Originally published in Issue 12
Taiwan’s plant factories are looking to meet the increasing demand for out-of-season and specialty greens and to reduce the dependence on imported food crops.
Plant factories in Taiwan are operated primarily by private companies. Currently there are less than 100 of these operations in the country, producing primarily salad greens. The market demand for plant factory product is good and companies are looking to produce crops that have low inputs and high yields.
Dr. Wei Fang, a professor in the Department of Bio-Industrial Mechatronics Engineering at National Taiwan University, has been doing research on plant factories since 1993. He has been studying the use of LEDs in plant factories since 1996. He has served as an international consultant for Japan’s plant factory association. He has also been invited to be a keynote speaker about plant factories in many countries, including the United States, China, Korea, Kuwait, Panama and Japan.
Hort Americas spoke with Dr. Fang about Taiwan’s plant factory industry, how it is developing and its potential for growth.
Q. How large is the average plant factory in Taiwan and can you describe what type of equipment is used in one of these operations?
A. Most of Taiwan’s plant factories are small, harvesting less than 1,000 plants each week. The largest factory has daily production of 6,000 plants at full capacity.
Some of the equipment being used in these operations include reverse osmosis water treatment, sanitation equipment, including electrolyzed oxidation and ultraviolet light treatment of water, air conditioning, air showers at the entrances for the removal of dust/small particles from people entering the facilities, hydroponic systems, artificial lighting including LEDs, T5 fluorescent lamps and cold cathode fluorescent lamps (CCFL), duct fans for air circulation, control of temperature, humidity, carbon dioxide concentration, pH and electrical conductivity (EC) of nutrient solutions, epoxy floors and thermally insulated walls.
Q. Are most of the plant factories located in renovated buildings or are the buildings housing these operations constructed specifically for these factories?
A. Almost all of the plant factories are located in renovated buildings. There are also two located in greenhouses.
Some people consider greenhouses equipped with artificial lights as a kind of plant factory. I don’t consider these greenhouses to be plant factories. In Taiwan only some orchid greenhouses have installed artificial lights. When I’m talking about plant factories I am always referring to plant factories equipped with artificial lights (PFAL).
Q. How do the plant factories in Taiwan compare in technology to the plant factories in other countries?
A. Taiwan has many advantages when it comes to the construction and operation of plant factories. Information and computer technology (ICT), LED lights, cheap labor and low utility fees, have led to lower construction and operating costs.
The market demand for plant factory product is good and produce prices are almost the same as Japan and much better compared with China. In China not many people eat salads. Also, it takes much more effort to convince the Chinese people that hydroponics and artificial lights can be used to produce healthy food crops. Taiwan overall is in a better situation for the development of the plant factory industry.
Q. Are most of Taiwan’s plant factories operated by private companies and/or corporations or are there some of these factories operated as family farms?
A. As of October 2015, there are 97 plant factories in Taiwan. Eighty-three are run by private companies and 14 by universities and research institutes. This information was collected by Photonics Industry & Technology Development Association, which has held four plant factory exhibitions in Taiwan. Greenhouses with artificial lights are not included in these figures.
Some companies operate multiple factories. There are currently no family-run plant factories in Taiwan.
Q. What are the most common crops grown in Taiwan’s plant factories?
A. Lettuce is the primary crop, with more than 20 varieties being produced. Brassica (Cruciferae) plants are the second largest crop. Specialty plants, including ice plant (Mesembryanthemum crystallinum) and rocket lettuce or arugula (Eruca sativa), which have high market value, have received a lot of attention in recent years.
Q. Are there any limits (i.e. space restrictions, size of the plants, light requirements, etc.) to the types of crops that can be grown in these plant factories?
A. There is no limit from a technology standpoint. However, from a business standpoint, only cost-effective crops are candidates for production.
Fast-growing, small plants that need low light levels that have a high economic value and a high harvest index are preferred. These plants have little waste. For example, with lettuce only its roots are discarded.
Tomatoes can be grown in plant factories, but only the fruit can be harvested, so they have a low harvest index. Tomatoes are only grown as seedlings in plant factories and then planted out into greenhouses for fruit production.
Q. How are most of the crops grown in the plant factories marketed to consumers (i.e. local grocery stores, large supermarket chains, farmers markets, restaurants, etc.)?
A. All of the above plus on the internet and through memberships, including community-supported agriculture and health clubs.
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Q. Is there any type of marketing done for plant factory crops on television, radio, online, newspaper, etc.?
A. No marketing is done through these channels. However, all of these channels introduced plant factories to the Taiwanese people. My colleagues and I have been visited and interviewed by these media several times. National Taiwan University offers a plant factory workshop twice a year. Consulting companies also offer one-day seminars on plant factories. The workshop and seminars are promoted online and in newspaper advertising.
Q. In regards to the production systems currently being used in plant factories, where could the greatest improvements be made?
A. No greatest improvements, only better improvements. These would include:
Identifying specific LED light spectra for specific crops.
Development of total performance evaluation techniques.
Ebb-and-flood systems are better than deep water and nutrient film techniques. Ebb-and-flood systems equipped with siphons are better than tradition ebb-and-flood systems.
In addition to salad greens, new crops with higher market value and higher concentrations of beneficial compounds for medicinal and cosmetic purposes are being investigated.
Q. What are the benefits/advantages of plant factories over greenhouse production and traditional field crop production?
A. A common question I encounter is: If the light from the sun is free, why not use it to produce crops in a greenhouse or in the open field? Also, there is the issue of having to use a lot of energy to operate the artificial lights in plant factories.
Making such a comparison requires looking at production from beginning to end of a crop. In traditional open field production, land preparation is needed to plant a crop. This requires having to operate some agricultural machinery. Upon harvest of a field crop, it likely has to be placed in cold storage and then shipped to markets, which are normally far from the original production sites.
For plant factories, one of the slogans we use is “Local for local.” This means local production for local consumption, so the food mileage and carbon footprint are small making plant factory production more environmentally sound.
Plant factories usually require no pesticides and less land, water and fertilizer to produce crops.
The plants harvested from plant factories don’t usually need to be washed before they’re eaten or cooked if they are grown in clean rooms. Plant factories can provide off-season and stable year-round production. Production can be done on demand and there are few risks associated with production.
Q. What are the benefits/advantages of greenhouse production over plant factories?
A. There are many more crops to choose from for greenhouse production. Also, greenhouses have lower production costs than plant factories.
Q. Do you think that Taiwan’s plant factories will be able to overcome their current limitations to compete with greenhouse and field production?
A. There really is no need for the plant factories to compete with greenhouse and field crop producers. They can operate hand-in-hand and serve different groups of customers.
For example, lettuce can only be grown in Taiwan during the winter season, but consumers eat a lot of it during the summer. Most of these out-of-season crops are imported from the United States.
The first goal of Taiwan’s plant factories is to replace these imported crops. Most of Taiwan’s plant factories have differentiated themselves from traditional farmers by producing different varieties or out-of-season plants with special properties, including high levels of iron, calcium, vitamins A and C and anti-oxidation capabilities and low potassium content.
Q. What aspects of plant factory production are being studied at National Taiwan University?
A. Ion selective sensors, LED spectra for particular purposes, fuel cells, and all technologies related to cost reduction and quality improvement of crops, facilities and systems.
For more: Dr. Wei Fang, National Taiwan University, Department of Bio-Industrial Mechatronics Engineering; weifang@ntu.edu.tw.
David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.
