Preliminary Report 1996 Wheat TriaIs INTRODUCTION: The following is the preliminary variety trial information for single (1996) and multiple year (1994-1996) comparisons in Minnesota. Average yield data for newer varieties which were only grown for one or two years have been adjusted mathematical to allow valid comparisons. Two-year and especially one-year data are less reliable and should be interpreted with caution. Similarly, averages across multiple environments, whether they are different years and/or locations, provide a better estimate of mean performance. The least significant difference or LSD is a statistical method to determine whether the observed yield differences between two varieties is due to true, genetic differences between the varieties or to interactions with other variables such as the presence of disease and difference in soil fertility. If the yield difference between two varieties equals or exceeds the LSD value, the higher yielding was indeed superior in yield. If the difference was less, the yield difference may have been due to environmental interactions rather than genetic differences, and we are unable to distinguish the better of the two. The 5% unit indicates that with 95% confidence, the observed difference is indeed a true difference in performance. Lowering this confidence level will allow more varieties to be different from each other, but increases the changes that false conclusions are drawn. SUMMARY: The 1996 season was just like 1995, different from the norm. Delayed planting, repeated flooding, orange wheat blossom midge, scab, and drought all impacted the wheat crop. Similar to 1995, scab was not present in production statewide, but rather limited to the northern tier counties. Yields in the southern part of the state were record breaking. The average yields of the southern locations (St. Paul, Waseca and Lamberton) was 62 bushels per acre this year. This compares to an average of 57 bushels per acre in 1995 and a three-year average of 52 bushels per acre. No data was collected at the West Central Experiment Station in Mor- ris this year. The northern locations (Crookston, Stephen, and Roseau) averaged 49 bushels per acre in 1996 compared to 43 bushels per acre last year and a three-year average of 39 bushels per acre. Table 4 presents the average grain yield for the combined locations in the north, south, and the whole state for both 1996 and the three-year averages. The varieties are ranked by maturity, not yield. In this year's yield trials, Nordic, Verde, and Marshall were among the highest yielding varieties across the southern locations. All varieties yielding more than 59.9 bushels per acre are within the first LSD 5% unit of 9.8 bushels per acre. Statistically meaning that we are unable to conclude that any variety within this group has a higher yield potential. The three-year average (1994- 1996) data shows Oxen, Hamer, Lars and Russ as top yielders. Again, any variety yielding more than 56.6 bushels per acre is within the first LSD unit of 5.1 bushels per acre, indicating that statistically we are unable to distinguish the varieties for their yield potential from one another. Verde, Hamer, Lars and Oxen were the top producing varieties across the northern locations this year. Although 13 varieties yielded more than 50.7 bushels per acre and are all within the first LSD unit of 8 bushels per acre. Over the three- year average (1994-1996), Lars and Norlander are on top. Similarly to the single year data, 10 varieties yielding more than 45.3 bushels per acre are all within the first LSD unit of 4.5 bushels per acre. Certainly, grain yield is very important in varietal choices. However, net return per acre in dollars is not simply a function of bushels but also of what management inputs (chemical, fertilizer, machinery) were needed to realize that yield. Response to disease, grain quality, and other agronomic characteristics like lodging susceptibility may impact your deci- sion as a function of your ability to manage these risks or limiting factors which could affect your net return per acre. Varietal characteristics are presented in Table 5. All values are three-year averages (1994-1996) except for scab values which are based on 1995 and 1996 data. The foliar disease rating is based on data from North Dakota State University trials. The foliar disease rating is based on a complex of leaf diseases, including Septoria, tan spot, and bacterial diseases. The rating does not differentiate among these diseases. Therefore, the rating should be used with care and only with consideration for varietal selection in areas where these diseases historically have been a problem or if the previous crop was either wheat or barley. The varietal response to scab is presented as a severity rating similar to the rating for leaf and stem rust. The resistance to spread in the head is presented in the severity rating and is one of the resistance mechanisms. In addition, a second rating is provided to characterize the ability of a variety to maintain sound, plump kernels despite disease symptoms. The ability to maintain sound, plump kernels is a second component to resistance. Variety selection for 1997 should again be a balance between yield potential, disease responses and quality parameters. Pioneer 2375 still dominates the average because of its tolerance to scab but has susceptibility to Septoria and tan spot. In addition, problems with shattering, lodging and poor competition with weeds increase as the variety is grown further north, especially north of US Highway 2. This year one new private and two new public varieties were released. The University of Minnesota released BacUp, while South Dakota State University released Oxen. Western Plant Breeders released Sharpshooter. Unfortunately, this variety was not included in the state yield trial. AgriPro's Gunner was included in the yield trial but release was delayed to 1997. Two varieties from the Agriculture Canada's program were also included in the results. AC Cora was tested for the second year and AC Domain was tested for the first time. A short description of each of the new entries, including Sharpshooter, is provided below. Except for Gunner, which will be increased for certified seed in 1997, dealers should have enough seed for at least 50,000 acres of each of these new varieties. NEW VARIETIES: 1. BacUp is an awned, very early maturing hard red spring wheat from the University of Minnesota with a low to intermediate yield potential. BacUp segregates for plant height and is susceptible to lodging and leaf disease, similar to Sharp but better than 2375. BacUp is both resistant to leaf and stem rust. Insufficient data from NDSU was available to provide a reliable foliar disease rating. BacUp is resistant to scab both for spread through the head or expressed in the severity rating as well as it's ability to maintain sound, plump kernels as expressed in the tolerance. BacUp has very high test weight, and very high grain protein percentage, as much as 2.0 percentage points higher than Grandin. The milling and baking quality are excellent, similar to Grandin. BacUp is specialty use wheat. Do not plant BacUp on more than 15 to 20% of your acreage. Use the high quality of BacUp to improve quality of other wheat through blending. 2. Oxen is an awned, medium early hard red spring wheat from South Dakota State University with a high yield potential and a wide area of adaptation. Oxen is a semi-dwarf wheat with short to intermediate plant height and intermediate to low resistance to lodging, similar to Kulm but better than Sharp. Oxen is moderately resistant to both leaf rust and stem rust. Oxen is moderately resistant to scab, similar to Butte 86, but less than 2375. Oxen has a medium test weight, similar to Russ and Verde, and a medium grain protein percentage, similar to 2375 or Hamer. The milling and baking quality are equal to Russ and 2375. 3. Sharpshooter is a new release from Western Plant Breeders derived from a cross of Sharp with a Chinese spring wheat, used as a source of resistance to scab. According to its breeder, Sharpshooter is very similar to Sharp in most agronomic, quality, and disease response characteristics. Sharpshooter differs from Sharp in its response to scab. Under heavy disease pressure, Sharpshooter can out yield Sharp while maintaining better seed quality. 4. Gunner is a late maturing variety from Agri-Pro with an intermediate to high yield potential. Gunner is a tall stature wheat with good resistance to lodging, similar to Marshall. Gunner is moderately susceptible to leaf rust, but resistant to stem rust. Based on limited data, Gunner has good foliar disease resistance, similar to Lars. Gunner is moderately resistant to moderately susceptible to scab, similar to 2375, and maintains test weight and sound kernels as good or close to 2375. Gunner has high grain protein percentage and medium high to high test weight, similar to Grandin. Milling and baking quality are medium to high, similar to Kulm.