Thesis Defence: Using controlled environment agriculture to evaluate light and nutrient management strategies for Cannabis sativa L. and Fragaria × ananassa (Duchesne ex Rozier)

Karina Jarzecki, supervised by Dr. Susan Murch, will defend their thesis titled “Using controlled environment agriculture to evaluate light and nutrient management strategies for Cannabis sativa L. and Fragaria × ananassa (Duchesne ex Rozier)” in partial fulfillment of the requirements for the degree of Master of Science in Biochemistry and Molecular Biology.

An abstract for Karina Jarzecki’s thesis is included below.

Defences are open to all members of the campus community as well as the general public. Registration is not required for in-person defences.

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Abstract

Controlled environment agriculture (CEA) consists of producing crops within indoor settings rather than in open fields. This thesis explores the integration of emerging techniques and technologies in CEA through two complementary studies focused on lighting and nutrient management, testing two high-value crops: Cannabis and strawberry. My first study investigated the influence of LED light spectra on the metabolism of in vitro Cannabis in advanced growth chambers. Plantlets were exposed for seven days to one of three lighting conditions: broad-white (control), red, or blue LED spectra. Meristematic tissue was then analyzed using a combination of commercial cannabinoid quantification, targeted metabolomics for plant hormones, and untargeted metabolomics for compound and pathway discovery. Blue light stimulated the accumulation of flavonoids and gibberellins, whereas red light led to increased concentrations of carboxylic acid derivatives. All treatments showed widespread amino acid conjugation. Many biosynthetic or metabolic pathways, particularly those involving tryptophan, tyrosine, and phenylalanine, were associated with shikimate and MEP/MVA pathways, connecting light to plant secondary metabolites. My second study developed and tested a proof-of-concept fertigation system for strawberries (Fragaria × ananassa), an emerging greenhouse crop experiencing rapid market expansion in Canada. Using a Youden square experimental design, the study evaluated the performance of advanced agriculture technology, or agri-tech, sensor systems (Vivent BioSignals and Grodan GroSens) alongside conventional laboratory analysis (ICP-OES), under various fertilizer treatments delivered by an automated irrigation system (NourishLabs). The system was stable across treatments, indicating a limited capacity to modulate nutrient uptake only through fertilizers. My work established correlations between sensors and lab analyses, especially for manganese across plant, substrate, and leachate samples. Together, these studies provide insights into both the potential and the practical limitations of integrating emerging technologies into CEA.