment) and IX.2C (Field Evaluation). 5.Significant Activities that Support Special Target Populations Yellow starthistle (YST) is a serious pest of Western rangelands. In FY 2004, USDA APHIS and the California Department of Food and Agriculture permitted expanded experimental releases of a fungal pathogen for biological control of YST. As a result of permit approvals and introduction into the state of California, the Nez Perce Biological Control Center has applied to APHIS for a permit to release P. jaceae in Idaho. 6.Technology Transfer Number of new CRADAs and MTAs 1 Number of non-peer reviewed presentations and proceedings 9 Review Publications Fisher, A.J., Woods, D.M., Smith, L., Bruckart, W.L. 2007. Developing an optimal release strategy for the rust fungus Puccinia jaceae var. solstitialis for biological control of Centaurea solstitialis (yellow starthistle). Biological Control. 42:161-171. Demers, A.M., Berner, D.K., Backman, P.A. 2006. Enchancing incidence of puccinia punctiformis, through mowing, to improve management of canada thistle (cirsium arvense). Biological Control 39 (2006) 481-488