Consider edible greens as an alternative crop

Growers of ornamental plants can use empty greenhouses during winter to produce a variety of edible greens.

By Tina Smith

Ornamental plant growers who close down their greenhouses for the winter may consider using an empty house to produce an alternative crop such as greens during the winter months. Production systems range from high tech hydroponic systems for lettuce to growing mixed greens in ground beds using minimal or no heat. Researchers in the Department of Plant Science at the State University of New York (SUNY)–Cobleskill, are using existing ebb and flow benching for short-term hydroponic raft lettuce production.
One thing that is common to most greens production systems is the use of a greenhouse structure. Since many greenhouses used to grow spring ornamentals are vacant between November and February, greens may be an alternative crop.

Start small
When growing a crop of greens for the first time, especially if new to vegetable production, begin on a small scale. Growers are advised to research the markets including demands for certain types of greens, harvesting techniques, post harvest handling, storage and packaging. Areas with winter farmers markets have seen a high demand for winter greens, though in some cases the market is getting saturated and competition is high.
Resources are available on growing greens in high tunnels that can be adapted to greenhouse production. It may take some trialing to develop a production system that works for your operation.


Greens being grown in ground beds.

Minimum heat production
Greenhouse growers who produce ornamental crops tend to grow greens in soilless mixes or compost in containers on benches. For production systems that use minimal heat, greens are sown from early September through the first week of October and harvested in November and December.

Scheduling
Planting times are one of the most critical factors for winter harvesting of greens. Successful growers develop planting schedules including expected harvest dates and record yields for future use.
Early sowing is necessary because greens achieve most of their growth before short days lengths and cold temperatures occur. The growth rate slows during the winter months due to cold temperatures and low light caused by cloudy weather and shorter day lengths. There is very little or no growth when the day length drops below 10 hours per day, which usually occurs at the end of November through the beginning of February in Massachusetts. If minimum heat is used, winter production of greens relies on the plants making their growth throughout the fall. Recent research at the University of New Hampshire suggests that some species are more sensitive to temperature than to light whereas others such as lettuce are more sensitive to light than to temperature.
One of the keys to success is to plant enough of a crop early in the season to be able to harvest through the cold season. For example, spinach may take several months to grow during colder months. Spinach seed should be sown in September and October so it is nearly full-sized in December and can be harvested through February.


Greens being grown in flats.

Types of greens
There are several types of greens that are grown for winter production, including Asian greens such as mizuna and tasoi, kale, lettuce (red and green leaf, oakleaf and romaine), mustards, gourmet cabbages, Swiss chard, spinach, arugula and claytonia.
If you unfamiliar with some of these greens, taste them first and check out recipes for greens that are new to you. This can help with the best way to market the different greens.
Lettuces are not as cold hardy as some other greens and some lettuce varieties are better adapted to cold weather and short days. Seed catalogs can help with specific growing requirements.
Spinach is very cold hardy. However, during the darkest period of winter, spinach grows very slowly. As the day length becomes longer spinach regrows rapidly and some varieties bolt before the end of winter (February or later).
Crucifers, including mustards, raab and Oriental greens such as pak choi and tatsoi, are good choices for cold-weather production. Swiss chard (Beta vulgaris), which is grown for its large tender leaves and rapid re-growth, is cold hardy and productive.
Growers have found it best to plant different varieties in separate production blocks rather than mixed them together, since growth rates and times of maturity are different. Trial several varieties because they may grow better under various light and temperature regimes. Some varieties are quicker to bolt than others. Mixed packages of greens can be created after they are harvested.

Cultural methods
Containers. Greens can be directly sown in a variety of containers. Open seed flats are popular and fit well on benches. Some growers cover the benches with landscape fabric and fill with medium to create one large bed.

Growing media and fertilization. Soilless media or composts are used for growing greens. Organic production requires growing media that have been approved by an organic certifying agent or have been designated OMRI certified. Plants need less fertilizer as the growth rate slows. Avoid over-fertilizing, which can lead to soft growth and aphid infestations.

Irrigation. Automatic sprinklers or hand watering can be used. Irrigate plants in the morning to allow foliage time to dry before temperatures drop at night, especially as the day length shortens. Under short days growth slows and less water is used. Avoid overwatering, which results in soft growth. Soft plants are less able to withstand cold and have less flavor.



Greens being grown on subirrigation benches.

Temperature. There are many options when it comes to temperature. Temperature affects the growth rate and also the flavor of greens. For example, arugula has a stronger flavor when grown at warm temperatures. Some growers produce a succession of greens harvesting every 14-21 days (micro-greens) at 50°F nights and 55°F days. Other growers provide minimal heat to maintain night temperatures of 37°F. On warm or sunny days, greenhouses are ventilated or the side walls are rolled up to increase air circulation depending on the structure.
Some growers use ground beds without supplemental heat. Some crops such as lettuce and arugula do not grow well without supplemental heat. Growers who are using high tunnels without heat tend to use row covers laid over crops on cold nights. The covers must be removed during the day to allow the plants to receive light. Greens cannot be harvested frozen and must be thawed before harvesting.

Light. Light affects the growth and flavor of greens. Decreased daylight results in slower growth. Increasing the temperature cannot compensate for the reduction in daylight. Greens tend to have a milder flavor under lower light. Mesclun grown under lower light is lighter colored than when grown under high light conditions.

Pests. Some of the pests that may be encountered when growing greens include downy mildew on lettuce and spinach (two different species of downy mildew). Some newer varieties of spinach are promoted as having resistance to many races of downy mildew. However, this resistance may not be for all races of the disease. Powdery mildew is a problem on lettuce under low light and high humidity conditions. Voles can be also be a problem when growing greens.

Harvesting and marketing. Greens can be harvested using a sharp knife, scissors or manually picked with no tools, one leaf at a time. Growers use both short and long blade knives. Greens can be harvested by either removing outer, larger leaves at regular intervals or by cutting the entire plant within an inch above the growing medium allowing the crown to remain. Leafy crops re-grow and can be harvested again.
Once greens are harvested, some growers move the crop to a storage area to bag them for sale. If the greens are dirty, then they need to be double rinsed and spun to remove excess moisture. Spinach tends to grow close to the ground and may need washing. Growing in a soilless medium or compost in containers on benches can eliminate this step.
Two popular markets for greens are winter farmers markets and restaurants. Many community-supported agriculture (CSA) farms are offering winter shares and some may be interested in buying in greens to add to the winter and storage crops they offer.
Tina Smith is with the UMass Extension Greenhouse Crops and Floriculture Program, (413) 545-5306; tsmith@umext.umass.edu.
This article first appeared in the July-August 2012 issue of the UMass Extension Floral Notes Newsletter.

References and Resources
1. Summer Flowers, Winter Greens; http://www.growingmagazine.com/print-7190.aspx
2. Four Season Farm: “Growing Winter Crops in Maine” and “The Winter Harvest Handbook”; http://www.fourseasonfarm.com/books/index.html
3. Cornell High Tunnels website: Cold Hardy Greens; http://www.hort.cornell.edu/hightunnel/crops/vegetables/salad_greens.htm
4. Michigan State University Hoop House website; http://hoophouse.msu.edu

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Solar Panels to Power University Greenhouse

Students and faculty at Southern Polytechnic State University in Marietta, Ga., will be studying and doing research in a new solar powered greenhouse.
by David Kuack

When Marietta Power & Water contacted Southern Polytechnic State University about a grant program that could benefit the school, administration officials were eager to listen. The grant program, which was being administered by the power company and Electric Cities of Georgia, would enable the university to install 24 solar panels while paying only 1/3 of the total cost.
Electric Cities of Georgia received the grant as part of the 2009 American Recovery and Investment Act. Marietta Power & Water used a portion of the grant money ($54,000) for the solar panels. The grant allowed for the installation of solar panels that will generate 15 kilowatts of electricity. The electricity generated by the panels is enough to power 225 light bulbs.
“The grant was for 15 kilowatts of solar panels so we divided the installation,” said Steve Kitchen, senior director of facilities management at the university.
Sixteen of the panels were installed on the roof of the Engineering Technology Center and generate 10 kilowatts of electricity. The remaining 5 kilowatts of electricity will be generated by eight solar panels that have been installed next to a new 25- by 35-foot greenhouse constructed adjacent to the ETC. Each of the panels measures about 4 feet wide by 7½ to 8 feet long. Both installations were covered by the grant.
The 5 kilowatts of electricity generated by the panels will be used to support the greenhouse during daylight hours. The electricity will be used to power lights and a heater. The greenhouse will be used primarily for academic and research purposes.
Upgrading the installation
Although the greenhouse is nearly complete, Kitchen said there may be some opportunities available for upgrading the system.
“If it made economic sense, there could be an expansion of the panels on the roof of the ETC building,” he said. “The other change that could occur is finding a means to store the electricity generated by the solar panels so that it could be used at night. The 5 kilowatts of electricity generated by the panels is more than enough to operate the greenhouse during the day. If there was a storage system to store the electricity generated, we could use it to power the greenhouse during the night as well.”
Easily maintained
The university will maintain the panels, which Kitchen said is relatively simple.
“The most frequent activity to maintain the panels is to make sure they are kept clean to operate at maximum efficiency,” he said. “It doesn’t take much more than rinsing them off with water to keep the dust off of them. They are so new right now we’re not sure how often they will have to be cleaned.”
Interest in alternative energy
Kitchen said the university has had limited exposure to working with solar power. Solar panels had been installed on the old engineering building.
“There is a small array of panels on that building, referred to as Building G,” he said. “The students with the support of the faculty have built an electric bicycle recharging station. I personally haven’t seen any electrical bicycles on campus, but we have a recharging station for them.”
Kitchen said that the university does have an alternative energy program and he expects that the faculty involved with that program will be interested in learning more about the solar panels. He said they are always interested in looking at alternative energy sources and would likely be supportive of an expansion of solar panel installation.
Kitchen said any consideration for use of alternative energy sources would probably not occur unless it was associated with a major renovation of one of the university’s buildings.
“There is no other building on campus that is currently using alternative energy sources.” Kitchen said. “Part of it is the faculty and the research they are doing and what they are teaching the students. The other part is the practicality and the cost associated with using alternative energy sources.
“Cost is a major factor. There is always a cost associated with bringing technology to campus. We are looking for projects, like what we did with Marietta Power, that we can team up with and offset the costs.
For more: Steve Kitchen, Southern Polytechnic State University, (678) 915-3939; skitchen@spsu.edu; http://www.spsu.edu.

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Hydroponic Fodder Trial

With drought affecting much of the United States I was reminded of a method to produce fresh
feed for livestock with minimal input: hydroponic fodder.  Hydroponic fodder production is simply that,
growing livestock feed (barley, oats, clover, alfalfa etc.) hydroponically.  Generally speaking, production time of
hydroponic fodder is rapid.  Barley for
example can be ready to harvest in as little as 7 days!  A
grower can expect approximately seven pounds of fodder for every one pound of barley seed. Possible additional benefits of hydroponic fodder include higher meat and milk production and better heat cycles.  So,
the Hort Americas Research Division set out to grow barley seed under LEDs in a
recirculating hydroponic system. Johnny’s Selected Seeds has a wide selection
of seed.  Johnny’s has organic barley
seed available in a variety of bag sizes.  We
selected two, 5 lb bags for just under $9.75 per bag.  Fifty pound bags are also available.  There are other bulk seed suppliers and we will continue to compare product and pricing.

Barley seed in propagation trays.

Upon receipt, the seed was poured into the propagation trays
at a depth of approximately 1/2”.  The
drainage holes were plugged and the seed was submerged in water for 24 hr.  After 24 hr. the water was drained
from the trays and discarded.  After
draining the water, a half-strength nutrient solution was prepared using Kimitec
brand fertilizer (see below).  Lighting was initiated
at Day 1 using GreenPower LED Deep Red / Blue 120 Production Modules (DRB 120).  The DRB 120s were placed over the center of
each tray at 12” above the table.  A Li-Cor
quantum sensor and meter (LI-205A) was used to measure instantaneous light
intensity.  Light intensity was
approximately 70 µmol·m-2·s-1
and photoperiod was 18 hr.  This produced
a DLI of approximately 4 to 5 mol·d-1.  To maintain adequate moisture and provide nutrition,
the seeds were irrigated every two hours for 5 minutes.  Radicles were visible at Day 1.  After two days root formation was
obvious.  At Day 3 coleoptiles began to
form and a full strength nutrient
solution was applied to the plants.  By Day 4, the coleoptiles appeared to double
in length and the first leaves were visible.  At Day
5, leaves continued to grow and the root mat was well developed. Plants appeared to be ready by Day 6, but we decided to continue growing the barley
for 7 full days before harvesting.  On Day
8 the fodder was harvested and delivered to a local goat farm within 40
minutes.  We want to thank Katherine of Harrison Farm for expressing interest in this trial and for allowing us to bring the fodder to her goats.

So in summary:

  • Day 0:
    • Seed poured directly into hydroponic
      propagation trays at a depth of ½”.
    • Seed soaked in water for 24 hr.
  • Day 1:
    • Drained/discarded the water from the trays
      after 24 hr.
    • Began irrigating with a half-strength
      nutrient solution every 2 hours for 5 minutes:
      • 2 ml of Espartan per gallon of water
      • 2 ml of Amifort per gallon of water
      • 6 ml of Caos per gallon of water
      • 3 ml of Tundamix per gallon of water
      • 0.5 tsp of MgSO4 per
        gallon
    • Lighting provided to seeds via DRB 120s
    • One DRB 120 was placed 12”
      above the center of each propagation tray (three total).
      • Light intensity was
        approximately 70 µmol·m-2·s-1. 
      • Photoperiod was 18 hr.
      • DLI was between approximately 4 to 5 mol·d-1.
      • Energy consumption per DRB 120 is 35 Watts
        •  Daily energy consumption = 1.89 kW per day
        • Total energy consumption (7 days) =  12.23 kW
        • Local electrical rate = $0.08 USD per kWh
          • Daily lighting cost = $0.15 USD per day
  • Day 2:
    • Continued irrigation and lighting protocol
  • Day 3:
    • Nutrient solution was increased to
      full strength:
      • 4 ml of Espartan per gallon of water
      • 6 ml of Bombardier per gallon of water
      • 13 ml of Caos per gallon of water
      • 6 ml of Tundamix per gallon of water
      • 1 tsp of MgSO4 per
        gallon
  • Day 4 through 7:
    • Continued irrigation and lighting protocol
  • Day 8:
    • The fodder was harvested and delivered to a local
      livestock farmer within 40 minutes.

NOTE: Nutrient regimen was a trial. Basically, we used  recommended Kimitec fertilizer rates per gallon for coco slab growing and applied it via a completely soilless, recirculating system.  We will continue to adjust the nutrition and should we conduct tissue analysis, we will post the results.  We have selected to postpone the discussion comparing the cost per ton of hydroponic fodder versus cost per ton of hay/grain.  To be continued…

Keep growing and make it a great day!
Cheers,
Dr. B.

Day 1 – radicle emergence
Day 2 – root formation

Day 3 – coleoptile formation

Day 4 – coleoptile and first leaf formation

Day 4 – coleoptile and first leaf formation

Day 4 – barley under LEDs

Day 5 – root formation

Day 6 – first leaf well developed

Day 7 – ready to harvest

Day 8 – harvested and delivered = happy goats!

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Hort Americas is offering a Vertical Growing System

Hort Americas is working to help those interested in Vertical Farming develop their ideas.

One thing needed is a “system” that allows new growers to test their theories.  Hort America’s feels they have come up with an option.

Hort Americas has developed a Vertical Growing cart that allows the grower to set up a germination area and a finished plant area.  The customer can customize the Horticulture LED Grow Lights (referring to light quality and quantity), the planting intensities, the crops and the nutrient selection.

The Vertical Growing Cart is heavy duty and portable, giving the grower the flexibility to try different locations and systems.

For more information on Vertical Farming using these customized carts, please email Hort Americas at infohortamericas@gmail.com.

Photos of the First Cart designed to be shipped from the farm to the market using nutrient film technique, LED grow lights and organic fertilizers.

Heavy Duty and Portable Vertical Growing Carts

This cart using Nutrient Film Technique (NFT) 

Stock Tank(s), Germination and Finished Production in one area.

Artificial Lighting Provided by Horticultural LED Grow Lights

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Hort Americas Partners Well Represented at Floriade 2012

Hort America’s Valued Vendor Partners are Important Participants in Floriade

Hort Americas’ partners Philips and Horticoop are participating in this year’s Floriade. Philips lighting has been installed in the Dutch pavilion My Green World. The 49-foot high pavilion forms a landmark in the Education & Innovation part of the exposition.
Within the pavilion is My Green Lab that includes a 16-foot tall structure made up of an eight-layer cultivation system. Each layer is fitted with Philips GreenPower LEDs under which fresh basil is being grown. Other than the LED lighting, the structure is completely dark, showing visitors how plants can be grown without sunlight.

Multilayer Horticultural LED Grow Light Display

Horticultural LED Grow Lights at Floriade 2012

My Green Lab is a futuristic and experimental part of My Green World where visitors can learn more about the challenges facing the planet in terms of energy supply, water conservation and food production. My Green Lab offers insight into a variety of topics including algae cultivation for biofuel production and photosynthesis and cultivation without light.
Also on display in the My Green World pavilion is a trellis carrier, which is marketed by Horticoop. This motorized rail system enables greenhouse workers to access any part of a commercial production facility. Partners in the development of the trellis carrier include TU Delft, Wageningen University, The Hague University and the Dutch Ministry of Economic Affairs, Agriculture and Innovation.

Horticoop participates in My Green World

Horticulture research, interactive game
Wageningen UR Greenhouse Horticulture, along with several greenhouse systems suppliers, is presenting research and new techniques for sustainable horticulture at Floriade. The Innovation Cluster is a modern greenhouse where five research themes are discussed: energy and climate, water and emissions, crop quality, crop protection and sustainable cultivation and production.
Wageningen UR Greenhouse Horticulture and TNO are presenting the game My Cool Greenhouse at Floriade. Through an interactive game on a touch table, visitors can experience and see how a perfect greenhouse is created and what is involved in its operation. The game is also available to play online.

University of Wageningen is playing an important educational role

High tech greenhouse video
Be sure to check out the YouTube video Innovatie Cluster Floriade.wmv. During this 2-minute video a group of children explore a high tech tomato greenhouse that has been built to provide sustainable growing. As they discover what happens in the greenhouse, the children learn how growing medium, water, carbon dioxide, air, environmental control, systems integration and research are combined to produce tasty tomatoes.

Floriade Dialogue 2009-2012
Floriade 2012 started a scientific and practical support program in 2009 called Floriade Dialogue 2009-2012  Floriade Dialogue presents discussions on issues of great social importance related to principals of sustainability with impact on the quality of life.
The emphasis of Floriade Dialogue in 2012 is to influence the process of social change needed to deal with the limitation of natural resources that global society will face in the future. Topics to be discussed during the Floriade Dialogue Sessions include:
1. Adequate and safe food production.
2. Responsible use of natural resources.
3. Balancing the built and natural environment.
4. Use of the potential of nature to improve the quality of life.
5. Regular access to enough high-quality food to lead active, healthy lives.
6. Expand economic growth and job creation through sustainable use of natural resources.
7. Strengthening horticultural and agricultural value chain operation and collaboration.
8. Generating logistic synergy and creating opportunities.
The outcome of the sessions will be published under the title “The Self-Supporting and Livable City”. The publications will be available online in two editions of “Change” magazine.

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Floriade 2012: U.S. greenhouse growers visit and revisit the Netherlands for ideas and inspiration.

Rick Brown of Riverview Flower Farm hunts for consumer-friendly plants at Floriade 2012

Florida industry leader and greenhouse grower Rick Brown visited Floriade in the Netherlands in search of plants that would survive for consumers under Florida’s weather extremes.

By David Kuack

Rick Brown of Riverview Flower Farm in Seffner, Fla., sells Florida Friendly Plants. That may not sound unique or different, but Brown said the horticulture industry needs to do a better job at the regional level of testing, promoting and retailing plants that meet consumers’ expectations.
“One of the problems at retail is there are so many different annuals to choose from,” Brown said. “Every year there is a subtle change, a little difference. But does that change really matter in the long run to the Florida consumer who is coming in for a red flowering plant? In some cases it does, but too often we are selling consumers something that is guaranteed to fail.
“How many consumers buy a universal cook-book combination basket of annuals, take it home and hang it in the sun and watch it quickly decline? They become dissatisfied because they have to water it twice a day and some species in the combination melt quickly in the Florida heat. What they thought they were buying was a pretty flower with growth potential. Unfortunately we are selling failure over and over again.”
Brown said part of the problem is that retailers, whether large chains or independents, want to sell something new and different—the latest and greatest rather than the tried and true. Just like in other parts of the country, there are peak periods in Florida when consumers are coming into the garden centers.
“It is during those times that retailers are going to have all of that “different stuff”, including kangaroo paws, calla lilies and other flowering potted lilies in their stores,” he said. “And that is the time when we are starting to go into hot weather here in Florida. These plants aren’t going to survive for Florida consumers. A customer may take home a combination annual basket and in two days she’s wondering why she bought it.
“New lines of nationally marketed dwarf buddleia or butterfly bush grow to half the size of traditional varieties. The dwarf plants only survive half as long due to the pressures of rust, spider mites and nematodes, which is the reason these buddleia are non-existent in Florida landscapes.”

Rick Brown and Sydney Park Brown at Floriade 2012

Looking for plants that survive
Brown visited Floriade for the first time in 1982. He hadn’t been back to the event in 30 years. Floriade is a horticultural exposition which is held in the Netherlands every 10 years. This year’s Floriade covers 163 acres and is open from April 5 through Oct. 7. It consists of gardens and pavilions including Villa Flora, the largest indoor flower exhibition in Europe.
One of the primary reasons that Brown went to this year’s Floriade was to look for new and different succulents. He has been growing succulents for six years.
“You’ve never seen all of the succulents,” he said. “There is always different ways of growing them to make them look different.”
Brown said succulents are good patio plants in Florida.
“They can sit outside and be neglected, exposed to a wide range of temperatures, light conditions and water conditions. They can take a lot of stress in Florida,” he said. “That’s why people like them so much and the sales are increasing. Succulents have always been available here, but the plants haven’t been promoted.”
Brown said another reason that succulent sales weren’t strong previously was because of their limited availability.
“Now we are offering the plants in more formats, including different sizes and different varieties, and making sure they are regularly available,” he said. “That’s what I was really looking for when I went to Floriade. I was pleasantly surprised by the displays they had there and picked up some ideas that we can possibly use here.”

Bird’s Eye View of Floriade 2012

Offering consumers options
Brown, who sells his products through Home Depot, offers succulent assortments of different species in a nine-count tray. He said the assortments, which can be transplanted into the consumer’s choice of containers, are doing very well. He is also offering sedum assortments in a nine-count tray that is also selling well.
A succulent product that Brown introduced last year is the Classic Living Walls™, which is a nine-count tray that can be hung.
“It’s nine 60-mm Elle pots that stay in their cells because they are rooted so well,” Brown said. “The tray has holes that enable the consumer to hang the plants on a wall. It’s the cheapest vertical garden a consumer can buy. It sells for $15 at retail. Other vertical gardens start at $150 per square foot plus the cost for maintenance. Consumers can hang our living wall on a fence or on the side of their house.
Brown said he built some frames that are used in the stores to show how to use the Classic Living Walls™.
“It kind of has a picture frame effect that is commonly used for living walls,” he said. “It’s part of our store display. We get asked for the frames occasionally, but not often enough to consider making the frames for sale.”
Brown said he isn’t currently looking to expand the living wall concept beyond succulents because many plants have limited application in this format.
“One problem with the living wall system is the plants still have to be watered,” he said. “With succulents, the tray can be taken down, the plants can be watered, and then the tray can be stuck back up. These plants are so forgiving. If other types of plants are used, it’s usually a short-lived event. Then there is maintenance too with other types of plants.”
Plants in the Classic Living Walls™ include different species of sedums, portulaca, senecios and kalanchoes.
“There is quite a selection of succulents that look good for quite a long time,” he said. “But it has been a learning experience over the years to come up with this collection of plants that work.”
Brown said he is looking for plants that have good shelf life in the stores and also good consumer performance.
“We are going back to plants that are easy to care for and last a long time,” he said. “I hear over and over again people tell me, “Those succulents I bought two years ago keep looking great and they multiply.” I rarely hear anyone say that they killed all of their succulents.”

Plants with potential
One plant that Brown saw at Floriade in several displays was rhipsalis or jungle cactus, which is an epiphytic plant.
“The plants looked really good in vertical gardens,” he said. We could start putting some of those in our assortments. And they looked really good in hanging baskets too.”
Another crop that Brown is excited about is the Garvinea line of perennial gerbera from Florist Holland BV. He started a relationship with the breeding company when he went to the Netherlands for the first time in 1982. He began growing gerbera in 1979 but had to discontinue their production because of the heavy disease and pest loads the plants encountered in Florida.
“We started out doing tissue-cultured plants, but they weren’t really adaptable for Florida landscapes,” Brown said. “They were short-lived because the leafminers, powdery mildew and other diseases would take them out. We could keep the plants growing outdoors as long as we kept spraying them for leafminers and diseases. But once the plants got into the homeowners’ hands, they couldn’t control the pests and diseases.”
Brown said the gerbera breeding 30 years later has addressed these problems. He said he has seen some trials with the Garvinea in Florida landscapes and the initial results have been good.
“I have seen the plants in California during multiple years in established plantings and they looked great,” he said.

Cactus and Succulent Display at Floriade 2012

Brown said that numerous kalanchoes were also displayed at Floriade.
“Kalanchoes live in Florida as a perennial,” he said. “I’m familiar with the different breeders and what is being developed among the kalanchoes.”
Euphorbia, including Euphorbia milii (crown of thorns), also does very well in Florida.
“I’m always looking for new euphorbia species,” he said. “I’m looking for new ideas on presentation and how to use them in combinations. I’m trying to make a better product to try and make a happier customer.”

For more: Riverview Flower Farm, http://www.floridafriendlyplants.com./
Photos courtesy of Riverview Flower Farm.

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

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Horticultural LED Grow Lights – Grower Looks to Increase Efficiency with LEDs

Filip Edstrom at Green Masters Inc. is seeking to quantify the advantages of switching from fluorescent to Horticultural LED Grow Lights in his company’s growth chamber.

By David Kuack

Filip Edstrom has seen the writing on the wall and it says “LEDs”. Edstrom, vice president at Green Masters Inc. in Apopka, Fla., said LED lights are where flat screen TVs and laptop computers were five to six years ago.
“If you look at what the cost of flat screens TVs and laptop computers are now compared to a few years ago. It’s just a matter of time for the volume of LEDs to go up and the cost to come down,” Edstrom said. “LEDs are the next wave in lights. This is something that has been going on in Europe and we are just starting to trial the lights.”

Cyclamen being grown under LEDs in a Germination Chamber

Why LEDs?
Green Masters, which is a flowering pot plant producer, operates a 1,000-square- foot growth chamber equipped with 480 4-foot fluorescent light fixtures. The chamber is air conditioned so that it can be used for seed germination and growing on some crops including cyclamen.
Edstrom considered LEDs because he was looking for lamps that were more energy efficient and generated less heat than the fluorescent lamps.
 “The cyclamen plugs can’t be grown outside during the summer. We have to grow them inside where it is cool,” Edstrom said.  “With nearly 500 fluorescent fixtures there is a considerable amount of heat generated,” he said. “Because it is an air conditioned room, the heat factor plays a big factor in how much air conditioning is needed and how much electricity is used. Energy savings is the primary reason for looking at the LEDs.”

No wasted energy
Working with Hort Americas, Edstrom has set up a trial to compare electricity usage and plant growth under the LEDs and fluorescent lamps.
“We are using the Philips GreenPower LED production module,” he said. The modules provide the dark red and blue wavelengths that the plants use so that we are not wasting energy on light the plants don’t use,” he said. “What we have been told is that by using these certain wavelengths the plants will actually be more compact so that there will be less need for growth regulators. Also by only putting on the light that the plants need we are being better stewards of the environment because we are not wasting energy.”
Edstrom is currently running a trial using one of the benches in the growth chamber that is equipped with the LED modules.
“The fluorescents were state of the art when we installed them in June 2000. There is really nothing in regards to fluorescent fixtures that is more efficient.”
Edstrom said replacing the 4-foot fluorescent lamp fixtures with the 120-centimeter LED modules has been very simple.
“We take out the 4-foot fluorescent fixture and mount the LED module and we’re good to go,” he said. “We didn’t have to make any changes to the height of the shelving. Take the fluorescent fixture out and put the LED module in. It’s that simple.”

Side by side comparison with traditional lighting and LED grow lights

Quantifying the benefits
Edstrom said the feedback on the performance of the LEDs from the grower who oversees the growth chamber has been positive.
“The grower has said the crops under the LEDs are growing just as well, probably a little bit better,” Edstrom said. “The plants that are under the LEDs seem to be a little more compact. The plants once they are out of the growth chamber and transplanted, they are performing just as well or a little bit better. The question is the payback there?”
Edstrom said that during the summer there is not a lot of production occurring in the 8 acres of greenhouses and shade houses. The company produces about 45 different crops, including annuals, perennials and herbs.
“We are trying to determine is there a crop or certain crops that benefit being under the LEDs,” he said. “We are also trying to determine is there a difference between each of the colors or varieties.”
Edstrom said initial light measurements have shown that the LEDs are delivering 5-10 percent more light vs. the fluorescents.
“Also, if we can shave off a week’s crop time in the chamber that is worth something,” he said. “Or if we can produce more compact plants without having to apply a PGR, that’s worth a lot.
“I can determine how much electricity I’m using and how much electricity I’m saving with that fixture. The variable that we don’t know yet and why we are doing this trial is if we can improve plant quality and reduce the crop time in the growth chamber. If we find that certain crops do better under the LEDs, those plants will go under the LEDS. For the others where there isn’t a big difference, those we’ll keep under fluorescent lamps.”
Edstrom said the initial cost of the LED lamps has come down and as the price continues to drop it will make financial sense to replace the old fluorescent fixtures.
“If we were building a brand new growth room today and we had to buy the bulbs and fixtures, we would choose the LEDs even though there is higher investment cost,” he said. “The payback would be much quicker.”

Gerberas being grown under Horticultural LED Grow Lights

For more: Green Masters Inc., (407) 889-2416; www.greenmastersinc.com. Hort Americas, www.hortamericas.com; infohortamericas@gmail.com.
David Kuack is a freelance technical writer in Fort Worth, Texas, dkuack@gmail.com.

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

OFA Short Course 2012 – Hydroponic Substrates, LEDs and Orchids

Hydroponic Cucumbers Propagated in XL-Coir Plugs from Hort Americas
Hydroponic Cucumbers Started in XL-Coir Plugs under LED Grow Lights

Hort Americas is spending the next couple of weeks preparing for the 2012 OFA Short Course in Columbus Ohio. (http://ofashortcourse.org/)

Please come visit us in booth 1051.  You will have a chance to see many crops propagated under LEDs, new hydroponic substrates and a new Orchid growing media.  You will also have a chance talk to Hort Americas about ideas behind vertical farming, urban agriculture, commercial hydroponic greenhouse production.

We hope to see you there.

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

Purdue University investigating the effects of LEDs

Below is a press release from Philips Horti (responsible for the Philips GreenPower Horticultural LEDs.)


Hort Americas is very proud to be very involved with this project and looks forward to speaking to many of you about this trial and others at the OFA Short Course 2012.
_________________________________________________________________________________

Now that Philips’ LED range has been certified for the American market a number of projects have immediately been started. One of them is taking place at Purdue University in the United States, to investigate the effects of LEDs during floriculture young plant (plug) production. Purdue started in 2010 with a four-year United States Department of Agriculture (USDA) Specialty Crops Research Initiative grant to improve and evaluate LED lighting for greenhouse use. The project is titled “Developing LED Lighting Technology and Practices for Sustainable Specialty-Crop Production.” The goal is to increase greenhouse yields and decrease producers’ energy costs. Cary Mitchell, a professor of horticulture and project director for the grant, said Purdue researchers will collaborate with Rutgers University, the University of Arizona, Michigan State University and Orbitec Technologies Corp. “We believe that LED supplemental lighting with a high red and blue ratio will produce high-quality marketable plugs at an earlier date than HPS supplemental lighting, the current industry standard.”

Philips Lighting is happy to cooperate with Purdue University to map out the possibilities for using LEDs in the greenhouse, with a view to finding a sustainable method of producing crops in a greenhouse. This will benefit the horticulture sector in America. The LED solutions of Philips lighting are based on years of experience and close co-operation with the horticultural world. Successful field tests with growers and breeders around the globe gave them an unparalleled knowledge of the growth effects of lighting on different crops throughout their growth cycle. It’s allowed Philips to create a unique approach to lighting with specific “light recipes” that can be tailored. A wide variety of crops can benefit from LED while it is possible now to grow in multilayer environments without any daylight. This is also proven in practice for the tissue culture segment as well.

“The high-intensity discharge lamps used today are inefficient. When you have acres and acres of greenhouses with these lamps in them, it really adds up,” Mitchell said. “With LED lighting, we should be able to do as well or better with much less energy.”
The specialty crop industry plays an enormously important part in American agriculture and is valued at approximately $50 billion every year. These projects will be key to providing specialty crop producers with the information and tools they need to successfully grow, process, and market safe and high-quality products. Mitchell’s work will include testing LED lighting on high-wire tomatoes. Those plants can grow taller than 20 feet, and traditional overhead lighting doesn’t reach the lower parts of many plants. Mitchell believes that using LED lights on the sides of plants will increase photosynthesis and flowering, improving yield.

Erik Runkle at Michigan State will test flower initiation of ornamental crops with different colors of LEDs, as well as performing project outreach. The Phillips and Purdue project will managed by Assistant Professor Roberto Lopez and graduate student Michael Ortiz. This research project will compare young bedding plant growth and development under traditional high pressure sodium lamp lighting to different combinations of red and blue Philips LED lighting. The goal is to find a sustainable lighting strategy of producing high-quality young plants in the shortest amount of time that will benefit the commercial floriculture in a greenhouse industry in America by consuming less energy. During the first phase of the trials the top 10 bedding plants produced in the United States will be investigated, such as petunias and geraniums. These bedding plant crops represent a large proportion of the total floriculture sector in America.  Philips GreenPower research modules are being used for the trials at Purdue University. The advantage of this lighting solution is that they are dimmable and available in various colors, including deep red, blue and far red. The initial test results are expected in June and final results are expected at the end of 2012. Hort Americas, Philips’ LED Horti Partner for the United States, is involved in this project, as well as Dr. Johann Buck as Technical Services Manager.

For further information contact:
Hort Americas at infohortamericas@gmail.com

Keith Robinson, Ag Communications
Purdue University
Tel.: (765) 494-2722
E-mail: robins89@purdue.edu
www.purdue.edu/newsroom/

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

Cutting Propagation in a Snap!

Ecke Ranch has developed a packaging system for shipping
offshore callus cuttings that can help growers lower input costs and reduce
production time by two weeks.
By David Kuack
Ecke Ranch offsite manager Jon-Paul Williams said the
biggest change that had occurred in the propagation of vegetative cuttings over
the last 25-30 years was when companies supplying domestic growers moved to
offshore production.
“The process of propagating those cuttings really hasn’t
changed,” Williams said. “There have been other advances in propagation
programs such as tissue culture, but in terms of how the cuttings are handled
very few changes have occurred.”
Once Ecke, which is headquartered in Encinitas, Calif.,
began to do offshore propagation, chief operating officer Steve Rinehart began
to ask what the company could do differently in regards to handling vegetative
cuttings.
“Steve had this vision of growers being able to receive
cuttings that were pre-stuck, that could be placed on the bench to root and
have the same results if they stuck the cuttings themselves without having the
labor costs and production input costs,” Williams said. “We have been working
with a company for about eight years to develop different kinds of packing
materials that could be used with offshore cuttings. Two years ago we
introduced the Ecke SNAP System™ (http://www.ecke.com/ecke/?page_id=1042) that
consists of a packing material for offshore callus cuttings that acts as a
rooting medium once the cuttings arrive here in the United States.”
Easy to root
Williams said that when Ecke began working on the SNAP
System the company started by trying to merge packing foam with a growing
medium.
“The company we worked with was familiar with plants,” he
said. “We worked with a number of different iterations of this product to get
to a material that we were satisfied with. The most important factor was once
the cuttings arrived on shore we wanted them to root well. The Ecke SNAP System
provides a really good environment for root development. There is a lot of
porosity, good water-holding capacity, but also good aeration.”
Clean callus
cuttings
Ecke has propagation facilities in Guatemala and Mexico.
Geraniums, poinsettias and spring annuals are stuck in a different medium prior
to being packed in the Ecke SNAP System.
“Cuttings are not callused in the SNAP packing material,”
Williams said. “Each variety has a different callusing time, usually anywhere
from 10 days to two weeks. Once the callus is established the cuttings are
removed from the medium and placed in the SNAP packing material.”
Williams said there are a couple of reasons the cuttings
are callused in a different medium.
“We want to ensure the cuttings do not root in the
packing material offshore,” he said. “We want to make sure we always comply
with all USDA requirements.”
Another reason for callusing the cuttings in a different
medium is to keep them clean.
“We don’t want algae or other organic matter in the
packing material or callus protector as we call it,” Williams said. “We want
the cuttings and packing material to be as clean as possible.”
Advantages of the SNAP
System
Williams said that like unrooted cuttings processing the
callus cuttings offshore is a quick process. For most customers there is
usually a 36-hour turnover. When a SNAP System order arrives at a customer’s
facility, they receive three strips of 26 cuttings in a tray that holds 78
cuttings.
“The advantages for the customer is that we have put the
first two weeks of production on in Guatemala or Mexico,” Williams said. “The
most challenging part of propagation for many growers is the first two weeks
typically for most crops. During this time they require the most heat, the most
intensive care. With the SNAP System that part is done offshore. Growers save
two weeks of propagation and the inputs that they would require during those
two weeks.”
When the cuttings arrive they are already in a pre-stuck
tray.
“It’s not a medium, it’s a packing material that doubles
as a medium,” Williams said. “When the cuttings arrive growers don’t need to
buy a tray or a rooting medium so they are saving on their inputs.”
Another advantage is the reduction in labor costs
involved with sticking cuttings.
“A typical grower sticks about 1,000 cuttings an hour,”
he said. “Depending on the variety it could be more or it could be less. So the
grower doesn’t have to pay someone to stick the cuttings. This helps to reduce
shrink losses on the bench.
“The advantage with the SNAP system is a grower is
handling 26 cuttings at a time. If a grower using the SNAP system can handle
500 trays in one hour that results in 13,000 cuttings being stuck in an hour
instead of 1,000 unrooted cuttings. That is a significant reduction in the
labor demand.”
Another advantage to the SNAP System is that all of the
grading has been done offshore eliminating the need for growers to grade the
cuttings once they arrive.
“They also don’t have to worry about inconsistent
callusing because that is done offshore,” Williams said. “The cuttings can be
planted, placed in the greenhouse, and then they move right into the next two
weeks of rooting. Typically during the two weeks that the callused cuttings are
rooting there is usually less heat needed, less risk and less labor during the
final rooting stage. We are trying to eliminate as many of the variables as
possible.”
Overcoming
propagation deficiencies
Williams said for those growers who may not have all the
right conditions for handling callus cuttings, the SNAP System may be a little
more forgiving.
“For growers who are doing direct stick the SNAP System
may work very well because sometimes growers have a tendency to over saturate
the medium.” Williams said. “This commonly occurs with poinsettias because
growers are sticking cuttings during the hottest time of the year. The SNAP
System can provide a little more flexibility preventing the area around the
base of the stem from becoming oversaturated. Also, growers who are doing
direct stick with poinsettias can’t afford to fail because they are typically
on a tight schedule.”
Other growers have found the callused cuttings in the
SNAP System to be a better alternative to rooted cuttings.
“We have customers in the Southwest who do a lot of
production in the summer, items like geraniums that require propagation during
a period when the outside temperature is 100°F and very low humidity,” Williams
said. “Unrooted cuttings struggle in this type of environment.”
Williams said growers in the Southeast have a similar
concern.
“We have customers who have issues producing geraniums
because of the high humidity levels during the summer that are needed for fall
orders,” he said. “They have found that the SNAP System is a very flexible
system for them.”
Williams said that other plant species that are
challenging to root any time of the year are easier to callus offshore.
“Some of the aromatic crops like agastache, lavender and
rosemary, these plants can have issues sticking them as unrooted cuttings,” he
said. “We can harvest the cuttings and stick them offshore and once they are
callused they don’t have that same sensitivity to shipping. The SNAP System is
also enabling us to look at some crops that in the past were difficult to root
or ship. With the SNAP System we can look at those crops again because this system
may eliminate some of those issues and allow us to add them to our offerings.
For more: Ecke
Ranch, (760) 753-1134; www.ecke.com.

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

Improving Greenhouse Production with LED Lights

U.S. researchers are looking at the potential benefits to
the propagation and production of greenhouse ornamental and vegetable crops
using LED lights.

By David Kuack
Although U.S. researchers have started studying the
effects of LED lights on the production of greenhouse ornamental and vegetable
crops, much of the data being used by American growers comes from studies done
in Europe. Purdue University horticulture professor Cary Mitchell said that studies
currently being done in the United States will provide growers with information
that is relevant to their production and climatic conditions.
Mitchell is leading a team of university researchers who
have received a $4.9 million grant, including $2.4 million from USDA, to study
LED lighting for greenhouse applications. Mitchell along with Purdue
horticulture professor Roberto Lopez is working with scientists and engineers at
the University of Arizona, Michigan State University, Rutgers University and
Orbital Technologies Corp. Mitchell is working with graduate student Celina
Gomez to study the impact of LED lights on the propagation and production of
high-wire tomatoes. Lopez and graduate students Christopher
Currey and Michael Ortiz are studying the use of LED lights on bedding plant
cuttings and plugs.
Propagation trials
Due to limited greenhouse research space, Gomez is using
one bench to compare the effect of providing supplemental light from a high
intensity discharge lamp or from LED lights with control plants that receive
only natural daylight. During the first year of the propagation study, Gomez is
conducting an experiment every month. The experiment includes a control group
of tomato seedlings that receive no supplemental light, an overhead HID lamp
that provides the industry standard and overhead LED arrays that provide three
different ratios of red to blue light.
“The propagation experiment is repeated for three weeks
every month,” Mitchell said. “We are measuring the differences in plant growth
from one month to the next. As we enter spring, the ambient light levels are
increasing. Gomez will measure the daily light integral (DLI) that is occurring
and the different red/blue ratios and what the plants prefer and determine what
they need. In addition to the plant metrics being collected, we are also
measuring the amount of electricity used for supplemental lighting.”
After the tomato seedlings reach the stage at which they
would be grafted onto the rootstock, data is being collected including plant
dry weight, height, stem diameter, leaf span and leaf area.
Mitchell said the propagation area that is equipped with
the lights receives 5 moles per square meter per day of supplemental light in
addition to the natural solar daily light integral that varies throughout the
year.
“Since we have only done the experiment a couple of times
so far this year, we’ve yet to see what kind of plant response pattern emerges,”
he said. The supplemental light we are providing now might not be enough light
during the dead of winter. Any benefits of supplemental light that occur during
the winter should disappear as the trials move later into spring. Once we have
obtained a full year profile of seedling response, we will be able to determine
the optimum amount of supplemental light to apply each month.
“One of the best management practices that we hope comes
of this long term study is to determine at what point it is important to use
supplemental lighting, as well as when it is no longer useful to do so.”
For the propagation study the tomato seedlings are
receiving supplemental light for 23 hours a day in order to achieve a daily
light integral of 5 moles per square meter per day.
Tomato seeds are being germinated in a substrate called
steadyGROWpro plugs. Six different tomato varieties are being tested: ‘Success’,
‘Komeett’, ‘Maxifort’, ‘Sheva-sheva’, ‘Liberty’ and ‘Felicity’. Seedlings of ‘Success’
and ‘Komeett’ are used for the production study after being grafted onto ‘Maxifort’.
These varieties were recommended by Marco de Bruin at Bushel Boy Farms in Owatonna, Minn., because they have
different growth habits.

Production trials
In the production experiments the grafted seedlings are
being transplanted into Coco Agro coir slabs.
“The lighting treatments containing both test cultivars
are blocked into separate half rows in order to determine if there are position
effects within the greenhouse that could affect yields,” Mitchell said.
The plants are being provided with supplemental light
twice a day. He said they are applying a daily light integral of 9 moles per
square meter per day.
“In early March we were lighting for 12 hours per day,”
Mitchell said. “Lighting usually starts well before sunrise and begins again
before the sun goes down.”
The first production study in 2012 began at the end of
January. Mitchell said the tomato plants that had received supplemental light
treatments were already setting fruit in early March.
“The control plants that didn’t receive any supplemental
light were way behind,” he said. “They were barely setting fruit. That’s what
you would expect in a cloudy region like Indiana.”
The first production experiment of 2012 will be
terminated after six months and a second will begin immediately. Mitchell said
the second experiment will be the exact opposite of the first in terms of solar
daily light integral changes.
“We want to see what challenges there are both with the
propagation and the production starting in the summer and going into the winter,”
he said. “If production is started in the greenhouse in July, the plants are
going to be receiving a lot of sunlight. As the photoperiod starts to shorten going
into fall that is when supplemental lighting will be more valuable.
“We are hoping to come up with recommendations for
growers in this region or in any other northern region that has cloudy weather regarding
when is the best time to start lighting their crops. We are also looking at
timing the production so that growers are not competing with home-grown or
field-grown tomatoes. That way the greenhouse growers are not competing with
availability and price for what’s being grown in backyards or in the field.”

Priming the ornamentals
propagation pump
Purdue horticulture professor
Roberto Lopez and graduate students Christopher Currey and Michael Ortiz are
studying the effect of supplemental light on the propagation of ornamental
vegetative cuttings and plugs.
“We’re looking at the top three
flowering crops that are produced from vegetative cuttings, which are
geraniums, petunias and New Guinea impatiens,” Lopez said. Currey and Ortiz are
comparing rooting, dry mass accumulation and other quality parameters under red
and blue LED lights to high pressure sodium lamps. Initial trials with cuttings
have shown that there are not a lot differences in terms of rooting time and
quality between the two light sources. Additionally, preliminary data is
showing no differences in the time to flower or quality of cuttings propagated
under the various LED lights and high pressure sodium lamps for the three
annual crops.
“Initially, the results
are very similar for
both rooted cuttings and finished plants,” Lopez said. “But this is very
preliminary. There were really no differences seen for these three crops. What
we were mainly trying to achieve was a certain daily light integral with both
the high pressure sodium and red and blue LEDs. With the additional trials that
we will be doing we will also be looking to quantify the amount of electricity
used by the high pressure sodium lights and the LEDs.”
Best timing,
amount of light
Lopez said none of the vegetative cuttings received
supplemental light during the first seven days of propagation because that is
when the cuttings are forming callus.
“A grower typically wouldn’t use lights during this
period unless the light level was really low,” he said. “During that period the
grower is trying to baby the cuttings to get them to form callus. If the light
level is too high during this period the cuttings could be stressed. After a
week the cuttings begin to form roots and start to photosynthesize. A grower
can maximize photosynthesis during rooting by increasing the daily light integral.”
Currey’s research and studies
Lopez performed at Michigan State University indicate growers should
provide a daily light integral of between 8-10 moles per square meter
per day to be able to increase rooting and the overall quality of the cutting.
Lopez and Ortiz are also
testing LED lights during plug propagation of celosia, cosmos, impatiens,
geranium, marigold, pansy and petunia.
“One of the biggest challenges with
plug production of annual bedding plants is keeping the plugs compact,” Ortiz
said. “Compact plugs ease transport in boxes and allow for a higher volume of
plugs to be transported at one time. This is definitely something to consider
as fuel prices continue to rise.
“Plugs are often grown in dense
288- or 504-cell trays that promote rapid stem elongation. We are using red and
far red LEDs in end-of-day treatments in an attempt to manipulate the
phytochrome-mediated genes that are responsible for stem elongation under dense
planting conditions. If LEDs can be used to control seedling height, the
industry can decrease its reliance on plant growth regulators.”
Lopez and Ortiz are also
investigating red and blue LEDs as a supplemental lighting source during winter
bedding plant plug production.
“The goal behind this
experiment is to quantify root development under different ratios of red and
blue LED light and high pressure sodium light,” Ortiz said. “We also are also
trying to determine if supplemental light from LEDs can offer more rapid root
development than light from high pressure sodium lamps. This can make a big
impact on energy use in the industry.”
Lopez said producing cuttings is much different than producing
plugs.
“With plugs a grower is starting out with plants that
have roots,” Lopez said. “A grower may end up being able to delay the sowing of
the plugs if he is using lights. We may find that the LEDs might prove to be
even more beneficial with plugs than with cuttings.”
For more: Cary Mitchell, Purdue
University, Department: Horticulture and Landscape Architecture, (765) 494-1347;
cmitchel@purdue.edu.
Roberto Lopez, Purdue University, Department of Horticulture
and Landscape Architecture, (765) 496-3425; rglopez@purdue.edu;

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

Horticultural LEDs in the News

Recently the popularity and interest of LED grow lights has increased dramatically.

To read some of these stories, check out the following links:

Learn about LED Lights installed in a Chinese University Greenhouse – http://www.lighting.philips.co.uk/application_areas/horticultural/news/201203-Philips-LEDs-in-Shanghai-Jiaotong-University-new-intelligent-greenhouse.wpd

Learn about Philips GreenPower LEDs in the Dutch Pavilion at Floriade 2012 –
http://www.lighting.philips.co.uk/application_areas/horticultural/news/201204-Philips-GreenPower-LEDs-in-Dutch-pavilion-at-Floriade.wpd

Learn about LEDs installed at the Stockbridge Technology Center in the United Kingdom –
http://www.lighting.philips.co.uk/application_areas/horticultural/news/201203-LED-research-facility-to-open-at-Stockbridge-Technology-Centre.wpd

Learn more about LEDs used at Kieft Seeds – http://www.lighting.philips.co.uk/pwc_li/main/shared/assets/downloads/pdf/horticulture/en/2012-04-FloraCultureInt-Philips-is-miles-ahead-in-LED-lighting-(Kieft-Pro-Seeds).pdf

Learn more about LEDs in Greenhouse Grown Tomatoes –
http://www.lighting.philips.co.uk/pwc_li/main/shared/assets/downloads/pdf/horticulture/en/201111-HHTR-Interlighting-for-tomatoes.pdf

Additional information and questions:

Please contact infohortamericas@gmail.com.

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

Creating the Right Orchid Mix

Hort Americas partners to produce an orchid growing substrate made with pine bark

Phalaenopsis
orchids account for the largest wholesale value ($96.8 million) of the orchids
sold in the United States, according to the USDA
2007 Census of Agriculture
. Phalaenopsis orchids are unlike most other
ornamental flowering plants produced by commercial growers. In their natural
habitats, most of these orchids are epiphytic, living on trees with their roots
exposed to the shaded, humid environment in which they thrive.
Orchid mix considerations
Steve Jarahian,
director of technical services at Oldcastle Lawn & Garden Inc., said the
growing medium used to grow phalaenopsis orchids is more open than traditional
peat-perlite mixes.
“When these
orchids are grown in a container, we are trying to provide an environment that
will give the roots enough air,” Jarahian said. The other criteria required for
traditional growing media still apply. The mix has to have the ability for the
orchid roots to absorb water and nutrients. Depending on the type of orchid
grown, if it has a very coarse root system, the plants need support.”
Jarahian said the
bark typically used for orchid growing mixes in the United States has come from
European or local sources. Growers on the West Coast have used redwood bark,
fir bark or osmunda fiber. He said other components of orchid mixes have
included expanded shale, clay and activated charcoal.
“With the
difficulties and cost of freight for shipping bark from Europe or from other
parts of United States, what we are trying to do is duplicate these other
growing mix components using locally-grown pine bark,” he said. “We are doing
something that is not typically done with pine bark.”
Oldcastle
Lawn & Garden has partnered with Hort Americas to develop and produce an
orchid growing mix made from larger size pine bark particles. Jarahian
considers the phalaenopsis orchid growing substrate that is available from Hort
Americas for commercial growers to be a medium-coarse mix.
“The particular
bark that we are working with is about 5/8- by ½-inch thick,” he said. “It’s a
solid thick particle so that it can provide enough air. It’s almost as thick as
it is wide.
“Other growing
mixes may contain bark particles, but they tend to be thin, smooth and
plate-like. The Hort Americas orchid mix bark is fairly light and has a rough
surface. That helps with the air space and how the roots adhere to the surface
of the particles. This bark wouldn’t be used to grow geraniums, poinsettias or
mums. Also, the orchid mix pine bark is not aged.”
Jarahian said
that the orchid mix bark comes from pine trees that are over 15 years old. Bark
from younger trees tends to be more flake-like. Multiple screenings are needed
to produce a consistent particle size with the thickness that is needed.
Jarahian said he
prefers the pine bark used in traditional growing mixes to be between nine to
12 months old. For the orchid mix, the bark needs to be no older than two to
four months old.
“Bark that is 12
to 18 months old is going to absorb water and it’s going to break down,” he
said. “The newer the bark the more consistent the mix will be in regards to
wetting and drying. If the bark absorbs too much water, then the grower can
encounter problems with Phytophthora root rot. Also, since older bark is going
to absorb water, fewer pallets of the orchid mix will be able to be shipped per
truckload because of the additional weight raising the freight costs.”
Other mix components
A spongy, fibrous
sphagnum moss imported from Chile is also incorporated into Hort Americas’
orchid mix.
“It’s the actual
sphagnum plant, not the decomposed sphagnum peat used in traditional potting
mixes,” Jarahian said. “The moss is added to provide some moisture holding
capacity.”
He said the
amount of moss that is incorporated can be reduced to increase the air space in
the mix. Lime is also added to the mix because pine bark tends to have an acid
pH.
Jarahian said
initially a starter fertilizer charge was added to the mix. The fertilizer is
no longer incorporated enabling growers to better control the soluble salts
level.
“We were putting
in a nutrient charge, but because of how pine bark ages, there was some
variability in the soluble salts level. On occasion a spike in the soluble
salts was hindering plant rooting.”
Johann Buck, Hort
Americas technical service manager, said the orchid mix produced in Europe
contains a starter fertilizer charge because without it growers were
experiencing a one to two week delay in production.
“This is due to
nutrient tie-up, usually nitrogen,” Buck said. “The age of the bark used in
Europe is much older than the U.S. bark. This means there is little fluctuation
in electrical conductivity (EC), so the European mix manufacturers can add a
starter charge.”
Buck said since
the U.S. bark is younger and due to the nature of the aging process, there can
be undesirable increases in the EC level.
“When orchid
plants, especially young plants, are exposed to EC levels above 0.8
milliSiemens per centimeter (mS·cm-1), root burn can occur,” he
said. “This can delay growth. Other containerized crops can tolerate an EC of
0.5 to as high as 3 mS·cm-1. With orchids the EC level has to be
constantly monitored and should be in a range of 0.5 to 0.8 mS·cm-1.
Everything that is done from week 1 to the day the plants are harvested impacts
them.”
For more: Steve Jarahian, Oldcastle Lawn & Garden Inc., steve.jarahian@oldcastleapg.com;
www.jollygardener.com. Johann
Buck, Hort Americas, jbuck@hortamericas.com;
www.hortamericas.com.

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

Organic Fertilizers with Dr. Danielle Treadwell at the University of Florida

Florida producers adding structures and organic
production
By David Kuack
An increasing number of Florida fruit and vegetable producers
are looking at implementing some type of protected environment production.
University of Florida-IFAS associate professor Danielle Treadwell said producers
are looking at a variety of structures including greenhouses, high tunnels and
hoop houses. She said some producers are looking at taking a portion of their
field acreage and adding covered production.
The reason for adding the structures varies. Treadwell
said producers are looking to take advantage of new or expanding markets for
specialty crops. Other producers plan to extend the season for crops that can
be damaged by freezing temperatures. Some producers are looking for
opportunities to expand their product mix with organically-grown crops.
Treadwell said market demand is the most important driver
for the construction of greenhouses, but that water is also a key factor.
“When you start talking about high tunnels and hoop
houses, producers are looking for water savings through better freeze
protection,” Treadwell said. “When there is a freeze in Florida the protection
is coming from overhead irrigation. A single farm can use millions of gallons
of water per freeze event. Producers of high value crops like blueberries and
strawberries are exploring high tunnel production to moderate the temperatures
under these structures and to apply less water.
“Florida producers are seeing increased restrictions on
water use,” she said. “They want to be ready. There are 18 million people in
the state so there is a high demand for water.”
Increased interest
in organic production
Some of the producers who have used traditional methods
and inputs are looking at taking advantage of the increased demand for organic
products. Treadwell said some of these producers have customers asking for
these products while others are looking to diversify their product mix. She
said this has led to producers asking suppliers for organic fertilizers
specifically for their crops.
“There are more manufacturers that are developing organic
fertilizers,” Treadwell said. “Some companies that have historically served
conventional farmers are now expanding their offerings because their customers
are diversifying.”
Treadwell said those producers who have adopted biologically-based
management strategies such as biological pest controls should have an easier
time converting to an organic production system.
“Producers who grow fruits and vegetables organically are
using biological controls,” she said. “There are very few controls approved for
use with conventional pesticides and even less for growing organically. When
you have an organic system in the greenhouse you have to rely on biological
controls. If you have an established biological program in the greenhouse you
are good to go. Through the efforts of university
researchers
(http://ocextension.ifas.ufl.edu/uf_workshop/pdffiles/Treadwell_Beyer_UFW222_2011.pdf)
and the producers we have done it and we have done it well here in Florida for
a number of years.”
Incorporating
organic fertilizers
Treadwell said producers seeking to implement organic
production and who already have a biological pest management system in place
should only have the fertilizer program to work out.
“How to keep the biology in the pot optimized so that
nutrients are transformed at a pace that the plants need–that’s the
challenge,” Treadwell said. “It’s finding that sweet spot of which fertilizer
to use, what analysis, and really honing down that application strategy.”
She said there are number of manufacturers that will
custom mix dry granular as well as soluble fertilizers that are compliant with
the USDA’s National Organic Standards.
“Producers can develop a relationship with a supplier
that does custom mixes and start experimenting to determine the best blend for
their crops. Then the next step is to put together a system of mixing tanks,
injectors and emitters that will deliver the fertilizer without clogging.”
Treadwell said it is best to mix the exact amount of
fertilizer solution that is needed. Holding the fertilizer solution at high
temperatures in the greenhouse can increase the rate of biological activity and
negatively impact the quality of the products.
A number of techniques have been tried at the university
to try to keep the fertilizer solution cool for a longer period of time. These
have included placing pop-up canopies over the tanks and injectors in the
greenhouses, wrapping the fertilizer tanks in reflective Mylar mulch and
submerging the fertilizer tanks in kiddy pools that contain recirculated well
water.
“Because the fertilizers used in organic systems are
plant- and animal-based nutrients with some minerals added in, these liquids
are suspended particulates in solution,” Treadwell said. “It’s not like
ammonium nitrate, which is a salt with ions that truly dissolve in water.”
Finding injectors that can handle the particulates in organic
solutions can be an issue.
“The injectors do clog,” Treadwell said. “It’s also very
easy for algae to grow so it’s really important to flush the injectors well
after applying the fertilizer solution.”
She said high greenhouse temperatures can also take a
toll on fertilizer injectors.
Organic fertilizer
factors
Treadwell said because most organic fertilizers are complexes
of multiple ingredients, the availability of individual ingredients may occur
at different rates. For this reason, she said, producers need to pay attention
to electrical conductivity levels during the season to have a better
understanding of release rates.
Even with the potential for excessively high or low soluble
salts, Treadwell said a limiting factor for certified organic fertilizers can
be the amount of nitrogen they contain.
“In compliant organic fertilizers the highest nitrogen
analysis available for dry granular fertilizers is around 15 percent,” she
said. “For solutions, the highest nitrogen analysis is around 5 percent. If
it’s greater than 15 or 5 percent, producers need to be sure that the
fertilizer is USDA compliant before they use it. That means a producer has to
apply quite a large volume of fertilizer in order to sustain the rapid growth
of the plants in a greenhouse because the temperatures are hot and the plants
are growing fast. It can be a little tricky, but it can be done. It just
requires a lot of management.”
Treadwell said using a combination of organic granular
and liquid fertilizers is helpful.
“It’s helpful to have a steady supply of nutrients in the
growing media using the granular forms and then supplementing with the liquid
form periodically through the season depending on the plants’ needs,” she said.

For more:
Danielle Treadwell, University of Florida, Department of Horticultural Sciences, (352) 273-4775; ddtreadw@ufl.edu.
David Kuack is a freelance
technical writer in Fort Worth, Texas, dkuack@gmail.com.
Organic Fertilizers use in strawberries (Spanish).


The University of Florida has produced a series of online
educational videos called Virtual Field
Day
(http://vfd.ifas.ufl.edu/). The videos present information on a variety
of topics (hydroponic production systems, soilless media, nutrient solution
delivery, pest management, harvesting and marketing) with visual support
including instructional how-tos. One of videos was made by associate professor
Danielle Treadwell who discusses the use
of organic fertilizers
(http://virtualfieldday.ifas.ufl.edu/gainesville/organic_produce/selecting_fertility_media.shtml)
in greenhouse vegetable production.Visit our corporate website at https://hortamericas.com

Choosing an organic fertilizer

By David Kuack
Growers looking to make the switch from traditional
inorganic fertilizers to organic fertilizers might feel a bit overwhelmed when
considering the number of options available. Kansas State University
horticulture professor Kim Williams said growers looking to use organic
fertilizers should start out trialing a small number of plants to avoid
sizeable losses. She also recommends that growers start with a commercially
blended organic fertilizer rather than a straight product like manure.
“It’s going to take some practice, some trialing, so
growers don’t burn their plants because that is another transitional change
compared to conventional starter nutrient charges,” Williams said. “Where a lot
of growers can get into trouble is incorporating manure or composted manure
into organic substrates as a starter nutrient charge. That is something that I
would not recommend doing for the novice organic grower. What sometimes happens
is high levels from the manure burn young seedlings. Fresh and incompletely
composted manure can also introduce disease problems and/or weed seeds into the
production system as well.”
Williams said that there can also be a lot of variability
in nutrient availability from products like bone and blood meal depending on
the source and their particle size.
“Different sources of bone meal for example are going to
have significantly different nutrient release rates,” she said. “This can
result in an excessive nutrient release too early in the production cycle. If
the grower is not expecting this, he can lose a lot of plants depending on
their stage of growth. Seedlings and plugs are much more sensitive than older
plants to high salts. It really does take some practice with a new nutrient
source.
“If a grower uses a commercially blended product as
opposed to manure from his neighbor’s horse farm, he is going to avoid
potential problems. I would recommend a commercially prepared organic product
like composted and processed turkey litter that is not going to contribute
disease problems.
Williams said growers should start with an organic
nutrient source that has a known N-P2O5-K2O
ratio and then trial it at a few different rates with a small number of plants
before using it extensively.
Supplying enough
nutrients
Williams said that growers who incorporate a preplant
organic fertilizer into their growing mix still need to provide additional
fertilizer to the production system.
“I have yet to use an organic nutrient source that didn’t
provide an initial nutrient release that was very significant,” she said.
“Nutrient release then tends to tail down quite a bit depending on the rate of
application, temperature and media moisture content, all of which influence
microbial breakdown of the organic material and thus nutrient release.
“This can be a challenge for growers. There is an initial
spike of nutrients released so growers have to protect against that by reducing
the rate of what they are adding as a preplant. But then their crops are going
to need supplemental nutrition later on when the soluble fraction of the
organic fertilizer is used up.”
Research conducted by Williams showed that organic
fertilizers bring a lot of microorganism populations with them into the
production system. It is these beneficial microbial populations that are then
contributing to the nutrient conversion.
“In our experience so far with organic fertilizers it has
not been necessary to do additional microbial inoculations when organic
fertilizers are used,” she said. “Growers who apply a preplant dry organic
fertilizer will start to get microbial activity even before applying a
supplemental liquid organic fertilizer. Growers who incorporate a preplant
fertilizer are providing microorganisms with a food source of carbon so that
the populations can really take off much more quickly than if they applied
conventional inorganic fertilizers. However, the disadvantage with the organic
fertilizers is that they are less predictable for growers. Managing nutrition
is more challenging since the growers are relying on microbial release of
nutrients from the organic sources.”
Williams said some growing media manufacturers are
producing organic potting mixes into which an organic fertilizer is
incorporated as a starter nutrient charge.
“Media manufacturers put in a preplant organic fertilizer
to provide a starter charge,” she said. “Then the growers can decide on a
schedule with supplemental soluble feed.”
Dry and liquid
formulations
Growers have the choice of both solid and liquid
formulations of organic fertilizers. Williams said many growers are applying a
dry preplant amendment to their potting mixes.
“Some growers have chosen to incorporate solid forms of
certain fertilizers such as bone meal that have a smaller nitrogen component or
something like feather meal that is going to take some time to break down.” she
said. “These growers then supplement with a liquid organic fertilizer.”
Williams said that organic fertilizer manufacturers are
making products that are more convenient to use and more consistent in their
nutrient formulations.
“There are some fertilizers that have more complete
nutrient formulations. These are the result of digested or fermented
combinations of a number of organic materials,” she said. “These types are
really the only way that a grower can get a somewhat balanced N-P2O5-K2O
ratio in a fertilizer.”
Williams said most of the commercial organic fertilizers
are very shelf stable. Because the formulations are so concentrated, microbial
populations cannot grow in them.
“When growers start to dilute these fertilizers in a
stock tank is when other micro-organisms can come in and start feeding on the
nutrients before the fertilizer solution is applied to the crops,” she said.
“When a fertilizer is taken out of the concentrated container and diluted down
in a stock tank is when organisms can grow in it. Growers have said that within
a couple of days organisms will be growing in the stock tank.”
Williams said to avoid problems with organic fertilizers
going bad, most growers mix up just enough tank solution to feed the plants
they want to fertilize that day.
“That’s also a disadvantage with organic fertilizers.
With inorganic fertilizers a grower can make up a month’s worth of stock
solution and let it sit there and not be concerned with it going bad,” she
said. “With organic fertilizers a grower has to mix up just enough to feed his
plants and if he has to do that every few days that’s a lot more work.”
Williams said another thing growers should consider when
choosing a soluble organic fertilizer is whether it can be used with their
current injector equipment.
“The grower needs to ask the question, “What fits into my
liquid fertilization system in terms of how I mix up liquid fertilizer and how
I apply it to my crop?” Some injectors will handle organic fertilizers better
than others. Some fertilizers can clog injector systems.”
Hydroponic
production
Williams said growers using conventional hydroponic
production systems generally tend to use fertilizers that contain very little
ammoniacal nitrogen compared to nitrate nitrogen. The reason is that the plants
can run into ammonium toxicity problems.
“A hydroponic system doesn’t have the buffering capacity
of a growing medium that has some cation exchange capacity,” she said. “The
substrate would hold some of the ammonium and not make it available for plant
uptake.
“If ammonium is in solution then it’s available for the
plant roots to take up. Ammonium can’t be stored in the plant cells like
nitrate can. If plants are absorbing too much nitrate, that’s not really a
problem because the excess can be stored in the vacuoles of the plants’ cells
and it’s not going to cause toxicity problems.
“When plants absorb ammonium they need to assimilate it
right away, their cells can’t store it. If the plants can’t use the ammonium
then it’s going to damage the cells and burn the plants.”
Williams is starting a hydroponic research project to
determine the differences in growing butterhead lettuce with organic and
inorganic fertilizers and different types of microbial inoculums.
For more: Kim
Williams, Kansas State University, Department of Horticulture, Forestry &
Recreation Resources, (785) 532-1434; kwilliam@ksu.edu.

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

Growing Outside the Box: The Modern Concept of Vertical Farming for a Greener Society

(as seen at Yahoo Finance.)

DALLAS, Jan 30th 2012 — Problem: By 2050, 80% of the population
will reside in urban centers and human population will increase by about 3 billion.
Estimated amount of NEW land needed for food: about 25% more than the entire
country of Brazil, however, 85% of suitable land for raising crops is already
in use (Source: NASA), making that needed expansion impossible.
Solution: Energy-reduction technology coupled with Controlled Environment
Agriculture (Greenhouse Grown Produce, Vertical Farming, Multilayer Production)
and other highly innovative horticultural/agricultural practices.
Controlled
Environment Agriculture provides farmers the ability to cultivate in greenhouses, warehouses, or
skyscrapers, allowing them
to think in cubic feet (not square),
farm new spaces, increase crop density, decrease actual land space, and secure
larger crops. Traditional
farms

can then revert to a natural state, reducing energy costs needed to transport
foods to consumers, and significantly alleviate land issues.
The EPA
takes special notice of practices like that as they push for a major
sustainability initiative to avert the crisis of depleted land resources.
Sustainability
Principle: Our well-being depends (directly or indirectly) on our natural
environment. Maintaining conditions for humans and nature to exist in
productive harmony fulfills social/economic requirements for present AND future
generations so we will continue to have the water, materials, and resources to
survive.
Sustainability has emerged as a result of significant concerns
about the unintended consequences of rapid population growth, economic changes,
and consumption of our natural resources. The EPA controls pollution and levels
of environmental protection, drawing on scientific advances and promoting green
business practices. Artificial lighting has become of specific interest for the
success of future farming initiatives.
Hort
Americas (www.HortAmericas.com), is, quite literally, lighting and leading the way, working
with powerhouses like Philips (www.Philips.com/horti) to innovate LEDs for Horticulture around
the world, reducing costs and energy consumption. The partnership with Philips
is only one example of their Mission: To link Global Manufacturers of
Horticultural Technologies with North American Farmers and Growers.
Commercial
growers and horticultural researchers are now using products like the Philips
GreenPower LEDs to solve many common-sense problems:
·        
Energy Savings in Growth Chambers
·        
Growing High Density Crops/Leafy Greens in
Warehouses – Decreases heat and amount of land needed
·        
Greenhouse Vegetable Crops – Decreased heat,
allows lights lower in the crop, increasing yield up to 20%
·        
Artificial Lighting of Ornamental Crops – Immediate
energy savings
·        
Vine Crops (Tomatoes, Peppers, Cucumbers) –
Yield improvement
·        
Flower, Strawberry Production – Increased flowering
Philips
GreenPower LEDs are available in multiple styles, lengths, and color ranges for
a variety of growing applications and needed work light.
Hort
Americas and their partners provide solutions for farms of all sizes and
capacities, from urban growing community projects to Vertical Farming,
hydroponics, and commercial horticulture, playing their role in making the
world a healthier, greener, more sustainable environment in a world dependent
on innovation.
CONTACT:
Chris
Higgins
+
1 469 532 2383
infohortamericas@gmail.com

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

Making the Switch to Organic Fertilizers

With increased interest in locally-grown crops, “natural”
products, and sustainably-certified production programs, an increasing number
of growers are looking at the feasibility of organic production. One of the
biggest changes for traditional growers seeking to grow organically is the
replacement of conventional fertilizers.
Growers looking to replace conventional fertilizers have
the option of applying either animal-based products like fish emulsion, bone
meal and blood meal; plant-based products including alfalfa meal, seed oil
extract and those derived from composts; and naturally occurring minerals such
as limestone and rock phosphate.
Slow release rate
Two of the major issues growers must consider when
switching to organic fertilizers is their low nitrogen-phosphorus-potassium
analysis and their slow release rate of these macronutrients. Cornell
University assistant horticulture professor Neil Mattson said conventional
liquid fertilizers like 20-10-20 provide nutrients that are readily available
to the plant roots. He said unlike conventional fertilizers, organic
fertilizers should be considered slow-release fertilizer sources since their
nutrients are released through decomposition and microbial activity.
“Plant-available nitrogen is what growers need to be
concerned with,” said Mattson. “It can be the limiting nutrient in organic
fertilizers. The organic fertilizer will list the amount of ammonium and nitrate,
these are the plant-available forms. The rest of the nitrogen may eventually be
available to the plants, but a microbial population has to be established to
convert the organic-bound nitrogen into ammonium or nitrate nitrogen.
“If a grower is looking at the immediate nutrient
availability or “greening” potential of a fertilizer, he needs to think about
what percentage of nitrogen is immediately available to the plants and how much
time it will take for the remaining nitrogen to become available. The grower
also has to be concerned about how much of the fertilizer will be leached from
the substrate.”
Mattson said growers applying organic fertilizers must
also pay close attention to the growing substrate to ensure conditions exist
that favor microbial activity that will hasten nutrient release from the
fertilizers. Growers may want to consider incorporating into the substrate a
source of microbial inoculum such as compost or some other commercial product
such as RootMate or R.S.S.I. Other factors that can impact microbial activity
include having a suitable food source in substrate, maintaining warm substrate
temperatures above 60°F, avoiding a water-logged substrate, and keeping the
substrate pH above 5.5.
Although most of Mattson’s studies with organic fertilizers
have been done in either conventional or organic potting mixes, he said even in
a hydroponic production system that a microbial population will become
established and will convert organically-bound nutrients into forms that are
available to the plants.
“The nitrogen may be bound in proteins and amino acids,”
he said. “The proteins eventually are degraded into amino acids, which get
degraded to ammonium or nitrate which are available to the plants.”
Nutrient
availability
Mattson said in a hydroponic production system, if a
plant needs a specific number of grams of nitrogen, it’s going to need that
amount whether it comes from a conventional fertilizer source or from an
organic source.
“A grower who previously used a conventional fertilizer
and switches to an organic fertilizer may need to increase the amount of
fertilizer applied depending on how much of the nitrogen is readily available,
and how quickly the microbial community can convert the remaining nitrogen to
plant-available forms,” he said.
Mattson said that with organic fertilizers it can be more
difficult to control the proportion or ratio of the nutrients to meet the
plants’ needs.
“With a conventional fertilizer the ratio is often
something like 4-1-4 for nitrogen-phosphorus-potassium,” he said. “Conventional
fertilizers that match up pretty well would be a 21-5-20 or 20-10-20. These
fertilizers actually give the plants the nutrients they need in about the right
proportion that the plants absorb them. For organic fertilizers I have not been
able to find any that have those same proportions.”
Mattson said the organic fertilizers he has worked with
tend to be high in phosphorus as compared to the nitrogen and relatively low in
potassium. However, he has yet to run into problems with deficiencies in the
organic fertilizer studies that he has done.
“Most of the studies I have done have been with
relatively short six-week crops,” he said. “This may have not been enough time
for the plants to experience deficiencies of potassium or show an excess of
phosphorus.”
Mattson advises growers producing longer term hydroponic
crops with organic fertilizers to regularly monitor soluble salts levels and to
also do tissue analysis.
“Nutrients like phosphorus that are supplied in excess
are going to accumulate so that the nutrient level is going to keep building
up,” he said. “Whereas nitrogen and potassium levels might be drawn down
quickly so that there might not be much left for the plants. A grower producing
a short term crop like lettuce or greens may not have to be as concerned with
deficiencies or excesses as a grower producing a longer term crop like tomatoes
or cucumbers. However, if a lettuce grower recaptures the water from a
reservoir and uses it for multiple crop cycles, there is an increased chance that
he could run into these nutrient imbalances.”
Monitoring
nutrient levels
Mattson said growers who are using organic fertilizers
need to do more testing in regards to pH, soluble salts and tissue analysis.
“Electrical conductivity measurements give the total
soluble salts which will help ensure that total salt levels have not built up
to dangerous levels that can burn the plants,” he said. “However, these
measurements don’t tell which particular nutrients built up to a high level.
“Growers who are producing a long term crop like tomatoes
should also be doing leaf tissue analysis. This test would help to determine
which nutrients are becoming deficient or excessive. A leaf tissue test
provides guidelines as to what the nutrient levels should be for long term
crops like tomatoes to sustain vigorous plant growth.”
While a tissue test will provide growers with information
about what nutrients have been deficient in the root zone over the past few
weeks, Mattson considers it to be more of a reactive test.
“A more proactive test would be for the grower to test
the nutrient solution periodically to see what is available to the plants,” he
said. “For a new crop that a grower is not accustomed to producing, it is a
good practice to run a tissue test every week or every two weeks. The grower
should pay attention to the trends that occur with the nutrients over time. The
grower can learn a lot from those trends. If the nitrogen level keeps going
down from week to week, the grower may be under fertilizing the plants or the
phosphorus level may keep building up from week to week indicating over
fertilization.”
For more: Neil
Mattson, Cornell University, Department of Horticulture, (607) 255-0621; nsm47@cornell.edu.

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

LED Grow Light Video from Hort Americas

Hort Americas is please to offer the first in a series of innovative educational videos geared toward commercial greenhouse growers and hydroponic vegetable growers in controlled environment agriculture facilities.

The first will be product videos that provide you (the viewer) the necessary facts and information you need to incorporate these tools at your growing facility.

The second will be educational only videos.  These videos will focus on horticultural and hydroponic topics.  Topics will range from managing the root zone to managing light.  Please email us at infohortamericas@gmail.com if there are any specific topics you would like to see tackled.

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

Seed Germination Using LEDs

By Johann Buck
and David Kuack
Light along with
water, oxygen and temperature are the environmental factors that affect seed
germination. Light can stimulate or inhibit seed germination or have no affect
at all. Some of the plants that require light for germination include:
ageratum, begonia, browallia, coleus, geranium, impatiens, lettuce, nicotiana,
petunia and snapdragon.
Many growers who
provide supplemental light for seed germination have used fluorescent lamp
fixtures. These lamps are typically suspended 6 to 12 inches above the seed
trays. The lights are generally operated for 14 to 16 hours a day.
Some growers who
operate more elaborate production facilities have installed high intensity
discharge (HID) lamps. These lamps can be used to provide supplemental light
for both germination and growing on a crop especially during dark weather
periods and the shorter days of the year.
Consider LEDs
The light
emitting diode (LED) is gaining interest among growers and other
horticultural-related companies, including breeders and plant propagators. LEDs
are more like computer chips than light bulbs because they are solid-state
semiconductor devices.
LEDs are more
efficient than incandescent and fluorescent lamps and comparable to HID lamps.
Unlike these traditional lamps, LEDs generally do not burn out. The life
expectancy of LEDs is based on the time (in hours) required for the light
output to drop below a percentage of the original maximum intensity under
optimal operating conditions.
Growers generally
replace their lamps when the light output drops below 90 percent. Those who
install LEDs can expect a long operating lifetime of approximately 25,000 to 50,000
hours. The LEDs’ long operational life reduces the costs associated with
replacement, disposal and labor. LEDs turn on and off instantly and do not
require warm-up time like HID lamps. LEDs also emit little or no radiant heat
enabling them to be placed closer to the plants. This allows growers to produce
multilayer crops without having to be concerned about having to remove excess
heat.

 

Improved light efficiency
Most plants use
light in the blue (450 nanometers) and red (660 nanometers) wavelengths of
photosynthetically active radiation for photosynthesis. LEDs designed for use
in horticultural applications emit light in the red or blue wavelengths. In
some cases far red light is needed by the plant and can be added to the overall
LED light recipe.
Changing the
light recipe enables growers to manipulate the light quality to specifically
match the plant species and stage of production. LEDs give growers the option
of changing the light quality to match what they are trying to accomplish with
a crop, be it speed up growth to reduce crop time, hasten and/or increase flowering,
improve plant quality, grow without daylight or increase plant production with
a multilayer cropping system.
Multilayer production systems
Both hobbyists
and professional growers have expressed an interest in using LEDs during seed
germination. For professional growers, a multilayer production system can be a
costly and time-consuming design and construction project. Because of these
issues, smaller growers believe that LED technology is unattainable. This is
not the case.
Many large
growers start with LEDs by conducting small scale trials. These trials are
comparable to what hobbyists or smaller growers would need to satisfy their
entire crop.
An example is the
Philips GreenPower LED Production Module. It is designed to replace fluorescent
lamp fixtures. The Production Modules are available in two lengths (4 and 5
feet). The Production Modules provide either a combination of deep red and blue
light or deep red and white light. The white light is useful for color
recognition of plants and is easier on the human eye. Most growers choose the
deep red and blue light Production Module because its price point is lower than
the deep red and white light module.
For most purposes one Production Module can replace two fluorescent tube lamps. For
example, growers commonly use a plant production footprint of 4 feet by 2 feet.
These dimensions are common for most flower shipping carts used by U.S.
growers.
Generally
speaking, 150 to 200 micromoles of deep red and blue (or white) light from LEDs
is adequate for seedling production based on an average photoperiod of 16
hours. This seed germination cart design would require three or four 4-feet
Production Modules. At 35 watts per module and using an average of $0.10 per
kilowatt-hour, one 4- by 2-feet cart shelf would cost $0.17 per day to light.
The price range for the Production Module depending on the length installed is
approximately $150 to $200 per module.  The useful life
expectancy for a Production Module is approximately 25,000 hours at 90% light intensity and 50,000 hours at 70%.
 
Real world experience
Kieft-Pro-Seeds
Holland, a breeder of F1 and open-pollinated annual and perennial
flower seed in Venhuizen, the Netherlands, recently installed a Philips LED
system. The set up consists of more than 7,000 LED lights (15 percent blue and
85 percent red). The LEDs are expected to last 10 times longer than a standard
fluorescent light system. The return on investment for the LED system is
expected to be less than three years.  Willem Koopman, seed
operations manager at Kieft, told FloraCulture
International
, that the company had been trialing the system for nearly
four years.
“Now we can start
to benefit from this fresh technology,” Koopman said. “This will include a 30
percent cost savings on our energy bills and will increase the efficiency of
our testing services by providing a more consistent light to our young
seedlings.
“We use the
special lighting in our germination testing chambers for our new and upcoming
products before they go on sale so that we can reliably inform the growers of
how many seeds will successfully turn into the premium product which we are
known for. Using this new system will also mean that the seedlings require less
watering because they will not dry out as quickly.”
Dr. Johann Buck
is technical services manager, Hort Americas, Euless, Texas,
jbuck@hortamericas.com; www.hortamericas.com. David Kuack is a freelance
technical writer in Fort Worth, Texas, dkuack@gmail.com.

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