Special Report, 2009 University of Minnesota, Small Grains Research Initiative Update

Examining Germplasm Response to Fungicide Application Before Variety Commercialization

Two small plot experiment sites were established during 2007 and 2008 within commercial production fields located in the Red River Valley. Seed of ten wheat germplasm lines expected to be developed into commercially-available varieties were received from private and public breeding programs (UM, North Dakota State University (NDSU), South Dakota State University (SDSU), Trigen, AgriPro, Westbred). Fungicide treatments were applied either preplant (seed treatment), herbicide application timing (Feekes growth stage (FGS) 2), and/or during the early flower growth stage (FGS 10.51). Leaf and head disease information were collected and grain was harvested to determine yield and quality responses from each treatment.

Overview By understanding how germplasm lines respond to fungicide treatments prior to commercialization, researchers can develop disease management recommendations that support increased yield and quality as soon as varieties are released. Disease management information remains a critical component in sustainably producing high yielding, good quality crops in the Red River Valley. During 2007-08, fungicide treatments had little effect on wheat production of lines. Fungal diseases did not limit production in either year. Differences in production were largely explained by genetics and environment.

Year 1 (2007). Tests were planted near Perley and Warren. Heavy and sustained rain was experienced throughout the Valley. The Perley site was flooded during mid-June. The Warren site was severely affected by an extended period of saturated soil. Many plants did not tiller, producing only a single culm with a dwarfed spike. The trial was harvested and data were collected. Results reflected the atypical growing conditions.

Year 2 (2008 ). Tests were planted near Warren and Mahnomen. Environmental conditions supported good crop growth, although severe storms were frequent at the Mahnomen site. Fungicide treatments were applied in a timely manner at the targeted crop growth stages. Disease incidence and severity ratings were collected from the Mahnomen site, but the Warren site had very little evidence of leaf or head disease. Harvest data were recorded for both sites and grain subsamples were sent to the Mycotoxin Lab in St. Paul for deoxynivalenol analysis.

Responses of ten wheat lines (00S01203W and S/W CompW submitted by AgriPro; 904-743 and 905-749 submitted by Westbred; Faller and ND05/1-2 submitted by NDSU; Hat trick submitted by Trigen; SD3868 submitted by SDSU; RB07 submitted by UM; and Oklee, a standard check) were recorded after exposure to seven disease management treatments (Table 1).

Disease Management - Each location x year was considered a unique environment for the statistical analysis. Three environments contributed data and were analyzed together (Warren-07; Warren-08; Mahnomen-08). Yields were significantly different between years and can be explained by the extended period of soil saturation that plants were exposed to in 2007 (Warren-07 = 25.2 bu/A; Warren-08 = 91.2 bu/A; Mahnomen-08 = 91.0 bu/A). Protein was highest in 2007 at 15.3%, while deoxynivalenol (DON, vom) was greater in Mahnomen-08.

 Stand count and yield data were significantly different (Table 2), but differences weren’t detected from fungicide treatments. Neither entry nor fungicide had an effect on test weight or DON levels. Fungicides didn’t influence protein levels, but the entry did.

Acknowledgements

This research was funded by the Minnesota Small Grains Initiative and supported by Westbred, NDSU, SDSU, UM, Trigen, AgriPro, BASF, Syngenta, and Bayer CropScience. The authors appreciate the excellent grower-cooperator support received from Dwight and Cindy Anderson (Warren, MN), Paul and Carol Houglum (Perley, MN), and Skaurud Grain Farms (Gary, MN).-- Charla Hollingsworth, Extension plant pathologist and Chris Motteberg, Plant pathology scientist