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Effects Of Blue And Green Light On Plant Growth And Development At Low And High Photosynthetic Photon Flux, Michael Chase Snowden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Research in photobiology dates back over 200 years with studies using primitive light sources. This early research identified photoreceptors and action spectra for specific regions of the light spectrum that are paramount for photosynthesis as well as growth and development that are still topics of interest today.

Photobiological research has become an area of increasing interest since the introduction of light-emitting diodes which allow for evaluating endless combinations of light spectra. Red light-light emitting diodes were the first to be introduced that had an electrical efficiency comparable to existing light sources. The research found that red light alone was not …

Effect Of Blue Light And Temperature On Leaf Expansion, Stem Elongation, And Growth, Tracy A. O. Dougher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Short height and high yield per unit energy in controlled environments are essential to the success of a food production system for spaceflight. Temperature and light quality can be manipulated in controlled environments to reduce plant height and increase yield. Although the effects of temperature on height and yield are well studied at ambient CO₂, temperature effects at elevated CO₂ with a hydroponic root zone are not well characterized. We studied soybean yield and height under two lamp types over a broad range of temperatures. Temperature had little effect on yield or height, but lamp type had …

Morphological Responses Of Wheat (Triticum Aestivum L.) To Changes In Phytochrome Photoequilibria, Blue Light And Photoperiod, Charles Barnes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wheat (Triticum aestivum, L.) plants were exposed to three different levels of phytochrome photoequilibria (φ), two different photoperiods, end-of-day far-red radiation, two different levels of blue (400-500 nm) light, three levels of photosynthetic photon flux (PPF), and two types of high intensity discharge lamp types. Tillering was reduced by lowered φ, by reduced amounts on blue light and by end-of-day far-red. Main culm development was increased by lowered φ, by increased PPF, and was reduced by shortened photoperiod and by reduced blue light. Leaf length was increased by increased PPF, lowered φ, and reduced blue light but was …