Search

Abstract This study investigated the potential of different wheat varieties to influence the performance of the subsequent wheat crop. In fall 2021, a single variety of winter wheat (cv. Norwest Tandem) was planted into standing wheat stubble in plots that were previously planted to five winter wheat varieties. At harvest, yield was significantly affected by the variety that had been planted in each plot during the first year of the trial. Specifically, wheat following the variety Pritchett yielded approximately 12% more than wheat following the variety Bobtail. While planting the second crop, residue from the winter wheat variety Norwest Duet caused the no‐till plot drill to plug (accumulate large amounts of soil and crop residue in front of openers) far more than residue from the other varieties. This indicates that varieties differ in their residue management requirements. These differences could be exploited to best fit different agricultural practices. This study highlights the potential importance of varietal effects that persist in the field after the field is harvested. However, more work is needed to understand varietal differences in residue management requirements and varietal effects of the successive crop before they can be fully leveraged in wheat breeding and genetics, wheat agronomy, variety testing programs, and eventually the producer's field.

Abstract Fusarium crown rot (FCR) of winter wheat (Triticum aestivum L.), caused by Fusarium pseudograminearm and Fusarium culmorum, is a yield‐limiting disease in arid wheat‐producing areas of the inland Pacific Northwest. Foliar fungicide applications and currently available seed treatments do not control FCR. Alternative crops that provide a rotational benefit to reduce disease are not economically feasible. Major‐gene resistance is unavailable, but there is preliminary evidence that some wheat and barley (Hordeum vulgare L.) cultivars are more resistant than others. We followed up on preliminary work by growing 14 varieties of winter wheat, planted with in‐furrow FCR inoculum, in 2018 and 2019 in Morrow County, Oregon—one of the world's driest wheat producing regions. Two barley cultivars were added to the experiment during the second year of research. Evaluations of cultivar resistance were made by conducting aboveground visual assessments by counting whiteheads, prematurely senesced wheat heads that are indicative of FCR infection. Whitehead count information was correlated with yield and grain volume weight data. Maximum whitehead counts were measured in plots of the FCR‐susceptible check cultivar ‘Stephens’. There was no evidence of a cultivar‐specific relationship between whitehead count and corresponding values for yield and grain volume weight. There was limited evidence that some cultivars have the capacity to compensate for effects of disease.

The Genome-Wide Association Studies approach was used to detect Quantitative Trait Loci associated with tocochromanol concentrations using a panel of 1,466 barley accessions. All major tocochromanol types- α-, β-, δ-, γ-tocopherol and tocotrienol- were assayed. We found 13 single nucleotide polymorphisms associated with the concentration of one or more of these tocochromanol forms in barley, seven of which were within 2 cM of sequences homologous to cloned genes associated with tocochromanol production in barley and/or other plants. These associations confirmed a prior report based on bi-parental QTL mapping. This knowledge will aid future efforts to better understand the role of tocochromanols in barley, with specific reference to abiotic stress resistance. It will also be useful in developing barley varieties with higher tocochromanol concentrations, although at current recommended daily consumption amounts, barley would not be an effective sole source of vitamin E. However, it could be an important contributor in the context of whole grains in a balanced diet.