The meeting convened at 1:00 p.m. on 25 June in Fort Collins, Colorado. Local arrangements were by Joe Hill and Bill Brown, Colorado State University. Approximately thirteen individuals participated (Table 1). The following information was discussed at the afternoon business meeting:
Our administrative advisor, Don Mathre, noted that we are now a Western Coordinating Committee rather than a Western Regional Coordinating Committee. The group is currently approved for three more years, until 2000. He further suggested that we would benefit through development of an electronic bulletin board and a homepage. Tim Murray has made a start on a homepage, and offered the Plant Pathology Department at WSU as the home for the page. Bob Forster volunteered to help on this effort. Tim further suggested the development of a Web Board, a persistent bulletin board wherein one can see both questions and responses in a continuing and organized fashion. Bob Johnston volunteered to help with this effort. The address for the Web Board would be plantpath.wsu.edu/wcc97. Topics to be included might be new diseases, problems in diagnosis, etc.
It was decided that further efforts will be made to involve midwestern participants, including Yue Jin from South Dakota and staff from Nebraska.
WCC-97 will meet in the Red River Valley in 1998, hosted by either the University of Minnesota or North Dakota State University.
California - The California wheat crop consists of spring cultivars that are fall-sown. For 1997, there are 510,000 acres of common wheat and 130,000 of durum. The acreage is down by 20% this year, primarily in response to uncertainty regarding the Karnal bunt embargo. There also was a significant loss of acreage in some locations due to flooding. Weather initially was wet and cool, followed by a dry period from February through May, and then some rainfall at harvest. Harvest was about two weeks earlier than normal. Yecora Roja acreage has been reduced in the San Joaquin Valley due to reductions in the seed market. There also currently are 100,000 acres of greenchop and 50,000 acres of durum wheat in the San Joaquin Valley. These changes have potential implications for development of wheat leaf rust. Barley acreage is about 250,000 acres.
Karnal bunt - There is not as much concern now that regulatory actions are based on bunted kernels rather than spores.
Stripe rust - early harvest reduced losses due to leaf and stripe rust on both wheat and barley. Nevertheless, there was still significant yield loss on susceptible barley cultivars. There are some decent resistant barley lines in the pipeline. In one strip-test, yield increased from 2,000 to 5,200 lbs./acre on the susceptible barley cultivar UC337. [Bill Brown noted that Folicur gives better protection than Tilt under severe barley stripe rust pressure; Bayleton will be pulled and replaced by Folicur.] Stripe rust was found on some wheat lines that are in the pipeline for release. Some stripe rust foci were seen last year on Express, the dominant cultivar in the Sacramento Valley.
Septoria - Septoria had a good start but did not develop subsequently.
Cal Qualset has been replaced by George Dubkoski.
Colorado - 2.8 million acres of wheat were planted in Colorado. Weather was unusually dry in winter and early spring. However, rains began in May and an average yield of 34 bushels/acre is expected.
There were no foliar, fungal diseases seen early in the season. However, some barley yellow dwarf virus, wheat streak mosaic, and Russian wheat aphid were seen. The new cultivar "Halt" is resistant to the Russian wheat aphid, but very susceptible to leaf rust.
The popularity of TAM 107 seems to have decreased the incidence of wheat streak mosaic because the mite does not prefer it. There is now a new biotype of the leaf curl mite that has attained 90% of the population in Kansas. Tam 107 and Halt are very susceptible to the disease. They become infected in the fall, but the infection then burns out. If it returns, it comes in late.
There was an epidemic of the High Plains Disease in the southwest corner of Colorado, perhaps because of early planting dates. Some fields had an incidence of 20%.
There has been an increase over the years in bacterial diseases on irrigated wheat in the San Luis Valley.
Idaho - Both the winter and spring crops are several weeks ahead of normal. Timely rains in June should provide for good yields. There were no widespread diseases this season.
Black chaff on wheat has not been a big problem in recent years, however samples have begun to come in this season, about a month earlier than normal. The southwest portion of the state is seeing quite a bit of black chaff, despite the fact that this usually is not a black chaff area. Elevated levels also are being seen on barley, where the correct name is now considered to be bacterial blight of barley.
In early season, necrotic spots were noted on seedlings that had high levels of fluorescent pseudomonads. In the past, have isolated Pseudomonas syringae pv. tabaci. Lesions look like spot blotch with chlorosis. The disease does not seem to develop past the early tillering stage.
Wheat streak mosaic - Incidences as high as 40-50% have been seen, but confined to spring wheat. This could be related to elevated temperatures in 1997. Mixed infections of wheat streak mosaic and high plains virus were found in sweet corn.
Cephalosporium stripe - has now been found in southern Idaho in a potato/winter wheat rotation.
Eyespot - Received a sample from southern Idaho with the most severe symptoms yet seen from that area.
Flag smut - was severe in two fields in southern Idaho where the disease apparently was present the previous year.
Tom Holtzer is now head of the Bioagricultural Sciences and Pest Management Department.
Minnesota - The crop was planted late due to snow. About 6% of the crop is headed at this time, as compared with the normal of 20% or more. Not many diseases were seen until the last week or two. Septoria and tan spot were just starting to be reported. The southern part of the Valley has been dry.
Fusarium head blight continues to be the biggest emphasis. Yield loss due to head blight in Minnesota was 33, 18, 5-8, and 5% in 1993, 94, 95, and 96, respectively. The decrease is partly due to a change in weather. There also has been a very rapid change towards less susceptible cultivars, especially 2375, which occupied 70% of the acreage in 1994. 2375 becomes infected, but fills kernels rapidly and in the presence of the toxin. The resistance in 2375 is not a Chinese source. 2375 is now declining in popularity due to agronomic problems. There are many resistant lines in the pipeline for release, with most carrying resistances from Chinese material. Head blight is more severe on durum wheat, and production of durum is now moving to the west in an attempt to escape the disease. All of resistance screening is being done with Fusarium graminearum. Seed treatments have been found to be effective in preventing the seedling blight phase of the disease. UM is hiring a molecular biologist in the Agronomy Department to look at head blight.
Montana - A predominant snow cover that fell on warm ground has made for favorable conditions for dwarf bunt. Flecking and distortion of leaves due to dwarf bunt have been seen. Dwarf bunt resistant lines in nurseries are not showing these symptoms. Fertility problems such as nitrogen deficiency are being seen due to high precipitation and cold temperatures.
In the northwest part of the state, dwarf bunt is a severe problem, and the white winter wheats have been severely affected by snow mold. However, this is a small portion of the state acreage, though the area has a high yield potential.
Barley yellow streak virus is a recurring problem in some areas. Plants appear gray early on. The vector dissipates after an inch of rain, but plants remain stunted. Yield loses of 25-30% can be experienced if have early drought and high populations of the vector (the wheat brown mite). The virus passes through the eggs of the brown wheat mite. Symptoms are similar to wheat streak mosaic. Often, just half of the leaf will show symptoms. The driving factor seems to be continuous barley.
In central Montana, there have been many rain events since Memorial Day. Expect to see many foliar diseases that have not been seen in recent years. Have seen many lesions that look like tan spot, many more than normal.
About 50% of Montana acreage is now planted into standing stubble, often using an air seeder. There seems to be much less disease associated with this practice. By 2000, 90% of spring wheat will be direct drilled into standing stubble, though it does not provide as good a stand as winter wheat.
Canadian workers have developed near-isogenic lines with and without resistance to common root rot. These lines were tested in five locations, with and without imazalil and other seed treatments. No yield responses were seen despite favorable conditions for the disease.
The new Barley Compendium may be out in September or October of 1997. A new Bioscience Building is under construction at Montana State University. MSU recently received a $500,000 grant to work on Karnal bunt. They must either work with dead spores or do work with live spores at the Fort Detrick facility.
Oregon - The 1996 average yield was 72 bu/acre, due to record rainfalls. In 1997, the state is seeing good rainfall but are expecting only average yields. The crop is ahead of normal in the Willamette Valley. In eastern Oregon, the crop is behind due to cold weather; rains have been ample and timely. Approximately 1 million acres of wheat were planted, about 80% winter and 20% spring. The increase in spring plantings was caused by higher rainfall and an increase in the practice of planting continuous spring wheat. Dick Smiley's work with continuous spring wheat indicates that such crops can look very ugly (uneven height, whiteheads, etc.), but yields look extremely good, often equal to a winter crop. Soil erosion during the 1996-97 winter wheat season has been very severe due to heavy rains.
In eastern Oregon, eyespot has been promoted by early-season rains, and more fungicide than usual has been sprayed. Resistant varieties are often planted in areas where the disease has historically been a problem. Cephalosporium stripe is still probably the #1 disease problem in eastern Oregon, though severity of the disease will likely be average or below average in 1997. Fusarium and Rhizoctonia root rots continue to be a problem in some areas. There has been little stripe rust this year due to adult plant resistance in common soft white winter wheats, adult plant resistance in the club wheat cultivar Rohde, and the use of club wheat cultivar mixtures. Some stripe rust problems may yet develop in spring crops. BYDV is present, but not very severe. Physiological leaf spot is not as severe as in some previous years?
The Septorias, especially S. tritici, are a continuing problem in the Willamette Valley and nearly every wheat field is sprayed for Septoria control. The resistance of the cultivar Gene to S. tritici has broken down. There currently is an increased emphasis on selection for moderate resistance, which may be more stable and also counter selection for increased pathogen aggressiveness as compared with susceptible cultivars. The new variety "Foote" possesses a very good level of such resistance. Leaf rust has begun to develop in the Willamette Valley late in the season, but will likely cause little yield reduction. In recent years, leaf rust has been reduced due to the presence of Septoria lesions and because fungicides applied for Septoria control also are effective against rust.
The cultivar Stephens still occupies 53% of the Oregon wheat area, 20 years after its release. The next most popular cultivar is Madsen, due to its resistance to eyespot, Cephalosporium stripe, and Septoria. The third most popular "cultivar" in Oregon is now cultivar mixtures, which continue to increase in popularity. The cultivar Rod is likely to increase in popularity due to its high and consistent yield potential and moderate resistance to Cephalosporium stripe.
There is currently an increased emphasis on screening for resistance against eyespot (using the isozyme marker for the VPM resistance, evaluating other sources of resistance, etc.) and Cephalosporium stripe (through development of a hydroponic, seedling-based screen).
Barley stripe rust seems to be well established in the Klamath Basin, but not yet in eastern Oregon. Progress continues on development of resistant barley cultivars.
Warren Kronstad will be retiring within the next 1.5 years. Cindy Ocamb has joined OSU as the new plant pathology specialist in charge of field and vegetable crops.
Washington - The current crop consists of 2.15 million acres of winter wheat, 400-450,000 acres of spring wheat, and 450,00 acres of spring barely. Good seedbed moisture allowed for good crop establishment at appropriate times. There was an October snowfall that stayed on the ground for 150 days, which ties the previous record for snow cover. Eltan is grown widely in snowmold country, and the crop is looking pretty good. Snow mold delays wheat maturity, but this probably will not be a problem. There was good winter survival throughout the state. The spring was cooler and wetter than normal, resulting in delayed spring planting and a winter crop that is 2-3 weeks behind normal. Fertility problems have been seen because of nutrient leaching caused by high precipitation.
Overall, disease problems seem to be less than average. There is some eyespot in low and intermediate rainfall areas due to timely rains, and more fungicide than normal is being applied in these areas because Madsen is not normally planted. Overall, however, eyespot is not very severe. Cephalosporium is present, but not in epidemic proportions. Eltan seems to have best resistance to Cephalosporium stripe among those cultivars tested. Under severe conditions, Eltan yielded 100 bu./acre, while Stephens was only at 30-35 bu./acre. Eltan also has excellent noodle quality, but does not have eyespot resistance. Physiologic leaf spot is severe in some areas, while there is only a little BYDV in scattered foci that did not spread.
Dry weather in May significantly slowed rust development. Both stripe rust and leaf rust are starting to increase in the Pullman area, but the soft white winter wheats in the Palouse region are very resistant. Leaf rust came in late on the winter wheats, and the spring wheats have good resistance. Hard reds and clubs were heavily rusted last year, but yield potential also was very high. Therefore, hard reds were sprayed for the first time. There is now an emergency label for Folicur on barley in Idaho, Oregon, and Washington and on wheat in Washington. Barley stripe rust was very heavy in western Washington. Tilt, Folicur, and Quadras all gave good control; Bayleton did not perform as well. There may be a label coming to extend the application time of Tilt past flag leaf emergence. Rely, a multiline is still the major club wheat cultivar in Oregon, and is holding up well.
Rollie Line is currently updating the expert system "MoreCrop" to include new geographic areas, new cultivars, and program changes.
In terms of personnel, Hei Leung has moved to IRRI, but his position will be replaced. They have also received permission to refill the western Washington extension plant pathology position. They have not yet received permission to refill Otis Maloy's position.
A barbecue and continuing discussions were provided at Bill Brown's home in the evening. Discussion continued on 26 June during the field tours, which included visits to Colorado State University pathology and breeding plots and the Anhauser-Busch malting and research/breeding facilities.
Table 1. Participants in the 1997 WCC-97 meeting.
Dan Biggerstaff Western Plant Breeders
Bill Brown Colorado State University
Ruth Dill-Macky University of Minnesota
Lee Jackson University of California at Davis
Bob Forster University of Idaho
Bill Grey Montana State University
Joe Hill Colorado State University
Bob Johnston Montana State University
Rollie Line USDA-ARS, Washington State University
Don Mathre Montana State University
Chris Mundt Oregon State University
Tim Murray Washington State University
Jack Riesselman Montana State University