Blog – Page 13 – Hort Americas

Could LEDs replace plant growth retardants?

Researchers at Michigan State University used LED lights to produce compact flower and tomato seedling plugs.

By David Kuack

Growers and researchers are studying the effects that specific light wavelengths can have on ornamental and edible crops. Research studies are focusing on the effect light wavelengths can have on a variety of plant processes including growth, flowering, fruiting and postharvest quality.

Michigan State University horticulture professor Erik Runkle and former graduate student, now floriculture/nursery production extension educator Heidi Wollaeger studied the impact the ratio of red to blue light can have on the production of annual bedding plant seedlings. They looked at the effects of red and blue light on impatiens, petunia, salvia and tomato plugs.

Photo 1, DSC_0404, Heidi Wollaeger, Mich. St. Univ.

Michigan State University floriculture/nursery production
extension educator Heidi Wollaeger and horticulture
professor Erik Runkle studied the impact that red and
blue light can have on bedding plant seedlings.
Photos courtesy of Heidi Wollaeger, Mich. St. Univ. Ext.

“These four species are very common bedding plants for U.S. growers,” said Wollaeger. “They are key crops for their sales. The tomato plugs were being grown as vegetable transplants and not for production as greenhouse tomatoes for fruiting.

“We have also used these four species in other lighting trials that we have done recently. We wanted to be able to extrapolate from one study to another. In previous studies we looked at green light and the ratios of blue, green and red light.”

Seed was sown into 128-cell plug trays at a commercial propagator and moved into a large growth chamber at the university within two days where LED and fluorescent light treatments began immediately. The plants were Stage 2 plugs when the light treatments began. The seedlings had cotyledons and no true leaves. They were under the light treatments throughout the entire duration of the study.

Light treatments

The bedding plant plugs were grown in a growth chamber equipped with six individual LED chambers. The plugs grown under fluorescent lamps were grown in a separate growth chamber.

For all light treatments, plants were exposed to 160 micromoles per square meter per second (µmol·m−2·s–1) for 18 hours a day.

Photo 2, DSC_0459, Heidi Wollaeger, Mich. St. Univ.

Plug trays of impatiens, petunia, salvia
and tomato were grown in a large growth
chamber at Michigan State where they
received LED or fluorescent light treatments.

“We chose 10 moles per day because that is a suggested light integral for most plants to be of at least moderate quality,” Wollaeger said.
“We didn’t want to deliver a light intensity much greater because as the intensity increases so does the light installation cost as well as the energy costs to run the lamps. We were implementing a practical light level for growers.”

Wollaeger said the study was terminated after four to five weeks because at that time the plants were ready for a commercial grower to transplant.

“This study simulated what growers would actually do in their facilities if they were to install a sole light source LED chamber,” she said. “They would use this high value propagation space to produce the propagules and then transplant them and put them into the greenhouse. These could be used by growers who are finishing the plants themselves or by a propagator who is selling the plugs to other growers.”

Light effects on bedding plants

Wollaeger said all of the species grown under the red light dominant background with at least 10 µmol·m−2·s–1 of blue light displayed desirable plant growth responses.

“These plants showed compact growth, thicker leaves and thicker stems,” she said. “As a general rule of thumb, growers should provide at least 10 µmol·m−2·s–1 of blue light if they are providing
a red dominant environment to increase plant quality, which results in compact, well-branched growth.

“This treatment might reduce the need for plant growth retardants. If the light environment is being altered to include more blue light in a sole-source environment, stem elongation is reduced. This will depend on the crop. Every crop has a different vigor depending on the species and cultivar. This study only looked at four commercially important species.”

Photo 3, R_B_LEDtomato, Heidi Wollaeger, Mich. St. Univ.

Four bedding plant species, including tomato, grown
under a red light dominant background and under at
least 10 µmol·m−2·s–1 of blue light
displayed desirable plant growth responses, including compact growth,
thicker leaves and thicker stems.

Plants grown under the fluorescent lamps usually produced the most chlorophyll, but also had the thinnest leaves. Impatiens and salvia had greater fresh shoot weight when exposed to treatments without blue light than with at least 80 µmol·m−2·s–1 of blue light.

Impatiens grown under a high proportion of blue light developed more flower buds. Wollaeger said whether this early flowering is a negative or positive effect depends on the plug cell size.

Photo 4, ImpatiensunderallblueLEDlight, Heidi Wollaeger, Mich. St. Univ.

Impatiens grown under a high proportion of blue light
developed more flower buds than
plants provided with mostly red light.

“If the plants are being grown in a small plug size like a 288 cell and will be transplanted into large finished containers, it might not be desirable for early bud development,” she said. “The formation of flower buds could impact the rooting of the plants, but that depends on the cell pack size. If a grower is transplanting the plugs directly into smaller containers, he might want earlier flowering.”

Reduction of tomato intumescences

A benefit of growing tomato plugs under high blue light levels and fluorescent lamps was the reduced incidence of leaf intumescences (sometimes called edema), which are small protrusions that form on leaves, stems and petioles. Wollaeger said this physiological disorder has been associated with a lack of ultraviolet light or blue light.

“This physiological disorder is cultivar specific,” she said. “Some cultivars are more prone to developing this disorder compared to others. ‘Early Girl’ is the cultivar that we used and it did develop intumescences under treatments with small amounts of blue light.”

More greenhouse research

This particular research study did not look at the effects of the light treatments after plants are moved into the greenhouse.
Wollaeger said Dr. Runkle’s lab is currently conducting another study to determine the lasting effect of light treatments on transplanted plugs.

“Whether or not a light treatment has any lasting effect once the propagules are transplanted and placed in the greenhouse is going to depend on the light environment in the finishing location,” she said. “If the daily light integral is at least 10 mol·m−2·d–1 during the plug stage, there is probably going to be some height suppression when the plants are finished in the greenhouse. I wouldn’t expect there would be a major lasting effect of stem elongation suppression once in the greenhouse.”

For more: Heidi
Wollaeger, Michigan State University Extension, Nazareth, MI; (269) 384-8010;
wollaege@anr.msu.edu; http://msue.anr.msu.edu/experts/heidi_wollaeger.

David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.

High tunnels enable growers to increase production of high-value berries

High tunnels can be a part of a production system that allows growers to produce berries year-round while improving fruit yields and quality.

Continue reading High tunnels enable growers to increase production of high-value berries

LEDs have the potential to change how crops are grown

The use of LED grow lights to provide specific light wavelengths could allow growers to increase nutritional values of edible crops, enhance the intensity of foliage and flower color and improve the postharvest longevity of ornamental and edible crops.

Improvement in the light intensity delivered by light emitting diodes (LEDs) is helping to expand their use for the production of both edible and ornamental crops. Research with LEDs has been going on for about 30 years. Only within the last 10 years have increases in the light
intensities of LEDs allowed researchers to study the direct effects of narrow wave bands of light on plant physiology.

“LEDs are now available to deliver all blue, all red, all green, all yellow light or mixtures,” said University of Tennessee plant sciences professor Dean Kopsell. “White LEDs are almost a broad spectrum light source. White LEDs are actually mostly blue light with a little bit of red, yellow and green light with a white phosphor over them.”

Kopsell and his colleagues at the University of Tennessee are studying the impact individual types of light can have on the nutritional qualities of edible crops. Their work is focusing on crops that can be produced relatively quickly in 25-35 days, including microgreens and baby greens. They have also begun looking at some herbal crops including basil, tarragon and chives.

Researchers at the University of Tennessee are finding that exposing plants like brassicas to blue light is having a significant effect on their nutritional values. Photos courtesy of Dean Kopsell, Univ. of Tenn.

“Some of the unique things we are finding are when we change the light quality environment, going away from broad band light sources like fluorescent, incandescent and HIDs, and exposing plants to narrow band wavelengths of red and blue light, many things are changing in the plants. These narrow bands of light are having an effect on several plant quality parameters from a metabolic standpoint.”

Potential of specific light wavelengths

University of Tennessee researchers have found that exposing plants to narrow wavelengths of the light spectrum has resulted in the increased production of antioxidants and anti-carcinogenic compounds within the plants.

“What is even more interesting is some of the primary metabolites like the mineral nutrients are also increasing,” Kopsell said. “We are shifting the light ratios and putting more blue light into the mix. Blue light is close to the ultraviolet (UV) range and has higher energy values than red light. Because of the higher energy level associated with blue light, the more blue light we are exposing the plants to, it seems the more significant the results are on nutritional values.

“We haven’t got hard data yet, but everything that we can see, smell and taste, these blue lights not only affect nutrient uptake, and anti-oxidant metabolism, but they also affect aromatic compounds and flavor compounds. They make them more intense.”

Although researchers have only recently begun to study the impact of narrow light wavelengths on plant physiology, Kopsell said this will be the major use of LEDs in future applications.

“Not only is a grower going to be able to select the type of light and intensity from the LED manufacturer, but eventually the grower will know when is the critical time to apply a specific amount of light to a crop. One of the things that we have seen with these short term crops is using the light as a finishing-off treatment. The crops are grown under regular light conditions like any grower would have the ability to do and then just before harvest the plants would receive a specific type of light for a certain period of time. This light treatment would stimulate the plant physiology uptake and metabolism right before the plants go to the retail market.”

Kopsell said research exposing leafy brassicas to blue light prior to harvest has intensified pigments and green leaf color.

“We increased the green pigments in the leaves so that they looked more vibrant,” he said. “Other research has shown that UV light increases the anthocyanin compounds in leaf lettuce. Providing a little UV light, which is blocked out in most greenhouse environments, at the right time, a grower can get a crop to color up quickly before the plants are shipped out. What we have done with leafy greens to intensify the color of the leaves can also be done with petal tissue. By changing the light quality a grower could get more vibrant flower colors.”

Need for fine tune management

Kopsell said whether plants are grown outdoors, in a greenhouse or in a closed controlled environment with artificial light, the plants are using specific wavelengths from the available light source.

“Horticulture, floriculture and agronomic researchers know how much light is needed in order to produce crops with broad spectrum light,” he said. “The million dollar question that hasn’t been answered is how much light is needed from LEDs to achieve that same level of production? It is going to be less than the daily light integral (DLI) from a broad spectrum light source. But, right now we can’t tell you how much less it’s going to be.

“Applying specific light wavelengths when the plants need them, whether it’s for juvenile growth, flowering or fruiting, we don’t have a good grasp on the amount of light that the plants actually need. If a grower is only going to supply his plants with red and blue light, how much less light can a grower use in that production system?”

One of the reasons that plants will not require as much light from LEDs is because of the reduction in light stresses.

University of Tennessee studies have shown LED grow lights provide a less stressful light environment for plants.

“Providing specific types of red and blue light, the amount of stress on plants is reduced because the plants don’t have to tolerate the light not being used for metabolism and physiology,” he said. “We have data that shows LEDs provide a less stressful light environment for plants. So we have to determine how much less light is needed. It is going to require an extra level of management to know what kind of light, how much light and when to apply it. Growers are going to be able to use LEDs to fine tune the light environment. It’s going to depend on the crop, how it’s being grown, where it’s being grown and how the crop will be used. Is it an ornamental, edible or medicinal crop? It’s not going to be as easy as sticking a seed or cutting into a substrate and letting Mother Nature take control. It’s really going to take some fine tune management. But the future looks bright so far.”

For more: Dean Kopsell, University of Tennessee, Plant Sciences Department, Institute of Agriculture, Knoxville, TN 37996-4561; (865) 974-1145; dkopsell@utk.edu.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.Visit our corporate website at https://hortamericas.com

Meeting the fertilization needs of greenhouse lettuce

Greenhouse lettuce can be a successful container or
hydroponic crop for ornamental plant growers looking to give edibles a try.

By David Kuack

Ornamental plant growers considering producing an edible
greenhouse crop may want to try lettuce. Neil Mattson, associate horticulture
professor at Cornell University, said lettuce is a plant with moderate
fertility needs.

“Grown hydroponically, lettuce has somewhat lower
fertility needs than a greenhouse tomato crop,”

Ornamental plant growers interested in growing edible
crops may want to try lettuce. It can be produced in
containers with a growing medium or hydroponically
in troughs or a float system (pictured).
Photos courtesy of Cornell University

Mattson said. “Grown as a
container crop, lettuce is relatively similar to petunia. However, lettuce has somewhat
greater calcium needs. Growers can produce a relatively good crop of lettuce in
containers, if they use a complete fertilizer at a moderate strength of 150
parts per million nitrogen.”

Mattson said head lettuce can be produced in containers similar
to a bedding plant crop. The seed would be planted into a plug tray for three
to four weeks. Transplanting the plugs into larger containers, the crop could
be finished in four to six weeks depending on light and temperature levels.

He said baby leaf lettuce can be grown in flats. The seed
is directly sown into the growing medium and grown for three to four weeks
until plants reach suitable size.

Calcium deficiency
tipburn

Leaf tipburn is a physiological disorder that can occur
when growing greenhouse lettuce. It can greatly impact the salability of a
crop.

“The main reason that tipburn occurs is the lettuce is
growing too fast under high light,” Mattson said. “For lettuce, the target
daily light integral is 17 moles per square meter per day. The light level should
be lower if there is poor air flow. If the light level goes higher than 17
moles, the rapid growth of young leaves is affected. There may be an inadequate
calcium supply, especially as the lettuce heads begin to mature and close. If
there is not enough air flow and not enough transpiration by the young leaves,
then not enough calcium can reach the leaves through the xylem sap. This can
cause tipburn to occur. It’s a case of pushing the plants too fast.”

Calcium
tipburn in lettuce is not a result of a lack of calcium
supplied to the plants,
but an inability of the plants to
transport enough calcium to the young leaves.

Mattson said in many cases, tipburn is not a result of a
lack of calcium supplied to the plants, but an inability of the plants to
transport enough calcium to the young leaves.

“For container-grown lettuce, there is typically enough
calcium if the growing medium has a lime charge and if the fertilizer water
solution contains more than 50 ppm calcium,” he said. “Many common bedding
plant fertilizers, including 20-20-20, 20-20-20 and 21-5-20, do not contain
calcium. These fertilizers are typically used with tap water sources that
contain moderate alkalinity. In many cases, these tap water sources also
contain sufficient calcium.”

Mattson said it is important for growers to test their
water sources to make sure adequate calcium is being supplied, either from the
water source or added into the fertility program. If calcium needs to be added,
calcium nitrate is most commonly used. However, calcium nitrate is not
compatible with most complete fertilizers.

“Usually if a grower has to add calcium, it can be done
using a separate stock tank or a separate injector,” Mattson said. “One
strategy is to use a separate injector for the calcium nitrate in a series with
a 20-10-20 fertilizer that is being added with a second injector. Adding 50 ppm
calcium from calcium nitrate should be sufficient.

“An alternative method of calcium application, if a
grower has only one injector is to rotate between two separate stock tanks, one
for calcium nitrate and one for the bedding plant fertilizer. A grower would then
rotate between the two fertilizers. For example, for two days he would use the
20-10-20 fertilizer and on the third day he would use the calcium nitrate
applied at 150 ppm.”

Production with
organic fertilizers

Mattson has been able to grow a relatively good crop of
container-grown lettuce using granular organic fertilizers incorporated into
the growing medium.

“We incorporated poultry-based organic fertilizer (Sustane
8-4-4) into the growing medium at a rate of 8 pounds per cubic yard for both
the seed germination and transplant growing mixes,” he said. “That provided
good fertility, but for optimum yields I would also suggest making some liquid
organic fertilizer applications, maybe two to three times a week as the plants
get older.”

Mattson said the organic granular fertilizer he used is
temperature-dependent and is broken down by soil microbes. Sustane 8-4-4 has a
45-day release period, but under very warm greenhouse temperatures Mattson has
noticed quicker release rates. He said there are other slow release organic
fertilizers with different release periods. For example, Verdanta EcoVita lists
a 75-100 day release period.

Monitoring
electrical conductivity and pH

One strategy that Mattson recommends growers do periodically
is to monitor the electrical conductivity (EC) and pH levels.

“Monitoring EC will help growers determine if the plants
are receiving sufficient fertility,” he said. “If a grower is incorporating a
slow release fertilizer, this is a good indicator of when additional fertilizer
needs to be added. An under-fertilized plant will show yellow lower leaves from
nitrogen deficiency.”

Monitoring
electrical conductivity (EC) can help avoid
under fertilizing lettuce plants,
which show yellow
lower leaves caused by nitrogen deficiency.

Mattson said monitoring pH is important as it impacts
nutrient availability. He said lettuce isn’t commonly susceptible to iron
deficiency, but it will start to show up when the pH starts to increase above
6.5-7.

“Monitoring EC and pH is especially important in
hydroponics,” he said. “A good grower who is producing his crop in a growing
medium in containers will monitor the pH every week or two. The pH may change
over the course of a week by maybe one unit.

“Growing hydroponically, a grower should be monitoring
the pH every day and make adjustments. Depending on the type of fertilizer and
the quality of the water, the pH in a hydroponic set up could change two units
in a day.”

Optimizing lettuce
production

Mattson said light and temperature are going to be the
drivers for how long it takes to finish a lettuce crop. Whether a grower is
producing the crop in containers with growing medium or hydroponically
shouldn’t have any effect on the length of production.

He said plant spacing can also impact the size of the
lettuce head. If plants are grown in small containers and spaced pot-to-pot,
the lettuce heads may not reach full size.

For greenhouse lettuce, Cornell University researchers
developed a hydroponic production model that enables growers to produce a
lettuce crop from seeding to harvest in 35 days if temperature and light
intensity are at optimum levels.

“When the light level isn’t optimized, a lettuce crop can
take more than 100 days from seeding to harvest,” Mattson said. “High pressure
sodium lamps would be the best lamps to use if a grower is looking to provide
supplemental light in a greenhouse to increase the daily light integral. For
the Cornell model we adjust the amount of light in the greenhouse based on the
amount of outdoor light. Seventeen moles per square meter per day is the daily
light integral we are aiming for with the model. The optimum temperature for
plant development is about 75ºF
during the day and 65ºF
at night.”

For more: Neil
Mattson, Cornell University, School of Integrative Plant Science; (607)
255-0621; nsm47@cornell.edu.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

Plant factories continue to evolve

As technology improves, plant factories have the
potential to operate in the U.S. and Canada to produce crops that are difficult
to grow using current conventional methods.

By David Kuack

When you hear the term “plant factory” what picture comes
to mind? University of Florida professor and mechanical engineer John Schueller
said the traditional definition of a plant factory is a place in which there is
no natural light and artificial light is used to produce plants.

“I’m more of a traditionalist in that I feel a plant
factory is a place that has mainly or only artificial lights in order to grow
plants,” Schueller said. “But a greenhouse with multiple levels of plants in
which natural light is the dominant source and is supplemented with artificial
light, I would also consider that to be a plant factory.

“People involved in protected plant agriculture,
including greenhouses and indoor plant factories, are displaying a lot of
creativity. There are a lot of different systems being tried out. It’s
difficult to make a hard and fast definition of a plant factory. A traditional
greenhouse with plants on raised benches or growing on the floor is not usually
recognized as a plant factory.”

Plant factory
automation

Schueller, who spoke at the Plant Factory Conference in
Kyoto, Japan, in Nov. 2014, said the most important automation that occurs in a
plant factory is during the growth stage.

“The application of light and fertilizer is when the main
automation occurs,” he said. “There is automation during planting when a grower
is trying to establish the plants. And there is also automation during
harvesting.”

University of Florida mechanical engineer John

Schueller
said the technology of plant factories

is improving with the main improvement

occurring with LED lighting.

Photos
courtesy of John Schueller, Univ. of Fla.

Schueller said during the Plant Factory Conference there
was a lot of discussion about which lights are the best for using in plant
factories.

“There are questions that still need to be answered about
what are the best wavelengths and what are the best cycles for different
crops,” he said “Even though there are a considerable number of plant
factories, we still don’t know what the optimal conditions are for growing
plants. There is a lot of variation and experimentation occurring.”

Schueller said automation in the plant factories will
probably occur with the planting practices before it happens with harvesting.

“In Japanese plant factories the finished plants are
brought to the harvesters,” he said. “There is automation to transfer the
plants. People are doing the harvesting of leafy greens, but they are brought
to the workers at an appropriate height and position so that they can be very
efficient and very productive. Obviously, if there are 14 layers of plants
under lights the plants are moved to the harvesters. But there is still some
human involvement in harvesting the plants.”

Schueller said an advantage to a plant factory is the
ability to precisely control the environment. “The technology is improving,” he
said. “The main improvement is with LED lighting. As LEDs become less expensive
and better that will help in the development of plant factories. Also, less
expensive sensors for measuring nutrient solutions are becoming available. As
growers gain more experience with this technology they get better at
controlling the production environment.”

Plant factory
economics

Schueller said economics play a big role in what will be
feasible in how these factories operate.

“The Japanese market for fresh fruits and vegetables is
much different than in the U.S. and Canada,” he said. “In the U.S. and Canada,
vegetables are cheaper. The market will not bear some of the costs that will be
accepted in Japan. In Japan consumers are willing to pay $40 for a watermelon.

“From an agricultural economic standpoint, it seems to me
the big advantage of a plant factory is that a grower can control the
production situation very well. The disadvantages are the energy costs for
running the artificial lights and the capital equipment costs. The best
opportunity is to produce a product that has certain characteristics, that has
no pesticides applied, that has no bacterial contamination, so that a grower
can demand a premium price for it.”

John
Schueller said one area of plant factory production
that shows great potential
is being able to develop
techniques that allow high end vegetables to have
nutritional characteristics that can be easily manipulated.

Schueller said one area of plant factory production that
shows great potential is being able to develop techniques that allow high end
vegetables to have nutritional characteristics that can be easily manipulated
more so than in other production environments.

“One of the Japanese plant factories that was built by
Fujitsu is growing lettuce which has a low potassium content,”
he said. “This lettuce is being produced for kidney dialysis patients and
people with chronic kidney disease. This type of crop has a lot of potential
for U.S. and Canadian markets. Developing vegetables that have nutritional
characteristics so that the markets will be able to tolerate higher production
costs that are associated with plant factories.”

Schueller said the plant factories in Japan can produce
leafy green vegetables in about 15 days.

“The production cycle needs to be as short as possible,”
he said. “If a plant factory is controlled properly and maintains sanitary
conditions, it is possible to produce leafy green vegetables with specific
nutrient characteristics without pesticides. For those types of crops a grower
can demand a premium price to pay for the equipment and energy to produce
them.”

Fast, precise
production

Schueller said the plant factories in Asia are producing
primarily leafy green vegetables.

“I expect these crops would have the greatest potential
in the U.S. as well,” he said. “As more consumers move away from iceberg
lettuce and romaine lettuce, they tend to look for other types of lettuce and
leafy greens and microgreens. There might be real potential with these crops
because they can usually be turned much more quickly.”

Japan
has over 200 plant factories. One of the reasons that
the country has experienced
a proliferation of these facilities
is food security. Sixty percent of the country’s
food is imported.

Schueller said some of the issues pushing plant factories
in Asia are related to domestic food production and land availability.

“Japan imports almost 60 percent of its food,” he said.
“For the Japanese it’s an issue of food security. Singapore has increased its
vegetable consumption from 7 percent to 8 percent. In Singapore there is a
limited amount of land. They are looking for ways to maximize food production
and plant factories offer them a solution. With plant factories that have
vertical farming they can push the production to maximize the space. In the
U.S. that isn’t a big concern. The plant factories in the U.S. that will be
successful are the ones that grow products that are difficult to produce using
conventional methods.”

For more: John
Schueller, University of Florida, Departments of Mechanical and Aerospace and Agricultural
and Biological Engineering; (352) 392-0822; schuejk@ufl.edu.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

A new Ohio State University farm-to-fork project offers students fresh produce

Ohio State University corporate executive chef Lesa
Holford has started growing edibles in a campus greenhouse for use in food
prepared for the school’s dining facilities.

By David Kuack

Since August, kale, basil and romaine lettuce have been
growing in an Ohio State University College of Agriculture greenhouse. These
crops aren’t part of a research project. They are being grown for use in the
preparation of food served at several campus dining facilities.

“We are growing about 1,200 plants,” said university
corporate executive chef Lesa Holford. “About 70 percent of the plants are
kale, 15 percent are basil and 15 percent are romaine. The plants were started
in August. We are still harvesting from the original kale and basil plants. In
late October we put in a second planting of 240 romaine plants.”

A learning experience

Holford, who has no formal training in plant production
other than her own backyard garden, said the project has been a learning
experience.

Research
associate Elaine Grassbaugh (left) of Ohio State’s
Department of Horticulture
and Crop Science, student
volunteer Courtney George, and corporate executive
chef
Lesa Holford harvest basil in a campus greenhouse.
Photo
by K.D. Chamberlain, CFAES Communications

“I randomly chose the crops that we are growing,” she
said. “I’m now looking to ask people in the College of Agriculture their
recommendations for additional crops. I’m interested in trying crops that might
have greater yields. I’m learning as I go.”

Holford has received assistance in producing and
harvesting the plants from the faculty and staff in the College of Agriculture.

“Greenhouse coordinators Jim Vent and Elaine Grassbaugh
are some of the people who are working with me,” Holford said. “They have shown
me how to harvest the crops. This includes where to cut the basil, how to
harvest the kale so that it continues to grow and how to cut the romaine so
that its leaves don’t start to turn yellow.

“They showed me how to germinate the seeds in a misting
room. They explained to me when to take the seedlings out of the misting room
and move them into the greenhouse to acclimate them before planting. I
initially grew the basil with the romaine. I now understand why you don’t put
warm temperature crops with cold temperature crops. It’s been an atmosphere of
learning and that’s what has been great.”

Utilizing university
ag products, facilities

Holford said the idea for growing in the greenhouse
evolved from using other ag products produced at another campus facility.

“We were using a lot of beef and pork products from the
university meat lab,” she said. “We actually reached the point where the lab
couldn’t produce enough of what we needed. So then we started tapping into the
student-run Waterman farm complex.

“I told the farm staff if they could grow it, we could
use it. We were buying produce from the farm, primarily lettuce. The quantities
were a little unpredictable. That is another reason why we decided to start
this project with the College of Agriculture. It gave us the opportunity of
learning while growing the food. It also gave us the opportunity to grow something
we had more control of. Being able to have more control over the food that we
offer our students is important.”

Holford said she hasn’t had any major challenges
producing the plants.

“We had some aphids that infested the terminals of a few kale
plants,” she said. “It wasn’t a major outbreak. We used an organic
horticultural oil to control the aphids.”

Fresh food
preparation

Holford said she decides what recipes the produce that is
harvested goes into.

“The produce is sent to the university’s central
production kitchen where it is used to make different foods served at various
locations around campus,” she said. “I usually deliver the produce when we have
enough to harvest.

“About 15-20 pounds of kale goes into the kale and bacon tarts
that are sold in six Grab ‘n Go cafes. The basil goes into the pesto that is
used to make Grab ‘n Go caprese sandwiches that are sold all over campus. The
romaine goes into Grab ‘n Go Caesar salads that are sold in about 20 different
dining locations.”

Kale
grown in an Ohio State University College of
Agriculture greenhouse will be
used in food served
at various campus dining facilities.
Photo
by Neil Hoyng, Ohio State University

Holford said more than 260 pounds of produce has been
harvested from the greenhouse.

“When we started to harvest the crops it was once a week,
but that has slowed down because of the weather,” she said. “The basil, in
particular, has really slowed down.”

Student
involvement

Prior to starting the project, volunteer help was
solicited from the student body to assist in the watering of the plants. Sustainable
Plant Systems Horticulture student Kathryn Losnes was hired to assist in the
growing and to coordinate the schedule of volunteers to water the plants.

“We had over 20 students who volunteered to water the
plants,” Holford said. “They are from various majors. We have a couple of
students who signed up from a vegetarian focus group. Some are from the school
of horticulture. Some of them just wanted to volunteer to work in the
greenhouse and grow the plants. We conducted an orientation so that the
volunteers could learn how to water the plants.”

Expansion plans

Based on the success Dining Services has had growing in
the greenhouse, Holford said she would like to expand the program to grow more
produce.

“I’m hoping that we will be able to expand production by next
summer,” she said. “We are looking at several options. We may be able to get
more bench space in the greenhouse we’re currently growing in. There may also
be an opportunity to put up a high tunnel next to the greenhouse or to put up a
high tunnel at Waterman farm or perhaps both. There are also some high tunnels
at the university’s Wooster campus that could be brought to the Waterman
facility, which is only 2 miles away from the greenhouse we’re using now.”

Holford said another future opportunity would be to
involve students in the university’s Culinary Science program in the project.

For more: Lesa
Holford, Ohio State University, University Dining Services; (614) 477-0240; holford.8@osu.edu;
http://cfaes.osu.edu/news/articles/kale-kale-the-gang%E2%80%99s-all-here-ohio-state-greenhouse-grows-produce-for-students.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gnail.com.

Visit our corporate website at https://hortamericas.com

Short course to focus on controlled environment agriculture

University of Arizona Controlled Environment Agriculture
Center is hosting the 14th annual short course focused on greenhouse production
and design.

The 14th annual Greenhouse Crop Production & Engineering Design Short Course,
March 22–27, 2015, will be held at the Westward Look Resort in Tucson, Ariz.
Hosted by the University of Arizona Controlled Environment Agriculture Center
(CEAC), the short course will include three full days of presentations on many
aspects of controlled environment agriculture (CEA). There will also be one day
of hands-on workshops at the CEAC campus.

University
of Arizona Controlled Environment Agriculture
Center will host the 14th annual Greenhouse
Crop Production
& Engineering Design Short Course, March 22–27, 2015.

The Short Course will feature 23 seminars
covering topics related to plant production, including crop selection, hydroponics,
aquaponics, lighting, fertilization, integrated pest management and food safety.
There will also be presentations related to growing structure design, environmental
control, high tunnels and urban agriculture. The nine hands-on workshops will
address several topics including tomato, lettuce and herb production,
fertigation, sensors and controls and the first experience with growing in a
greenhouse.

A
day of hands-on workshops during the Greenhouse Crop
Production &
Engineering Design Short Course will cover a
variety of topics including growing
lettuce and herbs in
floating systems.

An exhibitor room will enable conference attendees to meet
with industry professionals to discuss their current operations or any potential
projects they may be considering. The short course also provides an opportunity
for networking and information exchange between growers, engineers, scientists,
researchers, and other industry professionals.

Webcast option
Those unable to travel to Tucson to attend the Short Course
have the option of viewing the presentations streaming live or after the event
has concluded. For those who choose the live Webcast attendance option, they
will have the opportunity to ask questions of the presenters in real time. The
presentations will also be available for later viewing in a password protected
internet database.

For more: Aaron
Tevik, University of Arizona, CEA Building, Tucson, Ariz.; atevik@cals.arizoan.edu;
http://ag.arizona.edu/ceac.

Visit our corporate website at https://hortamericas.com

LEDs found to have multiple uses on multiple crops

Researchers at Purdue University are finding LEDs can
have positive effects on both ornamentals and leafy vegetables.

By David Kuack

As more research is done with light emitting diodes
(LEDs), scientists are discovering new ways to use the lights on ornamental and edible
plants. Researchers at Purdue University have done extensive studies on annual
bedding plants, comparing the growth of seedling plugs and vegetative cutting liners
under LEDs.

“My goal is to continue to do research with LEDs because
we are finding new and exciting results, especially with the indoor production
of young plants and microgreens,” said associate horticulture professor Roberto
Lopez. “Some of the work that we have been doing has shown the benefits of
LEDs.

“If you would have asked me two years ago if I would ever
try to produce plugs indoors and not in a greenhouse, I would have said no. If
you would have asked me five years ago if I would be working on greens or
vegetables, I would have said no. Now I am doing both of those things with
LEDs.”

Purdue University graduate student Joshua Craven
(left)
and associate horticulture professor Roberto Lopez are
studying the effects LED
lights have on ornamental
plants and leafy vegetables.
Photo by Tom Campbell, Purdue University

No need for
sunlight

Lopez and former graduate student Wesley Randall found
that greenhouse-grown seedling plugs of impatiens, marigold, petunia, vinca and
zonal geranium did as well or better when supplemented with LEDs compared to
plugs supplemented with light from high pressure sodium lamps. What Lopez found
surprising was the quality of the plugs produced in a growth room with LEDs as
the only light source.

“LEDs produce better plugs when they’re grown indoors
than when they are grown in a greenhouse with sunlight supplemented with light
from LEDs or high pressure sodium lamps,” Lopez said. “It is amazing how good
the plugs look grown in an indoor multilayer production system with LEDs. The
plugs are compact, sturdier and greener with a similar root and shoot dry mass
to greenhouse-grown plants supplemented with light from LEDs or high pressure
sodium lamps.”

One crop that Lopez said they are still “tweaking” with
LEDs is petunias.

“Petunias, which are long day plants, when moved from an
indoor grow room equipped with red and blue LEDs, encountered a slight delay in
flowering in the greenhouse,” he said. “We are going to see if exposing the
plants to far-red LED light prior to moving them into the greenhouse will
induce them to flower.”

Using LEDs to
intensify leaf, flower color

Lopez said many of the annual spring bedding plants grown
in greenhouses in northern climates are produced under low light levels. The
result is that some plants don’t produce the same intense foliage colors that
they would if they were grown outdoors.

“Plants grown in glass greenhouses are not exposed to the
sun’s ultraviolet light because it is blocked by the glass,” he said. “The
result is that crops like zonal geraniums and purple fountain grass (Pennisetum setaceum ‘Rubrum’) don’t
“color up” like they would outdoors. One of the things we noticed with zonal
geraniums was the dark patterns on the leaves stood out much more when the
amount of blue light was increased. We hypothesized and found it was a result
of an increase in anthocyanin production. We have also looked at geraniums that
have very dark foliage and found not only does leaf color darken, but flower
color can be made darker by exposing market-ready plants to red:blue LEDs.”

Lopez said the change in leaf color due to anthocyanin
production was also dramatic for purple fountain grass.

“Purple fountain grass is a very popular ornamental
species produced by many growers,” Lopez said. “Grown in the greenhouse, the
leaves appear to be dull green and not very purple. We found that putting the
plants under a combination of red and blue LEDs for one to two weeks of what we
are calling “end-of-production lighting” resulted in an attractive purple
color. UV light is what stimulates anthocyanin synthesis.”

He said in the case of purple fountain grass, only the
leaves exposed to the LED lights change color. Those leaves not exposed to the
LED light remain green.

Expanding studies
to vegetable crops

Seeing the positive results that occurred with LEDs and
purple fountain grass, Lopez and PhD student W. Garrett Owen expanded the
research to red leaf lettuce to see if they could produce a similar response.

“Trying to produce red leaf lettuce can be difficult for
greenhouse growers if they are producing crops under low daily light integrals
(DLIs),” Lopez said. “Growers producing red leaf lettuce under low DLIs are
essentially producing green lettuce.

“We placed red leaf lettuce under the same LED treatments
used for purple fountain grass and the plants colored up in three to five days.
Based on our research, red leaf lettuce and purple fountain grass can be placed
under a 50-50 red and blue LED combination prior to harvesting or shipping
triggering anthocyanin formation.”

Based
on Purdue University research,
red leaf lettuce can be placed under a
50-50 red
and blue LED combination prior
to harvesting triggering anthocyanin formation
intensifying
the lettuce‘s red color.
Photo courtesy of Roberto Lopez,
Purdue University

Based on the results related to LEDs and anthocyanin
formation, Lopez said the studies may be expanded to look at the impact of LED
light on ornamental cabbage and kale. “Growers, especially those in the South,
have a hard time coloring up ornamental cabbage and kale,” he said. “It is
primarily a temperature response, as the night temperatures get cooler the
plants start to color up.”

Lopez and Owen did a small study placing ornamental cabbage
and kale under LEDs that resulted in a minimal color change. When
greenhouse-grown plants were grown under cool night temperatures and exposed to
LEDs, they exhibited the most intense color.

“What we are proposing is for growers in warmer climates
who have access to coolers, is to use a cool temperature/LED treatment,” he
said. “We will be conducting this study next fall. Smaller container sizes like
4-inch pots, could be rolled on carts into a cooler and exposed to cool
temperatures and LED lights for three to four days prior to shipping enabling
the plants to color up.”

Customized
microgreens

Another study conducted by graduate students Joshua
Gerovac and Joshua Craver looked at the effect of LEDs on the growth of three
different microgreen species (kohlrabi, mustard and mizuna) in an indoor
multilayer production system. The study included three different light
qualities and three different DLIs (light quantity).

“Overall what we have seen is as the DLI increases, this
is for three microgreen species we trialed, the length of the hypocotyl,
basically the height of the microgreen, decreases,” Lopez said. “The more light
the plants are provided, the more compact they are. If the plants received 6
moles of light, they were much taller than if they received 18 moles of light.
Depending on the growers’ market, some customers might want microgreens that
are a little leggier or they might want plants that are more compact. That will
depend on market preference.”

The ideal LEDs

Lopez said the ideal vertical LED light module would
contain all of the wavelength colors.

“The vertical LED light with all the different colors
would enable growers to turn them on when they need them and off when they
don’t, depending on the stage of plant growth,” he said. “Once flowering begins
a grower doesn’t want stem elongation. Far-red light works for flowering so the
far-red would be turned on for the minimum amount of time required for
flowering. If the grower wants to increase the amount of anthocyanin in the
leaves or flowers, he can turn on the red and blue light near the end of the
crop. To be able to turn on specific colors when a growers needs them, that is
something I envision happening with LEDs.”

For more:
Roberto Lopez, Purdue University, Department of Horticulture and Landscape
Architecture; (765) 496-3425; rglopez@purdue.edu;
https://ag.purdue.edu/hla/lopezlab/Pages/default.aspx.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

Deardorff Family Farms donates school salad bar during Tour de Fresh

Deardorff Family Farms in Oxnard, Calif., donated a salad
bar to Sequoia Middle School in Newbury Park, Calif., on Oct. 15, 2014. The
donation was part of the Tour de Fresh four-day fundraising cycling event. The company was
a silver sponsor of the event.

Tom Deardorff II, president at Deardorff Family Farms,
who attended the launch of the salad bar at the school said he was amazed by
the response of students.

“Kids began to back up one behind the other in the two
lines going to the salad bar,” Deardorff said. “It was awesome. They were
smiling and joking and asking if they could use the big food trays instead of
the small trays. They went for it hard and fast and kept coming.

“I could hear the staff saying, “We need more salad. We
need more kiwi.” Kids were chomping on carrots and loving every bite. In the
end, it was probably a 65/35 split with 65 percent of the kids choosing to go
through the salad bar line.”

Deardorff
Family Farms donated a salad bar to Sequoia
Middle School in
Newbury Park, Calif., on Oct. 15, 2014.
The donation was part of the Tour de
Fresh four-day
fundraising cycling event that raised $124,303.

Tour de Fresh
exceeds fundraising goal

Tour de Fresh was the first collaborative fresh produce
industry event that raised funds for the United Fresh Start Foundation’s Let’s
Move Salad Bars to Schools campaign. The goal of Tour de Fresh and its
participants was to raise $120,000 to privately finance 40 new salad bars in
school districts across the country. The foundation exceeded its fundraising goal and raised $124,303, ensuring more than 40 schools will receive salad
bars.

The inaugural Tour de Fresh started in Monterey, Calif.,
on Oct. 13, and ended 275 miles later in Anaheim. The event aimed to bring
awareness to the LMSBTS program originally founded by Food Family Farming
Foundation, National Fruit and Vegetable Alliance, United Fresh Produce
Association Foundation and Whole Foods Market in support of First Lady Michelle
Obama’s Let’s Move! Initiative.

For more: Deardorff
Family Farms, (805) 487-7801; http://www.deardorfffamilyfarms.com. Tour de
Fresh, http://www.tourdefresh.com.

Visit our corporate website at https://hortamericas.com

Organic fertilizers provide option to grow more sustainably

Organic fertilizers offer growers another tool for
producing their crops with more sustainable inputs.

By David Kuack

Growers of both food and ornamental crops are facing
increased scrutiny regarding their production practices from the pesticides
they apply to the amount of water and energy they use. In October, Whole Foods
Market launched its Responsibly Grown
program. The company
said the purpose of this new rating system is to assess production practices
that impact human health and the environment. The system labels fresh fruits,
vegetables and flowers as “good,” “better” or “best.” The program also prohibits
the use of some of the hazardous neurotoxins still permitted in agriculture.

If growers implement more sustainable practices to
produce their crops, are consumers willing to pay more for them? A recent University of Florida study
focused on consumers’ willingness to spend more on ornamental plants based on
plant attributes related to sustainable production methods, container types and
origin of production. Consumers were willing to pay up to 16 cents more for
plants grown using energy-saving and sustainable production methods, plants
grown in non-conventional containers and plants grown locally.

Organic fertilizers
show potential

Claudio Pasian, horticulture associate professor at Ohio
State University in Columbus, said an increasing amount of pressure is being
put on growers related to the environment by both retailers and consumers.

“Growers may be forced by their clients to produce more
sustainable products, including more organic products,” Pasian said. “Here in
Ohio, like in other parts of the country, there are concerns with fertilizers
running off into waterways and leaching into ground water. In the future
“fertilizer” may become a taboo word for some people. For some people, perception is
reality. Using an organic fertilizer may help growers achieve a more
sustainable image with retailers and consumers.”

Based on research Pasian has conducted on ornamentals
plants and herbs, he said organic fertilizers look like a promising alternative
to traditional water soluble fertilizers. Like any new product or technology,
he said there are differences between traditional water soluble fertilizers and
organic fertilizers and growers will have to learn how to use them.

Pasian began his research on organic fertilizers as a
result of a substrate manufacturer seeking to conduct trials incorporating
organic fertilizer into some of its consumer growing mixes.

“The company wanted me to run some experiments with a
number of fertilizers,” he said. “There were no liquid organic fertilizers
tested because the purpose of the study was to incorporate the fertilizers into
growing mixes. All of the organic fertilizers tested were in a solid form,
either a powder or small granules. Most of the organic fertilizers were
animal-based. The control plants were treated with a 20-10-20 water soluble
fertilizer at 100 parts per million nitrogen.”

Pasian said two of three annuals (seed geranium, pansy
and petunia) grown with the organic fertilizers did very well. Although the
organically fertilized plants were smaller in size, he said they were
commercially salable.

Petunias grown with Miracle Gro Organic Choice All Purpose 7-1-2
at a rate of 5.9 grams per pot (left), Sustane 8-4-4 at a rate of 5.1 grams
per pot (center) and Osmocote 15-9-12 at a rate of 2.7 grams per
pot (right). Top = side view; Bottom = top view.
Photos courtesy of Claudio Pasian, Ohio State University

Pasian found the only plants that occasionally did not do
well with organic fertilizers were pansies. He has not conducted any further experiments
to determine why there were issues with pansies grown with organic fertilizers.

“I’m not sure why the pansies did not do as well as the
other species,” he said. “There were some phytotoxicity issues. The quality of
the plants was not as good and there was high rate of mortality.”

Expanding
fertilizer trials

After the initial trials with organic fertilizers showed
positive results, Pasian expanded his research with additional ornamental
plants. He compared incorporating Scotts Miracle Gro Organic Choice and Sustane
organic fertilizers to a controlled-release and water-soluble fertilizers. All
of the plants in the study were grown in 4½-inch pots containing Fafard 3B
bark-based growing mix without a fertilizer charge.

“I grew six annual bedding plant species (angelonia, seed
geranium, hypoestes, impatiens, pansy and petunia) with the different
fertilizers,” he said. “The plant growth for plants fertilized with the
controlled-release fertilizer and water soluble fertilizer were very similar.
In most cases the water-soluble fertilized plants were the largest, followed by
the controlled-release fertilizer and then the organically fertilized plants.

Seed geraniums grown with Peters 20-10-20 water soluble fertilizer
at a rate of 100 ppm nitrogen applied with irrigation as needed (left)
or with a single application of Sustane 8-4-4 at a rate of 2.6 grams
per 4.5-inch container (right).

“The plants grown with the organic fertilizers were
slightly smaller. But overall the organically fertilized plants did well. In
some cases, the plants being smaller could be a positive effect because that
means growers may not have to apply growth regulators.”

Trialing herbs and
perennials

Pasian has received a grant from the Horticultural
Research Institute to expand his organic fertilizer study to include herbs and
perennials. He worked with a local grower on the plant selection and chose
three herbs (basil, parsley and thyme) and three perennials (Nepeta cataria, rudbeckia and salvia). Like
the annuals study, the herbs and perennials were grown in 4½-inch pots
containing Fafard 3B bark-based growing mix without a fertilizer charge.

“In the case of basil, the initial application of organic
fertilizer was enough to finish the crop,” Pasian said. “One single application
incorporated into the growing mix before planting the plugs would be sufficient
for the production cycle. For thyme it would be very close to finish with one
application, almost the same as basil.”

Pasian is planning to repeat the trials with parsley
because he encountered some issues with heat stress and disease problems.

“During the parsley trial even the control plants had
problems,” he said. “The plants were grown during the summer so the warm
temperatures in the greenhouse may have contributed to the problems. I expect
when the parsley study is repeated during the winter and the temperatures have
cooled down the results will be different.”

Basil plants grown with Peters 20-10-20 water soluble fertilizer at
a rate of 100 ppm nitrogen applied with irrigation as needed (left)
and three rates of Miracle Gro Organic Choice (from left to right):
5.9, 4.5, or 3 grams per 4.5-inch container.

Pasian said since many perennials are long-term crops,
they will need additional applications of organic fertilizers.

“In the perennial trials, the first flush of growth with
the organic fertilizers was good,” he said. “But then the fertilizers ran out.
Applying a powder or a small granular organic fertilizer to each pot is not
realistic for growers. These organic fertilizers can be incorporated into the
growing mix prior to planting. Once these fertilizers are used by the plants, which
takes about five to six weeks, a grower can start applying a liquid organic
fertilizer. This could be a fish emulsion or similar type fertilizer.

“One single organic fertilizer application incorporated
into the growing mix is not enough. Additional fertilizer will need to be
applied probably more than once. The plants grew decently with one application,
but if larger plants are the goal then more fertilizer is going to be needed.”

Nepeta cataria
(catnip) grew very fast initially and was the first perennial to show
deficiency symptoms. Pasian said nepeta would require additional fertilizer
applications sooner.

Rudbeckia took much longer to show any deficiencies.
Pasian said since rudbeckia is a very slow crop with a longer production time,
it will need supplemental fertilizer applications.

“Organically fertilized rudbeckia produced a first flush
of growth that was as good as plants fed with water soluble and controlled-release
fertilizers,” he said. “But as time went on during production, the organically fertilized
plants needed another shot of fertilizer.

“I consider salvia to be an intermediate crop between
catnip and rudbeckia. I expect that salvia will require additional fertilizer
applications.”

Pasian will continue the trial with the same herbs and
perennials this winter and coming spring. The plants will be grown in 1-gallon
containers to match commercial production practices.

“This research is not being conducted with the goal of
changing how fertilization is done by most growers,” Pasian said. “Water soluble
fertilizers are excellent products that growers use successfully. This research
will provide growers with information on how to produce a crop that has been
fertilized in a more sustainable way to satisfy a small percent of their clients.

“Marketing is going to be the issue for growers. If they
grow plants with both organic and water soluble fertilizers, those grown with
the organic fertilizer are going to have to be marketed differently so the
consumers know the difference and can make their choice about which plants to
purchase.”

For more:
Claudio Pasian, Ohio State University, Department of Horticulture and Crop
Science, (614) 292-9941; pasian.1@osu.edu.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

University of Arizona Intensive Course will focus on hydroponic greenhouse tomato production

University of Arizona’s Hydroponic Greenhouse Tomato
Production Intensive Course is a six-day program that focuses on the specifics
of hydroponic greenhouse production.

The Hydroponic Greenhouse Tomato Production Intensive Course
will be conducted Jan. 4-9, 2015, at the University of Arizona in Tucson.
Hosted by the university’s Controlled Environment Agriculture Center, the
course will focus primarily on hydroponic greenhouse tomato production. The
course will be taught by hydroponic specialist and professor of plant sciences Pat
Rorabaugh.

University
of Arizona hydroponic specialist Pat Rorabaugh
(right)
will be the instructor for the Hydroponic Greenhouse Tomato
Production
Intensive Course, Jan. 4-9, 2015.

Course participants will be provided a combination of
classroom lecture and discussion and hands-on learning in a hydroponic
greenhouse. Classroom topics include: greenhouse basics, production costs and
supply sources, plant propagation, crop layout and scheduling, crop
maintenance, plant nutrition, plant protection and food safety. Teaching greenhouse
discussions will cover: crop training and pruning, plant maintenance, plant
pollination, fertilizer preparation, pest identification and control and harvesting
and grading.

Course participants will be provided a combination of
classroom lecture and
discussion and hands-on
learning in a hydroponic greenhouse.

Participants will receive over a dozen hours of training
in a hydroponic greenhouse and over 30 hours of classroom discussion and
lecture that will effectively instruct them on how to hydroponically produce
greenhouse tomatoes. The course will also feature a round table discussion with
greenhouse engineers, where participants can ask experts questions about greenhouse
design and operations. A closing dinner will feature a presentation by
University of Arizona professor Merle Jensen, who will discuss the
current state of controlled environment agriculture.

For more: Aaron
Tevik, University of Arizona, CEA Building, Tucson, Ariz.;
atevik@cals.arizona.edu; (520) 626-9566.

Visit our corporate website at https://hortamericas.com

Southwest Perennials improves production, shortens crop time with LEDs

Young plant grower Southwest Perennials has been able to
reduce the number of stock plants, increase the number of viable rooted
cuttings and shorten rooting times with LEDs.

By David Kuack

Jerry and Jonathan Soukup at Southwest Perennials in
Dallas, Texas, are constantly looking for ways to maximize production of their
starter plants. The father-son team produces over 300 varieties of primarily
heat- and drought-tolerant plants. The plants, 80 percent of which are
vegetatively propagated, are grown in 80,000 square feet of greenhouses at two
different locations. Plants are produced in 72- and 128-cell trays. One of the
things that the Soukups have done to run a labor-efficient operation is to keep
their cultural practices simple and repeatable.

Southwest Perennials produces around 4 million starter
plants annually. All of the young plants, both vegetative liners and seed plugs
and stock plants are grown in Berger BM6 standard growing mix to which RootShield is added.

“We’ve been using the same growing mix for nearly 10
years,” said Jerry. “The only thing we add is a layer of vermiculite on the top
of some seed-produced plug trays. The rest of the plants are grown in the
straight mix.”

LEDs have major
impact propagation

Jerry said the propagation system they have set up is
relatively simple using poly-covered 30- by 100-foot Quonset houses and
overhead mist. One new element that Jerry and Jonathan have added to their operation
is installing Philips GreenPower LED Deep Red/White Flowering Lamps and GreenPower
LED Deep Red/White/Far Red Flowering Lamps.

“At the 2013 Ohio Short Course, Hort Americas and Philips
Lighting were running a show special, buy 20 bulbs get 10 bulbs free,” Jerry
said. “We had heard and read about the benefits of LEDs so we decided it was a
relatively cheap investment to make to see if the lights had any effect on our
plants. We were on the skeptical side. I told Jonathan that we would invest a
couple thousand dollars on the lights and we’d see if there is any difference
with them.”

Jerry said it didn’t take long to see the benefits of the
LEDs on the plants. The bulbs were installed in mid-October and the plants
started to show the effects of the supplemental light in three to four weeks.

The Soukups were so pleased with the initial results that
they purchased an additional 70 bulbs.

“When we started in October, we were using 30 bulbs in
two houses,” Jerry said. “By March we were using 100 bulbs in 10 houses.

Jerry (left) and Jonathan Soukup

were so satisfied with the growth

results they got with the first 30 LED

bulbs
they purchased that they

bought an additional 70
bulbs.

“There is nothing else that is currently on the market
that could have as dramatic an effect on our production as these lights have
had,” Jerry said. “This is for propagation. It may be a different situation for
growers who are finishing the plants. What is ideal for us may not be ideal for
another grower. For our situation, these bulbs delivered a response that we
couldn’t have imagined.”

Changing
production methods

The Soukups maintain three different temperature regimes
in their greenhouses. Some of the most significant results from the LEDs
occurred when plants were grown under the lights and temperatures of 70ºF-72ºF.

“Ceratostigma, lantana and Salvia greggi showed some of the greatest growth,” Jerry said.
“Some plants grew so quickly that we had to move them out to the edge of the
greenhouse so they didn’t receive as much light. Some plants were actually
growing too vigorously under the warmer temperatures with lights and we had to move
them to cooler houses where the temperatures were in the 40s and 50s.

Vegetative cuttings taken from lit stock plants rooted in an
average of four weeks compared to cuttings from unlit stock
plants that rooted in six weeks.
Photo courtesy of Southwest Perennials.

“Some of the results that we saw under the lights we
wouldn’t have gotten by applying more fertilizer or increasing the
temperatures. It was simply the lights that were causing the plants to grow.”

Jerry said this is the first time that they didn’t
encounter any delays in plug growth because of cold temperatures and cloudy
weather.

Vegetative cuttings propagated under LEDs had a much higher
rooting rate.
Photo courtesy of Southwest Perennials.

“Previously there have been times in the propagation area
where cutting production would lag by 10-14 days in January, February and
March,” Jerry said. “This is the time of year when we really need to be
shipping the plugs, but they just aren’t ready. Usually the plants don’t have
enough roots. This year we didn’t see any kind of growth stall.

Jonathan said some of the plugs actually had to be cut
back because they were growing so vigorously.

“We were actually able to take cuttings off of the
cuttings,” Jonathan said. “Cuttings that were taken off of stock plants that
weren’t under the lights and then were placed under the lights did not root as
quickly as the cuttings taken from stock plants that were lit.”

Cuttings taken from lit stock plants rooted in an average
of four weeks compared to the cuttings from unlit stock plants that rooted in
six weeks.

“We also had a much higher rooting rate for the cuttings
propagated under the lights,” Jerry said. “With the lights we have the
opportunity to turn a crop of cuttings four to six times.”

Increased market
demand

Jerry said this has been a good year for his company as
well as his customers located in the 48 contiguous states. Southwest Perennials
markets most of its plants primarily through brokers and distributors.

“Last year our sales dropped off a little bit compared to
previous years,” Jerry said. “But we have seen a major increase in sales this
year. Sales started strong in January, which starts our peak shipping season,
and they have continued even into the fall this year.

“Sales didn’t end in the spring, they continued into the
summer and we are continuing to have steady sales. We are currently shipping
plants that we normally don’t ship at this time of the year. We have been
receiving orders for delivery in November through March that we haven’t gotten
in the past. People are saying that they had a good spring and they’re excited
about having a good fall. Some people I have talked with say they think this is
going to be a trend that continues over the next four to five years and
potentially longer. The increase in construction is a major driver in the
demand for ornamental plants.”

For more:
Southwest Perennials Inc., (214) 670-0955; perennials@earthlink.net;
http://www.southwestperennials.com.

David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

Growers, investors discuss horticultural opportunities

Attendees at the first “Realities of Growing Plants
Indoors” Short Course learned what it takes culturally to produce controlled
environment crops as well as how to finance and market their businesses.

By David Kuack

Based on the phone calls Gene Giacomelli receives at the
University of Arizona he said growers and would-be growers aren’t talking
enough to the people who are interested in investing in the industry.
Giacomelli, who is director of the university’s Controlled Environment
Agriculture Center and a professor in Agriculture and Biosystems Engineering,
saw an opportunity to bring the two groups together at the first “Realities of Growing Plants Indoors” Short Course,
which was held in Tucson in July.

“I receive phone calls regularly from investors wanting
to know about the possibilities of putting their money into production in
controlled environment agriculture,” Giacomelli said. “They feel they don’t
know enough about the industry. I was trying to get them together with growers
so that they could have some discussion. They had the opportunity to share
their vocabulary, their activities and the things that need to be done if they
want to invest in a successful business.

“This also applies to the growers, who are looking for potential
investors. Growers need to know how to make presentations and be able to
provide the information investors need in order to satisfy their stakeholders
if they are going to lend money or invest in a business.”

For the first 1½ days of the Short Course participants
were provided with the basics applied “how-to-grow” controlled environment
agriculture.


	Attendees at the first “Realities of Growing Plants Indoors” Short Course had the opportunity to tour a small, commercial- sized tomato greenhouse, a supplemental lighting research facility and a small grow box for greens. Photos courtesy of University of Arizona

“The grower-focused presentations had an emphasis on
indoor production, which included greenhouses and also closed environments such
as vertical farming,” Giacomelli said. “Topics included irrigation, climate
control and lighting. We gave them some applied horticultural information that
they should at least be aware of and then learn more about if they want to get
into this business and grow indoors.”

Getting down to
business

During the last half of the second day the Short Course
transitioned to the business side.

“A couple of business people spoke about their
entrepreneurial horticultural activities,” Giacomelli said. “This presentation
transitioned the discussion to the third day where we conducted an investor and
business forum.”

Prior to the start of the business forum attendees took a
2-hour tour of the university’s production and research facilities including a small,
commercial-sized tomato greenhouse, a supplemental lighting research facility
and a small grow box for greens from Japan.

“The growers and investors had an opportunity to see what
growing was like in a traditional greenhouse using the sun as the light source
as well as growing inside using only electrical lamps,” Giacomelli said.

The business forum included a panel of five participants
including a produce distributor, two entrepreneurs who started their own indoor
food production companies, a regional buyer for a national grocery store chain
and a philanthropist investor.

Members of a business forum panel who spoke to Short Course
attendees included a produce distributor, two entrepreneurs who
started their own indoor food production companies, a regional
buyer for a national grocery store chain and a philanthropist investor.

“By bringing the two groups together we tried to give
those growers and would-be-growers who are considering starting a horticultural
business a chance to hear from those people who could provide them with a
reality check,” Giacomelli said.

For more: Gene
Giacomelli, University of Arizona, Ag & Biosystems Engineering Department,
Controlled Environment Agriculture Center; (520) 626-9566;
giacomel@ag.arizona.edu; http://ag.arizona.edu/ceac.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

Growing through the California drought

Bill Phillimore, executive vice president at Paramount
Farming Co. in Shafter, Calif., spoke at this year’s Seeley Summit which
focused on water. Phillimore, whose company is a producer of a variety of tree
crops, discussed the impact the drought has had on water availability and
trying to operate under severe water restrictions.

By David Kuack

This year’s Seeley Summit focused on “Water: Horticulture’s Next Game Changer?”
Nowhere is the effect of water or lack of it more pronounced than in
California. Bill Phillimore, executive vice president at Paramount Farming Co.
in Shafter, Calif., knows firsthand the effects drought can have on an
agricultural producer. Phillimore’s administration responsibilities include the
handling of water and power issues.

Bill Phillimore, executive vice president at
Paramount Farming Co., whose responsibilities
include water and power issues, knows firsthand the
effects drought can have on an agricultural producer.

During this year’s Seeley Summit, Phillimore shared his
company’s experience dealing with severe drought conditions. He sat down with
Hort Americas to discuss what his company has experienced and what it is doing
to continue producing its crops during the drought.

1. How many acres
of production does your company have in California this year?

Paramount is farming more than 100,000 acres in 2014 with
a combination of citrus, almonds, pistachios and pomegranates.

2. How many acres
has your company taken out of production because of the drought?

We have managed to secure sufficient water for these
crops in 2014, but at very considerable expense. In some instances we are
applying less irrigation water than we would optimally prefer.

3. Has your
company ever faced the type of water restrictions it is facing in California
this year?

We have never faced water restrictions this severe in
California previously.

4. What is the
primary source of water for most of the crops your company is producing in
California?

Due to our size our water comes from a number of
different sources, including the State Water Project, exchange contractors and
the Kern River. In almost all instances, this water is supplemented by
groundwater which is being particularly heavily used in 2014.

5. What methods of
irrigation is your company using to water the crops? Were these the primary
irrigation methods prior to the occurrence of the severe drought conditions?

All our property is irrigated with drip or micro
sprinklers as it has been for more than the last 20 years. The drought has not
changed our methods of irrigation because we made the change to more efficient,
practical systems some years ago.

Paramount Farming Co. is farming more than 100,000 acres
this year with a combination of citrus, almonds, pistachios
and pomegranates.

6. During your
presentation at this year’s Seeley Summit you discussed how your company used previous
research to determine when specific plants need to be watered. Based on the
company’s findings, have you been successful at manipulating the water delivery
without having a negative impact on the plants?

We hope that we have timed the application of water,
especially in those crops where there has been reduced amounts, so that there
has been no negative effect on plants or yields. Although in determining the
schedule we have relied heavily on previous experiments conducted on our
property, this is obviously being done on a far greater scale and thus it is
not currently easy to assess either the long or short term effects.

7. During the
Seeley Summit you mentioned that some of the crops currently being grown in
Kern County, Calif., are unique to this region? Can you give some examples of
these crops and what is unique about the conditions under which they are grown?

In Kern County, where we have the majority of our
acreage, we share climate with the rest of the Central Valley in California
with some slightly greater extremes and different soil conditions. All these
environmental factors, which allow dormancy in the winter, but not usually
extreme low temperatures, and hot, dry summers, are particularly suited to the
production of pistachios, almonds, table grapes, carrots and citrus.

8. During the
Seeley Summit you discussed the Bay Delta Conservation Plan. Can you describe
what this plan is about?

Most precipitation in California occurs in the north of the
state while the majority of the usage, both urban and agricultural, occurs
south of the Sacramento-San Joaquin River Delta. One of the greatest challenges
that California has is how to move water through the delta to southern
California without environmental damage.

There is currently an ongoing process, otherwise known as
the Bay Delta Conservation Plan (BDCP), to move the point of diversion from the
south delta to the north delta and as part of the permits needed from the
federal wildlife agencies (U.S. Fish and Wildlife Service and National Marine
Fisheries Service) have a 50-year habitat conservation plan which would put an
end to the constant litigation of the delta. Our company is very interested in
this project and believes it is extremely important for the economic future of
the whole state.

Applications of reduced amounts of water to Paramount’s crops
are based on experiments conducted at the farm aimed at
avoiding any negative effects on the plants or their yields.

9. During the
Seeley Summit you expressed concerns that some agricultural trade associations
and other agricultural producers could be doing more to help ensure that
growers continue to have adequate water supplies. Could you please elaborate on
how you would like to see these groups become more involved with water-related issues?

I did express concern during the Seeley Summit that all
trade organizations do an adequate job of representing their members because
they do not always understand all the issues that they are being asked to
address. These organizations often spend too little time consulting their
members, especially when the organizations are covering a broad range of issues.
I do believe that all farmers of whatever size need to be conscious of this
fact and that unfortunately there is no substitute for their personal
involvement.
For more:
Paramount Farming Co., (661) 399-4456; http://www.paramountfarming.com.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com.

Grower goes vertical to increase production, revenue

Fresh cut flower grower Flowers By Bauers & Greenhouses has installed
a vertical production system to increase the production of ornamental and
edible crops.

By David Kuack

Flowers By Bauers & Greenhouses in Jarrettsville, Md., has been
growing fresh cut snapdragons since 1996. The company produces the snaps
year-round in perlite using a recycled nutrient solution. The flowers are sold
through the company’s own retail outlet and to retail florists in the surrounding
Baltimore, Washington, D.C., and Wilmington, Del., areas.

Matt Bauer, who is a partner in the company, said the
snaps go from a 20-week crop during the winter to a 10-week crop during the
summer.

“With the quicker crop time during the summer, half the
greenhouse goes out of production so we add sunflowers during that time,” Bauer
said. “The sunflowers are sold to the same customer base as the snaps. As the
days start to get shorter in the fall, the sunflowers come out and are replaced
with snaps for winter production.

Expanding
production space

Bauer said selling directly to retail florists has
allowed the company to achieve a higher price point, but has limited its
revenue.

“We are limited on how much we can raise the price on the
snaps,” Bauer said. “We wanted to get more money out of the production space we
currently have, so that is why we decided to go to a vertical production
system.”

Charles Bauer (left) and his son Matt installed
a vertical production system in their existing
greenhouse rather than expanding
their
operation with additional greenhouse space.

Photo by Edwin
Remsberg, Univ. of Md.

Bauer said additional production space could be built on
to the existing structure, but it would not make a major impact on the
company’s income.

“Where we are operating the greenhouse now we are limited
as to how much we could expand,” he said. “Another reason we chose to go
vertical was the little investment we had to make compared to the income we
could generate from that space. We are only adding troughs and the
infrastructure to install them. Everything else we needed to grow the
additional crops is already there.”

Since the greenhouse has a gutter height of 12 feet,
Bauer has been able to install a three-tier vertical system.
“We have five bays with 6-foot wide by 100-foot long
rolling benches that have support hoops,” he said. “There are hoops that go
over the benches every 10 feet. We ran a metal suspension tube on each side of
the benches. We installed troughs on top of the suspension bars. I can also
suspend cables from the greenhouse trusses so that another layer of troughs can
be added.

Bauer said when he first proposed the three-tier vertical
production system to the University of Maryland researchers he is working with,
they were concerned with the impact the additional overhead crops would have on
the snapdragons.

“Adding the other crops above the snaps lowers the light
levels, but only adds about a week to the snaps’ production schedule,” he said.
“We aren’t using any supplemental lights. The double layer poly the greenhouse
is covered with provides diffused light. The quality of the snaps hasn’t
suffered with the additional crops. And the income we are generating with the
added production offsets the additional crop time.”

Lettuce added to product
mix

The crops that Bauer has grown in the vertical production
system include a summer crop of celosia, Dianthus
barbatus (Sweet William) and European gourmet bibb lettuce. This summer he
is trialing a crop of Matthiola incana
(stock).

“We grow everything in perlite, which is not reused,”
Bauer said. “We compost the perlite and plant debris that is left over. We used
to grow in perlite grow bags that we reused for five to seven years. We found
that as the bags are reused there are more roots which can change the whole
dynamics of how the plants need to be watered and can impact the quality of the
snapdragons. Another reason for using perlite with the lettuce is it keeps the
roots cooler during the summer and can help prevent bolting. The temperature
can reach 100ºF
during the summer and we have not had any issues with bolting. We also use high
pressure mist to help lower the temperature.”

Bauer said he trialed the bibb lettuce for two years
before he started growing it as a regular crop. Initially he fertilized the
lettuce with the same nutrient solution that he was using for the snapdragons.

Flowers By Bauers & Greenhouses is growing a
European gourmet bibb lettuce in
a vertical
production system along with other cut flower crops.

Photo courtesy of
Flowers by Bauer’s.

“When we began trialing the lettuce we applied the snap
nutrient solution. It worked, but the flavor of lettuce was off,” he said. “When
we started growing the lettuce we used a commercially blended fertilizer. My
father has since developed our own custom fertilizer mix for the lettuce.”

Bauer said well water is used for all the crops. It is
run through a series of sand filters before being applied with a closed-loop
irrigation system.

“Our well water is almost like distilled water,” he said.
“We don’t do any type of water treatment for disease control. We have a small
storage tank for the nutrient solution so we are constantly drawing it down and
filling it back up. The water doesn’t sit very long, it is always moving. We
constantly monitor the electrical conductivity and pH.”

Bauer said that he is planning to grow the lettuce
year-round.

“We expect that we will be able to grow five to six crops
of lettuce per year,” he said. “We run the temperatures cooler at night, around
50ºF, because the
snapdragons do better under those conditions. If we raised the night
temperature to 65ºF
we could probably produce nine to 10 crops of lettuce a year. We want to keep
the temperatures cooler for the flowers.”

Bauer said he has overhead production space to grow 600
heads of lettuce per week. He said one of the biggest adjustments was how much
faster the lettuce grows compared to the cut flowers he is growing.

“A lettuce crop during the summer is harvested in six
weeks,” he said. “During the winter and growing under cooler temperatures, the
lettuce finishes in eight to nine weeks.”

Creating a local market

One of the advantages that Bauer had with trying to sell
the lettuce was having an established customer base. The lettuce is marketed in
plastic clam shells with a label that reads: “Flowers By Bauers, Eat Healthy,
Feel Better.”

“I contacted the University of Maryland extension service
prior to growing the lettuce to see what kind of regulations and requirements
were in place for edible crops,” he said. “If we sold the lettuce from our
flower shop and from our delivery trucks within the state, there weren’t any
major issues. If we were to sell the lettuce to supermarkets like Wegmans or
Giant, we would have to become GAP certified.”

Bauer visited with his customers telling them about the
lettuce and how it was produced. He said he offered them samples and once they
tried it that was enough to convince them to start buying it.

Bauer said some of the most enthusiastic customers for
the lettuce are women between the ages of 25 and 35 who have children.

“When I first started marketing the lettuce, I would also
take some of the flowers in five-stem bunches,” he said. “I visited hair salons
and other businesses in Jarrettsville that are women-driven. Whatever I sell in
lettuce, I always double the sale with flowers. The mothers would buy the
lettuce for their families because it was healthy. But they would buy the
flowers for themselves because they made them happy. With the lettuce, they
will only buy so much. But with the flowers, there doesn’t seem to be a limit.”

Matt Bauer is excited by the response he has
received from retail
florists and consumers to
the locally-grown cut flower and
lettuce crops
he is producing in the same
greenhouse.

Photo by Edwin Remsberg,
Univ. of Md.

Bauer visits local businesses every Thursday with lettuce
and bunches of flowers.

“Initially everyone in the community thought the lettuce
was for decorative purposes because we hadn’t sold an edible crop before,” he
said. “They didn’t know they could eat it. I determined that I had to get out
and let people know this was edible lettuce.

“Another thing is listening to what your customers are
saying. The retail florists that I sell to ask what else do we grow. I listen
to them to find out what they’d like to be able to buy from me. I’ll try
growing it to see if I can produce it and whether it is feasible on a
commercial scale.”

For more: Flowers
By Bauers & Greenhouses; mb.harcream@mindspring.com;
http://www.flowersbybauers.com.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

Using Grodan for Lettuce and Herbs

Using Grodan for Lettuce and Herbs

In recent years there has been
a worldwide increase
in the consumption
of lettuce and fresh herbs. Naturally this has led to an increase in production. More and more growers are now opting to use GRODAN
as their substrate.

The benefits of
using GRODAN in the production process are:

It is an
inert and hygienic substrate
The speed and
uniformity of germination and growth.
There is
sufficient substrate volume to propagate to the
desired plant size.
Once it is
placed in the gutter or raft system the
propagation blocks provide further stability.

Inert and clean

GRODAN stone wool
is an inert and hygienic
substrate, so it provides your crop with a clean,
disease free start. Furthermore, stone wool retains its structure throughout the cultivation
cycle. Filters remain clean and free from blockages, cleaning between crops is
easier and more importantly, faster, allowing less downtime between crops. The
fact that it is also inert means that all applied nutrients and
water are directly available for the growing crop. The combination of faster turnaround
and faster growth adds to the possibility of extra cultivation cycles during
the year.

Uniformity and speed of germination and growth

One of the most critical
stages of cultivation is germination. Seed holes cut into the stone wool plugs provide
the perfect air/water ratio around the seed which facilitates a high
germination percentage. More importantly, as the stone wool substrate is
uniformly saturated, each seed has the same germination environment, which provides uniformity in
emergence and initial growth. The speed and uniformity of growth which
follows results in a higher quality end product. It also provides a crucial opportunity
for additional cultivation cycles during the year.

Substrate volume to propagate the desired plant size

There are two distinguishable
stages in the production process; propagation and final production.

With the propagation of lettuce, a favorable microclimate is required. This is partly achieved
by retaining a high plant density.
In GRODAN trials, we have seen that when the propagation period
is extended (21-24 days), the microclimate created results in more speed in
final production. Also, as larger plants are used, the production cycle is shortened,
once again providing an opportunity for additional cultivation cycles during
the year.

In order to extend the propagation
period you also require a larger substrate volume (i.e. AO
36/40 or MM40/40). This larger volume allows more root growth and
more stability. Crucially, it also
allows irrigation to be managed. Often in propagation, too much water is given.
This results in weaker plants with greater susceptibility to disease.
Having the right irrigation strategy with the right substrate volume will give
you the possibility to be critical to the moment of irrigation. Having a precise irrigation
strategy will also retain the roots within the plug and therefore result in less
damage during transplanting.

To improve the irrigation strategy, we would suggest that you weigh
the blocks or AO sheets to decide if irrigation is needed (table 1).

Table 1. Indicative weights to irrigate the blocks or AO sheets.
Grodan product	Approximate substrate volume	Indicative weight to base irrigation on (±60% WC)
MM 40/40	64 ml per block	40 gram per block
AO 36/40	40 ml per plug 3926ml per sheet	24 gram per plug 2.4 kg per sheet

Stability during use in gutter or raft system

Depending on the production system
which is used, the
GRODAN propagation component provides a certain degree of stability. For plants in
gutter systems, suitable products are MM blocks or the AX
plugs (figure 1). For plants in a raft system an AO plug is recommended, as its tapered
base makes planting
into the raft faster.

Figure 1. Left picture showing Grodan AX plugs with basil seedlings, middle Grodan MM
blocks with lettuce during propagation stage, right picture showing Grodan AO
plug.

Conclusion

GRODAN stone wool
will give you an inert, clean substrate which provides fast, uniform
germination and growth. Whether you have a raft or gutter system, we have a plug or block that
will fit your needs.

For more information
contact Hort Americas at 469-532-2383 or customerservice@hortamericas.com

Visit our corporate website at https://hortamericas.com

Improving research in controlled environment facilities

University researchers, extension specialists, industry
representatives and USDA officials are working together to improve how research
is conducted in controlled environment structures, including greenhouses.

By David Kuack

North Central Extension & Research Activity–101
(NCERA-101) is a committee of the USDA
organized to help plant scientists understand how to use controlled environment
technology. The committee initially began in 1969 when plant scientists in the
American Society for Horticultural Science began to discuss how to effectively
use growth chambers to ensure consistent and comparable growth data. When the
committee was organized in 1976 as the North Central Research-101 (NCR-101)
committee, the group expanded to include all plant science researchers and
began encouraging private industry groups to participate.

NCERA-101 was organized to help plant scientists understand
how to use controlled environment technology.
Photo courtesy of University of Alaska

NCERA-101 now has
over 160 members from 102 institutions and industries. There are even members
from outside the United States.

“NCERA-101 is a project with USDA,” said University of
Alaska horticulture professor Meriam Karlsson, who is the chairperson of the
committee. “USDA has several of these working groups or committees that work on
special topics. This committee is particularly large compared to some of the
others because of the involvement of industry members along with researchers.”

Poster child for
cooperation

Karlsson said the NCERA committee has to apply for
renewal every five years to keep operating and to keep receiving funding from
USDA. The USDA funding is distributed to land grant universities and their
experiment stations.

“The committee is open to industry and non-university
persons working with controlled environment technology appropriate for plant
research and production,” said Karlsson. “That is part of the reason the
committee has become so large. Industry members provide input and support the
work the university and extension personnel are doing. We can also communicate directly
to the industry members what kind of technology is needed in both greenhouses
and growth chambers in order to control the environment.”

Karlsson said USDA officials are very happy with the way
NCERA-101
has been operating with the communication and cooperation that is occurring
between university scientists and industry members.

“USDA officials tell us this is how they would like other
committees to work together on multi-state projects,” she said. “USDA works
with a sizable list of working groups,
including animal sciences, forage, insects and diseases. There is no limit in
regards to the number of members the committee can have, although to keep
focused the group needs to remain manageable. NCERA-101 also collaborates with
similar working groups in Europe and Australia. In two years the meeting will
be international and held in Australia.”

Information sharing

As chairperson, Karlsson prepares an annual report and
the committee holds an annual meeting, which occurred in Alaska earlier this
year.

“During the meeting there is information sharing among
the members,” she said. “Everybody is asked to give station reports and talk
about what they are working on. It primarily has to do with how the researchers
are using controlled environment technology. It could be greenhouses, but much
of the research is being done in growth chambers, phytotrons and biotrons. The
discussions are very specific about how to run the growth chambers and what
kind of variables to measure.”

Karlsson said one of the hot topics of discussion among
the members is lighting and LEDs.

“Right now it’s very confusing as to how to evaluate LEDs,”
she said. “This is one of the committee’s areas of focus—light measurement, how
to provide sufficient light and how to use light. When using artificial lamps
there isn’t a natural spectrum.”

Another topic of discussion has been about humidity and
its effect on plants.

“How do you measure humidity and provide it
consistently?” Karlsson said. “Much of the discussion is related to how to
characterize the environment. The same types of discussions also occur
regarding the instrumentation that is used to measure these variables. The
committee works on developing guidelines for measuring these essential
variables.”

The guidelines developed by the committee can then be
used by scientists worldwide to consistently measure environmental conditions
regardless of where the research is conducted.

“Industry members also discuss the challenges they face
in regards to developing the measuring instrumentation that the scientists are
telling them is needed,” she said. “The scientists want the equipment to
measure a variable with limited influence of other factors.”

New greenhouse
open house

During this year’s NCERA-101 annual meeting, which was hosted
by the University of Alaska Fairbanks, Karlsson had the opportunity to show off
the new teaching and research greenhouse that was recently completed. The
4,500-square-foot Nexus greenhouse consists of an upper and lower level. The
upper level, which was completed in 2012, is used for teaching and
instructional purposes. The lower level, which was finished earlier this year, will
be used for research.

The new greenhouses at the University of Alaska
are equipped with high pressure sodium lamps.
Photo courtesy of University of Alaska

The greenhouses are equipped with both blackout and
shade/energy curtains. There is also a Mee fog system which is used to cool the
greenhouses and to increase the humidity.

“During the winter the natural humidity is really low,”
Karlsson said. “During the summer when the temperatures can reach into the 80s,
the fog system keeps the greenhouses cool.”

Karlsson said when the greenhouses were being planned
during 2010-2011 the decision was made to install high pressure sodium lamps.

“At the time the technology for the LEDs was not
developed enough for us to choose them,” she said. “We are doing research with
LEDs because the cost of electricity here is very expensive and LEDs are anticipated
to be more efficient. I expect LEDs will make a big difference for the
commercial greenhouse industry in the state. We are looking at how we can get
enough light from LEDs to substitute for high pressure sodium to promote the
kind of growth we want to have. And we need to determine how plants respond to
different light qualities under our growing conditions.”

Interest in food
crops

Karlsson said there is a lot of interest in many
communities in Alaska about hydroponics and the production of food crops.

University of Alaska researchers are studying the

feasibility of growing a variety of edible crops.

“Alaska is at the end of the supply line so there is a
lot of interest in extending the growing season and even possibly growing
during the winter months,” she said. “We are looking at growing hydroponically and what is the
easiest way to produce leafy greens, lettuce, tomatoes and cucumbers. Even
though Alaska is known for having major natural gas and oil reserves, having an
affordable energy source is one of the obstacles that has to be addressed. Some
communities have access to natural gas, which is almost an unlimited resource.”

Karlsson said because of Alaska’s cold, dark winters,
there is interest in growing hydroponically with vertical shelf systems.

“There is also a lot of interest in greenhouses and high
tunnels,” she said. “Alaska is a big state. South of Anchorage on the Kenai
peninsula, high tunnels are used to start the season earlier in the spring and
to extend fall production. The climate is more moderate there. As you go
further north, it doesn’t make sense to put up a high tunnel. Greenhouses would
be a better choice. Even during the summer when there is plenty of light, some
heat would be needed in the greenhouses to maintain the warmer temperatures the
crops would need.”

For more:
Meriam Karlsson, University of Alaska Fairbanks, (907) 474-7005;
mgkarlsson@alaska.edu.

David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

Creating the ideal environment for orchid production

Green Circle Growers continually works to improve and
refine the production environment for the orchids in its “Just Add Ice Orchids”
program.

By David Kuack

Green Circle Growers in Oberlin, Ohio, is serious about
producing orchids. It grows 6.5 million phalaenopsis orchids annually in 25
acres of Venlo-style glass greenhouses built specifically for orchid
production.

Green Circle Growers’ goal is to produce the most uniform,
highest quality orchids.

“We have a high efficiency production system,” said
grower manager Frank Paul. “Everything is standardized. Everything follows a
certain path through our facility.”

Paul said orchids are very manipulative. The greenhouses
are divided into vegetative areas and generative areas. All of the vegetative
areas are at 83ºF
and 65 percent relative humidity. The greenhouses are equipped with a high
pressure fog system for humidity control and also receive supplemental carbon
dioxide.

“Throughout the different vegetative stages of orchid
production the light levels are slowly increased, but the temperature and
humidity remain fairly similar,” he said. “The young plant stage is an average
26 weeks. After the young plant stage, the mature plants in 5-inch pots remain
in a vegetative stage for about 24 weeks before being moved into a cooling
stage.

“Only when the plants are large enough to produce good
quality flower spikes are they moved into the cooling stage. During the cooling
stage, the temperatures are lowered to an average of 70ºF along with an
increase in light levels that initiates the flower spikes. From flower
initiation to shipping is 19 weeks.”

In order to produce plants as uniform as possible, a set
of grading steps was implemented. A camera is used for objective grade
determination.

“Whatever plants are not up to size receive a longer
period of time in the vegetative stage,” Paul said. “Once plants reach the size
that is necessary to produce good quality flower spikes they are moved to the
generative or cooling stage. Our goal is to make the output as uniform as
possible at the highest possible quality.”

Creating the
“perfect” environment

Paul said being able to grow a quality orchid comes down
to the ability to modify the climate conditions to create the perfect growth
environment.

“It is very focused on climate control and climate
control software,” he said. “The first 26 weeks in the young plant stage is by
far the most critical stage. The most important thing is to maintain a stable
growth speed along the way. Disturbances in the growing environment at this
stage can result in a significantly higher percentage of disease and losses.
Those problems can start to a small extent in the young plant stage. Typically
the chances for problems increase once the plants move to the mature vegetative
stage. The problems can be major depending on the level of disturbance
experienced by the plants. That’s why it is so important to keep things stable
at all times. Disturbances include fluctuations in temperature, moisture
levels, soluble salts and pH.”

Grower manager Frank Paul said being able

to grow a quality orchid comes down to the

ability to modify the climate conditions to

create the perfect growth environment.

The greenhouses are equipped with several different
curtains, including indoor and outdoor shade curtains. The outside curtains
help keep the heat out during the summer.

One indoor curtain is primarily for energy savings. The
houses also are equipped with Harmony light diffusion/energy saving curtains.
This white polyester screen brings more light to the plants from all directions
helping to stimulate growth. At night it acts as heat retention curtain.

“Orchids are natural shade plants,” Paul said. “They use
fairly low light levels. They don’t like direct sunlight at all so that is why
we are using the Harmony curtains during the day to diffuse the light.”

All of the greenhouses are equipped with high pressure
sodium lamps. In the generative stage areas of the greenhouses the plants need
higher light levels. The greenhouse curtains are open several hours during the
day in those houses. In the vegetative stage greenhouses the Harmony curtains are usually closed 99 percent of the time.

The HID lamps are used primarily during the winter.

“Phalaenopsis are not daylight sensitive, but we try to
maintain a 14-hour day all of the time,” Paul said. “The lamps help to maintain
stable growth at all times. We usually start using them during the second half
of August and run them for one to three hours every morning, gradually
increasing the operating time toward the shortest natural day in December.”

Sweating the small
stuff

Paul said the greenhouses are very open and equipped with
open-structured benches which allow for greater airflow.

“In order to maintain 70ºF during the summer three large chillers have been
installed that produce 38ºF
water,” he said. “The water is pumped to climate optimizers which help to cool
down the air during the warmer months. The climate optimizers located under the
benches are used for both heating and cooling. They can switch back and forth.
The optimizers over the top of the benches are used for cooling only. The
optimizers are basically large air conditioning units through which either cold
or hot water is pumped. The cooled or heated air is sucked through a radiator
and blown through tubes which distribute the air.”

Climate optimizers located under the benches are used for

both heating and cooling. The optimizers are like large air

conditioning units through which either cold or hot water

is pumped.

Paul said orchids are very sensitive to high salt levels.
The soluble salts (electrical conductivity) and pH of the water are monitored
daily.

“We do frequent soil and water sample analyses,” he said.
“We have an in-house water lab that does weekly analyses of specific elements
in the water.”

Rain water is the irrigation water source and is treated
with chlorine dioxide.

“Rain water is relatively clean, but it is important to
keep the water pipes and irrigation lines clean,” Paul said. “Irrigation water
is the primary source of spreading infection. Chlorine dioxide helps to
suppress pathogens from spreading.”

The greenhouses were initially equipped with boom
irrigation, but Paul has been looking at potentially installing an overhead
sprinkler system.

“The booms are spray bars that move over the tops of the
plants up to 10 times during an irrigation cycle,” he said. “The overhead sprinkler
system is a permanent irrigation line, which provides a steadier flow of water
falling on the plants. Overhead irrigation is more constant and allows the
water to flow down through the growing medium and along the sides of the pot
for better leaching. The medium for the finished plants is a mixture of bark
chips and sphagnum peat. Foam is added to the medium in the young plant stage
for the first 26 weeks. All of the drain water is collected into ponds and
reused on other plants in our facilities. It is not reused on the orchids.”

Paul said growing issues with orchids are not seasonally
related. Diseases are the biggest challenge.

“Pseudomonas and Fusarium are very common diseases in
orchid production,” he said. “Pseudomonas is a bacterial disease associated
with the foliage. Fusarium is a fungus that attacks the crown of the plant.
Unstable growth makes the plants more susceptible to these diseases. If the
plants are kept wet too long that makes them more susceptible. Phalaenopsis has
to be dried out before going into the night.”

Paul said the best defense against everything for orchids
is maintaining a healthy plant.

“Creating the ideal conditions for a healthy growing
plant is our main focus,” he said. “Once you get away from that, diseases and
insects become more of a problem. It’s all related to keeping the plants
growing healthy and active at a steady pace all of the time.”

Expanding the Just Add Ice program

The main crop in Green Circle Growers’ “Just Add Ice Orchids”
program
is 5-inch phalaenopsis orchids. As the Just Add Ice name implies, consumers are
directed to use three ice cubes per week to water the plants.

The company has expanded the program with mini-orchids,
anthuriums, bonzi, bromeliads and Pachira
aquatica, called the money tree.

“The mini-orchids account for 10-15 percent of our orchid
sales,” said grower manager Frank Paul. “We are looking to grow the
mini-orchids to 30-40 percent of the program’s sales in the next couple years.
The mini-orchids are also phalaenopsis species.”

The mini-orchids follow similar steps to the other
phalaenopsis, but conditions slightly vary. Because the growing medium is
different for the mini-orchids, there are different requirements regarding
fertilization, irrigation and the cooling process for spike initiation.

Paul said the greenhouses being used for orchid
production are also suitable for anthuriums and bromeliads. Although these
tropical plants finish in about the same time (10-11 months) for the mature
plant stage as the phalaenopsis orchids, they do not follow the same production
schedule. He said the greenhouses designated for phalaenopsis are only used for
orchids.

“The anthurium and bromeliad crops could be grown in the
orchid greenhouses,” he said. “However, because each of these crops requires
its own specific climate conditions and its own specific climate conditions and
has a unique production schedule, we dedicate specific greenhouses to one crop
only.”

For more: Green Circle Growers, (440) 775-1411; fpaul@greencirclegrowers.com; http://www.greencirclegrowers.com; http://www.justaddiceorchids.com.

David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.

Visit our corporate website at https://hortamericas.com

New online tool enables growers to diagnose strawberry problems

Scientists and IT developers at North Carolina State University are creating an online diagnostic tool that will assist strawberry growers in determining and resolving crop-related issues.

Starting June 30 strawberry growers will have a new online diagnostic tool to help them identify problems they may encounter with their crops. As part of the National Strawberry Sustainability Initiative grant, which is funded by the Walmart Foundation, a group of North Carolina State University scientists and extension IT developers
are creating a web-based interactive diagnostic key for growers. It will have application to both outdoor- and indoor-produced strawberries throughout the United States.

The key will be accessible through users’ computers, tablets and smart phones. It will be available through the North Carolina Cooperative Extension Strawberry Growers Information website.

A holistic approach

Brian Whipker, professor of floriculture–research and extension, who heads up the project, said the key
is based on attributes.

“There are 21 insect pests, 26 diseases, 14 nutritional disorders and 26 physiological disorders in the key,” Whipker said. “It covers the primary sources of problems. The herbicide damage probably won’t have application to greenhouse production, but almost everything else, including the diseases, nutritional disorders, and most of the physiological disorders and insects will apply.

“When users log onto the website there is a filter on the left side of the homepage that is based on four categories (insect, disease, nutritional and disorder) that they can sort by. The term physiological was replaced by the word disorder.”

A user can click on the insect category and receive all 21 insect pests.

“If the users don’t want to search by type then they can choose differentials based on leaf condition that has 12 options or leaf color that has 10 options,” Whipker said. “They can also search by leaf location, which has six options. Fruit conditions have eight options, including size, texture and color. There are also attributes for root and crown problems.”

The strawberry diagnostic tool being developed at North Carolina State University covers 88 different attributes, including nutritional disorders such as boron toxicity (top) and iron deficiency (bottom).

Filters narrow problem identification

Whipker said the key allows users to narrow down the problem identification by using a series of filters.

“If a grower has interveinal chlorosis, the key can filter the problem down to 12 options,” he said. “The grower can add another filter for mature leaves, which narrows the choices down to four options. The key then filters for a combination of interveinal chlorosis and mature leaves.

There are other characteristics that are listed and the grower can read down that list and sort the problem cause from there. There is one thumbnail photo of each problem that the user can choose from.”

There are different headers for each of the four categories. For diseases there are headers for causal agents including the scientific names. The headers for nutritional disorders include Problem (i.e., iron deficiency); Symptoms (with photographs and a listing of similar problems like mimics); Additional Information; Diagnostic Tips; Corrective Measures and Management.

Whipker said once a grower chooses what he thinks is causing the disorder, he can click on the problem and is taken to a fact sheet.

“There are 88 attributes and there is a fact sheet on each one,” he said. “Most of the fact sheets are two pages long. Some of the disease fact sheets are four to six pages. There are also some hyperlinks for other online resource publications that are available.”

Additional crop information

Whipker said the key template that was used for the strawberry diagnostic tool would have application to other crops.

“Diagnostics are my driving force,” he said. “I have invested $20,000 in a system that can induce nutrient disorders. I’d like towork on the nutrient disorders of greens and herbs. Currently there is no diagnostic key available for herbs.”

Whipker has also produced a nutrient disorder guide for tomatoes, “Tomatoes: Troubleshooting Guide to Nutritional Disorders”.

N.C. State University horticulture professor Brian Whipker has released a book on tomato nutrient disorders that were greenhouse-induced.

“We produced an iPad-based book for the tomato disorders,” he said. “It is also available as a print-on-demand book at Lulu.com.

“The tomato disorder publication is more applicable to greenhouse tomatoes than field-grown. All of the tomato nutrient disorders were greenhouse-induced. A field-based system is more forgiving. With a hydroponic or water-production system there is no residual. If a grower forgets to put in boron, the plants are going to show the deficiency symptoms.”

For more: Brian Whipker, North Carolina State
University, Department of Horticultural Science; brian_whipker@ncsu.edu.

A team effort

North Carolina State University team members on the “Strawberry Diagnostics: a Problem Solving Tool” project include:
Hannah Burrack, Department of Entomology
Frank Louws and Barbara Shew, Department of Plant Pathology

Rocco Schiavone, Jeremy Pattison and Brian Whipker, Department of Horticultural Science
Rob Ladd (developer) and Rhonda Conlon, Extension Information Technology

David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.

Update on trialing supplemental lights in Hawaii

By David Kuack

On Dec. 14, 2014, a Hort Americas blog update was posted about University of Hawaii graduate student Robert Saito, who is
comparing the growth of pak choi (Chinese cabbage) under T5 fluorescent lamps
and Philips GreenPower LED Production Module Deep Red/Blue 120 fixtures. Saito
has conducted seven trials. The first four trials were preliminary to determine
the best growing medium and which plants should be used to measure light effect
differences. Initially Saito was planning to grow mizuna, but he ran into
issues with micronutrient deficiencies and switched to pak choi instead. Both
of these leafy greens are in the Brassica family.

University of Hawaii graduate student Robert Saito is studying
the differences in growth of pak choi under fluorescent (top)
and LED lights (bottom).
Photos courtesy of Robert Saito

Preliminary results
Saito has measured fresh weight, height and chlorophyll
content of the plants grown under the two light sources.

“I also took SPAD readings to measure the relative chlorophyll
and there were differences among the treatments,” Saito said. “I am now going
to run the data statistically to see if there was a significant difference.”

Plant samples are also being analyzed for nutrient
content to see what kind of nutritional value they can offer to consumers.

“I am doing a tissue analysis to measure some of the
secondary metabolites,” he said. “I am looking at total phenolics, carotenoids
and glucosinolates. A mineral nutrient analyses will measure such things as
total nitrogen, phosphorus and potassium. Once the mineral and tissue analyses
are done then I hope to publish the results.”

For more:
Robert Saito, University of Hawaii, College of Tropical Agriculture and Human
Resources, Manoa, Hawaii; rjnsaiot@hawaii.edu.
David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack @gmail.com.

Visit our corporate website at https://hortamericas.com

Category: Blog

Could LEDs replace plant growth retardants?

Researchers at Michigan State University used LED lights to produce compact flower and tomato seedling plugs.

High tunnels enable growers to increase production of high-value berries

High tunnels can be a part of a production system that allows growers to produce berries year-round while improving fruit yields and quality.

LEDs have the potential to change how crops are grown

The use of LED grow lights to provide specific light wavelengths could allow growers to increase nutritional values of edible crops, enhance the intensity of foliage and flower color and improve the postharvest longevity of ornamental and edible crops.

Potential of specific light wavelengths

Need for fine tune management

Meeting the fertilization needs of greenhouse lettuce

Plant factories continue to evolve

A new Ohio State University farm-to-fork project offers students fresh produce

Short course to focus on controlled environment agriculture

LEDs found to have multiple uses on multiple crops

Deardorff Family Farms donates school salad bar during Tour de Fresh

Organic fertilizers provide option to grow more sustainably

University of Arizona Intensive Course will focus on hydroponic greenhouse tomato production

Southwest Perennials improves production, shortens crop time with LEDs

Growers, investors discuss horticultural opportunities

Growing through the California drought

Grower goes vertical to increase production, revenue

Using Grodan for Lettuce and Herbs

Improving research in controlled environment facilities

Creating the ideal environment for orchid production

New online tool enables growers to diagnose strawberry problems

Update on trialing supplemental lights in Hawaii

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