Exploration of the Impacts of Differing Fertility Concentrations on the Fertilizer Uptake and Biomass Production of Brassica carinata During Different Life-Stages 
Paul Cockson, MS Seminar
Under the direction of Dr. Brian E. Whipker, Chair of Advisory Committee
Wednesday, October 14, 2020 at 8:00 AM
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Meeting ID: 932 5343 5736

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Abstract
This work will highlight the contributions of the NC State research team under USDA-NIFA grant 2016-1123, and more specifically the MS work of Paul Cockson. This multi-state and institution grant are establishing baseline research for a new and emerging oilseed crop for the South and Southeast: Brassica carinata (commonly referred to as Ethiopian mustard or simply carinata). This crop is a cool season cover crop which produces an oil that is high in long and very long chain fatty acids (LCFA and VLCFA) which are then refined into a plethora of secondary products foremost in importance is an aviation fuel.

The work at NC State focused on establishing critical and optimal mineral fertility needs for B. carinata by exploring different fertility rates for twelve macro and microelements (nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), magnesium (Mg), iron (Fe), boron (B), copper (Cu), zinc (Zn), manganese (Mn), and molybdenum (Mo)). When establishing fertility recommendations for a new and emerging crop, varying rates of fertilizers are applied and the impacts on the plant’s growth are tracked. The production of biomass, visual symptoms of nutrient stress, and the concentration of mineral fertility within the most recently mature leaves (MRM) are cataloged. These data act as a baseline to establish the lowest and greatest concentration of fertility which can be present in the plant, the visual indicators and symptoms associated with a specific fertility deficiency, and how these nutrients will impact the biomass production of a plant. Within B. carinata, given it is planted as a cover crop, biomass production is important to maximize cover to reduce erosion, to optimize the scavenging potential of nutrients within the soil to prevent those resources from leaching, and to ensure enough branching is produced to obtain optimal yield. The optimization of leaf tissue concentrations indicate adequate fertility is being administered which in turn helps maximize yield and increase certain fatty acids within the seeds.

The above indicators (biomass production, visual symptoms, leaf tissue concentrations, and the fatty acid composition of the seeds) was accomplished through four main avenues of inquiry: (1) Establishment of critical deficiency visual symptoms and leaf tissue concentrations under mineral fertility deficiency conditions, (2) The establishment of biomass and leaf tissue mineral accumulation for the above twelve macro and micronutrients over the life stages of the plant, (3) The analysis of the lipidome by NMR and gas chromatography for the micronutrient fertility rates (4) The summation and packaging of the above information into a web based diagnostic key to aid growers and stakeholders in the identification of mineral fertility deficiencies through a decision matrix.

Plants were grown in a modified recirculating hydroponic system at varying fertility rates for the above elements adjusted down from a modified Hoagland’s solution. These six fertility rates (0, 25, 50, 75, 87.5, and 100% of a full-strength Hoagland’s solution) were supplied to B. carinata plants and leaf tissue mineral concentration and above ground biomass production was recorded over the plant’s distinct stages of growth (rosette, bolting, flowering, and pod-set). Additionally, the impacts of these varying mineral nutrients on the lipidome of the seeds was explored for the micronutrients. Additionally, visual symptoms of nutrient deficiencies were cataloged throughout the experiment for the diagnostic key.

This full lifecycle assessment resulted in maximal tissue values to be detected at varying stages of growth indicating that B. carinata fertility requirements vary based on element and life stage. Additionally, visual nutrient deficiencies resulted in visual symptoms at differing fertility treatments. The creation of the visual diagnostic key is being formulated based on the above work and will launch before the end of 2020. This seminar will highlight the above work with brevity in mind given time constraints. Please join Paul Cockson as he shares his two-year journey of discovery with B. carinata.