• Extended photosynthetically active radiation can increase plant growth

    Published on August 12, 2024
    There is merit to extending the photosynthetically active radiation (PAR) waveband to include far-red light, which is termed extended PAR, or ePAR.

  • The transient effects of indoor lighting on lettuce production

    Published on May 2, 2024
    We compared the effects of end-of-production ultraviolet-A and blue light to earlier or continuous application of either waveband on red-leaf lettuce yield and quality grown indoors.

  • Lighting plants indoors, without sunlight

    Published on May 10, 2023
    Although expensive, there are potential benefits to growing indoors. This article provides an overview of some major considerations when developing an indoor lighting system.

  • Advancements in horticultural lighting

    Published on March 5, 2023
    The science, engineering, and application of horticultural lighting continues to advance with developments in light-emitting diode (LED) technology.

  • A closer look at the effect of white LEDs on plant performance

    Published on January 5, 2023
    This article summarizes an experiment with lettuce and kale when grown indoors under different white light-emitting diodes (LEDs).

  • Getting started with supplemental greenhouse LED lighting

    Published on November 16, 2022
    Light-emitting diodes (LEDs) come in all shapes and sizes, emit different colors and intensities, and have a range of energy efficacies. This article outlines how to get started with supplemental greenhouse lighting with LEDs.

  • Far-red light in greenhouse and indoor farming

    Published on October 6, 2022
    Far red is a waveband of light that is marginally visible to us but has profound effects on plant growth and development; it increases both plant elongation and biomass accumulation.

  • More questions answered

    Published on August 3, 2022
    In part two of this four-part series, we respond to questions about lighting, carbon dioxide enrichment, co-optimization, and sterility within indoor farms.

  • Futuristic light(ing) in horticulture

    Published on August 1, 2022
    Light-emitting diodes are rapidly advancing, but there are other technologies that supplement or modify the solar spectrum that could also have applications in horticulture.

  • The shade-avoidance response

    Published on May 11, 2022
    When other plants are nearby, they detect changes in the light environment and try to out-compete their neighbors. Understanding this shade-avoidance response can help growers to promote or prevent this response, depending on the growth desired.

  • Light and temperature responses of bedding plants

    Published on March 9, 2022
    We have quantified the temperature and light responses of common bedding plant crops to better understand their impacts on production time and quality.

  • Blue light as a PGR

    Published on February 7, 2022
    Blue light generally inhibits extension growth and thus can act as a plant growth retardant (PGR), particularly when crops are grown indoors or in greenhouses during low-light periods.

  • A closer look at LED efficacy

    Published on January 5, 2022
    This article discusses recent advances in the efficacy (energy efficiency) of light-emitting diodes for plant applications.

  • Far-red and PPFD: A tale of two lettuce cultivars

    Published on October 5, 2021
    In part 3 of a 5-part series on the indoor production of leafy greens, the interactive effects of far-red light and light intensity on lettuce growth are discussed.

  • Light spectrum for different applications

    Published on September 8, 2021
    This article discusses the effects of the light spectrum on plants, and conceptually how it can be used for different greenhouse and indoor crop production applications.

  • Differentiating broad spectra

    Published on September 6, 2021
    In part 2 of a 5-part series on the production of leafy greens indoors, this article discusses how substituting white light (broad spectra) with red and/or blue light influences lettuce production.

  • Increasing the daily light integral

    Published on August 6, 2021
    The daily light integral (DLI) refers to the cumulative amount of light received per day, which influences the quality and yield of horticultural crops. This article discusses ways to increase the DLI for plants grown in greenhouses.

  • LEDs: More than μmol×J–1

    Published on July 7, 2021
    Light-emitting diodes (LEDs) are known for their efficiency at converting electricity into light. While efficacy is a very important consideration, there is more to them than just their μmol×J–1.

  • The indoor lighting guide: Growing seedlings under LEDs

    Published on July 1, 2021
    This 24-page guide provides research-based information about producing young plants indoors (without sunlight) under LEDs. Developed in partnership with GrowerTalks magazine.

  • LEDs on lettuce: White light vs. red+blue light

    Published on June 7, 2021
    In the first article of a five-part series on indoor production of leafy greens, we join the lighting debate discussing white versus red and blue light from a crop production perspective.

  • Light fixtures and their photon fluxes

    Published on May 6, 2021
    LED fixture come in all shapes, sizes and outputs — more technically, photon fluxes and spectra. This article explains the photon flux emitted by a light fixture and why it is important.

  • “Hidden” benefits of supplemental lighting

    Published on April 7, 2021
    High light can at least partly decrease the effects of other environmental parameters on greenhouse crops. These can be considered “hidden” benefits because the effects are often not obvious.

  • Sole-source (lighting) for seed

    Published on April 5, 2021
    By producing plants indoors under sole-source lighting, not only can we control plant traits by manipulating the light quality and/or quantity. but we can potentially produce more resilient plants.

  • Maximizing photosynthesis, minimizing respiration

    Published on March 7, 2021
    Conceptually, anything growers can do to increase photosynthesis and decrease respiration can increase growth, leading to thicker stems, faster rooting, more branches, and more and larger flowers and fruits

  • Making sense of light sensors

    Published on February 10, 2021
    In this article, we discuss light sensors, light units, and how to convert light units from a greenhouse environmental control computer into more meaningful values.