2007 Annual Report 1a.Objectives (from AD-416) The objective is to evaluate the resistance of public and private soybean varieties and breeding lines to the most serious diseases present in the southern United States. 1b.Approach (from AD-416) The Delta Research and Extension Center, Mississippi Agricultural and Forestry Experiment Station, Stoneville, Mississippi, will obtain seed from the entries in the Mississippi Soybean State Variety Trials, which averages 205 entries in Maturity Groups IV-VI. Additional seed of Maturity Group III and breeding lines from the USDA soybean breeder at Stoneville will also be obtained. These varieties and breeding lines will be screened for resistance to the following diseases: (1). Stem Canker -- The Toothpick method of inoculation will be used to evaluate resistance to this disease; (2). Frogeye Leaf Spot -- Spores from selected races which are prevalent in Mississippi will be sprayed on the soybeans; (3). Cercospora blight, purple leaf stain -- Leaves and immature pods will be inoculated; (4). Charcoal rot -- Plants will be grown in field infested with the casual fungus; and (5). Soybean rust -- Entries planted in replicated plots will be evaluated for natural infection. Other foliar diseases of soybean will be evaluated if present in field plots. 3.Progress Report This report serves to document research conducted under a Specific Cooperative Agreement between ARS and Mississippi Agricultural Forestry & Experiment Station (MAFES). Additional details of the research can be found in the report of in-house project 6402-21220-007-00D, "Genetic and Cultural Methods to Reduce Soybean Yield Losses to Diseases and Environmental Stress." Three hundred and fourteen entries in the Mississippi State Soybean variety trials were evaluated for resistance to the following diseases: 1. Stem Canker; Entries were inoculated with toothpicks infested with the stem canker fungus and were rated for disease resistance. Early and late planted trials were conducted. Results were reported in Plant Disease Management Reports. 2. Frogeye leaf spot; Entries were sprayed with a spore suspension of frogeye leaf spot. In 2006, environmental conditions were not favorable to disease development and there was very little frogeye development in the trials. 3. Purple Pod Rot; Mature green pods were collected from each entry and sprayed with the fungus. Pods were incubated in a moist chamber and rated for disease development after two weeks. 4. Charcoal rot; Entries were inoculated with charcoal rot by incorporating charcoal rot infested grain in with the seed at planting. Plots were rated at harvest. Seed treatment fungicides were evaluated for control of Rhizoctonia and Pythium. Some trials were inoculated at planting. A trial was conducted to determine if seed treatment with a trizole fungicide would delay the onset of soybean rust or charcoal. There were some differences in charcoal rot development between the treatments. However, no rust developed in the trial. A series of five foliar fungicide trials were conducted to evaluated foliar fungicides. Environmental conditions were not favorable for disease development and very little disease developed in the trials. Foliar fungicide treatment did not significantly increase yields in 2007. There was no soybean rust present in the trials. ADODR used site visit and telephone conferences to monitor activities of the project.