Progress 10/01/19 to 09/30/20
Outputs Target Audience:Higher education students, state and national researchers, extension personnel, commercial producers, community members. Changes/Problems:The pandemic has reduced in-person activities and the connectivity with students and the public. Virtual and online opportunities have been engaged and used where possible. Combinations of traditional communication lines with those developed during the pandemic are anticipated to work well and more effectively for outreach and dissemination of information in the future. What opportunities for training and professional development has the project provided?Various communication channels are used to reach and meet the needs for information, education and training to various groups throughout the state. We are continuously communicating with producers and individuals interested in pursuing or already engaged in the use of various production systems such as fields, high tunnels, greenhouses and indoor controlled environments. Training opportunities in topics related to horticultural production are regularly offered and presented to students at secondary and post-secondary levels. Presentations are also provided at local, regional, national and international meetings, conferences and workshops on crop production in various environments including greenhouses, high tunnels, season extension techniques and field conditions. The limited in-person contacts and meetings in 2020 changed and reduced the number of direct interactions. As communities and the university are hopefully able to resume activities and events in 2021, traditional interactions along with online tools for training and development are likely to continue and increase. How have the results been disseminated to communities of interest?Presentations are provided at local, regional, national and international meetings, conferences and workshops on crop production in various environments including greenhouses and other indoor growing approaches, high tunnels, season extension techniques, and field conditions. In the fall of 2019 and early 2020 prior to the pandemic, activities and conferences were conducted on schedule. As in-person events were reduced or canceled in 2020, online opportunities increased. Several conferences, workshops and meetings went online with opportunities for participation, presentations and the display of research findings and information. What do you plan to do during the next reporting period to accomplish the goals?We are continuing the initiated studies and are adapting research protocols based on earlier findings to more effectively use the available greenhouse research facility. The setup for the LED research is updated for improved efficiency. Our outreach efforts are anticipated to go back to events similar to those provided prior to March 2020 along with methods that worked well during the pandemic to provide information at grower gatherings, response to information requests, scientific and producer oriented publications, and formal instructional secondary and post-secondary activities.
Impacts What was accomplished under these goals?
Spinach is a popular leafy green with a public perception of providing higher nutritional quality than many other salad greens. Flower initiation and bolting occur under long day conditions resulting in limited or discontinued leaf formation. Cultivar selections of spinach with less tendency for flower initiation under long days or warm growing conditions are available. Field production can nevertheless be limited, as many cultivars still tend to form flowers under less than optimal temperature or photoperiodic conditions. To meet year round requests for locally grown high quality spinach, shifting from field production to greenhouses and other controlled environments is an option. Light emitting diodes offer opportunities to design spectral environments in support of productivity and nutritional quality. The impact of light quality on soluble solids content (°Brix), yield, dry matter accumulation and mineral nutrient content in fresh spinach were evaluated. Spinach was grown under panels of LEDs and compared to greenhouse growing conditions with natural or supplemented light. The cultivar Seaside was selected as it has a more limited tendency to initiate flowers and bolt. The light quality treatments included blue LEDs (peak emission at 450 nm), red LEDs (50:50, peaks at 625 and 660 nm), blue/red LEDs (20:40:40, peaks at 450, 625 and 660 nm), and white LEDs (5000K). In addition, T5 fluorescent (4100 K) and natural greenhouse light supplemented with high-pressure sodium (HPS) irradiance were evaluated in a greenhouse covered with the acrylic material DEGLAS®. The growing areas of LEDs and fluorescent lamps were separated and shielded from natural and greenhouse light using an opaque blackout material. Plants were grown at a constant 21 ± 2°C with a 16 hour photoperiod at a photosynthetic photon flux of approximately 150 µmol·m-2s-1. The fresh- and dry weights were considerably smaller for plants grown in the greenhouse environment under natural and HPS lighting. Flowers formed quickly in the greenhouse grown spinach that resulted in limited leaf- and overall growth. Some spinach grown under blue LEDs also formed flowers with overall smaller fresh weights. The largest fresh weights were in the blue/red LEDs at 125.67 ± 9.16 grams per plant. The white LEDs also supported good growth (112.06 ± 4.86 g) while the red and fluorescent environments produced similar sized spinach. The proportion dry weight varied between 7.5 to 8.5 percent. The only exception was in the blue environment were the ratio of dry weight per plant was closer to 10 percent of the fresh weight. There was a trend for higher °Brix under blue LEDs with a value of 8.6 ± 0.65. To further evaluate the use and significance of LED light spectrums for growing spinach, the mineral nutrient content and quality were also determined. There were no significant differences in the content on a dry weight basis of nitrogen, calcium, iron or zinc among growing conditions. For potassium and magnesium, the highest content was recorded in the control treatment (natural light with HPS). For phosphorous, sulfur and boron on the other hand, the control treatment resulted in the least amounts. There was a trend for high values in the blue/red LED environment for manganese and copper, although not significantly different from the HPS control for copper. The 16 hour day length was used to ensure appropriate levels of daily light were provided for overall growth. Although Seaside is considered slow bolting, there was a tendency for bolting and flowering in the greenhouse environment throughout the year. The relationship between natural and HPS light is seasonally synchronized for adequate greenhouse irradiance and may influence the bolting response. The proportion for instance, of red to far-red wavelengths in the spectrum may activate flower initiation. In general, the LED environments countered or delayed flowering under the 16 hour day length to allow growth for satisfactory harvest. The only exception was the exclusively blue growing environment where flowering was observed. LEDs offer opportunities to establish a variety of temporal and spatial lighting environments to support productivity and nutritional quality of spinach. Additional studies are needed to more precisely identify the importance of the spectral energy distribution for overall growth, flowering and the nutritional quality of spinach grown in greenhouses and controlled environments. 1. Advance production and management techniques for Alaska agricultural production in greenhouses and controlled environment production facilities through novel technologies, methods and innovations. Several studies are in progress for determining the effects and potential implementations of LEDs for greenhouse and controlled environment production. Sustainable greenhouse systems that are specifically well suited and efficient for high latitude vegetable production are also evaluated. 2. Develop sustainable greenhouse control methods to improve resource use efficiency, climate uniformity, production quality, productivity and yields. LEDs with expected higher energy efficiency and adjustable spectrum, suggest improved resource use while allowing for a more uniform growing environment to support crop productivity and quality. Greenhouse production systems that are based on the extended daylight hours in the summer and transitioning into less light demanding crops during the winter can be expected more resource efficient and sustainable in northern climates. 3. Disseminate information about controlled environment technologies, methods and approaches to producers throughout the state. As we gain knowledge and understanding of LEDs and other production techniques, we anticipate additional publications and outreach efforts in this area. 4. Teach up-to-date greenhouse, indoor farming and controlled environment technologies to beginners, producers, and students in formal educational programs. In the fall of 2019, the course Applied Plant Science was offered to undergraduate students. This course had a significant emphasis on the sustainable use of resources and the management of light and other climatic conditions. The courses Principles of Sustainable Agriculture and Greenhouse Management were offered in the spring of 2020. The college level greenhouse management course includes substantial information on modern control and management techniques for greenhouses and controlled environments. Understanding and implementing greenhouse and season extension environments are essential for efficient local northern crop production. These courses were completely transitioned to online delivery mid-semester due to Covid. 5. Publish research findings, prepare educational materials, and exchange information with stakeholders, extension personnel and researchers in the U.S. and internationally Results and experiences on the efficient use of LEDs, protocols for spinach production and the nutritional value of locally grown produce and herbs have been communicated at state, national and international scientific conferences, as well as in post-secondary education and producer oriented gatherings. The annual ASHS (American society for horticultural science) meeting was held online in August of 2020. This conference provided information and several presentations on findings related to the use and adaptation of LED lighting technologies in research and crop production along with the use and implementation of controlled environment facilities for crop production in various geographic locations and climates. Although the online conference was well attended and allowed for individual and direct contacts, the interactions were more limited and an in-person meeting is more desirable. The international conference on Light in Horticulture planned for June 2020 was postponed to May 2021.
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2021
Citation:
Karlsson, M. 2021. Light quality affects growth and nutrient content in basil. Acta Horticulturae (in press).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Karlsson, M. 2020. Nutritional quality of locally grown Alaska produce. Alaska Sustainable Agriculture conference.
- Type:
Other
Status:
Published
Year Published:
2020
Citation:
Karlsson, M. 2020. Light quality affects growth and nutrient content of spinach. HortScience 55(9):S234
- Type:
Journal Articles
Status:
Accepted
Year Published:
2021
Citation:
Wilkinson, A., H. Penn, M. Karlsson, C. Gerlach. 2021. Controlled environment agriculture and containerized food production systems, part of a diversified, sustainable and resilient food system? J. Agriculture, Food Systems, and Community Development.
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Progress 10/01/18 to 09/30/19
Outputs Target Audience:Higher education students, state and national researchers, extension personnel, commercial prodcuers, community members. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Several types of communication channels are used to reach and meet the needs for information, education and training to various groups throughout the state. We are continuously communicating with producers and individuals interested in pursuing or already engaged in the use of various production systems such as fields, high tunnels, greenhouses and indoor controlled environments. Training opportunities in topics related to horticultural production are regularly offered and presented to students at secondary and post-secondary levels. Presentations are also provided at local, regional, national and international meetings, conferences and workshops on crop production in various environments including greenhouses, high tunnels, season extension techniques and field conditions. How have the results been disseminated to communities of interest?Presentations are provided at local, regional, national and international meetings, conferences and workshops on crop production in various environments including greenhouses and other indoor growing approaches, high tunnels, season extension techniques, and field conditions. Posters of recent findings are displayed and made available at various gatherings related to university activities, educational outreach and community events. What do you plan to do during the next reporting period to accomplish the goals?We are continuing the initiated studies and are adapting research protocols to more effectively use the available research greenhouse facility. The setup for the LED research is updated for improved efficiency. Our outreach efforts include grower gatherings, responses to requests for information, scientific and producer oriented publications, and formal instructional secondary and post-secondary activities.
Impacts What was accomplished under these goals?
The nutritional content of fresh produce available to consumers in stores, at farmer markets and locally grown was evaluated in Fairbanks, Alaska. The study was conducted to determine potential differences between locally grown produce and produce available in local stores from various sources. The included vegetable crops were tomatoes, colored bell peppers, English cucumbers, kale, butterhead- and romaine lettuce. Samples were collected throughout the summer months when vegetables were locally produced and available. Analysis for mineral nutrition included nitrogen, phosphorous, potassium, calcium, magnesium, sulfur, iron, manganese, boron, copper and zinc. Brix analysis was used to determine levels of soluble solids and sugar content. Although the nutrient content varied among vegetables procured from stores, farmers markets or locally grown, the mineral levels within a particular crop were less variable. The highest amounts in percent of dry weight for nitrogen (5.0 ± 0.60), phosphorous (0.7 ± 0.27) and potassium (5.8 ± 1.75) were recorded for butterhead- and romaine lettuce. Iron content was also significantly higher with more than 200 ppm in the two types of lettuce. The analysis showed produce grown locally or obtained from the farmers market generally had greater Brix values to suggest higher sugar content than produce from local stores. The Brix value for locally grown red bell peppers for instance, was 8.7 ± 0.68 compared to 5.5 ± 0.36 for a similar store bought pepper. Three cultivars (Aroma 2, Dolly and Nufar) of the culinary herb basil grown in six light qualities were evaluated for mineral and sugar content. The treatments included blue LEDs (peak emission at 450 nm), red LEDs (50:50, peaks at 625 and 660 nm), blue/red LEDs (20:40:40, peaks at 450, 625 and 660 nm), and white LEDs (5000K). In addition, T5 fluorescent (4100 K) and natural greenhouse light supplemented with high-pressure sodium irradiance were used. Plants were grown at a constant 21 ± 2°C with a 16-hour photoperiod at a photosynthetic photon flux of approximately 150 µmol·m-2s-1. The plants were grown from seeding under the specific light qualities and the experiment was terminated after 50 days. Brix analysis was used to determine soluble solids and sugar content in recently mature leaves. There was a trend for higher Brix under blue LEDs among cultivars. The cultivar Aroma 2 had in general the greatest Brix values to suggest higher sugar content than in leaves of Dolly or Nufar. Brix values above 4.0 were consistently recorded for Aroma 2 except in the white LED environment. The blue/red environment supported growth and top dry weight well for Aroma 2 and Nufar. Least dry weight was observed for all cultivars under fluorescent irradiance. Dolly appeared to be less suitable for control environment production than Aroma 2 or Nufar based on dry weight accumulation. Soluble solids were also appreciably lower for Dolly with the exception of the blue LED environment. 1. Advance production and management techniques for Alaska agricultural production in greenhouses and controlled environment production facilities through novel technologies, methods and innovations. Several studies are in progress to determine the effects and potential implementations of LEDs for greenhouse and controlled environment production. Sustainable and efficient greenhouse systems to produce vegetables that are specifically suited to high latitudes are also evaluated 2. Develop sustainable greenhouse control methods to improve resource use efficiency, climate uniformity, production quality, productivity and yields. LEDs with expected higher energy efficiency and adjustable spectrum, suggest improved resource use while allowing for a more uniform growing environment to support crop productivity and quality. Greenhouse production systems taking advantage of the extended daylight hours in the summer and transitioning into less light demanding crops during the winter can be expected more resource efficient and sustainable in northern climates. 3. Disseminate information about controlled environment technologies, methods and approaches to producers throughout the state. As we gain knowledge and understanding of LEDs and other production techniques, we anticipate additional publications and outreach efforts in this area. 4. Teach up-to-date greenhouse, indoor farming and controlled environment technologies to beginners, producers, and students in formal educational programs. In the fall of 2018, the course Applied Plant Science was offered to undergraduate students. This course had a significant emphasis on the sustainable use of resources and the management of light and other climatic conditions. The courses Principles of Sustainable Agriculture and Greenhouse Management were offered in the spring of 2019. The college level greenhouse management course includes substantial information on modern control and management techniques for greenhouses and controlled environments. Understanding and implementing greenhouse and season extension environments are essential for efficient local northern crop production. 5. Publish research findings, prepare educational materials, and exchange information with stakeholders, extension personnel and researchers in the U.S. and internationally. Results and experiences on the efficient use of LEDs, protocols for greenhouse bell-pepper production and the nutritional value of locally grown produce have been communicated at state, national and international scientific conferences, as well as in post-secondary education and producer oriented gatherings. The annual ASHS (American society for horticultural science) meeting was in July of 2019. This conference provided extensive opportunities for information exchange and discussions relative to the use and adaptation of LED lighting technologies in research and crop production along with the use and implementation of controlled environment facilities for crop production in various geographic locations and climates.
Publications
- Type:
Other
Status:
Published
Year Published:
2019
Citation:
Karlsson, M. 2019. Nutritional quality of Alaska grown produce. HortScience 54(9):S277.
- Type:
Journal Articles
Status:
Accepted
Year Published:
2020
Citation:
Karlsson, M. 2020. Light quality affects growth and nutrient content in basil. Acta Horticulturae (in press).
- Type:
Other
Status:
Published
Year Published:
2018
Citation:
Grandfield, M. and M. Karlsson. 2018. Sustained fruit load development in greenhouse bell peppers. HortScience 53(9):S385.
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