The Sustainability of Organic Grain Production on the Canadian Prairies—A Review

Demand for organically produced food products is increasing rapidly in North America, driven by a perception that organic agriculture results in fewer negative environmental impacts and yields greater benefits for human health than conventional systems. Despite the increasing interest in organic grain production on the Canadian Prairies, a number of challenges remain to be addressed to ensure its long-term sustainability. In this review, we summarize Western Canadian research into organic crop production and evaluate its agronomic, environmental, and economic sustainability

Does Wheat Cultivar Choice Affect Crop Quality and Soil Microbial Communities in Cropping Systems?

Wheat (Triticum aestivum L.) cultivars may have differential effects on soil microbial communities and the breadmaking quality of harvested grain. We compared six Canadian spring wheat cultivars under organic and conventional management systems for yield, breadmaking quality and soil phospholipid fatty acid analysis (PLFA) profile. Yields were lower, but protein levels were higher in the organic system. Cultivars differed for quality traits, but all cultivars had acceptable levels for processing. There were small differences in PLFA profiles for cultivars in the conventional system, but none in the organic system. More significant correlations between grain quality and PLFA measures were present in the organic system. Protein levels and breadmaking quality at least equal to conventional systems can be achieved in organic systems. Wheat cultivars differed for grain quality in both organic and conventional systems, and culivars altered the soil microbial profile in conventional systems. Microbes may play a greater role in determining crop quality in organic systems than in conventional systems

WEEDS PROMOTE THE DEVELOPMENT OF ARBUSCULAR MYCORRHIZAL FUNGI IN ORGANIC WHEAT FIELDS

Understanding the interaction between aboveground vegetation and arbuscular mycorrhizal fungi (AMF) in organic agriculture is of great importance to develop more efficient and sustainable agricultural production systems. This study was conducted to evaluate the effect of weeds on AMF and the effect of AMF on wheat (Triticum aestivum L.) grain quality in an organic field in the weed-free and weedy conditions. The soil microbial profile was characterized using phospholipid fatty acids (PLFA) analysis. We found that the presence of weeds increased the proportion of AMF. The enhanced activity of AMF did not affect the quality of wheat grain grown with sufficient soil phosphorus (P)

The sustainability of organic grain production on the Canadian prairies: A review

Demand for organically produced food products is increasing rapidly in North America, driven by a perception that organic agriculture results in fewer negative environmental impacts and yields greater benefits for human health than conventional systems. Despite the increasing interest in organic grain production on the Canadian Prairies, a number of challenges remain to be addressed to ensure its long-term sustainability. In this review, we summarize Western Canadian research into organic crop production and evaluate its agronomic, environmental, and economic sustainability

Improvement of the agricultural sustainability and livelihoods of poor farmers through biotechnology : reality or speculation?

Poverty reduction, food security, and agricultural sustainability require that the livelihoods of poor farmers be improved. The potential of biotechnology to improve the livelihoods and agricultural sustainability of farmers has been hotly debated and primarily focused on “modern” agricultural biotechnology. Biotechnology is much broader than this narrow focus and includes “traditional” biotechnologies, as well as, industrial and medical sectors. Different biotechnology types have different effects and these impacts are molded by the macro-economic policies of the countries where they are implemented. Generally, the problems of poor farmers are not technological and the benefits of biotechnology are unlikely to reach poor farmers unless these ‘non-technical’ problems are addressed first

Suitability of felt traps to monitor oviposition by the cabbage maggot (Diptera: AnthomyiidaeC)

The effectiveness of felt egg traps to detect oviposition by the cabbage maggot, Delia radicum (L.), was studied under field conditions for cabbage, Brassica oleracea L. var. capitata L. (Brassicaceae), and rutabaga, Brassica napus L. var. napobrassica (L.) Reichenb. (Brassicaceae), in 1994 and 1995. The numbers of eggs laid on traps were compared with the numbers deposited in the soil next to the plant. Also, the incidence of oviposition (i.e., the percentage of samples with eggs) on soil and traps was compared. A total of 5160 eggs was collected from 5208 samples, but just 16% of all samples had eggs. For cabbage, early in the 1994 season, the incidence of oviposition in soil samples was double that on traps, and the number of eggs per sample was greater also. Oviposition incidence and the number of eggs per sample during the rest of the summer were similar. In the 1995 cabbage trial, the incidence of oviposition early in the season was again higher in soil samples than on traps, and there were fewer eggs per trap than per soil sample. For rutabaga, the number of eggs was similar using both methods early in the second generation, but from mid-August there were more eggs per trap than per soil sample. The incidence of oviposition in the rutabaga trial was similar on traps and in soil through most of the experiment. In this study, felt traps did not adequately detect the timing of cabbage maggot oviposition in the critical early season

Stem height and harvest management influence conservation biological control of wheat stem sawfly by endemic parasitoids.

The wheat stem sawfly (WSS; Cephus cinctus Norton (Hymenoptera: Cephidae)) is a serious pest of wheat (Triticum aestivum L.) in the Great Plains of North America. Two species of parasitoids, Bracon cephi Gahan and B. lissogaster Muesebeck, effectively attack C. cinctus; therefore, agronomic practices must strive to conserve these endemic parasitoids. Our objectives were 1) to establish distribution and within host infestation patterns of Bracon parasitoids, and 2) to study parasitoid responses to genetics, stubble height and straw management at harvest. Field surveys and harvest management studies were conducted in the southern Prairies of Canada and in Montana, USA. Harvest management consisted of 3 harvesting heights, 1) low, harvest near ground level to cut and thresh all material above the soil surface, 2) harvest stubble height = 15 cm, and 3) spikes only and two levels of straw management, 1) Chopped straw, or, 2) Not chopped. Most overwintering parasitoid cocoons (>80%) occurred in the bottom third (0 – 15 cm) of standing wheat stems, and the common harvest practice of chopping straw reduced adult parasitoid emergence. However, the incremental benefit of not chopping straw doesn’t justify elimination of the practice as residue management is critically important in conservation farming. Compared to a low cutting height, increasing harvesting heights to 15 cm, or higher to remove only the grain spikes, increased total emergence of Bracon cephi by 40% and 60%, respectively. Thus, the optimal conservation of wheat stem sawfly parasitoids can be achieved with easily-adopted practices on-farm without compromising sustainable production principles.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author

Eema Canada Western Red Spring wheat

Eema Canada Western Red spring wheat was developed at the University of Alberta using the single-seed descent breeding method. In three years of evaluation in the Western Bread Wheat Registration trials from 2020 to 2022, Eema produced 4.5% higher grain yield compared to the highest-yielding check, AAC Brandon, although the difference was not statistically significant. It matured one day later than AAC Brandon. Eema’s plants were 6.5 cm shorter than Glenn, but had similar height to AAC Brandon, AAC Viewfield, and Carberry, and exhibited lodging tolerance comparable to the checks. Eema’s test weight was lower, while the grain protein content was within the range of the checks. Its grain weight was higher than AAC Viewfield and similar to the other checks. Eema demonstrated strong disease resistance, being rated ‘Resistant’ to the prevalent races of stem and stripe rusts, and common bunt, ‘Moderately Resistant’ to leaf rust, whereas ‘Moderately Susceptible’ to Fusarium head blight. Three years of end-use quality evaluation confirmed that Eema meets the standards for the CWRS wheat market class, with an improvement in flour yield. Overall, Eema offers a modest increase in grain yield and enhanced end-use quality compared to AAC Brandon, making it a suitable option for cultivation in the wheat-growing regions of Western Canada.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author

Genomic Prediction Accuracy of Stripe Rust in Six Spring Wheat Populations by Modeling Genotype by Environment Interaction

Some previous studies have assessed the predictive ability of genome-wide selection on stripe (yellow) rust resistance in wheat, but the effect of genotype by environment interaction (GEI) in prediction accuracies has not been well studied in diverse genetic backgrounds. Here, we compared the predictive ability of a model based on phenotypic data only (M1), the main effect of phenotype and molecular markers (M2), and a model that incorporated GEI (M3) using three cross-validations (CV1, CV2, and CV0) scenarios of interest to breeders in six spring wheat populations. Each population was evaluated at three to eight field nurseries and genotyped with either the DArTseq technology or the wheat 90K single nucleotide polymorphism arrays, of which a subset of 1,058- 23,795 polymorphic markers were used for the analyses. In the CV1 scenario, the mean prediction accuracies of the M1, M2, and M3 models across the six populations varied from 0.11 to 0.07, from 0.22 to 0.49, and from 0.19 to 0.48, respectively. Mean accuracies obtained using the M3 model in the CV1 scenario were significantly greater than the M2 model in two populations, the same in three populations, and smaller in one population. In both the CV2 and CV0 scenarios, the mean prediction accuracies of the three models varied from 0.53 to 0.84 and were not significantly different in all populations, except the Attila/CDC Go in the CV2, where the M3 model gave greater accuracy than both the M1 and M2 models. Overall, the M3 model increased prediction accuracies in some populations by up to 12.4% and decreased accuracy in others by up to 17.4%, demonstrating inconsistent results among genetic backgrounds that require considering each population separately. This is the first comprehensive genome-wide prediction study that investigated details of the effect of GEI on stripe rust resistance across diverse spring wheat populations

Identification of Disease Resistance Parents and Genome-Wide Association Mapping of Resistance in Spring Wheat

The likelihood of success in developing modern cultivars depend on multiple factors, including the identification of suitable parents to initiate new crosses, and characterizations of genomic regions associated with target traits. The objectives of the present study were to (a) determine the best economic weights of four major wheat diseases (leaf spot, common bunt, leaf rust, and stripe rust) and grain yield for multi-trait restrictive linear phenotypic selection index (RLPSI), (b) select the top 10% cultivars and lines (hereafter referred as genotypes) with better resistance to combinations of the four diseases and acceptable grain yield as potential parents, and (c) map genomic regions associated with resistance to each disease using genome-wide association study (GWAS). A diversity panel of 196 spring wheat genotypes was evaluated for their reaction to stripe rust at eight environments, leaf rust at four environments, leaf spot at three environments, common bunt at two environments, and grain yield at five environments. The panel was genotyped with the Wheat 90K SNP array and a few KASP SNPs of which we used 23,342 markers for statistical analyses. The RLPSI analysis performed by restricting the expected genetic gain for yield displayed significant (p \u3c 0.05) differences among the 3125 economic weights. Using the best four economic weights, a subset of 22 of the 196 genotypes were selected as potential parents with resistance to the four diseases and acceptable grain yield. GWAS identified 37 genomic regions, which included 12 for common bunt, 13 for leaf rust, 5 for stripe rust, and 7 for leaf spot. Each genomic region explained from 6.6 to 16.9% and together accounted for 39.4% of the stripe rust, 49.1% of the leaf spot, 94.0% of the leaf rust, and 97.9% of the common bunt phenotypic variance combined across all environments. Results from this study provide valuable information for wheat breeders selecting parental combinations for new crosses to develop improved germplasm with enhanced resistance to the four diseases as well as the physical positions of genomic regions that confer resistance, which facilitates direct comparisons for independent mapping studies in the future