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'KS4719' (Reg. no. CV‐28, PI 697260) is a winter canola cultivar (Brassica napus L.) that possesses superior winterhardiness, greater lodging resistance, and improved pod shattering. KS4719 first drew attention when a devastating cold snap in November 2014 caused much of the winter canola crop to winter kill. KS4719 winter survival scores were 15 and 121% greater than the check cultivars 'Sumner' and 'Wichita', respectively, at Kansas State University's lone surviving trial site in northern Oklahoma. In the National Winter Canola Variety Trial (NWCVT) testing, the winter survival score of KS4719 was equivalent to 'Torrington', the most winter hardy commercially available cultivar. Across two sites of the 2015–2016 Great Plains Canola Variety Trial (GPCVT), KS4719 showed significantly improved pod shatter compared with the check cultivars. Across 14 NWCVT sites in the U.S. Great Plains, grain yield did not differ from the check cultivars; however, KS4719 did yield 5 and 19% more than 'Surefire' and Torrington, respectively, the two most recent cultivar releases from the Kansas State University canola breeding program. Over five site‐years, KS4719 averaged 9% lodging, while Torrington averaged 19%. It is theorized that the improved lodging resistance of KS4719 comes from a stem and root system that is less prone to rotting in saturated soils. Greater winterhardiness is in part due to protection of the lower stem (rosette) throughout the winter months. Core Ideas: KS4719 winter canola is a new cultivar release from Kansas State University.KS4719 possesses exceptional winterhardiness.KS4719 is less prone to lodging in saturated soils. [ABSTRACT FROM AUTHOR]

The impact of heat stress coinciding with reproductive stages in winter canola was studied using walk‐in controlled environment chambers and field‐based tents. Six different cultivars (46W94, Edimax CL, Mercedes, Popular, DKW44‐10 and DKW46‐15) were used in both the experiments following a split‐plot design. Under controlled environment chambers, all six cultivars were exposed to HDT (day/night; 34/15°C), HNT (23/20°C), HDNT (34/20°C) and control (23/15°C) conditions for 14 days coinciding with flowering. Under field conditions, custom built 'heat tents' were used to impose heat stress starting seven days after 50% of flowering till maturity. The results demonstrated that HDT and HDNT induced significant impact on floral morphology, extreme levels of floral sterility and complete yield loss with two weeks of stress exposure during flowering. However, biomass, seed weight and oil concentration at maturity were either significantly increased or unchanged which demonstrated significant post‐stress phenotypic plasticity in canola to overcome damage caused by short episode of HDT and HDNT during flowering. The long duration heat stress under field conditions recorded significant decrease in yield parameters and oil concentration in the canola cultivars. Incorporating greater post‐stress phenotypic plasticity will help develop canola as an ideal alternative crop under future climates associated with enhanced frequency of short heat stress episodes coinciding with critical reproductive stages. [ABSTRACT FROM AUTHOR]

Winter canola (Brassica napus L.) production has increased in the Great Plains as producers seek a rotational and alternative crop to winter wheat (Triticum aestivum L). However, limited information is available if canola could be used for dual‐purpose without significantly affecting grain yield. The objectives of this study were to (a) investigate dual‐purpose potential and (b) impact of companion crops on growth, survival, biomass, and grain yield of canola. The study was conducted in 2011 and 2012 at Garden City, KS. The experimental design of the study was a randomized complete block design with split‐plot arrangement. Main plot treatments were a factorial of canola cultivars (Griffin or Wichita) and companion crop treatments (none, spring triticale [× Triticosecale Wittm. ex A. Camus], winter triticale, radish [Raphanus raphanistrum subsp. sativus (L.) Domin], and turnip [Brassica rapa var. rapa L.]), and the split‐plot treatments were single‐purpose (grain only) or dual‐purpose (grain and forage) management. Averaged across cultivars and years, grain yield was 70% greater when canola was used for single‐purpose (grain‐only) compared with dual‐purpose. Griffin grain yield tended to be relatively greater than Wichita in dual‐purpose use. Averaged across the two years, turnip as a companion crop decreased canola yield by 38% but resulted in greater forage accumulation. In conclusion, dual‐purpose canola has a grain yield penalty, but effects may vary by cultivar. Companion cropping did not benefit canola and in some cases negatively affected grain yield. When grain production is the primary objective, both companion cropping and forage use should be avoided. [ABSTRACT FROM AUTHOR]

Winter canola (Brassica napus L.) is highly sensitive to increasing temperatures during the reproductive and pod‐filling stages. Although the impact of high day‐time temperature stress on yield and quality has been documented in canola, similar information under high night‐time temperature (HNT) stress is not available. Using six hybrids and four open‐pollinated cultivars, we observed a marked shift in peak flowering towards earlier, cooler hours of the morning under HNT. Averaged across two independent experiments, the photochemical efficiency of photosystem II was significantly decreased (3%), with a significant increase in thylakoid membrane damage (13%) in the leaves of susceptible cultivars under HNT stress. Similarly, the susceptible cultivars also recorded significant reduction in biomass (34%), pod number (22%), pod weight (37%) and total seed weight (40%) per plant while the same set of agronomic traits were not affected among the tolerant cultivars. Quantitative impact of heat stress was confirmed with increased sensitivity to HNT exposure from gametogenesis until maturity resulting in a significantly higher yield loss compared to stress exposure from post‐flowering till maturity. HNT significantly decreased oil concentration, but increased protein concentration and saturated fatty acid levels in seeds of the susceptible cultivars. However, HNT had no impact on the unsaturated fatty acids in both hybrids and the open‐pollinated cultivars. Breeding targets based on fatty acid composition for enhancing canola seed quality may not be easily amenable due to the inconsistency documented with the compositional changes under heat stress. In summary, our findings conclude that canola hybrids are better suited to regions experiencing heat stress, compared to open‐pollinated cultivars, indicating the possibility of a complete shift to hybrid canola cultivation under predicted hotter climates in the future. [ABSTRACT FROM AUTHOR]

Canola (Brassica napus L. cv. 'Canola') production has both economic and agronomic advantages. The objectives of this review were to summarize the key management factors determining crop productivity and to propose plausible pathways to narrow the gap between actual and potential yield. A synthesis study was conducted on data available from performance trials and by reviewing >100 reports in peerreviewed journals, extension publications, and websites. The main outcomes obtained from this synthesis suggested that canola attainable yield could be 4 Mg ha-1 with a potential maximum yield of 7 Mg ha-1. However, actual average yields in North America region were ~1.7 Mg ha-1 for the period 2000 to 2014. Available inseason water, water distribution at critical stages, and nutrient supply (soil plus fertilizer) all contribute to a significant portion of canola yield. Other management factors such as seeding rate, rotation, and cultivar selection substantially affect plant performance. Tillage might have an economic and environmental effect, but overall, the outcome of the meta-analysis did not show significant effect on yield. The review suggests that water supply, balanced nutrition, early planting (for both winter and spring types) in shallow depth (10-19 mm), high seeding rate (6 kg ha-1), and diverse rotation (canola every 3 or 4 yr) are among the best management practices to increase yields. Future lines of research should focus on improving planting operations that diminish early-season heterogeneity, finetuning optimal seeding rates based on modern varieties at varying yield environments, and searching for compatible hybrids to replant without heterogeneity at harvest. [ABSTRACT FROM AUTHOR]

Successful winter canola (Brassica napus L.) production creates diversity and provides crop rotation alternatives for producers. Stand establishment and winter survival are among the main determinants of success in winter canola production. The objective of this research was to investigate the impact of environment, crop management, genetics and their interactions on canola stand establishment, survival, yield, and oil and protein content. Two datasets were analyzed: results from the National Winter Canola Variety Trials conducted from 2003 to 2012 and data from experiments conducted for 3 yr (2010-2012) in Manhattan, KS, to assess the impact of planting date, tillage, and cultivar on canola yield and survival. Canola has the potential to yield up to 7 Mg ha-1; however, actual yields were usually in the range of 0 to 4 Mg ha-1. The average oil content of canola seeds was 40%, but the potential extended to 47%. Environment, defined as a combination of year and location, was responsible for the majority of variation in yield, oil content, stand establishment, and survival of winter canola. Planting in mid to late August and early September benefited yield most of the time compared with planting late in September or October in the Great Plains and Midwestern United States. Only with extremely early or late planting did tillage improve winter survival and yield compared with no-till. Crown height of canola was greater in no-till treatments compared with conventional tillage treatments, but a significant relationship was not observed between crown height and winter survival or yield. Cultivars differed significantly in yield, survival, and crown height, but no cultivars were consistently superior in no-till conditions or with plantings outside of the recommended time frame. [ABSTRACT FROM AUTHOR]

Winter canola generally produces greater yields than spring canola. However, its range is limited due to its inability to withstand the harsh winter conditions that occur in many northern regions of the U.S.A. To identify loci associated with freezing tolerance in canola, we conducted a genome-wide association study (GWAS) using a genotyped diversity panel containing 399 accessions consisting primarily of winter canola. One-month-old greenhouse grown plants were subsequently cold-acclimated for two months in an environmental growth chamber prior to phenotyping for freezing survival using a visual damage scale and chlorophyll fluorescence (Fv/Fo). There was reasonable correlation observed between visual damage and chlorophyll fluorescence ratings among the top associated loci; the results indicated that some loci contributed to both freezing damage/tolerance and photosynthetic efficiency. The resulting numerical values for phenotypes were used for association analyses with the identified SNPs. Thirteen significant markers were identified on nine chromosomes for the phenotypes scored, with several showing significance for multiple phenotypes. Twenty-five candidate genes were identified as previously associated with freezing tolerance, photosynthesis, or cold-responsive in canola or Arabidopsis. [ABSTRACT FROM AUTHOR]

A diverse population (429 member) of canola (Brassica napus L.) consisting primarily of winter biotypes was assembled and used in genome-wide association studies. Genotype by sequencing analysis of the population identified and mapped 290,972 high-quality markers ranging from 18.5 to 82.4% missing markers per line and an average of 36.8%. After interpolation, 251,575 high-quality markers remained. After filtering for markers with low minor allele counts (count > 5), we were left with 190,375 markers. The average distance between these markers is 4463 bases with a median of 69 and a range from 1 to 281,248 bases. The heterozygosity among the imputed population ranges from 0.9 to 11.0% with an average of 5.4%. The filtered and imputed dataset was used to determine population structure and kinship, which indicated that the population had minimal structure with the best K value of 2–3. These results also indicated that the majority of the population has substantial sequence from a single population with sub-clusters of, and admixtures with, a very small number of other populations. Analysis of chromosomal linkage disequilibrium decay ranged from ~7 Kb for chromosome A01 to ~68 Kb for chromosome C01. Local linkage decay rates determined for all 500 kb windows with a 10kb sliding step indicated a wide range of linkage disequilibrium decay rates, indicating numerous crossover hotspots within this population, and provide a resource for determining the likely limits of linkage disequilibrium from any given marker in which to identify candidate genes. This population and the resources provided here should serve as helpful tools for investigating genetics in winter canola. [ABSTRACT FROM AUTHOR]

Canola (Brassica napus L.) is a major oilseed crop for edible and industrial uses. Climate change, characterized by extreme heat and drought conditions, can affect canola seed yield and quality (protein and oil), restricting grower capacity to keep pace with growing demand. However, estimating the influence of future climate on such complex traits is challenging due to biophysical interactions and crop adaptations to abiotic stresses. Current scientific literature reports contrasting impacts on the effect of heat and drought for canola productivity, mainly linked to changes in magnitude and duration of the stress. To better understand how drought and heat affect canola seed yield and quality (mainly protein and oil), a meta-analysis was executed to compile a total of 39 papers (1794 observations). The aims of this research were to i) quantify the impact of different timing and duration of heat and drought stresses on canola seed yield, oil yield, and seed quality (oil and protein concentration), and ii) study the effect of short-term stresses on seed quality, yield and its components (seed number and seed weight). This review study highlighted the magnitude and direction of overall and different stress impacts on canola; and some of the main limitations in the current scientific literature. Briefly, the main outcomes of this review highlighted that i) early heat stress(before end of flowering) had the largest impact on canola seed yield, as a short stress, ii) drought caused greatest yield impact when imposed for a long duration during flowering or a shorter duration during pod setting, and iii) short stresses had large impacts on seed oil concentration mainly during pod setting. More studies with standard stress levels and detailed information of abiotic stresses on reproductive growth stages are needed. This meta-analysis provides critical information for crop management, guiding development of cultivars linked to tolerance to abiotic stresses for breeding programs, and the future direction of canola adoption and production. • Contrasting heat and drought impacts on canola/rapeseed were reported in the literature. • This meta-analysis dissected abiotic stress timing and duration. • Highest negative impacts on yield were observed with stresses imposed before the end of flowering. • Seed oil and protein concentration were affected following abiotic short stresses during pod setting. [ABSTRACT FROM AUTHOR]

Canola (Brassica napus L.) is a dual-purpose oilseed crop with a potential to close an increasing demand/supply gap for biofuel production. To increase oil production, it is imperative to identify the best production regions and to understand these environments the production environments to inform management decisions. The aims of this study were to) characterize water stress patterns in the major US winter canola production and its implications to determine regions with similar yield and oil production. With this purpose, a field observed dataset was curated from the National Winter Canola Variety Trial (NWCVT). This dataset comprises 88 sites covering around 26 US states for the 2003–2019 time period and includes phenology data and the description of the management practices for more than 400 varieties. The observed flowering date, maturity date, yield, and oil concentration were used to train and evaluate APSIM Canola. Crop phenology and seed yield presented adequate model performance (Normalized Root Mean Square Error (NRMSE)= 0.08, 0.19; Kling-Gupta model Efficiency (KGE)= 0.89, 0.68, respectively) while model performance was inferior for oil concentration (NRMSE=0.49, KGE=0.08). Three spatial clusters were defined based on water stress frequency, yield, and oil concentration. Geographically from East to West, yield and oil productivity decreased with increasing water stress frequency. This study provides new insights on identifying potential regions for oil production and on closing the increasing demand/supply gap. [Display omitted] • Water stress in grain filling significantly affects yield and oil (70 % site-years) • Three spatial clusters were determined by water stress frequency, yield, and oil • Eastern and central regions showed the highest yields (∼4 Mg ha−1) with < 25 % stress • Eastern and central regions evidenced high potential for increased oil productivity [ABSTRACT FROM AUTHOR]

• Canola winter survival was linked to minimum temperature and its fluctuations • High probability of canola winter survival reported south latitude 35°N in US • There is potential to develop canola genotypes with tolerance to winter-kill • Semi-tolerant canola types for winter survival are already broadly used in US • Canola winter survival response driven by air temperatures and windchill The introduction of winter canola (Brassica napus L.) into rotations with winter wheat (Triticum aestivum L.) in the United States (US) revealed economic and agronomic benefits as well as improved weed and pest control. Canola stand establishment during the fall and plant survival over the winter are critical to the success of this crop. The environment plays a key role influencing survival, but in-depth evaluation of meteorological factors has not been conducted. This research study aimed to: i) identify meteorological factors underpinning winter canola survival, ii) build probabilistic response models based on historical meteorological data for different severities of winter kill across the US, and iii) define areas of adaptation of current germplasm. A winter survival dataset was compiled from the National Winter Canola Variety Trials from 2003 until 2018 (190 site-years) and auxiliary meteorological data over the last 40 years. A regression tree analysis indicated that meteorological variables related to minimum temperature, fluctuating temperatures above and below 0°C, and windchill during the cold period were the main factors accounting for winter kill. Cold periods across all site-years were classified into three clusters: cold periods with high (96%), medium (70%), and low (28%) average plant winter survival. For 94 US sites, the probabilities of these conditions were calculated and summarized in a map that defined areas of adaptation: a large area south of 35° N latitude for the US was identified with greater potential for overwintering success. Based on the response under multiple meteorological conditions, four distinct genotype survival groups were identified (tolerant, semi-tolerant, semi-susceptible, and susceptible). Groups with a greater number of genotypes differ in the impact of meteorological conditions on survival for the medium cluster. In regions with more favorable conditions for overwintering success, farmers may be open to introducing this crop to diversify their farming system. [ABSTRACT FROM AUTHOR]

• Skipping irrigation at the vegetative stage improves water use efficiency in canola. • Soil water extraction depth was similar across irrigation treatments and cultivars. • Canola extracted maximum soil water when stressed during reproductive stage or throughout growing season. The rapid depletion rate of the Ogallala aquifer threatens agriculture sustainability in the U.S. Southern Great Plains (SGP). Adoption of drought tolerant crop with suitable irrigation strategy is critical to improve water use efficiency and sustain crop production in the region. The objective of the study was to assess soil water extraction pattern and water use efficiency of spring canola (Brassica napus L.) under deficit irrigation strategy (DI). Three diverse canola cultivars ('H930', 'H955' and 'L140') were grown under four different irrigation treatments; full-season irrigation (FI), no irrigation at the vegetative stage (VS), no irrigation at the reproductive stage (RS) and dryland (DL). Treatment VS extracted similar amount (20 mm) of total water from planting to harvest as FI in wetter year of 2015. However, VS extracted 10 mm of extra water from soil depth down to 1.6 m until harvest compared to FI in drier year of 2016. As water extraction during reproductive stage in 2016 was almost similar (70 and 67 mm in FI and VS, respectively) in VS and FI, most of the extra water extracted was utilized during vegetative stage when irrigation was skipped in VS. Canola sustained vegetative growth utilizing soil water extraction and efficiently utilized irrigation received during reproductive stage to reduce seasonal evapotranspiration (ET) in VS compared to FI. Treatment RS and DL also reduced seasonal ET, but they reduced average 11 and 13 % oil content compared to FI in 2015 and 2016, respectively. The VS had similar oil content as FI and optimized water use efficiency for biomass (WUE pb), and seed (WUE sy) and oil (WUE oy) yields. Among cultivars, L140 consistently had the greatest WUE pb in both experimental years and 34 and 36 % greater WUE sy and WUE oy in 2016 compared to both H930 and H955, respectively. Adopting spring canola cultivar L140 and skipping irrigation during vegetative stage could maximize water productivity in water deficit conditions of the SGP. [ABSTRACT FROM AUTHOR]