Interested Members of the University Community are invited to attend the Final Oral Examination for the Degree of Doctor of Philosophy of Jason Lanoue of the Department of Plant Agriculture.

Date: April 17th, 2020
Time: 9:00AM

Via Zoom

Please contact pagrad@uoguelph.ca for the link.

Thesis Title: From Lab to Greenhouse: Shedding Light on the Role of Spectral Quality and CO₂ Concentration in Tomato (Solanum lycopersicum L.) Production

Advisory Committee                                                               Examination Committee

Dr. Bernard Grodzinski, Advisor                                                Dr. David Wolyn, Chair

Dr. Xiuming Hao, Co-advisor                                                     Dr. Leonid Satvich, External examiner 

Dr. Rong Cao                                                                             Dr. Joseph Colasanti

Dr. Ian Tetlow                                                                             Dr. Bernard Grodzinski

Dr. Eric Lyons                                                                             Dr. Xiuming Hao

ABSTRACT

During the light limiting winter months in Canada and other northern countries, supplementary lighting is needed during greenhouse production to meet consumer demand for fresh vegetables. The advancements in light-emitting diodes (LEDs) have made them a viable source for supplementary lighting, with many advantages over traditionally high pressure sodium (HPS) luminaries. Due to their low heat emittance, compact design, and ability to supply wavelength specific light, LEDs provide an unparalleled flexibility in the development and implementation of lighting strategies for crop production. This thesis is an investigation of spectral quality and CO₂ concentration and how these factors can affect tomato (Solanum lycopersicum L.) growth specifically tailored towards the implementation of LED lighting fixtures in commercial production. Fundamental pathways such as CO₂ and H₂O gas exchange at both the leaf and whole plant level as well as the process of carbon export were examined under a variety of spectral qualities and CO₂ concentrations. Results from experiments involving whole plant gas exchange and carbon export were then used during a production style greenhouse experiment where the effects of continuous lighting on tomato physiology and yield were assessed. Results from this thesis increase our understanding of how fundamental pathways such as CO₂ and H₂O gas exchange respond to abiotic stress. Further, utilizing our laboratory results, a novel greenhouse continuous lighting strategy was designed which increased early yield and overall sustainability of tomato production during light limiting periods.