COLORADO
COLORADO STATE UNIVERSITY
Department of Soil and Crop Sciences, Ft. Collins, CO 85023, USA.
S. Haley, J. Stromberger, B. Clifford, S. Clayschulte, T. Mulat, E. Ball, A. Brown, F. Pardina-Malbrán, M. Collins, and J. Butler.
Production conditions, test sites, and variety distribution. Total winter wheat production in 2002 was estimated at 36.3 x 10^6^ bu, a 60 % decrease from the 2001 crop and 57 % lower than the 5-year average. Average grain yield, at 22 bu/acre, was 3 1 % lower than in 2001 and 38 % lower than the 5-year average. The area harvested for grain was estimated at 1.65 x 10^6^ acres, down from 2.0 x 10^6^ in 2001.
In 2001-02, the breeding program conducted field trials at four main locations in eastern Colorado (Akron, Burlington, Julesburg, and Walsh) in addition to the main location at the ARDEC research facility near Fort Collins. Overall, environmental conditions experienced at these locations were highly adverse for successful wheat test-plot research and selection. At Akron, timely planting with good soil moisture led to excellent stand establishment, autumn growth, and spring regrowth. Sustained high temperatures and drought stress during spring and summer reduced yield (to about 70 % of average) and limited the expression of yield differences among test entries. At Burlington, timely planting with good soil moisture led to good stand establishment and autumn growth. Dry soil conditions during the winter, and moderately cold air and soil temperatures, combined to induce a low level of winter injury, particularly in materials with marginal adaptation. High temperatures and a nearly complete lack of spring and summer precipitation led to abandonment of all trials prior to harvest. At Julesburg, later than normal planting (1 October) led to reduced establishment and autumn growth. Spring regrowth was accompanied by dry soil conditions that extended through to harvest and reduced yield (to about 75 % of average) and limited the expression of yield differences among test entries. At Walsh, marginal soil moisture at planting (and extending through to harvest), combined with moderately cold soil temperatures during winter, led to poor stands, significant winter injury, excessive nongenetic field variation, and subsequent abandoning of most of the breeding trials (with the exception of the Dryland Variety Trial, UVPT) prior to harvest. At Fort Collins (irrigated location), timely planting and good soil moisture led to excellent establishment, autumn growth, and spring regrowth. Delayed spring irrigation (first irrigation 1 May), a severe spring freeze event (9 May), and a severe hailstorm 2 weeks prior to harvest collectively resulted in low and erratic yields.
In cooperation with the CSU Variety Testing Program under the direction of CSU Extension Agronomist Dr. Jerry Johnson, cultivars and experimental lines also were tested at six dryland trial locations (UVPT; Bennett, Briggsdale, Cheyenne Wells, Genoa, Lamar, and Sheridan Lake) and three irrigated trial locations in Colorado (IVPT; Haxtun, Rocky Ford, and Center in the San Luis Valley). Growing conditions at each of the UVPT locations were very much similar to the four main, dryland-breeding locations, with winter injury, spring freeze injury, high temperatures with dry winds, and severe drought stress complicating evaluation and selection. Only two of the six UVPT locations were harvested (Lamar and Bennett), although excessive nongenetic field variation at Lamar made the data of very questionable value for selection and cultivar recommendation. The Genoa location was not harvested because of a severe hailstorm prior to harvest, whereas the Briggsdale location was not harvested because of severe spring freeze injury. The Sheridan Lake and Cheyenne Wells locations were not harvested because of severe winter injury as a result of very dry soil conditions and moderately cold winter temperatures. Both the Rocky Ford and Haxtun IVPT locations were successfully harvested, although yields were reduced somewhat below optimum because of high temperatures and dry winds throughout spring and summer. The Center IVPT location, added in 200102 as an official IVPT testing location, was abandoned in the spring due to a high level of winter injury.
Very little or no virus (BYD or WSM) or insect (RWA, greenbug, or bird cherry-oat aphid) pressure was observed at any of the wheat trial locations. Common dryland root rot was observed at several dryland trial locations and adversely affected yield. A low level of stripe rust infection was observed at the Haxtun IVPT location, much lower than the epidemic observed in 2001. Leaf rust was observed at very low levels at both the Haxtun IVPT location and the Fort Collins-ARDEC irrigated location.
Planted acreage estimates for the 2002 crop were as follows: Akron - 25.3 %; Prairie Red - 13.9 %; TAM 107 - 13.6 %; Jagger - 6.7 %; Yumar - 4.8 %; Lamar - 3.6 %; Prowers - 3.5 %; Enhancer - 2.7 %; Halt - 2.6 %; Prowers 99 - 2.4 %; Trego - 2.4 %; Alliance - 2.3 %; TAM 110 - 2.3 %; and Yuma - 2.1 %.
New releases. In August 2002, one new winter wheat cultivar was formally released. The new cultivar, named Ankor, was derived from the crosses and backcrosses 'Akron/Halt//4*Akron' (about 94 % Akron parentage) made between 1994 and 1998. Halt and Akron are cultivars released by CSU in 1994. Halt has the Dn4 gene, the source of RWA resistance in Ankor. Ankor is an awned, white-chaffed, medium-maturity, semidwarf HRWW. Ankor is medium maturing (144.8 days to heading from 1 January), about 3.5 days later than Prairie Red and similar to Akron. Plant height of Ankor is medium-short (30.1 inches), 1.7 inches taller than TAM 107 and similar to Akron. Coleoptile length of Ankor is slightly less than that of Prairie Red and similar to that of Akron. The straw strength of Ankor is good, slightly better than that of Akron based on limited evaluation and observation in the 2002 Irrigated Variety Performance Trial (IVPT). Ankor was tested in Colorado Dryland Variety Performance Trials (Colorado UVPT) during 2001 and 2002. Averaged over eight dryland trial locations in 2001, Ankor (41.6 bu/acre) yielded less than Akron (43.2 bu/acre) and greater than Prairie Red (40.7 bu/acre). Averaged over three dryland trial locations in 2002, Ankor (33.7 bu/acre) yielded more than Akron (33.2 bu/acre) and less than Prairie Red (34.6 bu/acre). Averaged over 11 locations in 2001 and 2002, Ankor (39.4 bu/acre) yielded more than Prairie Red (39.0 bu/acre) and less than Akron (40.4 bu/acre). Test weight averages from dryland trials in 2001 and 2002 show that Ankor (56.8 lb/bu) has similar test weight to both Akron (57.0 lb/bu) and Prairie Red (56.8 lb/bu). Ankor was tested in Colorado Irrigated Variety Performance Trials (Colorado IVPT) during 2002. Averaged over three irrigated trial locations in 2002, Ankor (78.9 bu/acre) yielded more than Akron (69.5 bu/acre), Prairie Red (73.2 bu/acre), and Yumar (74.6 bu/acre). Linear regression analysis of yield response from low-yielding dryland to high-yielding, irrigated conditions suggests that Ankor may have a more favorable yield response at higher dryland and irrigated yield levels than Akron. On the basis of field evaluations in Colorado and coöperative evaluations through the USDA Regional Testing Program, Ankor has a similar response to that of Akron to prevalent diseases and insects in the westcentral Great Plains. Ankor is moderately resistant to stem rust, susceptible to leaf rust, and susceptible to both WSMV and BYDV. Ankor is susceptible to the Great Plains biotype of Hessian fly, susceptible to greenbug, and resistant to RWA. Milling and bread baking quality of Ankor was evaluated from multi-location grain composite samples collected in 2000 and 2001 and four individual-location, grain samples collected in 2001. Relative to the recurrent parent Akron, Ankor had very similar average values for key milling and baking-quality traits. Based on summaries from the USDA Hard Winter Wheat Quality Database, Ankor appeared to have a slightly better baking quality than Akron.
In 2001-02, 31 advanced experimental lines were tested in the Dryland Variety Trial (UVPT). Of these lines, eight were Clearfield™ wheat lines, 11 were HWW lines with RWA resistance, and 10 were HRW lines either in their first or second year of statewide testing in the UVPT. Because of the overall lack of sound data from the UVPT and yield compression among entries where the UVPT was successfully harvested, decisions on experimental line retention and advance were extremely challenging. Selection intensity was relaxed slightly and more lines than normal were retained for further testing in the 2003 UVPT. Of the lines mentioned above, eight HRW lines, six Clearfield™ lines (all HRW types), and six HWW lines were retained and advanced (19 total).
Small-scale seed increases of each of the lines retained for further testing were planted in the autumn of 2002. The HRW lines are being increased under irrigation at Fort Collins while the Clearfield™ and HWW lines are being increased in Yuma, Arizona, largely because of isolation needs (particularly for the HWW lines) and capabilities in Yuma. Seed supply from any of these lines that perform well in 2003 should be adequate to enable Foundation Seed increase in 2003-04 (for earliest possible release in autumn 2004). In addition to continued yield testing, extensive milling and baking quality evaluations will be done on these materials during winter 2002-03 in the CSU Wheat Quality Lab, the USDA-ARS Quality Lab (Manhattan, KS), and by various private-industry collaborators.
As mentioned previously, the Irrigated Variety Trial was planted at four locations but only Haxtun and Rocky Ford provided useful yield data. Although none of the experimental lines were at the top, as was the case in 2001 (particularly with CO980607 and CO980630), we will of course continue to focus breeding and germ plasm enhancement efforts toward irrigated wheat. Continued management of trials at ARDEC in Fort Collins for high yields and exploitation of high yielding germ plasm from other production areas (e.g., CIMMYTMexico and Pacific Northwest materials) should help to achieve these objectives.
Several graduate student research projects are currently underway or were completed in 200102. Althoguh we expect that these research projects will contribute vital information to direct breeding efforts, both the breeding project and the students benefit in many other ways though student involvement in the overall breeding program. Briefly, these include the following important areas of research:
A spring wheat breeding effort initiated in 1996 progressed to the selection of 12 spring wheat lines from advanced yield trials in 2001. These lines were included in replicated, variety trials in eastern Colorado in 2002. Each of these lines was derived by intercrossing a RWA-resistant line from Montana State University (MTRWA116) with public and private wheat cultivars with primary adaptation in the northern Great Plains region. Unfortunately, all of the trials in eastern Colorado were abandoned and no data were obtained. The trials and evaluations will be repeated in 2003 with the hopes of identifying a spring wheat line with potential for release. A new set of crosses was initiated in 2002 using the RWA-resistant lines and adapted lines from the HRSW region as parents. These populations will be advanced through several cycles of single-seed descent in the greenhouse.
A multi-institutional grant effort, coördinated through the University of CaliforniaDavis, from the USDA-IFAFS grant-funding agency was awarded in April 2001. The focus of this grant, entitled 'Bringing Genomics to the Wheat Fields', is to utilize DNA-marker technology as a means to transfer desirable quality and pest-resistance traits into released cultivars and elite experimental lines. Our program at CSU is one of 12 public, plant-breeding programs involved in this effort, with Dr. Nora Lapitan serving as co-investigator in our effort at CSU. We have chosen recently released cultivars or advanced experimental lines (e.g., Avalanche, Above, Ankor, CO970547, Stanton, and Lakin) as target parents to transfer or combine genes for WSMV and BYDV tolerance (from wheatgrass), high grain-protein content (from wild durum wheats), and RWA resistance. In summer 2002, we completed our first cycle of MAS for the target traits and will be completing two more cycles in our autumn 2002 and spring 2003 greenhouse cycles. The duration of the project is 4 years, with the release of several improved cultivars and germ plasm lines anticipated at the end of the project.
In 2001-02, several facilities and equipment improvements were realized, include
In addition to the above items, the Plant Science Building renovation is nearing completion (targeted for December 2002), the primary benefit for our program (in addition to air-conditioned office space for the project leader) is a renovated and expanded wheat quality laboratory that will house the bread-baking equipment from the Food Science Department. We are very excited about all of these important improvements and the positive impact that they promise to make to our program.