Trade Articles

How Can Modeling Help To Grow A Better Indoor Farm Lettuce Crop?

In this installment of Urban Ag News' OptimIA series, David Kucack conducts an interview with Murat Kacira (University of Arizona) and Chieri Kubota (Ohio State University) discuss how they are using crop modeling to identify the most favorable environmental parameters to optimize growth, yield and to prevent tipburn for indoor farm lettuce crops.

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Where Can You Get Accurate Information About Indoor Farm Production?

In this installment of Urban Ag News' OptimIA series, David Kucack conducts an interview with Erik Runkle (Michigan State University) and Chieri Kubota (Ohio State University) to discuss the OptimIA project's efforts to share their indoor farm research findings with the controlled environment agriculture industry and the public through a variety of educational and informational outlets.

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What Impact Does Light Have On Controlled Environment Leafy Greens Production?

In this installment of Urban Ag News' OptimIA series, David Kucack conducts an interview with Erik Runkle and Roberto Lopez (Michigan State University) to discuss their research studying the impact that light and its interaction with other environmental parameters can have on indoor leafy greens production.

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How Do You Overcome The Environmental Challenges Of Indoor Farming?

In this installment of Urban Ag News' OptimIA series, David Kucack conducts an interview with Murat Kacira (University of Arizona) and Cary Mitchell (Purdue University) to discuss how the OptimIA project is working to solve the environmental control issues facing indoor farm growers.

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How Is OptimIA Helping Vertical Farms Grow More Efficiently And Economically?

In this installment of Urban Ag News' OptimIA series, David Kucack conducts an interview with Erik Runkle (Michigan State University) and Chieri Kubota (Ohio State University) to learn more about the OptimIA project and their mission to offer production and economic information that is useful, timely and applicable to the indoor farm industry.

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Can Leafy Greens Be Profitably Grown In Indoor Farms?

In this installment of Urban Ag News' OptimIA series, David Kucack conducts an interview with Simone Valle de Souza (Michigan State University) to discuss the profitably of leafy greens when grown in controlled environment agriculture (CEA) conditions and whether consumers are willing to pay a higher price for CEA grown produce.

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How Can You Manipulate The Environment To Improve Leafy Greens Production?

In this installment of Urban Ag News' OptimIA series, David Kucack conducts an interview with Roberto Lopez (Michigan State University) to explore the research conducted by the OptimIA project including how the environment can be manipulated to improve crop quality, increase yields and change the plant morphology of leafy greens.

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Pericarp Cracking and Moisture Management to Improve Spinach Germination

August 2023

Chieri Kubota, Samuel Offenbecher, and Robert Conrad

More Questions Answered

In part two of Inside Grower's four-part series, OptimIA researchers continue to answer questions about indoor farms. Part two focuses on answering questions concerning "lighting, carbon dioxide enrichment, co-optimization and sterility".

Runkle E., M. Kacira, and C. Mitchell. 2022. More Questions Answered. Inside Grower 10(3):16–17.

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Indoor Farming FAQs

In part one of Inside Grower's four-part series, researchers answer questions on the basics of indoor farming and its challenges and opportunities.

Lopez. R., C. Kubota, E. Runkle and C. Mitchell. 2022. Indoor Farming FAQs. Inside Grower 10(2):48–49.

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Photoperiod, Light Intensity and Daily Light Integral

Researchers answer the question of whether it matters how a daily light intergral is delivered by investigating the interactions between the PPFD and photoperiod on lettuce growth.

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Fixed vs. Dynamic Light Quality for Indoor Hydroponic Lettuce

Researchers tailored the light spectrum for each growth phase of indoor hydroponic lettuce to determine how a fixed light spectrum directly compares to dynamic light spectra when it comes to crop yield and size, and is it worth moving seedlings to different light spectrums or investing in color-turnable light fixures.

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Lighting up basil flavor

In this fifth article of our six-part series on potted and hydroponic culinary herb research at Michigan State University, we will show you how you can improve the flavor of basil with light intensity.

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Sustaining the Future with Precision Horticulture and Engineering

In the last few years, the precision horticulture and engineering domain has been seeing a technological transition with a focal shift from mechanization to real-time sensing and big-data driven decision support as well as smart actuation with robotic systems both in the field and within controlled environment horticulture, which includes greenhouses and indoor farming.

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LEDs on Lettuce: White Light vs. Red + Blue Light

Today, growers can choose from a wide range of LED fixtures with different specifications. The selection depends on factors including the fixture cost, efficacy (the photon output per unit energy), the light spectrum, the form factor, and the light responses of crops.

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Differentiating Broad Spectra

Unlike red + blue LEDs, broadspectrum (white) LEDs can reveal the true colors of plants, which facilitates the inspection of crop growth, nutrient conditions, insects, and diseases in a visually pleasing environment.

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Utilizing Supplemental Lighting in Urban Crop Production Environments

Electric lighting is needed to either supplement naturally available sunlight, extend day length or serve as the sole source of light.

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Monitoring Carbon Dioxide in Controlled Environments

Carbon dioxide is an odorless and colorless trace gas. Today, ambient CO2 levels outdoors comprise 0.04% of atmospheric volume, or around 400 parts per million, ppm. Plants take up CO2 by diffusion, through small pores called stomates that are primarily located on the underside of leaves. The opening and closing of stomates can be influenced by leaf and air temperatures, light levels, humidity, water stress, CO2 concentration, and oxygen (O2) in the air and leaf. Thus, if any of these environmental or cultural factors used for photosynthesis are limiting in the greenhouse, plant growth and yield are less.

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Purpling of Leaves

The purple color in leaves comes from pigments called anthocyanins. These pigments also give many red- and purple-colored fruits and flowers their color, as well as tree species that turn a reddish color in autumn. The concentration of anthocyanins is influenced by several factors, including environmental conditions (especially light and temperature) and the pH and presence of metal ions (such as iron and magnesium) in the growing substrate.

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Maximizing Photosynthesis, Minimizing Respiration

Plants use the energy from light to convert carbon dioxide (CO2) and water into sugars and oxygen, which is the process everyone knows as photosynthesis. The sugars can be stored by the plant, transported to other plant parts, and used to fuel

growth and the functioning of cells. When one of the inputs to photosynthesis is limiting, there is less energy to support plant maintenance and growth.

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LEDs: More than μmol×J–1

The term “efficacy” refers to this electricity-to-photon conversion. Efficacy is determined by dividing the quantity of light emitted by a fixture (technically speaking, the photosynthetic photon flux, in μmol×s–1) by the electricity consumed to emit that light (in watts, W). Because one watt equals one joule per second (J×s–1), the unit for efficacy is μmol×J–1.

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Light Fixtures and Their Photon Fluxes

Until recently, there were only three major types of lighting fixtures used for the production of plants in controlled environments: incandescent bulbs for photoperiodic lighting, high-pressure sodium fixtures for supplemental lighting in

greenhouses, and fluorescent tubes for plant production indoors.

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Culinary Herbs: Balancing Light and Average Daily Temperature

In this fourth article in a five part series on potted and hydroponic culinary herb research at Michigan State University (MSU), we will show you how temperature and light interact to influence herb growth, development, and foliage color.

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Green and Blue Lighting

Substituting green light for blue (400–500 nm) light under a fixed intensity of

red (600–700 nm) light increased leaf expansion and shoot biomass of lettuce and kale. However, because green and blue light can have opposing effects on growth processes, it was unclear whether the increased growth was caused by increasing green light, decreasing blue light or both.

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Green and Far-red LED Lighting

Indoor production of leafy greens, Part I: Substituting green or far-red light for blue

light can increase lettuce and kale yields.

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Including Far Red in an LED Lighting Spectrum

Far red (FR) is a one of the radiation (or light) wavebands that regulates plant growth and development. Many people consider FR as radiation with wavelengths between 700 and 800 nm, although 700 to 750 nm is, by far, the most active.

By definition, FR is just outside the photosynthetically active radiation (PAR) waveband, but it can directly and indirectly increase growth.

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Infrared Thermometers for Monitoring Plant and Substrate Temperatures

Temperature is defined as thermal energy and influences seed germination,

rooting of cuttings and seedlings, leaf expansion and flowering, plant

architecture and quality, and cropping time. In this article, we will discuss the importance of having a hand-held infrared (IR) thermometer in your toolkit.

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LEDs for Propagation?

Are you interested in rooting cuttings under light-emitting diodes (LEDs), but

hesitate to install LEDs in a propagation greenhouse where they may be exposed

to high humidity and maybe only be used for three to four months a year? Fear

no more. Researchers at Michigan State University (MSU) have investigated the application and use of LEDs for sole-source lighting (SSL) during herbaceous perennial propagation.

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Know your Light Levels

Follow these guidelines to accurately measure photosynthetic light levels with meters in the greenhouse

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Urban Crop Production in Vertical Farms

Indoor vertical farming systems or plant factories use controlled environment

agriculture (CEA) technologies to grow high-value horticulture. Optimizing the use of resources such as energy, water, nutrients and CO2 is essential for the long-term viability of vertical farm systems, where energy intensive lighting and HVAC

systems can account for close to one third of the overall operational costs.

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Culinary Herbs: To Flower or not to Flower?

The critical photoperiods of new cultivars of culinary herbs have yet to be determined, so researchers set out to observe whether changes in photoperiod

or day length influence flower initiation in herbs like basil, oregano, mint and more.

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Common Plant Production Acronyms

There are many acronyms used when discussing the production of crops in controlled environments. Acronyms are usually

abbreviations formed from the initial letters of other words.

We sometimes read or hear them without fully understanding their

meaning, and that’s especially the case for people new to the industry and/or for those whose first language is not English.

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Early Scaling-Up Challenges with LED Lighting

Relative to other lighting technologies on the market today, we are still in early days of commercial-scale implementation of LEDs as a supplemental lighting source.

The demand for LEDs is huge, and based on the promising science and engineering behind the technology, it is justifiable. Has the demand outpaced the reliable supply of component parts? Will the industry mature fast enough to alleviate the technology’s implementation issues? While we are optimistic, as with any new technology, it is important to know that there can still be some hiccups with commercial implementation

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Lighting Basil Seedlings

In last article of a four-part series, researchers from Michigan State University share science-based information about indoor production of leafy greens and herbs.

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Controlled Environment Agriculture (CEA) Carbon Dioxide Injection

In this third article of a four-part series, researchers from Michigan State University share science-based information about indoor production of leafy greens and herbs.

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Indoor Production of Herb Seedlings: Light Intensity & Carbon Dioxide

In this second article of our five-part series on culinary herb research at Michigan State University (MSU), we will highlight the results of pushing the lighting and carbon dioxide envelope during the production of dill, parsley, and sage seedlings indoors without sunlight.

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