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OREGON STATE UNIVERSITY

Department of Crop and Soil Science, Corvallis, OR 97331-3002 USA.

R.S. Karow.

Wheat was harvested from 955,000 acres in 1996 in comparison to 904,000 in 1995. Improved wheat prices spurred grower interest. A small amount of CRP acreage was returned to production. Exceptional rainfall in eastern Oregon lead to record high yields in many areas, including spring wheat yields equal to or better than winter yields in some locations. The estimated 1996 state-average yield is 70.8 bu/acre. Floods in western Oregon necessitated reseeding of fields where winter crops were drowned out or were weakened to the point where disease (mostly take-all) and weeds overwhelmed the crop.

Most acreage was again white common or club wheats (97.8 %), but red wheats have shown small gains in recent years. Grower interest is greatest in HRSW. Some growers have successfully attained white wheat yield levels, while achieving desired hard red protein levels. Because most fertilization is done during the fallow season, nitrogen was applied in anticipation of typical yields. The extremely high yields obtained in most areas resulted in low white wheat protein levels. The state average protein level, based on a random sampling of over 2,000-grain lots conducted by the Oregon Wheat Commission, was 9.3 % with a range of 5.3-15.6. Protein values less than 5.5 % also were observed in some research plots. Plots yields were in excess of 65 bu/acre at a location with a long-term yield average of 38 bu/acre.

No new wheat cultivars were released by Oregon State University in 1996, but releases of two common soft white winters, one winter club, one winter hard white, and one spring hard white are anticipated in 1997. Oregon's club wheat breeding program is now being run as a cooperative effort with Dr. Jim Anderson, USDA-ARS, in Pullman, Washington. The Oregon program is based out of the Columbia Basin Agricultural Research Center in Pendleton.

SOUTH DAKOTA

SOUTH DAKOTA STATE UNIVERSITY, AND USDA-ARS NORTHERN GRAIN INSECT RESEARCH LABORATORY (NGIRL)

Plant Science and Biology/Microbiology Departments, Brookings, SD 57007, USA.

Personnel.

Dr. Yang Yen has joined the SDSU faculty in the Department of Biology and Microbiology. He received his Ph.D in Agronomy from the University of Missouri-Columbia and was an assistant professor in the Department of Agronomy, University of Nebraska. Dr. Yen will teach cytogenetics and plant tissue culture and also participate in teaching plant physiology and cell biology. Dr. Yen will continue his research exploring the interphase between qualitative and quantitative genetics by studying the reciprocal recombinant chromosome lines between wheat cultivars Cheyenne and Wichita. Constructing chromosome-specific genomic DNA libraries for wheat is another project in his lab. After Dr. Yen's arrival at SDSU, Dr. Mingan You and Mr. Qihua Cai joined his lab as a research associate and research assistant, respectively.

Spring wheat breeding.

J.C. Rudd, B.G. Farber, Y. Jin, R. Rudd, S. Zhu, and R. Devkota.

Production. The 1996 HRSW production in South Dakota was 83.3 million bushels from 2.25 million acres. The average yield of 37 bu/acre is an all-time high, breaking the previous record set in 1992 of 34 bu/acre. The excellent yields were results of favorable growing conditions. Precipitation was timely but not excessive, and temperatures were below normal. Foliar diseases and head scab were less prevalent than in recent years. Durum production in the state was 720,000 bushels from 24,000 acres, with an average grain yield of 30 bu/acre.

New Release. SD3156, being released under the proposed name of Forge, is an early, standard-height, HRSW from the cross `Butte 86/SD8061'. The pedigree of SD8061 is `Sharp/Guard'. Forge has been in the SDSU advanced yield trials since 1993, the SDSU crop performance trials since 1994, in the Uniform Regional Hard Red Spring Wheat Nursery in 1994 and 1995, and in the Wheat Quality Council trials in 1995 and 1996. Forge is phenotypically similar to Butte 86 and Sharp, but is higher yielding, 1-day earlier, and slightly shorter. Yield is slightly less than that of Russ and Oxen. Test weight is equal to or greater than that of Butte 86, and the protein content is between those of Prospect and Butte 86. The cultivar is medium in protein content and is a mellow-mixing wheat. Forge is resistant to the prevalent races of stem rust in South Dakota but has shown moderately susceptible reactions in inoculated nurseries. Forge is resistant to the prevalent races of leaf rust and is equal to, or better than, 2375 for scab resistance.

Increase with intent to release. SD3249 is being increased with the intent to release in 1998. The line is an early, standard-height, HRSW from the cross `SD3080/Dalen'. The pedigree of SD3080 is `Butte 86/SD3004'. The most significant features of SD3249 are its high test weight and tolerance to head scab. The line has been in SDSU advanced trials since 1995 and was tested in the Uniform Regional Scab Nursery in 1995 and in the Uniform Regional Hard Red Spring Wheat Nursery in 1996. In comparison to Butte 86, SD3249 has a similar grain yield, 1-day earlier in heading, slightly taller, 2 pounds per bushel higher in test weight, and slightly higher in protein. SD3249 is resistant to the prevalent races of leaf and stem rust, and although it has better tolerance to scab than 2375, is not considered resistant. The scab tolerance of SD3249 can best be described as kernel retention in the presence of scab. Increase of SD3249 was put on an accelerated program because of its scab tolerance. We do not have the quantity of yield, agronomic, and quality data as we usually do before increasing with intent to release.

Fusarium head scab screening. The development of scab-resistant cultivars is the principal component of an integrated research effort energized by the scab epidemics of recent years. South Dakota State University is using both field and greenhouse screening to evaluate resistant sources and identify lines for advance. We currently evaluate and advance three generations per year (two in the greenhouse and one in the field) under inoculated mist-irrigated nurseries. Approximately half of the populations evaluated can trace the source of scab resistance to Sumai 3. The other half of the populations are crosses with various `field-tolerant', advanced breeding lines. Although the level of resistance in the advanced breeding lines is not as high as that found in Sumai 3-derived materials, they are very desirable agronomically and offer genetic variability. The breeding approach is to steadily recombine different resistance sources while at the same time selecting for resistance and desirable agronomics. We have a 200-m² greenhouse dedicated entirely to screening for scab resistance. Hills (5 seed/hill, hills 15 cm apart) are planted in soil-beds, misting begins before anthesis, and inoculum is by both spraying a spore suspension and spreading colonized grain. We can evaluate 4,500 hills in each greenhouse cycle (the autumn cycle is September-December, and the spring cycle is January-April). Survivors of the greenhouse cycles are then evaluated in a mist-irrigated field nursery for scab resistance and agronomics. The mist-irrigated field nursery is currently 1 acre and can be expanded to 6 acres at the current location. Inoculum is provided by both spraying at anthesis and spreading colonized grain.

Last winter we screened over 7,000 hills for scab resistance in the greenhouse. 1,073 selections survived the greenhouse screening and were planted in the field as head rows. These were evaluated for agronomics, and 185 were kept. These are currently being increased in Arizona with the intent of growing replicated yield trials in 1997. A sample from each of the selections is being screened again this winter in the greenhouse to verify the scab resistance.

With the objective of developing a technique to screen large numbers of segregating populations, three inoculation techniques were compared. Plants of 10 known varieties, three replications for each technique, were grown in three high-disease environments. The single floret inoculation technique was the most precise technique used and consisted of placing a single drop of inoculum in the central floret of each spike at anthesis. The plants were sprayed with a macroconidia suspension at anthesis and again 1 week later. Inoculum for the third technique was provided by spreading Fusarium-colonized wheat and corn seed in the plots on a weekly basis. Visual symptoms were recorded 21 days after initial inoculation, and the percent `tombstone' kernels was estimated after harvest. Highly susceptible and resistant cultivars or lines ranked similarly with all inoculation techniques and disease scoring systems. Ranking of moderately resistant and moderately susceptible cultivars was more dependent on technique or disease scoring system.

We concluded that the single floret inoculation is best for identifying resistance derived from Chinese germplasm, but spray inoculation appears to be a better choice to identify moderately resistant lines. To consistently identify moderately resistant lines, we have to evaluate kernels and visual symptoms on the spikes. Moderately resistant adapted lines will be extremely valuable, and we must continue to identify them until we have a high level of resistance bred into adapted germplasm.

Publications.

Rudd JC. 1996. Breeding spring wheat for scab resistance in the USA. In: Proc. Fusarium head scab: global status and future prospects (Dubin J ed). 13-17 October 1996, CIMMYT, Mexico (in press).

Rudd RC, Jin Y, and Rudd JC. 1996. Comparison of inoculation methods for greenhouse evaluation of Fusarium head blight in wheat. Agron Abstr p. 76.

Xu Y. 1996. Effects of Abscisic acid on wheat anther culture system. M.S. Thesis. South Dakota State University.

Zhu S and Rudd JC. 1996. Rapid selection for drought tolerance in wheat through anther culture. Agron Abstr p. 71.

Winter wheat breeding and genetics.

S.D. Haley, S.A. Kalsbeck, F. Hakizimana, Z. Zhang, and A. Bagci.

Personnel Change. In February, 1997, Mr. Steve Kalsbeck joined the winter wheat program as a Research Associate, succeeding the project technician (Roy Schut) who retired from service in May, 1996. Steve has farmed (occasionally winter or spring wheat, but mostly corn and soybeans) near the Estelline area for a number of years and brings both a positive attitude and a wealth of experience to the program.

Production. Winter wheat production in South Dakota in 1996 was estimated at 55.3 million bushels from 1.58 million harvested acres (2.0 million planted acres), for an average of 35 bu/acre. This yield level was 6 % less than the 1995 crop (37 bu/acre), but 3 % more than the average of the previous 5 years (34 bu/acre). Total production was the fifth highest on record and 18 % more than the average of the previous 5 years. Although total production and yield averages might be indicative of generally favorable production conditions, preharvest acreage losses (expressed as the percent difference between planted and harvested acreage) were 27 %, compared to the 14 % average loss experienced over both the previous 5- and 10-year periods.

The high level of acreage loss in 1996 was attributed to both an above-average level of winterkill and unusually severe soil blowing conditions in the spring (particularly 22-26 April). In many areas, important factors contributing toward the losses were delayed planting, because of high grasshopper populations in the autumn, dry soil conditions at planting, and reduced crop growth in response to cool temperatures in the fall. Stand reductions during the winter and early spring contributed in many cases to a delay in crop development (because of enhanced soil moisture conditions in the reduced stand) and average heading dates as much as 2 weeks behind normal. The delay in crop development fortunately did not lead to reduced yields, because of untypical cool weather that occurred throughout the grain-filling period.

In addition to stand losses during the winter, leaf spotting diseases (tan spot and Septoria) also were significant adverse factors for production throughout the state. In many cases, infection levels were as high in conventional summer-fallow plantings as they were in stubble-back plantings. Although other disease and insect problems have not been major problems over the last few years (most notably stem rust and wheat streak mosaic virus), breeding efforts to address these problems will be continued.

Testing Sites. In 1996, the winter wheat breeding program conducted testing at nine sites in South Dakota. These environments included: both Aurora and Brookings (Brookings Co.); Watertown (Codington Co.); Highmore (Hyde Co.); Selby (Walworth Co.); Winner (Tripp Co.); Wall (Pennington Co.); and both irrigated and dryland environments at the Dakota Lakes Research Farm east of Pierre (Hughes Co.). In addition to these testing environments, collaborative testing of the South Dakota Advanced Yield Trial (AYT) was made at Bison, SD (Perkins Co., in cooperation with Clair Stymiest and John Rickertson at the SDSU West River Agricultural Research and Extension Center, Rapid City) and Hemingford, NE (in collaboration with Dr. P. Stephen Baenziger, University of Nebraska, Lincoln).

Management of two of the main breeding sites, Selby and Winner, was altered slightly for the 1996 crop year. At Winner, planting will be no-till into spring wheat stubble, an increasingly popular production practice in South Dakota. This planting regime will potentially provide an environment favorable for the development of tan spot and Septoria leaf spot diseases and allow more consistent and predictable disease pressure for selection purposes. Conversely, planting at Selby will be no-till into pea stubble, a production environment where diseases will be less important, but where differential winter survival responses would be expected on a more consistent basis.

Collaborative testing with programs in adjacent states also is being given increased attention. The winter wheat breeding program at North Dakota State University was discontinued after the loss of a breeder in 1996. We have initiated a cooperative arrangement with Dr. Erik Eriksmoen, the NDSU Agronomist at Hettinger, North Dakota, for testing of the South Dakota Advanced Yield Trial because the North Dakota testing environments are quite useful to our program. This trial location, in addition to the continued testing of the AYT in the Nebraska panhandle, will prove valuable in determining the range of adaptation of materials developed by the breeding program.

As for producers, the 1996 crop year was a very difficult year for the breeding program. Several sites were lost to a variety of conditions: at Watertown, nurseries were lost due to near-complete winterkill; at Aurora, the nurseries were abandoned following a high level of winterkill that was extremely variable throughout the field; at Highmore, winter annual weed pressure (especially cheatgrass) overran the yield nurseries; at Wall, poor fall stand establishment, winterkill, blowing, and finally hail took their toll and nothing was left to harvest; at Dakota Lakes (in the dryland plot only), winterkill, followed by a high level of cheatgrass pressure (especially where stands were thinned during the winter), made some of the nurseries too variable for reliable data interpretation.

Cultivar releases and foundation seed increases. A new cultivar, named Windstar (tested as NE90625), was released for the autumn 1996 planting. Windstar was developed by the University of Nebraska and released cooperatively with the USDA-ARS and the South Dakota Agricultural Experiment Station. In South Dakota, Windstar is a medium-late (similar to Rose) and medium-height (similar to Arapahoe) HRWW with good winter hardiness and a very short coleoptile (similar to Alliance). Windstar is moderately resistant to stem rust and moderately susceptible to both leaf rust and WSMV. In 2 years of testing in the South Dakota Crops Performance Testing (CPT) Variety Trial, Windstar has performed very well in many areas of the state. End-use quality data (consisting of grain protein measurements in South Dakota and milling and baking data from the regional testing program) suggest that Windstar would be most closely comparable with Alliance, Niobrara, and Redland.

Two winter wheat experimental lines are under increase with the intent to release in autumn, 1997. The first of these, SD89119 (pedigree: Brule/Agate), is a medium-height and medium-maturing (similar to Arapahoe) HRWW with good winter hardiness, exceptional end-use quality characteristics and good yield performance in its maturity range. In 4 years of testing in the CPT Variety Trial, the average yield of SD89119 has been roughly equal to that of Arapahoe, with about a 1.5 lbs/bu test weight advantage over Arapahoe. SD89119 is moderately resistant to prevalent races of the stem rust pathogen, and susceptible to leaf rust, tan spot, Septoria leaf blotch, and WSMV. The coleoptile length (considered important for optimum autumn stand establishment) of SD89119 is very long (similar to that of Scout 66) and the straw strength is considered medium (similar to Roughrider and Arapahoe). This experimental line would be positioned as a high end-use quality replacement for Siouxland and complement to Arapahoe.

The second experimental line on large-scale increase, SD89153 (pedigree: TAM-105/Winoka), is a medium-late maturity, standard-height (very similar to Rose) line with good winter hardiness, good end-use quality characteristics, and superior yield performance in its maturity range. In 3 years of testing in the CPT Variety Trial, the average yield of SD89153 has been about 1-2 bu/acre greater than Rose and Seward with a higher test weight than any other entry in the trials (0.5 lbs/bu advantage over Rose, 2.5 lbs/bu advantage over Seward). SD89153 is moderately susceptible to prevalent races of the stem rust pathogen and susceptible to leaf rust. SD89153 is resistant in greenhouse seedling screening with isolates of the Septoria leaf blotch pathogen and has shown good leaf spotting scores in field nurseries. Greenhouse seedling screening with South Dakota isolates of WSMV suggest a moderate level of tolerance (slightly less than that of Dawn, but greater than that of most available varieties). The coleoptile length of SD89153 is very long (similar to that of Scout 66) and the straw strength is considered good (slightly better than that of Rose). This experimental line would be positioned as a high end-use quality replacement for both Rose and Seward.

Three advanced experimental lines are under preliminary foundation seed increase (4-6 acres) for earliest possible release in autumn, 1998. These lines are as follows:

- SD92107 (Brule//Bennett/Chisholm/3/Arapahoe) is a medium-height and medium-maturity (similar to Arapahoe) HRWW with very good winter hardiness, a long coleoptile, good test weight and quality characteristics, and superior yield performance in its maturity range. SD92107 possesses a very broad disease resistance package being resistant or moderately resistant to stem rust, leaf rust, WSMV, and leaf-spot diseases (tan spot and Septoria).

- SD92191 (OK81306//SD82102/Norwin) is a medium-tall, medium-late (similar to Roughrider) HRWW with very good winter hardiness, a very long coleoptile, good test weight and quality characteristics, and superior yield performance in its maturity range. SD92191 is moderately resistant to stem rust, moderately susceptible to leaf-spot diseases (tan spot and Septoria), and susceptible to leaf rust and WSMV.

- SD92227 (SD76463-16//SD82195/SD82144) is a medium-height and medium-maturity (similar to Arapahoe) HRWW with very good winter hardiness (similar to that of Roughrider), a medium-long coleoptile, and good test weight and quality characteristics. SD92227 also possesses a very good disease resistance package, being moderately resistant to stem rust, leaf rust, WSMV, and leaf-spot diseases (tan spot and Septoria).

Coleoptile length. Mr. Frederick Hakizimana is nearing completion of thesis research on various aspects of coleoptile length measurements. Results obtained thus far provide clear evidence that seed source has little effect on the repeatability of the coleoptile length testing procedure, a finding with very practical implications for our screening procedures. A simultaneous survey of Great Plains wheat germplasm sources for semidwarfing genes and coleoptile length should provide additional information on the distribution of semidwarf genes and adapted sources of such genes that do not tend to reduce coleoptile length compared to standard height genotypes.

Wheat streak mosaic virus. In collaboration with Dr. Marie Langham, SDSU Virologist, Mr. Frederick Hakizimana will be continuing with Ph.D. research to evaluate several aspects of WSMV resistance or tolerance. During winter 1995-96, very promising results from our greenhouse WSMV screen were obtained, with very consistent reactions being observed and checks of known response reacting as expected. As a follow-up, Mr. Hakizimana is working to extend the screening procedure to a blast-inoculated field nursery to test the association between the greenhouse tolerance ratings and yield reduction in response to WSMV. Additional plans are to examine the genetic control of tolerance in several promising genotypes, which were identified in the greenhouse testing procedure.

Leaf spotting diseases. A new graduate student, Ms. Xiuling Zhang, joined the program in January 1996 to work toward an M.S. degree. Ms. Zhang has worked for several years with the Wheat Germplasm Institute at the Chinese Academy of Agricultural Sciences. Working collaboratively with Dr. Yue Jin, Ms. Zhang has developed and refined routine greenhouse seedling screening procedures for both tan spot and Septoria leaf blotch. Ms. Zhang also has developed a diallel set of crosses to examine combining ability of several promising sources of resistance. Ms. Zhang is now a research associate in Dr. Jin's program as of December, 1996.

Wheat end-use quality. A new graduate student, Mr. Ahmet Bagci, joined the program in September, 1996, to begin work on an M.S. degree. Mr. Bagci has been working for several years with the CIMMYT program in Turkey and comes to us with funding from the World Bank (administered through Winrock International). Mr. Bagci's thesis research will focus on integrating computerized mixograph (recently purchased by the South Dakota Crop Improvement Association) and SDS-sedimentation tests into our quality testing procedures and determining the utility of these techniques in predicting composite baking parameters.

World Wide Web (WWW) home page. In May 1996, a home page for the winter wheat breeding and genetics program was launched on the Internet's World Wide Web. On this page, visitors can learn about the program and personnel, and also access such information as: current winter wheat variety trial data, annual reports, data from current screening activities, and links to other wheat-related information resources on the Internet. As time allows,

we plan to continue to update the page with information of interest to winter wheat producers in South Dakota. The URL (Internet address) for the home page is: <http://www.sdstate.edu/~wpls/http/winwheat/wwhome.html>.

Soil fertility and production research.

H. J. Woodard, A. Bly, and D. Winther.

An experiment investigating the effect of applied N on 15 hard red winter and hard red spring wheat varieties representing differing maturity dates was conducted at Brookings, SD. The fertilizer N treatments consisted of either a control N treatment where no N was applied or a recommended N rate as ammonium nitrate (dry 34-0-0) broadcast on the surface after planting. Early shoot tissue growth was sampled at early jointing (Feeke's stage 5-6) and soft dough stages (Feeke's stage 11.3). Grain was harvested for yield and other parameters. The grain yield from early-maturing varieties was the greatest, because of the advancement of physiological maturity before the onset of heat and drought stress that was observed later in the grain fill period for later maturing varieties. Significantly higher early shoot tissue and soft dough growth were observed with the recommended N rate compared to the control N treatment. Grain test weight and yield were statistically unaffected by N treatment. However, there were indications that differences exist in N-use efficiency among varieties for vegetative growth, even when the temporal effects of stress were considered.

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