Leafy Greens in Controlled Environments

  • Photoperiod, light intensity, and daily light integral

    Published on March 2, 2022
    We report and discuss research results when growing lettuce indoors under different light intensities and photoperiods under a range of daily light integrals.

  • Fixed vs. dynamic light quality for indoor hydroponic lettuce

    Published on February 2, 2022
    We present research results with lettuce plants grown indoors under a fixed lighting spectrum versus changing the spectrum during production.

  • Water vapor-pressure deficit

    Published on December 6, 2021
    The driving force for plant water loss is best described by the vapor-pressure deficit (VPD). This article discusses VPD classifications and what values are suitable during crop production.

  • The buzz of secondary metabolites

    Published on November 9, 2021
    Secondary metabolites can be an important plant quality characteristic, especially in specialty crops that are ingested. They can be modified through breeding activities as well as by plant culture and the environment.

  • 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.

  • Challenges of growing vertically in greenhouses

    Published on June 8, 2021
    There is a wide range of vertical farming approaches for greenhouse cultivation, but there are also challenges, some of which cannot easily be overcome.

  • 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.

  • Purpling of leaves

    Published on January 8, 2021
    There are many specialty crops that naturally have red, purple or almost black foliage, while others turn those colors when conditions are unfavorable. This article briefly reviews the factors that influence the purpling of leaves.

  • Leafy greens: Sole-source light intensity

    Published on June 6, 2019
    Indoor production of leafy greens, Part 4 of 4: Research shows that providing high-intensity sole-source lighting to seedlings can increase harvestable yield of fresh-cut basil.

  • Crops suitable for vertical farming

    Published on April 10, 2019
    The costs to build and operate an indoor (vertical) farm are high, so only certain types of crops are potentially profitable. This articles discusses some some of the crop characteristics that lend themselves to indoor production.

  • Leafy greens: Carbon dioxide injection

    Published on April 1, 2019
    Indoor production of leafy greens, Part 3 of 4: Is carbon dioxide enrichment beneficial for indoor production of basil seedlings?

  • Green and blue LED lighting

    Published on March 6, 2019
    Indoor production of leafy greens, Part 2 of 4: How green light affects lettuce growth can depend on blue and red light.

  • Leafy greens: Green & far red LED lighting

    Published on February 1, 2019
    Indoor production of leafy greens, Part 1 of 4: Substituting green or far-red light for blue light can increase lettuce and kale yields.

  • Factors that influence leaf coloration

    Published on November 15, 2017
    Growers usually focus on quality attributes that relate to flowering, but this article reviews cultural and environmental factors that influence foliage color.