CEREAL RUST BULLETIN Report No. 7 June 18, 2002 Issued by: Cereal Disease Laboratory U.S. Department of Agriculture Agricultural Research Service University of Minnesota 1551 Lindig St, St. Paul, MN 55108-6052 (612) 625-6299 FAX (651) 649-5054 markh@cdl.umn.edu For the latest cereal rust news from the field, subscribe to the cereal-rust-survey mail list. To subscribe, send an email message with the word subscribe in the message body (not subject line) to: cereal-rust-survey-request@coafes.umn.edu Reports from this mail list as well as all Cereal Rust Bulletins are maintained on the CDL website (http://www.cdl.umn.edu). ------------------------------------------------------------- Wheat leaf rust is widespread from South Dakota to Ohio. Wheat stripe rust is widespread, but lighter than last year throughout the central U.S. ------------------------------------------------------------- Winter wheat harvest has begun from southern Indiana to southern Kansas. Most of the northern planted spring small grains are near the normal growth stage for this time of the year. Wheat stem rust. There have been no new reports of wheat stem rust in the U. S. since CRB #6 (http://www.cdl.umn.edu/crb/2002crb/01crb6.html) when stem rust infections were very light in a plot in central Kansas. Wheat leaf rust. During the second week in June, trace-40% leaf rust severities were reported in plots and traces in fields of soft red winter wheat cultivars from northeastern Missouri to northwestern Ohio (Fig. 1) at the early to late berry maturity stage. One exception was a 60% severity reading in a field of a susceptible cultivar in northwestern Ohio. The cooler than normal temperatures during the last part of May and first part of June slowed leaf rust development. This year in Kansas, leaf rust was severe in the southern part of the state in late May, but then hot temperatures slowed rust development and with the crop near maturity, less rust was produced for areas further north. By the second week in June in southeastern Nebraska fields, leaf rust incidence ranged from 30 to 100% and the leaves had 2 to 200 pustules per leaf. Drought-like conditions in areas like western Nebraska has slowed leaf rust development. By mid-June, light leaf rust was observed on the flag leaves of hard red winter wheats in an east central South Dakota nursery. During the third week in June, 10% leaf rust severities were observed at the anthesis maturity stage in susceptible winter wheat in east central Minnesota plots. Infections were noted on flag and flag-2 leaves which probably means there were two spore showers. One that occurred within the last 7-days and one that occurred 16 to 21 days ago. Another interesting observation was the infections on cultivars with Lr9 resistance which is unusual for these plots. Traces of leaf rust also were observed on the susceptible spring wheat Baart at the east central Minnesota station. Weather conditions are ideal for further rust development in these plots. Traces of leaf rust were found in two fields in northwestern Minnesota the third week of June. In early June, 50- 75% leaf rust severities were found on susceptible cultivars in a nursery in western Virginia and east central Maryland. Traces of leaf rust were found in central New York fields in mid-June . Light leaf rust was observed in southwestern Ontario in mid-June. Wheat stripe rust. In mid-June, trace to 10% stripe rust severities were observed in plots and traces in fields of soft red winter wheat cultivars in northeastern Missouri to northwestern Ohio. In mid-June, traces of stripe rust were found in winter wheat plots in south central Wisconsin. Stripe rust development in the northern soft red winter wheat growing area is less than last year on the same date. Conditions were conducive for rust development in May but then moisture became the limiting factor in many areas and rust development ceased. Since early June, there have been no new reports of stripe rust development in the northern hard red winter wheat area. In mid-June, stripe rust was found in east central Maryland wheat plots. In mid-June in eastern and central Washington, stripe rust was increasing on susceptible cultivars. Weather conditions have been conducive for rust increase in eastern Washington. Oat stem rust. There have been few reports of oat stem since CRB #5 (http://www.cdl.umn.edu/crb/2002crb/02crb5.html). Oat crown rust. Traces of crown rust were found in a field in southeastern Iowa. Buckthorn. Moderate to severe crown rust infection was observed on lower leaves of oat in spreader rows close to the St. Paul, Minnesota buckthorn nursery. Barley stem rust. There have been no more reports of barley stem rust this year. Barley leaf rust. There have been no new reports of barley leaf rust since CRB #5. Stripe rust on barley. In mid-June, stripe rust was severe on susceptible barley varieties in central Washington and starting to increase on varieties in eastern Washington fields. Rye leaf rust. In mid-June, traces of leaf rust were reported in a rye field in northeastern Indiana. Rye stem rust. There have been no reports of rye stem rust this year. Stem rust on barberry. In mid-June, aecial infections were common on common barberry bushes in southeastern Minnesota.