Hard Red Spring Wheat Cultivars Research Articles

Evaluation of Ergot Resistance in Hard Red Spring Wheat in North Dakota.

Higher levels of ergot (Claviceps purpurea (Fr.)) Tul. were reported in North Dakota hard red spring wheat (HRSW) in 2018, leading to questions pertaining to management and cultivar resistance. To better understand pathogen and HRSW cultivar responses, greenhouse experiments were conducted from 2020 to 2021 to evaluate aggressiveness of nine C. purpurea isolates and ergot resistance in 21 HRSW cultivars. Results from the aggressiveness assay indicated significant cultivar by isolate interactions for total weight of sclerotia produced and ergot incidence. Mean data across all cultivar by isolate combinations suggested isolates CC-3 and IA-Tim were the most aggressive and subsequently used in ergot resistance experiments. Results from ergot resistance screening indicated none of the HRSW cultivars were immune to C. purpurea as all cultivars produced sclerotia. However, differences in ergot incidence, kernel incidence, aborted kernel incidence, total sclerotia weight, sclerotia length, and sclerotia width occurred among cultivars. Both 'ND-Frohberg' and 'TCG-Spitfire' had the lowest ergot incidence values and were among the lowest in total sclerotia weight. 'Waldron' and 'LCS-Trigger' had the highest ergot incidence and the highest total sclerotia weight. Given that most concerns with ergot occur post-harvest, we suggest two categories to describe ergot resistance: host resistance (fate of inoculation for a stigma) and logistical resistance (size characteristics of a sclerotium that influence its ability to remain with a seed lot after harvest and cleaning). This research provides a strong foundation on our understanding of HRSW resistance to ergot that will influence variety decisions in ergot-prone areas in North Dakota.

The Grain Number Increase 1 alleles GNI‐A1‐105Y and ‐105K increase grain number in spring wheat

AbstractWheat (Triticum aestivum L.) has inflorescences made up of multiple spikelets arranged along a central rachis, with each spikelet producing between one and four grains. The Grain Number Increase 1 (GNI‐A1) gene wheat directly influences grain number per spikelet and grain size. Three naturally occurring alleles have been described previously: GNI‐A1‐105N, 105Y, and 105K. This project's goal was to characterize the impact of these alleles within hard red spring wheat cultivars in Montana, where each of the alleles is common. The 105N allele and the 105K allele were compared through analysis of an F5 Vida by Spring‐Yellowstone recombinant inbred line (RIL) population, and with near isogenic lines (NILs) derived from the same population. The 105N allele and the 105Y allele were compared with NILs derived from an F4 Lanning by Egan RIL population. We analyzed the impact of each of the three alleles and compared their effects on inflorescence architecture, grain size, grain yield, grain quality, and milling quality under Bozeman, MT, field conditions. Data show that either loss‐of‐function alleles (105Y and 105K) increased grain number per spikelet by 5% when compared to the more functional allele (105N) across all years and environments tested. Overall grain size was not significantly reduced and there was also not a significant increase in overall grain yield.

EFFECTS OF GENOTYPE, WEATHER, FHB FUNGICIDE AND PRE-HARVEST GLYPHOSATE ON GRAIN QUALITY OF HARD RED SPRING WHEAT IN WESTERN CANADA

Diverse growing season weather in Western Canada has large effects on wheat quality. Management practices, such as pesticide application, may also affect wheat quality, but are largely unknown. This study measured pesticide application effects on grain quality for six hard red spring wheat cultivars over three growing seasons at four prairie locations. Each Siteyear included (i) an untreated control, (ii) fungicide applied at anthesis for Fusarium head blight (FHB) control, (iii) pre-harvest glyphosate applied at physiological maturity, and (iv) a combination of both pesticides. Generally warmer and drier conditions in 2015 and 2017 compared to 2016, resulted in wheat with higher grades, test weight, thousand-kernel weight, and grain protein content but lower Fusarium damaged kernel (FDK) content. Siteyear, reflecting weather variation by location, was the major factor affecting grain quality, contributing from 39% to 77% of total variance. Rainfall variation was greater than that for air temperature and appeared to be the main weather factor affecting quality. Genotype had a significant impact on grain quality but contributed 1% to 20% of total variance. The pesticide treatments had a significant effect on several quality parameters, but they contributed only 0.2% to 2% to total variance, implying that they have no detrimental effect on wheat grain quality when applied as recommended. Fungicide significantly reduced FDK level in four of ten Siteyears, all with high FDK levels, but not when applied at the low FDK Siteyears. Fungicide for FHB control should be used only when weather is conducive to high FHB disease pressure.

Effect of Copper Sulfate Pentahydrate and Cultivar Resistance on Reducing Bacterial Leaf Streak in Hard Red Spring Wheat in North Dakota

Bacterial leaf streak (BLS) is one of the most significant foliar diseases affecting hard red spring wheat (HRSW) production in North Dakota. The most effective management tool for BLS is the use of host resistance; however, the adoption and availability of resistant cultivars is limited for HRSW producers. This has led to questions pertaining to the use of copper-based products to suppress BLS severity in HRSW production. Four field experiments were conducted from 2020 to 2022 in North Dakota to evaluate the efficacy of copper sulfate pentahydrate (CSP) applied at the flag leaf stage on reducing BLS severity and protecting HRSW yield and test weight. Experiments were conducted in a randomized complete block design with a split-plot arrangement with four replications. Three treatments served as the main plots (noninoculated, inoculated, and inoculated + CSP applied at flag leaf). Five HRSW cultivars varying in host resistance served as subplots. A high level of disease occurred across all experiments. A combined analysis suggested that the use of CSP did not provide adequate BLS suppression and did not protect HRSW yield or test weight regardless of HRSW susceptibility. The lowest mean yield loss was associated with the moderately resistant cultivar Boost (9%), and the highest was associated with the susceptible cultivar SY Rockford (19%). Variability in yield loss values among cultivars suggests that more research is needed to strengthen our understanding of BLS in HRSW.

Linkage drag analysis in three Aegilops speltoides introgressions carrying Sr47 in modern durum and hard red spring wheat germplasm.

Yield and quality tests of wheat lines derived from RWG35 show they carry little, or no linkage drag and are the preferred source of Sr47 for stem rust resistance. Three durum wheat (Triticum turgidum L. subsp. durum) lines, RWG35, RWG36, and RWG37 carrying slightly different Aegilops speltoides introgressions, but each carrying the Sr47 stem rust resistance gene, were backcrossed to three durum and three hard red spring (HRS) wheat (Triticum aestivum L.) cultivars to produce 18 backcross populations. Each population was backcrossed to the recurrent parent six times and prepared for yield trials to test for linkage drag. Lines carrying the introgression (S-lines) were compared to euploid sibling lines (W-lines) and their parent. Yield trials were conducted from 2018 to 2021 at three locations. Three agronomic and several quality traits were studied. In durum, lines derived from RWG35 had little or no linkage drag. Lines derived from RWG36 and RWG37 still retained linkage drag, most notably involving yield and thousand kernel weight, but also test weight, falling number, kernel hardness index, semolina extract, semolina protein content, semolina brightness, and peak height. In HRS wheat, the results were more complex, though the general result of RWG35 lines having little or no linkage drag and RWG36 and RWG37 lines retaining linkage drag still applied. But there was heterogeneity in the Glenn35S lines, and Linkert lines had problems combining with the Ae. speltoides introgressions. We concluded that introgressions derived from RWG35 either had eliminated linkage drag or any negative effects were minor in nature. We recommend that breeders who wish to incorporate Sr47 into their cultivars should work exclusively with germplasm derived from RWG35.

Characterization of Brazilian spring wheat germplasm and its potential for increasing wheat genetic diversity in Canada.

In the present era of climate instability, Canadian wheat production has been frequently affected by abiotic stresses and by dynamic populations of pathogens and pests that are more virulent and aggressive over time. Genetic diversity is fundamental to guarantee sustainable and improved wheat production. In the past, the genetics of Brazilian cultivars, such as Frontana, have been studied by Canadian researchers and consequently, Brazilian germplasm has been used to breed Canadian wheat cultivars. The objective of this study was to characterize a collection of Brazilian germplasm under Canadian growing conditions, including the reaction of the Brazilian germplasm to Canadian isolates/pathogens and to predict the presence of certain genes in an effort to increase genetic diversity, improve genetic gain and resilience of Canadian wheat. Over 100 Brazilian hard red spring wheat cultivars released from 1986 to 2016 were evaluated for their agronomic performance in eastern Canada. Some cultivars showed good adaptability, with several cultivars being superior or statistically equal to the highest yielding Canadian checks. Several Brazilian cultivars had excellent resistance to leaf rust, even though only a few of these tested positive for the presence of either Lr34 or Lr16, two of the most common resistance genes in Canadian wheat. Resistance for stem rust, stripe rust and powdery mildew was variable among the Brazilian cultivars. However, many Brazilian cultivars had high levels of resistance to Canadian and African - Ug99 strains of stem rust. Many Brazilian cultivars had good Fusarium head blight (FHB) resistance, which appears to be derived from Frontana. In contrast FHB resistance in Canadian wheat is largely based on the Chinese variety, Sumai-3. The Brazilian germplasm is a valuable source of semi-dwarf (Rht) genes, and 75% of the Brazilian collection possessed Rht-B1b. Many cultivars in the Brazilian collection were found to be genetically distinct from Canadian wheat, making them a valuable resource to increase the disease resistance and genetic variability in Canada and elsewhere.

Forefront Canada Prairie spring red wheat

Forefront is an awned hard red spring wheat ( Triticum aestivum L.) cultivar with high yield potential, shorter stature with good lodging tolerance, and excellent rust resistance. During the three years of testing in the High Yield Wheat Cooperative test (2017–19), Forefront yielded similar to and matured one day later than the highest yielding check cultivar AAC Foray. Forefront had 10 cm shorter plants than AAC Foray, with a similar lodging score. Forefront had slightly higher test weight, lower grain weight, and higher grain protein content than AAC Foray. Forefront was rated “resistant” to the prevalent races of leaf, stem, and stripe rusts, whereas “moderately susceptible” to common bunt and Fusarium head blight (FHB) during the three years of testing. The end-use quality characteristics of Forefront were within the range of the checks of the Canada Prairie Spring Red market class.

AAC Westlock Canada Prairie Spring Red wheat

AAC Westlock, an awned hard red spring wheat ( Triticum aestivum L.) cultivar, combines high grain yield and good agronomic characteristics with excellent resistance to leaf, stripe, and stem rust (including variants of Ug99), Fusarium head blight (FHB), and common bunt. Based on 40 station-years of registration trial data from 2018 to 2020, the grain yield of AAC Westlock was 1% higher than AAC Foray and 7% over AAC Penhold. AAC Westlock was significantly shorter than AAC Foray, had straw strength similar to AAC Penhold, and maturity similar to AAC Foray. AAC Westlock had similar test weight and protein concentration but lower thousand kernel weight as compared to AAC Foray. AAC Westlock had milling and baking quality suitable for grades of the Canada Prairie Spring Red wheat market class.

Durum wheat Teosinte Branched1 null mutations increase tillering

AbstractWheat (Triticum spp.) yield is increased by either producing and testing variants of yield‐limiting genes or crossing to create new allelic combinations. Tiller number and seeds per tiller influence wheat yield, and both are impacted by the Teosinte Branched1 (TB1) gene. We screened 16 hard red spring wheat (Triticum aestivum L.) cultivars, 15 hard red winter wheat cultivars and lines, and 10 durum wheat [Triticum turgidum L. subsp. durum (Desf.) van Slageren] cultivars and lines commonly grown in Montana and found several previously reported TB1 missense alleles along with one new silent and a missense TB1‐A1 allele among the 16 hard red spring wheat cultivars but no TB1 null alleles. Among the 10 durum cultivars, five carried a TB1‐B1‐S184G missense allele and all winter wheat cultivars carried wild‐type TB1 alleles. To determine the impact of TB1 null alleles, this study examined durum wheat genotypes varying for TB1 null alleles created by ethyl methanesulfonate (EMS) mutagenesis. The goal was to determine the impact of TB1 null alleles on tillering, agronomic, and seed traits. The impact of TB1 null alleles was studied alone and together in field trials. The TB1 single‐ and double‐null mutants produced up to 15% more tillers and 18% with positive trends toward increased plant biomass. The results of this research demonstrate that the integration of EMS‐derived TB1 null alleles may prove useful in increasing small‐grain tillering to optimize plant biomass and yield under different growing conditions.

Variation of Macro- and Microelements, and Trace Metals in Spring Wheat Genetic Resources in Siberia.

Western Siberia is one of the major spring wheat regions of Russia, cultivating over 7 Mha. The objective of the study was to evaluate the variation of macro- and microelements, and of trace metals in four distinct groups of genetic resources: primary synthetics from CIMMYT (37 entries), primary synthetics from Japan (8), US hard red spring wheat cultivars (14), and material from the Kazakhstan–Siberian Network on Spring Wheat Improvement (KASIB) (74). The experiment was conducted at Omsk State Agrarian University, using a random complete block design with four replicates in 2017 and 2018. Concentrations of 15 elements were included in the analysis: macroelements, Ca, K, Mg, P, and S; microelements, Fe, Cu, Mn, and Zn; toxic trace elements, Cd, Co, Ni; and trace elements, Mo, Rb, and Sr. Protein content was found to be positively correlated with the concentrations of 11 of the elements in one or both years. Multiple regression was used to adjust the concentration of each element, based on significant correlations with agronomic traits and macroelements. All 15 elements were evaluated for their suitability for genetic enhancement, considering phenotypic variation, their share of the genetic component in this variation, as well as the dependence of the element concentration on other traits. Three trace elements (Sr, Mo, and Co) were identified as traits that were relatively easy to enhance through breeding. These were followed by Ca, Cd, Rb, and K. The important biofortification elements Mn and Zn were among the traits that were difficult to enhance genetically. The CIMMYT and Japanese synthetics had significantly higher concentrations of K and Sr, compared to the local check. The Japanese synthetics also had the highest concentrations of Ca, S, Cd, and Mo. The US cultivars had concentrations of Ca as high as the Japanese synthetics, and the highest concentrations of Mg and Fe. KASIB’s germplasm had near-average values for most elements. Superior germplasm, with high macro- and microelement concentrations and low trace-element concentrations, was found in all groups of material included.

AAC Perform red spring wheat

AAC Perform, an awned hard red spring wheat (Triticum aestivum L.) cultivar, combines high grain yield and good agronomic characteristics with excellent resistance to leaf, stem, and stripe rust. Based on 43 station years of registration trial data from 2017 to 2019, the grain yield of AAC Perform was about 6% higher than AAC Foray and about 12% over AAC Penhold. AAC Perform was significantly shorter than AAC Foray and had straw strength similar to AAC Penhold. It was about two days later maturing than AAC Foray. AAC Perform had similar test weight, smaller kernel size and lower protein concentration as compared with AAC Foray. AAC Perform had milling and baking quality suitable for grades of the Canada Prairie Spring Red wheat market class.

The effect of auxins on amelioration of heat stress‐induced wheat (Triticum aestivum L.) grain loss

AbstractHigh temperature stress during the reproductive growth stage of wheat (Triticum aestivum L.) can cause extensive yield losses. As the plant hormone auxin is a key regulator of reproductive development, we studied the effect of auxins on grain yield in five wheat lines exposed to moderate heat stress (34–35°C) for 6 h per day for 6 days during early flowering (booting stage to anthesis). ‘CDC Go’, a semi‐dwarf (Rht‐B1b) cultivar, responded to auxin application (1 µM) by producing higher grain number and yield under control and heat stress conditions. The effect of five different auxins on grain yield in ‘CDC Go’ was dependent on spike developmental stage at application and position within the spike, with 4‐Cl‐IAA at 1 µM being the most effective auxin treatment. The presence of Rht dwarfing mutant alleles of Rht‐B1 and Rht‐D1 alone did not increase auxin‐induced grain yield when tested in lines isogenic for these alleles. In the field, 4‐Cl‐IAA (1 µM) increased grain yield by 6%–8% only in ‘CDC Go’, one of six hard red spring wheat cultivars tested over two growing seasons in the western Canadian prairies. When 4‐Cl‐IAA application increased grain yield and number, the grain protein content was not affected; when it maintained grain yield in plants with lower biomass, grain protein content was reduced. Our field results suggested that both genotype and environment affect auxin‐induced enhancement of wheat grain yield. We recommend testing target environments with heat stress as a focus of a breeding programme along with further testing of auxin as a crop enhancement tool.

Adult Plant Leaf Rust Resistance in AC Taber Wheat Maps to Chromosomes 2BS and 3BS.

AC Taber is a hard red spring wheat cultivar that has had long-lasting resistance to the leaf rust fungus Puccinia triticina. The objective of this study was to determine the chromosome location of the leaf rust resistance genes in AC Taber. The leaf rust-susceptible cultivar Thatcher was crossed with AC Taber to develop an F6 recombinant inbred line (RIL) population. The RILs and parents were evaluated for segregation of leaf rust resistance in five field plot tests and in two seedling tests to race BBBDB of P. triticina. A genetic map of the RIL population was developed using 90,000 single nucleotide polymorphism markers with the Illumina Infinium iSelect 90K wheat bead array. Quantitative trait loci (QTLs) with significant effects for lower leaf rust severity in the field plot tests were found on chromosomes 2BS and 3BS. The same QTLs also had significant effects for lower infection type in seedlings to leaf rust race BBBDB. The gene on 2BS was the adult plant resistance gene Lr13, and the gene on 3BS mapped to the same region as the adult plant resistance gene Lr74 and other QTLs for leaf rust resistance. Kompetitive allele-specific PCR assay markers linked to the 2BS and 3BS regions were developed and should be useful for marker-based selection of these genes.

AAC Redstar hard red spring wheat

AAC Redstar is an early maturing, high-yielding hard red spring wheat (Triticum aestivum L.) cultivar that is well adapted to the northern Canadian Prairies and eligible for grades of Canada Western Red Spring (CWRS) wheat. Over 3 yr (2016–2018) of testing in the Parkland Wheat Cooperative registration trials, AAC Redstar was 11% higher yielding than AC Splendor, 6% higher than Parata, and 4% higher than Glenn and Carberry. AAC Redstar matured 3 d earlier than Glenn, 2 d earlier than Carberry, and had similar maturity to Parata. AAC Redstar was shorter than all checks except Carberry and had better lodging resistance compared with all the check cultivars in the registration trial. The test weight and thousand-kernel weight of AAC Redstar were similar to Carberry. The grain protein concentration of AAC Redstar was 0.2% lower than Carberry. AAC Redstar was rated moderately resistant to Fusarium head blight, leaf rust, stripe rust, and common bunt. AAC Redstar had resistant reactions to loose smut and stem rust. AAC Redstar was registered under the CWRS market class.

A Decision Support System to Guide Grower Selection of Optimal Seeding Rates of Wheat Cultivars in Diverse Environments.

Seeding rate in hard red spring wheat (HRSW; Triticum aestivum L.) production impacts input cost and grain yield. Predicting the optimal seeding rate (OSR) for HRSW cultivars can eliminate the need for costly seeding rate research and growers using OSRs can maximize yield and seeding efficiency. Data were compiled from seeding rate studies conducted in 32 environments in the Northern Plains United States to determine the OSR of HRSW cultivars grown in diverse environments. Twelve cultivars with diverse genetic and phenotypic characteristics were evaluated at five seeding rates in 2013–2015, and nine cultivars were evaluated in 2017–2018. OSR varied among cultivar within environments. Cultivar x environment interactions were explored with the objective of developing a decision support system (DSS) to aid growers in determining the OSR for the cultivar they select, and for the environment in which it is sown. A 10-fold repeated cross-validation of the seeding rate data was used to fit 10 decision tree models and the most robust model was selected based on minimizing the value for model variance. The final decision tree model for predicting OSR of HRSW cultivars in diverse environments was considered the most reliable as bias was minimized by pruning methods, and model variance was acceptable for OSR predictions (RMSE = 1.24). Findings from this model were used to develop the grower DSS for determining OSR dependent on cultivar straw strength (as a measure of lodging resistance), tillering capacity, and yield of the environment. Recommendations for OSR ranged from 3.1 to 4.5 million seeds ha–1. Growers can benefit from using this DSS by sowing at OSR relative to their average yields; especially when seeding new HRSW cultivars.

Solvent retention capacity and swelling index of glutenin in hard red wheat flour as possible indicators of rheological and baking quality characteristics

To overcome the cost and expense of milling and baking hundreds of samples in wheat breeding programs, cereal chemists have developed various rapid predictive tests for end-use quality assessment. In this study, five small-scale rapid tests, including Solvent Retention Capacity (SRC) and Swelling Index of Glutenin (SIG), were compared for viability and accuracy to determine end-use quality using small quantities of flour. The tests were applied on commercial hard red spring and hard red winter wheat cultivars from two of the three main production regions in South Africa. Rheological and bread-baking characteristics were related to results of the rapid tests. Highly significant cultivar differences were seen for all rheological and baking-related characteristics, and SRC and SIG parameters, with a strong genotype effect. The environment effect was also highly significant across regions, especially for flour protein content (FPC), which affected the rheological and baking-related characteristics differently across the regions. Correlations among SRC, SIG, rheological, and baking quality-related parameters were highly significant, but inconsistent for the two production regions. Only lactic acid SRC and SIG correlated consistently with the rheological and baking quality-related characteristics in both production regions.

AAC Crossfield red spring wheat

AAC Crossfield, an awned hard red spring wheat (Triticum aestivum L.) cultivar, combines high grain yield and good agronomic characteristics with excellent resistance to leaf, stem, and stripe rust. AAC Crossfield is significantly shorter than Conquer and AAC Foray, and has maturity, straw strength, and test weight similar to the check cultivars. AAC Crossfield has improved farinograph stability and is eligible for grade in the Canada Prairie Spring Red wheat market class.

Proteomic Analysis of Proteins Responsive to Drought and Low Temperature Stress in a Hard Red Spring Wheat Cultivar.

Drought stress is becoming more prevalent with global warming, and has been shown to have large effects on gluten proteins linked to wheat bread making quality. Likewise, low temperature stress can detrimentally affect proteins in wheat. This study was done to determine the differential abundance of high molecular weight (HMW) glutenin proteins in a drought and low temperature stressed high quality hard red spring wheat cultivar (PAN3478), against a control. The treatments were applied in the greenhouse at the soft dough stage. HMW glutenin proteins were extracted from the flour, and were separated by using two-dimensional gel electrophoresis. Protein spots that had p values lower than 0.05 and fold values equal to or greater than 1.2 were considered to be significantly differentially abundant. These proteins were further analyzed by using tandem mass spectrometry. There was a 1.3 to 1.8 fold change in 17 protein spots due to the cold treatment. The drought treatment caused a 1.3 to 3.8 fold change in 19 protein spots. These spots matched either HMW or low molecular weight (LMW) glutenin subunits. In the latter case, the C subunits of LMW glutenins were notably found to be up-regulated under both stress conditions. All the proteins that have been identified can directly influence dough characteristics. Data are available via ProteomeXchange with the identifier PXD017578.

Effect of salts from the lyotropic series on the handling properties of dough prepared from two hard red spring wheat cultivars of differing quality

The influence of select salts from the lyotropic series (NH4Cl, KCl, NaCl, MgCl2, CaCl2, and MgSO4) on the rheology and stickiness of dough prepared from a strong (Pembina) and a weak (Harvest) hard red spring wheat flour were examined at a 1 and 2% salt levels, with water mobility and water association with different dough components also being assessed at the 1% salt level. Overall, Pembina was found to develop stronger gluten networks that were more resilient than those of Harvest as evident from a lower tan δ and less compliance during shear creep recovery rheology. However, the effect of salt-type differed based on cultivar. Pembina showed lower dough stickiness than Harvest in all cases. NH4Cl decreased dough stickiness the most for both cultivars. The use of alternative salts affected the association of water with the starch-fraction and gluten-fraction in doughs, and this effect was cultivar-dependent.

Genetic and Environmental Predictors for Determining Optimal Seeding Rates of Diverse Wheat Cultivars

Seeding rate for maximum grain yield can differ for diverse hard red spring wheat (HRSW) (Triticum aestivum L.) cultivars and is derived from a yield response curve to seeding rates. Six groups of HRSW cultivars with combinations of Rht-B, Rht-D, and Ppd-D genes were planted at five seeding rates in 21 environments during 2013–2015 throughout Minnesota and eastern North Dakota, USA. Seeding rates ranged from 1.59 to 5.55 million seeds ha−1 and planting timings were optimal and delayed dates. An analysis of covariance predictive model with 13 predetermined training environments was built for yield and tillering, and validated with eight predetermined environments. Optimal seeding rates from the yield model were not predictive for yield, with latitude of the environment negatively skewing the predictions from observed values. A second yield model fit to only the six lowest-yielding environments (<4.8 Mg ha−1) was more predictive (R2 = 0.44), and revealed yield response to seeding rate was influenced by cultivar traits for photoperiod response (Ppd-D gene) and plant stature (semi-dwarfing gene Rht-D). The tillering model was also predictive for the validation environments, with a R2 of 0.71. Using regression predictions for yield and tillering from training and validation datasets with HRSW genetic and geographic predictors shows promise to help recommend seeding rates for future environments.