International Symposium focuses on horticultural lighting research

Exclusives from Urban Ag News

Originally published in Issue 15, October 2016

Scientists, university researchers, graduate students and industry representatives from 25 countries attended the 8th International Symposium on Light in Horticulture at Michigan State University.

Michigan State University hosted the 8th International Symposium on Light in Horticulture from May 22-26, 2016. This was the first time the symposium, which began in 1969, was held in the United States. The symposium was attended by 250 people from 25 countries.

Michigan State horticulture professors Roberto Lopez and Erik Runkle were the organizers and co-conveners of the symposium.

“The symposium is part of the International Society for Horticultural Science,” Lopez said. “The light symposium is held every three to five years.”

Lopez, who is the chair of the ISHS Workgroup Light in Horticulture, said he and Runkle began working on the symposium three years ago.

“ISHS is similar to the American Society for Horticultural Science, but ISHS is for international participation,” Lopez said. “ISHS, which has more than 130 working groups, also holds an international congress every four years. It is open to all of its members, making for a very large scientific meeting. The 30th International Horticultural Congress is scheduled for Istanbul, Turkey, in 2018.”

Lopez said light symposium attendees made up a very diverse group that included scientists, researchers, graduate students, growers and members of various companies which helped sponsor the event.

“There are two ISHS conferences that I typically attend, this light symposium and the International Symposium on New Ornamental Crops,” he said. “The ornamentals symposium attracts more people because ornamentals and floriculture are more general than lighting. Lighting is more specific to certain countries and northern latitudes or to places that are just now starting to produce plants indoors. This would include primarily Europe, the U.S., Canada, Korea and Japan. These were the countries that had the most participants at the light symposium. In terms of the number of oral and poster sessions, there were an equal number of researchers focused on ornamentals and vegetables.”

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Horticulture industry steps up

Lopez said planning the light symposium and preparing the written proceedings that accompany it are very time consuming.

“There is a lot of speculation as to what the conference is going to cost and how many people are going to attend,” he said. “As hosts we take on the financial burden because we really don’t know what the attendance will be. Erik and I anticipated 200-300 participants based on the previous symposium that was held in the Netherlands in 2012.”

Lopez said they received financial support from 25 industry companies.

The 8th International Symposium on Light in Horticulture was held at Michigan State University in May and attended by 250 people from 25 countries. Photos courtesy of Roberto Lopez, Michigan State University

“There were different categories of sponsorship, including three prime sponsors for the symposium’s opening reception, banquet and tours. There were three additional levels of sponsorship, platinum, gold and silver. Sponsoring companies included many of the leading plant light companies, plant breeding companies, distributors, an industry association and the trade press.

“The sponsors were recognized on the light symposium’s website, as well as banners that were hung in different locations during the symposium. The sponsors received a lot of exposure and those at the prime and platinum levels had vendor booths that featured product information and samples. Because of the sponsors’ financial support, we were able to lower the cost of the registration fee for attendees. We were also able to subsidize the graduate student registration cost.”

There were 35 graduate students who presented both oral and poster sessions. The students came from several different countries.

“We also had a graduate student poster competition,” Lopez said. “Three winners were awarded. There were three judges, all representatives from academia in the U.S., Europe and Japan. The poster winners were awarded certificates and monetary awards provided by a sponsor company.”

Organizing the presentations

Lopez said he and Runkle began accepting abstracts from potential symposium presenters in Feb. 2015.

“There is a scientific committee that consists of 39 people, most of whom have a PhD. or are working toward a PhD.,” he said. “Over 90 percent of the committee members are from academia, but there are also industry members.

“We had a call for abstracts so people would submit an abstract based on the research they wanted to present. Participants who submitted abstracts indicated whether they wanted to do an oral or poster presentation. The scientific committee members reviewed the abstracts. Often times we had to send them back because there was definitely a language barrier in some cases. Often times some researchers needed help with the English translation. A lot of the researchers wanted to do oral presentations, but unfortunately there wasn’t enough time during the symposium.”

Three winners were awarded during a graduate student poster competition.
From left to right: Mich. St. Univ. horticulture professor Ryan Warner, Purdue Univ. graduate student Garrett Owen (3rd place),
Univ. of Ga. graduate student Shuyang Zhen (1st place),
Mich. St. Univ. graduate student Qingwu (William) Meng (2nd place),
Mich. St. Univ. horticulture professors Erik Runkle and Roberto Lopez.

Lopez said committee members decided that some of the abstracts were more appropriate as posters than as oral presentations. There were 52 oral presentations and 78 poster presentations.

“We created 11 different oral sessions and within those sessions we tried our best to place the presentations appropriately under those titles,” he said. “The largest session was on light quality and optimization. There were an equal number of U.S. and European presenters in that session.

“The next largest session was supplemental lighting of vegetable crops. That one had research presenters mostly from Canada and Europe. No U.S. researchers did presentations in that session. Light for ornamental crops and sole-source lighting of vegetable crops were the next largest sessions.”

In addition to organizing the symposium presentations, Lopez and Runkle along with Iowa State University horticulture professor Chris Currey were co-editors of the Acta Horticulturae publication, Proceedings of the VIII International Symposium on Light in Horticulture.

“The majority of presentations published in the proceedings are the oral ones with a few of the poster presentations,” Lopez said. “We did request everyone who was going to do an oral presentation to write a manuscript. There were also some people who were doing posters that also submitted manuscripts. These were peer reviewed by the scientific committee.”

The Acta Horticulturae light symposium proceedings are available on the ISHS website for 105 euros.

Along with the researchers who did oral presentations there were four invited speakers, two from the United States, one from the Netherlands and one from New Zealand.

“The invited speaker presentations were longer and spurred a lot of conversation,” Lopez said. “The invited speakers started off specific topic sessions. They would give an overview of that session and then the presenters would go into their research talks.

“The invited speakers discussed future approaches to better understanding of light quality on plant growth and development. Others talked about UV light and horticulture. Kevin Folta from the University of Florida, who was one of the invited speakers, discussed how to control the light spectrum to manipulate plant responses such as growth, flavor and pigmentation.”

The next ISHS Light Symposium is tentatively scheduled for June 2020 in Alnarp, Sweden, and will be organized by the Swedish University of Agricultural Sciences.


For more:  Roberto Lopez, Michigan State University, Department of Horticulture, East Lansing, MI 48824;
(517) 353-0342;;

Erik Runkle, Michigan State University, Department of Horticulture,
East Lansing, MI 48824;
(517) 353-0350;;

David Kuack is a freelance technical writer in Fort Worth, Texas;

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