Agriculture

To investigate cytokinins (CKs) in nematodes, CK profiles of a free-living Caenorhabditis elegans and a plant parasitic Heterodera glycines (soybean cyst nematode, SCN) were determined at the egg and larval stages. SCN had higher total CK level than C. elegans; however, CKs in SCN were mostly inactive precursors, whereas C. elegans had more bioactive forms. This is the first study to show that methylthiols are present in nematodes and may affect plant infection. In infectious SCN larvae, methylthiol levels were much higher than in eggs or C. elegans larvae. Furthermore, The CK profiles of SCN-susceptible and resistant Glycine max cultivars at three developmental stages revealed that, regardless of the resistance level, SCN infection caused an increase in root CKs. One resistant cultivar, Pion 93Y05, showed significantly high levels of bioactive N6-isopentenyladenine (iP) in the non-infected roots which indicated a potential role of CKs in soybean resistance to SCN.

Author Keywords: Cytokinins, HPLC-MS/MS, Nematode, SCN resistance, Soybean

This qualitative study examines the applicability, impact, best practices, sustainability and livestock welfare implications of mobile processing service operation in central Ontario. Grounded theory concepts were utilized to analyze data generated from semi-structured interviews and a community focus group, supplemented by an initial exploratory literature review, and focused review approach to refine emergent categories. It was found that there is interest in, applicability for, and food system-sustainability benefit from mobile processing services, but market competition and regulatory context impede the profitability of operation, not just for mobile service, but for existing provincial plants. Public support for mobile or regionalized processing resources could address many of the sustainability concerns in our regional livestock production and consumption systems, but where appetite for such political action does not exist, solutions are required if we hope to address the continuing centralization, commodification, traditional profit-maximization and negative externality generation of our industrialized agri-food production system.

Author Keywords: agri-business production and distribution, livestock welfare, mobile abattoirs and livestock processing, regional food systems, rural-urban relations, sustainability

Currently, UAVs are deployed to measure crop health in a timely manner by mapping vegetation indices. A study using two different fields was conducted in order to search for a relationship that may exist between crop health and soil fertility. A UAV equipped with sensor technology was used for mapping of vegetation indices which were then statistically compared to soil nutrient data collected via soil sampling. Elevation data was also collected which was then statistically compared to soil nutrients as well as crop health. Results of this study were unfortunately impacted by variables outside of the researcher's control. Moisture became the greatest limiting factor in 2016 followed by an excess of rain in 2017. Results did not show any promising correlations as moisture uncontrollably became the defining variable. Further research in a more controlled setting will need to be conducted in order to explore this potential relationship.

Author Keywords: Agriculture, Multispectral Imagery, Precision Agriculture, Proximal Soil Sensing, Remote Sensing, Unmanned Aerial Vehicle

Olives have been grown in the Mediterranean region for millennia and have been a staple crop in many of its cultures. This was never more true than during the Hellenistic (323 – 133 BC) and Roman (133 BC – AD 450) periods in the Mediterranean. This thesis examines the territory of the Roman city of Sagalassos in the region of Pisidia, modern province of Burdur, and determines if olives could have been cultivated in the territory. While there have been studies that state olives were cultivated in the territory during the Hellenistic and Roman periods, modern farmers as well as agronomic manuals state that such growth is not possible. This thesis present data that indicates that olives were grown in the territory of Sagalassos, but also examines the conditions olives require to grow and if such conditions existed in Pisidia. Through this I will be able to conclude whether the past presentation of data has does indeed prove that olives were grown within the territory of Sagalassos.

Author Keywords: Agricultural Decision Making, Olives, Pisidia, Roman Agriculture, Sagalassos, Turkey

This thesis re-imagines the social sustainability of civic agriculture. This entails critically examining the idea of sustainability and exposing why a tendency to undertheorize its social dimension is problematic for how we think about sustainability, and consequently for how we do sustainability. What is demonstrated is that we can overcome this tendency by adopting Stephen McKenzie's understanding of social sustainability as a positive condition and/or process within a community. Once brought into contact with the concept of civic agriculture as presented by Thomas A. Lyson, and expanded upon by others, this broadened understanding of social sustainability reveals that we can think of civic agriculture as both a means to, and an expression of, social sustainability. Specifically, this thesis argues that it is civic agriculture's community problem-solving dimension which animates civic agriculture in such a way that it creates the sort of condition and/or enables the sort of process which reflect aspects associated with a substantive and/or procedural understanding of social sustainability. This re-imagining of the social sustainability of civic agriculture provides ways to defend civic agriculture from its critics and is exemplified by drawing from a personal encounter with civic agriculture. In the end, it is proposed that in light of this research there are now good reasons to re-examine civic agriculture and to critically re-imagine what qualifies who as a civic agriculturalist so that the contextual nature of the social sustainability of civic agriculture can be better respected.

Author Keywords: civic agriculture, community problem solving, local food systems, social sustainability, Stephen McKenzie, Thomas A. Lyson

The global food system has been criticized for being environmentally, economically and socially unsustainable. As part of a local food movement, farmers' markets (FM) are undergoing a revival in response to the escalating food system globalization of the past century. Despite the prevalence of FMs as formalized organizations, there remains a significant range in their operational strategies. Through 41 questionnaires and 17 interviews with market administrators across Ontario, in collaboration with the Haliburton County Farmers' Market Association, I explored these strategies and analyzed the influence of community characteristics on FM operations. Factors that appear to have a significant impact on FM governance and management are market size and age, willingness to adapt to change, and relationships with external organizations. My findings suggest that democratic vendor engagement and documentation of procedural systems can help optimize market administration. In terms of vendor relationships, primary concerns include regulation of resellers, diplomatic vendor pool design, and creation of a collaborative atmosphere. As well, I conclude that customers are best viewed as socially invested stakeholders with a strong interest in learning about local food production.

Author Keywords: farmers' markets, global food system, local food systems, Ontario farmers' markets, sustainability

This thesis proposes an agro-ecological zoning (AEZ) methodology of southern Ontario for the characterization and mapping of agro-ecological zones during the historical term (1981-2010), and their shifts into the long-term (2041-2070) projected climate period. Agro-ecological zones are homogenous areas with a unique combination of climate, soil, and landscape features that are important for crop growth. Future climate variables were derived from Earth System Models (EMSs) using a high emission climate forcing scenario from the Intergovernmental Panel on Climate Change 5th Assessment Report. The spatiotemporal shifts in agro-ecological zones with projected climate change are analyzed using the changes to the length of growing period (LGP) and crop heat units (CHU), and their manifestation in agro-climatic zones (ACZ). There are significant increases to the LGP and CHU into the long-term future. Two historical ACZs exist in the long-term future, and have decreased in area and shifted northward from their historical locations.

Author Keywords: Agro-climatic Zones, Agro-ecological Zones, Agro-ecological Zoning, Climate Change, Crop Heat Units, Length of Growing Period

Livestock predation by wild predators is a frequent and complicated issue, often cited as a significant factor in the decline of livestock production and justification for killing predators. Coyotes (Canis latrans) are the primary predators of sheep in Ontario. Some farms appear to be more susceptible to predation than others, despite the use of mitigation techniques. I explored land cover in the vicinity of farms as a potential influence on the level of predation, as coyote abundance and wild prey are correlated with certain habitat types. Using model competition, I show that landscape explains little variation in predation levels over all farms, but can explain 27% of variation in the percent of a flock killed. Total forest edge habitat and distance between forest patches were both positively associated with losses, suggesting a reduction in forest cover surrounding a farm puts the flock at greater risk. In addition, I tested four disruptive deterrents for effectiveness at protecting flocks. A matched-pairs analysis did not show a statistically significant benefit of these non-lethal mitigation tools.

Author Keywords: Alternative Prey, Canis latrans, Coyote, Landscape, Predation Deterrents, Sheep

Cytokinins (CKs) are a family of plant phytohormones responsible for many areas of plant growth and development. There are four free base types of CKs found in higher plants, trans-zeatin (tZ), N6-(∆2-isopentenyl)adenine (iP), cis-Zeatin (cZ) and dihydrozeatin (DZ). CK biosynthesis is regulated by adenosine phosphate-isopentenyltransferase (IPT), which is encoded by a multi-gene family in many plant species. There are two types of IPT pathways responsible for CK production, the tRNA pathway and the AMP (ATP/ADP) pathway. The tRNA pathway putatively produces cZ and the latter predominantly produces iP type nucleotides. CKs have long been studied for their role in stress tolerance, signal transduction, and involvement in many areas of plant growth and development. This study focuses on the role of CKs and CK biosynthesis by IPT during kernel development and comparisons of its regulation in high and low yielding barley and oat lines. The sequence of a putative IPT encoding gene in barley and oat was identified by a blast search of other known IPT gene fragments in closely related species. Quantitative Real time PCR results based on primers designed for the putative barley and oat IPT gene revealed changes in expression of IPT during different stages of kernel development, but no significance difference was associated with yield. Correlation of IPT gene expression in barley with cZ CK profiles measured by HPLC-MS/MS, confirms a putative IPT gene is a tRNA- IPT. HPLC-MS/MS results reveal some CK types, such as benzyladenine, are more predominant in higher yielding lines. This suggests different types of CKs play a role in yield production. Future studies on more IPT genes in the barley and oat IPT gene family will outline a more clear representation of the role of IPT in barley kernel development.

Author Keywords: Benzyladenine, Cereal grain, Cytokinin, Isopentenyl Transferase, Mass Spectrometry, Real Time PCR

Soil mineralizable nitrogen (N) is the main component of soil N supply in humid temperate regions and should be considered in N fertilizer recommendations. The objectives of this study were to determine the potentially mineralizable N parameters, and improve N fertilizer recommendations by evaluating a suite of soil N tests in southwestern Ontario. The study was conducted over the 2013 and 2014 growing seasons using 19 field sites across southwestern Ontario. The average potentially mineralizable N (N0) and readily mineralizable N (Pool I) were 147 mg kg-1 and 42 mg kg-1, respectively. Pool I was the only soil N test that successfully predicted RY in 2013. The PPNT and water soluble N (WSN) concentration (0-30cm depth) at planting were the best predictors of fertilizer N requirement when combing data from 2013 and 2014. When soils were categorized based on soil texture, the relationships also improved. Our findings suggest that N fertilizer recommendations for grain corn can be improved, however, further field validations are required.

Author Keywords: corn, nitrogen, nitrogen mineralization, soil nitrogen supply, soil N test, southwestern Ontario