It is quite common for both start-up and experienced commercial hydroponic growers to feel they need a math degree when it comes to calculating the necessary micro and macro elements of their water soluble fertilizer.Hort Americas has solved the equation with their specially formulated 9-7-37 Hydroponic Fertilizer. Hort Americas has developed this unique fertilizer in cooperation with CEA hydroponic specialists, academicians and researchers to meet the nutritional needs of crops produced by hydroponic leafy green growers.
Designed for leafy greens, culinary herbs, micro greens and other crops grown hydroponically
Can be used as a constant feed or as a supplement
Delivers essential nutrients for efficient uptake by the root system
Unique TPA (Thermal Poly Aspartic Acid) additive which enhances the plants ability to uptake phosphorus
To assist the grower even further, Hort Americas has developed a helpful hydroponic fertilizer calculator within part 3 of a 3-part instruction video series found on the Hort Americas website
Hort Americas recommends the grower have their source water tested by a professional water analysis laboratory to determine the macro and micro nutrient levels, pH, EC and total alkalinity before assessing appropriate rates for their fertilizers.
Hort Americas is an innovative leader in North America’s controlled environment agriculture industry (CEA) and strives to continually innovate in agriculture via premium technical support, professional salesmanship, unmatched customer service and outstanding products to our customers in the United States, Canada, Mexico and the Caribbean.
For questions, support or to purchase → Click Here!
Dr. Frits Went and the Pursuit of the McCree Curve
Dr. Bruce Bugbee of Utah State University was the opening speaker at the 2016 International Society for Horticulture Science Symposium on Light in Horticulture. Dr. Bugbee talks candidly with me about how understanding history can give us a keen insight into today’s botanical questions about light and the outlook of our future.
For more information on Dr. Bugbee’s program visit these sites:
A study of data collected in the 2007 and 2012 Census of Agriculture shows that direct-to-consumer sales could help growers remain in business longer.
In January 2015 a group of economists at the USDA-Economic Research Service released the publication “Trends in U.S. Local and Regional Food Systems: A Report to Congress”. The purpose of the report was to provide Congress with information regarding the “scope of and trends in local and regional food systems.”
As the demand for local food continues to increase along with consumer interest in locally-grown, USDA has made it one of its priorities looking at related topics including improving the rural economy, expanding food access and increasing nutrition, assisting agricultural producers and strengthening local markets.
Defining direct-to- consumer sales Nigel Key, a USDA-ERS economist and co-author of the Congressional report, studied some of the data that was collected to determine if direct-to- consumer sales had an impact on the survivability of farmers.
“I examined farms that sold directly to consumers, which is a subset of local food producers,” Key said. “I looked at whether farms that had direct-to- consumer sales were more likely to survive longer in business and grow more or less compared to farms that don’t do direct-to-consumer sales. That was the focus of my research.”
Key said direct-to- consumer sales would include roadside stands, farmers markets, pick-your-own farms, on-farm stores and community supported agriculture.
“These sales wouldn’t include intermediaries that would aggregate the food and then sell it to schools or to supermarkets,” he said. “It also wouldn’t include selling to restaurants that then prepare the food and sell it to consumers. That would be local food, but that wouldn’t be selling directly to consumers.”
Tracking business survival
Key used the 2007 and 2012 Census of Agriculture data, which essentially includes all farms.
“We looked at all farms and broke them out by their sales categories: $1-$10,000; $10,000-$50,000, $50,000-$250,000 and over $250,000,” he said. “The Census of Agriculture is conducted every five years. The last one was in 2012 and the one before that was 2007.
“Looking at the 2007 census at producers who were selling directly to consumers, we determined how many of those producers showed up in the 2012 census and were still in business. We compared this data to the farmers who weren’t selling directly to consumers in 2007 and how many of those producers showed up in the 2012 census. We tracked business survival rate.”
Key said that 55.3 percent of all farms showed up again in the 2012 census compared to 60.9 percent of those producers with direct-to- consumer sales. The higher survival rate for direct-to-consumer sale producers was true for all of the different size sales categories. There was a significant increase in the probability of survival occurring for farmers with direct-to- consumer sales.
“The small farmers only had a 45.3 percent rate of survival compared to 72.8 percent for large farmers, but in every category survival was higher for direct-to- consumer sales,” he said. “For large growers with direct-to-consumer sales survival was higher, 78.1 percent. For the small direct-to- consumer sales farmers, survivability was 54.9 percent. In every sales category, there was a higher survival rate for direct-to- consumer sales farmers. We also looked at beginning farmers. These are farmers who have been in business less than 10 years. We basically saw the same effects.”
Reasons for increased survivability
Key said one of the reasons that there is a higher survival rate among farmers doing direct-to-consumer sales, is the amount of time these farmers are spending marketing their product.
“The direct-to- consumer farmers may be getting a higher price, but they are also spending more time marketing their product,” he said. “So in a sense they are a farmer and a marketer. As a result, for the same level of sales they don’t need as much farm equipment and they don’t need as much land. From the data we saw farmers who sell directly to consumers have $20 worth of machinery per dollar of sales compared to $31 worth of machinery per dollar of sales for those farmers who market through conventional channels.
“We saw similar results for the amount of land being farmed. Direct-to- consumer farmers had $240 in land per dollar sold compared to $309 in land per dollar sold for farmers selling through conventional channels. If a farmer doesn’t have to have as much land and machinery then he doesn’t have to borrow as much money.”
Key said farmers who were doing direct-to- consumer sales also had less debt.
“With less debt, the direct-to- consumer farmers likely have lower interest payments relative to their assets so they have a lower debt-to- asset ratio,” he said. “A lower debt-to- asset ratio makes a farmer less susceptible to production and market shocks.”
Slower growth rates
When Key looked at the growth of farms that remained in business in both 2007 and 2012, the farmers with direct-to- consumer sales had slower growth than the farmers with no direct-to-consumer sales.
“It’s kind of puzzling, why would these direct-to- consumer farmers have higher survival rates and lower growth rates?” he said. “One possibility is the direct-to- consumer sales tend to be more labor intensive. So given the same amount of sales, the direct-to- consumer farmers were hiring substantially less labor. So it makes it difficult to expand if expanding means having to hire someone. That can be a costly upgrade as compared to purchasing more land where a farmer can farm more of the land himself. Even though a farmer may not be able to grow the business, he may be able to survive.
“These direct-to- consumer farmers may also enjoy their work more. They like interacting with their customers. We don’t have any data to support that, but those are just my thoughts.”
For more: Nigel Key, USDA-Economic Research Service, Resource and Rural Economics Division, Farm Economy Branch; (202) 694-5567; nkey@ers.usda.gov.
David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.
Rutgers University researchers are studying the viability of growing ethnic specialty crops in greenhouses and hoop houses for local and regional sales.
While consumer demand for organic products continues to increase so does the demand for locally grown produce. USDA reports that industry data estimates that U.S. local food sales totaled at least $12 billion in 2014, up from $5 billion in 2008. To support this growing local market USDA has provided more than $1 billion in investments to over 40,000 local and regional food businesses and infrastructure projects since 2009.
Focusing on Asian and Hispanic crops
Researchers at Rutgers University in New Brunswick, N.J., have studied the potential market for ethnic specialty crops along the U.S. East Coast. Based on the results of their findings the researchers are now looking at those crops which have the potential to be adapted to greenhouse and hoop house production.
“At Rutgers we have a specialty crop research group,” said Albert Ayeni, who is ethnic crop research specialist. “We have been funded for about $2 million by the USDA. Our research group, led by Dr. Ramu Govindasamy, has documented the rapidly increasing population of Asians (Chinese and Asian Indians) and Hispanics (Mexicans and Puerto Ricans) on the U.S. East Coast. As of 2010 the population of these ethnic groups stood at about 6 million people.
“We are looking at two broad ethnic groups, Asian and Hispanics. We are studying what kind of crops these two ethnic groups are asking for that can be grown in New Jersey and other states along the East Coast. We have done a comprehensive study of what are the demands for these ethnic crops. We also studied the average prices for which these crops are sold.”
Some of the crops that the Rutgers researchers have studied include: exotic peppers (Capsicum spp.), roselle (Hibiscus sabdariffa) and tiger nuts (Cyperus esculentus cv. sativus), amaranth (Amaranthus spp.), African eggplant (Solanum aethiopicum) and okra (Abelmoschus esculentus).
Ayeni said okra is a popular crop in the southern U.S., but is not grown much in the Northeast.
“Based on our studies, these crops on the East Coast are sold in different ways– by the pound, ounce or in a bunch,” Ayeni said. “A bunch can vary from a $1.50 to $2 or more depending on the crop and market. We are looking at what the price limits are depending on which part of the East Coast the crops are sold. We are studying the markets in Florida, Massachusetts and New Jersey.
“We have conducted studies and collected information that could help growers determine which are the best ethnic crops economically. This could help growers know what to grow to target specific ethnic niches. Location has a lot to do with what price can be charged for a crop. What we found is that some products can be sold for twice as much in bigger markets like New York City.”
Ethnic specialty crop trials Ayeni said extensive greenhouse and hoop house trials have been done with exotic peppers, roselle and tiger nuts (chufa).
“This is the second year that we have worked with roselle,” he said. “We have worked with tiger nuts for about four years and exotic peppers since 2009.
Exotic peppers have been studied by Rutgers University researchers since 2009. The fruit is in high demand by Africans, Asians and Hispanics. Photos courtesy of Albert Ayeni, Rutgers Univ.
The peppers contain high levels of capsaicin which has numerous significant health values along with high amounts of vitamin A. The fruit is in high demand by Africans, Asians and Hispanics.
Roselle contains high levels of antioxidants and facilitates iron bioavailability. Its leaves are in high demand by Asian Indians and Hispanics. Its fruit is in high demand by Africans and Hispanics.
Tiger nuts are considered a super snack food. These gluten-free tubers are high in fiber and vitamins with a moderate level of iron. Tubers are highly sought after by Africans and the U.S. market is growing rapidly.
“With a greenhouse most of these crops can be grown any time of the year,” Ayeni said. “If roselle is grown outdoors, it can’t be planted in this part of country until the middle of May to early June because it is a tropical plant. Plants can be harvested for foliage from July until October. For the cultivars we are currently evaluating, outdoor production for flowers and fruit is not feasible for African Green, African Red and Indian Red types. For these roselle types, the onset of frost in late October and early November stops further plant growth or kills the plants, preventing flower/fruit maturity.
“This is a limitation for field production. However, the “kenaf” type roselle, identified as Indian Green in our studies, can be grown from June to October in New Jersey. With this roselle type, the leaves and fiber are of greater economic significance than the fruit.”
Roselle (Hibiscus sabdariffa) is grown for both its leaves and fruit. The leaves are in high demand by Asian Indians and Hispanics. Its fruit is in high demand by Africans and Hispanics.
Ayeni said roselle grows well in the greenhouse year round. In a hoop house the yields were not as high as the greenhouse. Supplemental lighting was used in the greenhouse trials during winter to grow roselle.
“The plants respond well to supplemental light,” he said. “For the supplemental lighting we used high pressure sodium lights and provided 16 hours of photoperiod in a 24-hour cycle. In the greenhouse, supplemental lighting can be used to produce a significant quantity of foliage any time of the year.
Research results
Jalapeno/serrano-type peppers grow and fruit well under greenhouse and hoop house conditions.
Sweet minibells and African poblano do better in a greenhouse than in a hoop house. The habanero/African bird’s-eye- type performs poorly in both the greenhouse and the hoop house.
Roselle grows and fruits better in the greenhouse than in the hoop house. In other trials, roselle exhibited greater growth in the hoop house. Ayeni said more research needs to be conducted to understand how time of planting affects performance in a hoop house.
Tiger nuts thrived much better in the hoop house than in the greenhouse. Considerable adjustments are needed to controlled environment parameters in the greenhouse, probably temperature and light, to be able to mimic the hoop house conditions that produced high tuber yields.
Tiger nuts (Cyperus esculentus cv. sativus) grew better under hoop house conditions than in a greenhouse. The plant’s gluten-free tubers are high in fiber and vitamins and are considered a super snack food.
Ayeni said they also want to compare plant production in pots versus growing the plants directly in the soil under cover (i.e. tunnel production).
“The market for locally grown ethnic foods continues to expand,” Ayeni said. “We want to encourage growers to consider ethnic specialty crops so they may target production to meet the rapidly growing demand in the United States. These crops lend themselves to year-round production for sale, including at farmers markets.
“In general, immigrants from all over the world cherish the plant varieties that are prevalent in the food systems of their home countries. I would be delighted to see Rutgers University lead the way in promoting local production to make these crops available as fresh as possible to a growing consumer population.”
For more:Albert Ayeni, Rutgers University, Department of Plant Biology and Pathology, New
Growers at all levels of experience can benefits from four week courses.
For the second year, the University of Florida Institute of Food and Agricultural Sciences Extension will be offering online training courses in English and Spanish starting on May 30. The courses are to be geared towards helping grower staffs make better crop management decisions.
Each course runs for 4 weeks, costs $200 per participant, and includes a personalized certificate of completion. Each week there are two streaming video lessons, readings and assignments (about 3-4 hours total commitment per week), which can be accessed at any time of day. Bilingual PhD instructors can be accessed via text chat and discussion features. For more information, go to backpocketgrower.org under “training” and “online courses”.
The schedule of online courses planned for 2016 includes:
The first course, Greenhouse 101, is ideal for new employees, or employees with practical experience but lacking in formal horticulture training. Topics covered are plant parts and functions, photosynthesis and growth, greenhouse technology, flowering, compactness and branching, irrigation, nutrition, and plant health.
Nutrient Management 1, Disease Management and Weed Management are courses geared towards grower staff with some experience and training, or at the entry-university level.
Nutrient Management 2 is an advanced course for the experienced, well-trained grower, those at the upper-university level.
This is part 3 in the 3 part series on hydroponic fertilizers from Hort Americas. This video focuses on how to build and adjust a hydroponic fertilizer formula based on the quality of your source water. Fertilizer formulas mentioned in this video are specific to leafy greens, culinary herbs and lettuces.
At Hort Americas, we are proud to be sponsors of Urban Ag News. They continue to raise the bar on covering the latest innovations and technology in urban agriculture and vertical farming. We hope you enjoy their latest issue as much as we do!
Urban Ag News’ Issue 13 cover story looks at Green Sense Farms’ efforts to meet the increasing demand for clean, safe produce in both the U.S. and China. Founding farmer and CEO Robert Colangelo talks about how his company is opening additional vertical farming operations in both countries along with a training facility to create job-ready graduates to grow in controlled environments.
Thinking about installing a water treatment system for your growing operation? University of Florida professor Paul Fisher said you should know your goals before investing in a treatment system. A treatment system won’t add value to your product, but it will reduce the risk of crop losses.
Duron Chavis, indoor urban farm director at Virginia State University, is helping citizens of Richmond and Petersburg, Va., have access to locally-grown produce year round. His efforts along with community leaders and university colleagues are helping people eat and live healthier through urban agriculture.
ISSUE 13 INCLUDES:
On the cover: Robert Colangelo,founding farmer and CEO at Green Sense Farms Green Sense Farms to expand its Vertical Farming Operations in the U.S. and China
Helping people eat, live healthier through urban agriculture, with Duron Chavis
An Interview with NASA’s Dr. Gary Stutte
Urban Ag Zoning: Lessons from San Antonio
NY SunWorks: Is the future of farming in public schools?
Know your goals before investing in a water treatment system
Tour de Fresh 2016 by Chris Higgins
Indoor Ag Con Las Vegas April 2016 e-Gro Webinars Japan Plant Factories Special Report by Eri Hayashi FDCEA 2016 Events to Attend University of Arizona, CEAC, Patricia Rorabaugh Retires Infographic: Living Wage Calculation for Dallas, Texas
News from the Industry features these and more:
How LED lighting treatments affect greenhouse tomato quality AeroFarms offers new level of safety and flavor for delicious, nutritious leafy greens Dr. Roberto Lopez joins Michigan State University Horticulture faculty Lettuce See The Future: LED Lighting Helps Farming Go High-Tech In Japan Interim president and CEO of AmericanHort steps down Growtainer and Glenn Behrman HydroGarden starts international school sponsorship to mark 20th year in business The Diane Rehm Show: The Growth Of Large-Scale Indoor Urban Farming GreenTech 2016 to be packed with inspiring sessions and speakers CropKing Introductory Grower Workshop 2016 Tour de Fresh Sponsorships Available Now New white paper available on the immense potential of Asia’s Indoor Ag Industry Critical Foodscapes: what does the future hold for urban gardening? New Case study on Urban Produce available from Hort Americas Study Finds Philips LED Lights Provide Improved Energy Efficiency and Production for Growing Food Crops in Space Sustainable Agriculture Training / Cal Poly Pomona Launch New Hybrid Course and a New School Name
Using only a fraction of the electricity that traditional bulbs use, LED Light Bulbs are becoming increasingly more and more popular each day. Whether you are a home owner or a commercial property owner, there is an obvious incentive to install them – both for cost savings and a reduced impact on the environment.
On average, the typical commercial LED bulb lasts nearly 30 years – talk about never hearing a “screw in a light bulb” joke again!
Regardless of whether you think hydroponic production can be organic, the bottom line is all methods of food production should be considered when trying to feed a growing world population.
There is currently much discussion and debate occurring about whether hydroponic production can be labeled as organic. In September 2015 the USDA’s National Organic Program appointed a 16-member task force to look at hydroponic and aquaponic production practices and how they align with USDA organic regulations.
Gene Giacomelli, director of the Controlled Environment Agriculture Center (CEAC) at the University of Arizona, said that regardless of whether plants are being grown using a traditional organic approach or one of the various combinations of hydroponics practices (soilless culture), fundamentally all of these production methods are simply attempting to grow plants for their economic, nutritional and social values. The goal is to use the best available techniques to produce crops of highest quality with the minimum of resources.
“Regardless of the production method, plants must be provided with the environment they need to grow,” Giacomelli said. “The basics of growing plants besides light, carbon dioxide, water and the potential of their crop genetics, there are plant nutrients that have to be distributed to the plant roots.
“Consider that the nutrients have to be dissolved in the water near the roots. Then the water with the nutrients is absorbed through the root membrane. Plants are basically harvesting the nutrients from the water adjacent to their root system. Where nutrients come from or how they get there are not important in the plants’ decision to use a nutrient. If a nutrient is present and the plants need it, they’ll use it.”
Soil, soilless or no soil
Giacomelli said using traditional farming practices including organic production, field-grown plants grow for a while in the soil until the nutrients are depleted. Then the soil’s nutrients can be recharged by incorporating animal and plant manures.
“One of the ways to grow plants is in soil and to apply components that will break down naturally from plant manures and animal manures,” he said. “Nutrients from these manures can be dissolved in the water and absorbed by the plant roots.”
Giacomelli said plants can also be grown in many different ways and as long as the water and nutrients are delivered to the roots the plants will grow.
“However, there are benefits for the growers to use hydroponics, such as avoiding issues with soil-borne diseases, soil-hosted insects, poor soil drainage and aeration, which are detrimental to plant growth,” he said. “Many growers have made the switch to soilless substrates for their root zone, which can be made of organic components, but may not contain any soil from the Earth. These organic root zone materials can be placed within containers that may be extended as one for an entire row of plants, or for small units as for individual plants. USDA regulations allow for organic growers to produce their plants in containers. That is legal.”
Hydroponic growers can avoid issues with soil-borne diseases, soil-hosted insects, poor soil drainage and aeration. Photo courtesy of American Hydroponics
Giacomelli said there are natural microorganisms in soil that surround the root system and presumably encourage the effectiveness of the nutrients found in the root zone of the plant.
“Can this also occur in a hydroponic system or a pure water culture system since there is little or no substrate at all?” he said. “What if the grower is making a compost tea or purchasing a formulation that is a natural degradation of plant or animal manures and takes the supernatant liquid and then injects it through the irrigation system and pumps the microbes through the water? Aquaponics uses fish waste to fertilize the plants. Is this considered organic?”
Giacomelli said one of the things being studied is the production of quality greens in aquaponic systems using low nitrate levels.
“These nitrate levels are lower than what would be used in a typical hydroponic system,” he said. “We are trying to figure out what is allowing this to occur. Is it the water movement around the roots? Or are there some microbiological agents helping the plants be more efficient in extracting those limited nitrate molecules in the water? We must work with a microbiologist to help us answer these questions.”
Comparing production methods
Giacomelli said one of the fundamental questions when discussing growing organically is whether the food produced is better than food grown using other production methods.
“‘Better’ could mean nutritionally or it could mean for food safety,” he said. “Usually if it’s organic then there are no pesticides. What I do know is exactly what is on the tomatoes coming out of our university greenhouses. I don’t know necessarily what is on an organic tomato coming out of a field. There is less insect and disease pressure in a greenhouse than in an open field, and thus a lesser need for control procedures.
“Growers trying to produce food in resource-limited locations, such as where water is scarce or phosphorus is hard to find, are going to have other factors to consider when choosing how to grow their plants. In these situations growers are going to want to capture and recycle the water and nutrient solution.”
Gene Giacomelli, director of the University of Arizona’s Controlled Environment Agriculture Center, said since there is less insect and disease pressure in a greenhouse than in an open field, there is a less need for control procedures.
Giacomelli said there are environmental ramifications which should come into discussion about organics.
“What does organic production and its demands do to the environment?” he said. “A system that recycles water and nutrients has an energy expense, but this balances out in the gain of water and nutrients.
“We began looking at things like how many grams of edible biomass did we produce per kilowatt hour of electricity. Or, can we produce more edible biomass per input of electric power using containerized growing in controlled environments? Or what about edible biomass produced per input of plant nutrients? Comparing field organic production to a recirculating hydroponic system, the field organics systems cannot compare from a balanced budget viewpoint. Resource use efficiency is greater in a containerized system.”
The impact of light
Giacomelli said light has never been a consideration when talking about whether a crop is organic. But he expects in the future it will be.
Only recently have we been able to talk about artificial light and its relation to growing plants organically,” he said. “When plants receive a full spectrum of light from the sun, the plants pick and choose what’s naturally available and uses it.
“When plants are exposed to very narrow light spectra from LEDs, particularly red and blue light, plants will grow. There are indications that there are other wavelengths that have been and will be discovered and proven to change the growth rate of plants. This could impact the production, as well change the potential quality of the plants. Plants grown under these wavelengths could be higher in lycopene or sugars or some other nutritional compounds. Based on the recipe of light given to plants, they could be grown more efficiently while enhancing their nutritional value. We await the results from the research that is rapidly proceeding.”
Looking at the big picture
While defining what is organic and what isn’t may be more important to some growers than others, Giacomelli said the agricultural industry shouldn’t lose sight of the big goal.
“I want the field organic industry to grow and I want the organic hydroponic industry to also grow,” he said. “By their development and expansion, we will help feed people. We are going to need both. There are places where both of them should be done and places where neither of them should be done. They are not mutually exclusive. We need to look at the practical aspects. Give me the bottom line based on all these factors and I will be able to tell you whether to grow in controlled environments. On the other hand, if you have the right climate and can grow outdoors organically that works too.
“We will never be able to feed all of the people in the world by a strict traditional organic definition of food production alone. There will be other agricultural practices that may not be organic or be somewhere in between. However, container production of food within controlled environments can help to meet a demand for organic food production.”
For more: Gene Giacomelli, University of Arizona, College of Agriculture and Life Sciences, Agricultural and Biosystems Engineering, Tucson, Ariz. 85721; (520) 626-9566; giacomel@ag.arizona.edu; http://ceac.arizona.edu
David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.
Choosing a Hydroponic Substrate: Tips From the Pros
Hort Americas has partnered with Upstart Farmers – Bright Agrotech to offer a free webinar on choosing a hydroponic substrate!
Knowing what your hydroponic system needs can be hard. To help you out, Dr. Nate from Bright Agrotech, Chris Higgins, and Tyler Baras from HortAmericas lent their experience and knowledge in choosing a hydroponic substrate.
Hydroponic medium/substrate selection is one of the most important decisions you’ll make as a grower. Substrate selection effects germination, growth rates, and operation costs. Each substrate option has unique benefits and limitations.
We’re joined by the experts at Hort Americas to dive deep into these considerations so that you can make an informed decision about your growing medium.
Some of the factors to consider when choosing a hydroponic substrate are cost, ease of use, compatibility with hydroponic system, accessibility, water retention, and sustainability.
In this webinar, you’ll learn about:
-Moisture Retention (particle size, shape, porosity)
-Adjusting Irrigation for Specific Substrates
-Cultural Practices (substrate preparation, germination conditions, crop size/staging)
-Cost
-Sustainability
-Comparison of Common Hydroponic Substrates
Greenhouse and controlled environment agriculture growers who are participating in USDA’s GAP program are expected to have an easier time meeting Food Safety Modernization Act rules.
The burden of proving a grower is exempt from the Food and Drug Administration’s Food Safety Modernization Act’s rule falls squarely on the shoulders of the growers. Phil Tocco, food safety educator at Michigan State University Extension, said there are growers who will be exempt from meeting the Act’s rules.
If you missed the e-GRO webinar “Managing Nutrient Solutions for Hydroponic Leafy Greens and Herbs” on Jan. 22, 2016, which was sponsored by Hort Americas, you can still view the webinar on YouTube.
Hydroponic greens and herbs are produced in systems with recirculating nutrient solutions. In order to maintain productive and quality crops, it is important to know how to properly maintain the nutrient solutions. Dr. Chris Currey at Iowa State University and Dr. Neil Mattson at Cornell University discuss strategies for managing pH and EC, formulating nutrient solutions and identifying common nutrient disorders.
Part 1: Common production systems, pH and EC management
Presented by Dr. Chris Currey, Iowa State University
Part 2: Nutrient solution recipes, common nutrient disorders
An agreement between Colorado State University and Philips Lighting to equip its new 27,000-square-foot horticulture center with LEDs will put the focus on using the lights for improving ornamental and vegetable plant production.
When officials at Colorado State University went looking for property to build a new football stadium they didn’t have to look far. They decided that the land on which the 65-year-old W.D. Holley Plant Environment Research Center resided was the perfect location for the new stadium.
“The old horticulture facility, which had been built in 1949, was considered a hot property by school officials,” said Steve Newman, who is greenhouse crops extension specialist and professor of floriculture. “To replace the old site, the university provided the department with a new $7.5 million 27,000-square-foot research and teaching facility. There is also a 3-acre outdoor area for plant trials.
“The horticulture center was built in eight months. The university facilities team that I worked with to design and build the center was awesome.”
Greenhouse specs
The horticulture center’s new greenhouse is a Nexus Vail model frame which is covered with Thermaglas polycarbonate. It is equipped with Ludvig Svensson retractable heat curtains and Wadsworth Control vents, Modine Effinity 93 natural gas unit heaters and American Coolair fan boxes. The control technology is all Wadsworth Control Systems.
Colorado State University’s 65-year-old W.D. Holley Plant Environment Research Center has been replaced with a new $7.5 million 27,000-square-foot research and teaching facility.
The 21,000-square-foot greenhouse is divided into six bays. All of the bays are connected by a ventilation corridor that has a 20-foot high gutter line. One bay will contain a Crop King NFT trough system consisting of six modules. The other half of the bay will be equipped with a traditional raft culture set up that has six 5-foot by 10-foot rafts.
“I’m a hard core supporter of Colorado companies,” Newman said. “We are also trying to make the greenhouse as energy efficient as we can.”
Perfect timing
In December 2014, Ron DeKok, North America director of business development, Philips Horticulture LED Solutions, visited Newman to discuss supporting LED research at Colorado State.
“Ron visited me on the same day I was given permission to talk about the budget for the center,” Newman said. “The timing was perfect. He asked me what kind of LED research CSU wanted to do and I asked him how committed Philips was to supporting LED research at the university. He said let’s equip the facility with Philips lighting and we’ll do research projects together.
“The greenhouse is being equipped with the latest Philips horticulture LED fixtures, including top lighting, interlighting and flowering lamps. One house will have suspended interlighting modules for high wire vegetables. We are looking at being able to do all kinds of ornamental and vegetable plant research using different combinations of the fixtures.”
Crops to be studied
Newman said it hasn’t been determined yet how much of the greenhouse space will be dedicated to ornamental and vegetables crops.
Steve Newman, who is Colorado State’s greenhouse crops extension specialist and professor of floriculture, said the new horticulture center will be used for research, teaching and training.
“I expect the research is going to be about 60 percent ornamentals and 40 percent vegetables, but that could change,” he said. “Initially the greenhouse vegetable production will be used primarily for teaching and demonstration. We will get into the vegetable research later.
“Our primary focus initially is going to be on ornamental plug production and reducing plant bench time after transplanting. This includes whether we can grow better quality plugs using LEDs with less plant growth regulators. We will be looking at root development under LED lights, trying to increase rooting and production efficiency. This includes trying to improve rooting of stage 4 tissue culture propagules coming out of overseas production.”
Newman said fellow researcher and horticulture professor Bill Bauerle is planning to use the greenhouse’s corridor to study hops production using LEDs.
“Northern Colorado is becoming a central location for craft breweries,” Newman said. “There is a lot of interest in locally grown hops for the craft breweries.
“The 20-foot high ventilation corridor is ideal for growing hops. We are redesigning and reconfiguring to install the LED interlighting in order to get good vegetative growth. The hops plants will receive natural light from above and the LED interlighting between the rows. The local craft brewers are very interested in the hops research that we are planning to do.”
Collaborative research
Newman said that Philips has some of its own research agenda items that it would like to study in the horticulture center.
“The research that the company wants to do is not that different than the research that we want to do,” he said. “What Philips is planning to look at fits in with everything else that we are doing in many ways. The company will be making some specific requests. The company will be funding those project directly just like any other research program.
“The Philips research team I’m working with is very grower-oriented. The company is interested in finding out how many LED lights does it take to produce a bedding plant crop more
efficiently. How LEDs can be used to produce better quality plants. Meanwhile we will be doing our own research taking advantage of the lights. The hops research was not an agenda item for the company four months ago. Bauerle went to company officials and said let’s do this hops research and they agreed that it was worth doing.”
Philips Lighting has some of its own research items that it would like to study in Colorado State’s horticulture center, but the research is not much different than what university scientists want to do.
Newman said that Philips is interested in looking at vegetable production for the warehouse farming market, which it refers to as its city farming program.
“Unfortunately we don’t have the type of facility set up to do the warehouse style growing on site,” Newman said. “I would like to see us go into that type of production eventually. Initially with our vegetable crops we will look at biomass production. We will be putting in NFT lettuce trials.
“We also want to study nutraceutical compounds, including vitamins, and if LEDs can increase the production of nutraceuticals in vegetables. I am working with my colleagues in the horticulture and food science departments looking at the mouth feel in regards to high quality lettuce production. We will also probably look at tomatoes to increase production efficiency, plant yield, and lycopene development in the fruit. We will probably start looking to do that research in the fall.”
Future plans
Newman said he is in negotiations with the university’s dining services department to produce vegetables for its dining centers.
“I am in negotiations with dining services, which is looking to start vegan salad bars in the dining halls,” he said. “Dining services wants to put in salad bars with as much produce as possible grown in Colorado. They would like to have a certain percentage of that produce be CSU student grown. We are going to redo our student farm to try to accomplish that during the growing season. We will also be trying to grow as much of the leafy greens in this new facility to provide to the dining services’ salad bars.
“I am also working very closely with a university environmental hygiene staff person. We have to be sure that we are in compliance so that whatever produce we sell to the dining halls is as safe as it needs to be. We have to set up a good agricultural practices (GAP) plan and to review the guidelines of the Food Safety Modernization Act that just went into effect. The students who are growing the produce have to be trained in the exact practices they need to follow to deliver quality, safe food. The students have to be taught the proper ways of growing and handling food from the greenhouse to the table. All of the practices that we have to incorporate are the same as if we were going to sell the produce to a retail grocery store.”
For more: Steve Newman, Colorado State University, Department of Horticulture and Landscape Architecture; (970) 491-7118; Steven.Newman@ColoState.edu.
David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.
While providing the proper soluble salts and pH levels are important in hydroponic systems, don’t overlook the significance of maintaining the optimum temperature, oxygen concentration and microbe level in the nutrient solution.
Maintaining the proper soluble salts (electrical conductivity) level and pH are critical in hydroponic systems like nutrient film technique and floating rafts. While monitoring these properties are important, growers should not overlook the importance that temperature, oxygen level and microbial activity play in the growth of plants in these production systems.
“It’s not as much about maintaining root health as it is about managing the conditions in the rhizosphere, which is the region around the plant roots,” said Rosa Raudales, assistant professor of horticulture and greenhouse extension specialist at the University of Connecticut. “The area around the roots undergoes a lot of biological and chemical activity. Microorganisms in the rhizosphere feed on the exudate of the roots. Managing the rhizosphere and the conditions in the nutrient solution are critical to maintaining plant health.”
Factors that can impact root health in hydroponic systems include soluble salts, pH, temperature, oxygen level and beneficial microbial activity. Photo courtesy of Rosa Raudales, Univ. of Conn.
Maintain optimum root temperatures
While providing the proper air temperature in a greenhouse or controlled environment agriculture system is important, maintaining the optimum root temperature can have a bigger impact on the health and production time of a crop.
“If higher temperatures are maintained in the root zone then the plants are going to lose a lot of energy,” Raudales said. “Temperatures above the optimum in the root zone affect the cell membrane integrity of the roots. A disruption of the cell membranes affects the function of the roots resulting in less nutrient uptake, which affects crop cycles and yields.
“If plants are grown at root temperatures lower than the optimum, the plants grow slower because their metabolism is slower. In the worst case scenario, if freezing temperatures occur then ice crystals could form in the cells resulting in cell leakage and cell disruption.”
Cornell University researchers have conducted studies (http://www.cornellcea.com/attachments/Cornell%20CEA%20Lettuce%20Handbook%20.pdf) to identify the specific temperatures that are ideal for hydroponically-grown vegetables.
“Cornell researchers found the temperature of the nutrient solution had a greater effect than the air temperature,” Raudales said. “Lettuce plants exposed to air temperatures ranging between17ºC (62.6ºF) and 31ºC (87.8ºF) had consistent yields as long as the nutrient solution had a consistent temperature of 24ºC (75.2ºF). This research was done in the 1990s, but it still has application today.
“Cornell researchers did a similar study with spinach and they found the optimum root temperature was 22ºC (72ºF). They tested air temperatures ranging from 16ºC to 33ºC (60.8ºF-91.4ºF) and they found as long as the root temperature was 22ºC, the air temperature could be in that range and plants still produced optimum yields. For tomatoes the optimum root temperature is 25ºC (77ºF).”
Raudales said growers who are producing hydroponic leafy greens like lettuce and spinach have the option of installing a water heater to maintain the optimum root temperatures.
“It is easier and less expensive to heat the nutrient solution than to keep the whole greenhouse warm,” she said. “Heating the greenhouse does not make economic sense, when the research indicates that the temperature of the nutrient solution is a more important factor. If a grower is producing lettuce and spinach, which can tolerate lower air temperatures, it makes sense to run the greenhouses cooler and to install a water heater to adjust the nutrient solution temperature.”
Maintain adequate oxygen levels
Raudales said the dissolved oxygen level in a hydroponic solution needs to be maintained so respiration can occur in the roots.
“When oxygen levels are low in the root zone, the roots do not take up the nutrients required for growth,” she said. “Low oxygen levels cause increased ethylene production in the roots. If there are higher ethylene levels in the roots then the roots start to mature and die. The more oxygen present, the better the nutrient uptake and the better the root system.”
Raudales said there is also an inverse relationship between the oxygen level and solution temperature.
“If the root zone temperature is high, then the oxygen level is going to go down,” she said. “This is another reason why the root zone temperature is so important. The optimum oxygen level should be greater or equal to 6 parts per million of dissolved oxygen in the root zone. Plants should be able to handle 6-10 ppm without any problems.”
Raudales said growers who are using nutrient film technique systems typically don’t need to do any type of aeration. The movement caused by the flow of the water is usually enough to keep the oxygen level high enough in the solution.
Raudales said growers who are using floating rafts usually incorporate some type of oxygen-generating system.
“There are different ways of oxygenating the water,” she said. “One is aerating the water where air is being pumped into the water. Air is not pure oxygen, but it contains enough oxygen for what is needed in the hydroponic solution.”
Growers who are using floating rafts usually incorporate some type of oxygen-generating system to ensure the oxygen level is 6 parts per million or higher.
Raudales said another reason for maintaining a high oxygen level in the hydroponic solution is the effect it can have on pathogenic fungal zoospores.
“If there is more oxygen, then zoospores don’t survive as well,” she said. “Zoospores don’t want completely anaerobic conditions, but they do better in conditions where there is less oxygen.
Pathogens of concern include Phytophthora, Pythium, Thielaviopsis basicola and Xanthomonas.
“Growers should try to keep the oxygen level high. If there are warmer temperatures, then there are lower oxygen levels. When there are lower oxygen levels the plants are not as healthy and more zoospores tend to survive. This is one of the reasons why there tends to be more disease issues during the summer than during the winter.”
Raudales said growers who are using floating rafts should be measuring the oxygen level regularly. Meters for measuring dissolved oxygen look like pH meters and are simple to operate.
Maintain beneficial microbes
Raudales said beneficial microbes are present naturally in water. Commercial products with beneficial microbes can also be incorporated into the hydroponic solution.
“Growers who are using the floating rafts tend to treat the nutrient solution like gold,” she said.
“They don’t want to replace it because they have a solution which is very high in beneficial microbes. Growers can inoculate the nutrient solution with a commercial biocontrol product or they can allow the good microbes to build up with time.
“As long as growers maintain the other parameters at optimum levels, including root temperature, pH, nutrients and oxygen levels, there typically isn’t a problem with diseases. This is very comparable to what happens with plants grown in substrates. The microbes build up naturally in the water just like in a substrate. These microbes feed on the exudates of the roots.
They need carbon sources that they wouldn’t get just from the nutrient solution. The system has to be clean, but it doesn’t have to be clean to the point of having to start with a fresh solution every time a new crop is planted.”
For more: Rosa Raudales, University of Connecticut, Department of Plant Science and Landscape Architecture; (860) 486-6043; rosa.raudales@uconn.edu; http://www.greenhouse.uconn.edu.
David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.
Although greenhouse and controlled environment agriculture growers may be exempt from implementing Food Safety Modernization Act rules, produce buyers may make compliance mandatory.
U.S. Centers for Disease Control and Prevention estimates 48 million people are sickened each year by foodborne pathogens. Of those people about 128,000 are hospitalized and 3,000 die each year.
On Nov. 13, 2015, U.S. Food and Drug Administration finalized three rules of the Food Safety Modernization Act. The purpose of FSMA, according to a FDA press release is to prevent foodborne illness “that, for the first time, establish enforceable safety standards for produce farms and makes importers accountable for verifying that imported food meets U.S. safety standards.” FDA said FSMA’s “final rules will help produce farmers and food importers take steps to prevent problems before they occur.”
“The recent multistate outbreak of Salmonella in imported cucumbers that has killed four Americans, hospitalized 157 and sickened hundreds more, is exactly the kind of outbreak these rules can help prevent,” said Michael Taylor, FDA deputy commissioner for foods and veterinary medicine. “The FDA is working with partners across the government and industry to prevent foodborne outbreaks. The rules will help better protect consumers from foodborne illness and strengthen their confidence that modern preventive practices are in place, no matter where in the world the food is produced.”
The three final rules released by FDA in November are the Produce Safety rule, the Foreign Supplier Verification Programs rule and the Accredited Third-Party Certification rule. FDA has finalized five of the seven major rules that implement the core of FSMA. In September 2015, FDA released the Preventive Controls for Human Food rule, which mandates preventive practices in food processing and storage facilities.
Produce Safety rule
The Produce Safety rule is the one rule that should have the biggest impact on outdoor farmers, greenhouse growers and controlled environment agriculture (CEA) growers. FDA used public comments and input collected during farm visits, meetings and listening sessions to develop a rule it says aims at reducing contamination risk while providing flexibility for farmers and growers.
This rule “establishes science-based standards for growing, harvesting, packing and holding produce that are designed to work effectively for food safety across the wide diversity of produce farms.” The rule’s standards include “requirements for water quality, employee health and hygiene, wild and domesticated animals, biological soil amendments of animal origin such as compost and manure, equipment, tools and buildings.” The rule’s standards have been designed to “help minimize the risk of serious illness or death from consumption of contaminated produce.”
The Food Safety Modernization Act’s Produce Safety rule includes standards for water quality, employee health and hygiene, equipment, tools and buildings.
One crop that the rule specifically addresses is the production of sprouts, which have been frequently associated with illness outbreaks. FDA reports that between 1996 and 2014, there were 43 outbreaks, 2,405 illnesses, 171 hospitalizations and three deaths associated with sprouts. Among the outbreaks was the first documented case of Listeria monocytogenes associated with sprouts in the United States. This crop is particularly vulnerable to microbial contamination because of the warm, moist conditions in which they are produced.
Exemptions to the Produce Safety rule
The earliest compliance date for the Produce Safety rule for some farms is two year after the effective date of the final rule. There are exemptions to the rule for some producers. These include farms that have an average annual value of produce sold during the previous three-year period of $25,000 or less. Also to be eligible for a qualified exemption, the farm must meet two requirements:
1. The farm must have food sales averaging less than $500,000 per year during the previous three years.
2. The farm’s sales to qualified end-users must exceed sales to all others combined during the previous three years. A qualified end-user is either (a) the consumer of the food or (b) a restaurant or retail food establishment that is located in the same state or the same Indian reservation as the farm or not more than 275 miles away.
Buyers driving food safety regulations
Dr. Elizabeth Bihn, director of the Produce Safety Alliance at Cornell University, said prior to FSMA, buyer demand has been the primary driver for implementation of food safety practices. “Consumers are buyers, but they are not protecting a name brand like Kroger or Wegmans or Wal-Mart,” Bihn said. “These companies are protecting their brands. They are going to have much higher stipulations for food safety then the consumers at farmers markets. There is some consumer demand for increased accountability for food safety, but it’s not as big a driver as the retail buyers’ demand. This includes most large food retailers.”
Even if greenhouse and controlled environment agriculture growers of food crops are exempt from the Food Safety Modernization Act, they may be pressured by buyers to adhere to the Act’s rules.
Bihn said greenhouse vegetable growers and CEA growers may receive added pressure from buyers to follow FSMA whether or not they are exempt from it.
“If a buyer tells a grower, “I’m not buying your produce unless you have a third party audit,” and the grower wants that company’s account, then the grower is going to do the audit,” Bihn said. “Legally a grower may be exempt from the regulation, but a buyer may say it doesn’t matter, the grower will still have to meet the regulation. There are still going to be markets that don’t require growers to meet the regulation if their operations are exempt from it. If you are a greenhouse grower who sells to a market that’s not requiring compliance with FSMA and you are exempt from the regulation, you may not have to do anything related to the regulation. Also, I can see third party audits, like the Harmonized GAPs audit, being updated to align with the rules to make sure that growers who have audits done meet the federal regulations as well.”
Increased interest in food safety
Even before the final rules were released, Bihn said she is receiving increased inquiries from greenhouse growers about food safety. “Greenhouse growers are trying to decide if they are subject to FSMA rules and how the required practices might fit with what they do with their greenhouses,” she said. “They are trying to figure out if they need to be concerned with meeting food safety regulations. They are going to be in the same situation as field farmers and asking the same questions. Are buyers asking the growers to meet the regulations? Greenhouse growers not subject to the regulations could easily get pushed into following the regulations if their buyers tell them in order to do business with them, the growers must follow the regulations.”
Bihn said her job is to help guide produce growers, whether they are field farmers, urban farmers, greenhouse growers or CEA growers, toward implementing food safety practices.
“Initially there may be frustration, hostility and denial,” she said. “All of those things will occur when growers first hear what they have to do. When they finally sit down and start to learn something about food safety and start to ask how can I fix this, then they start to make progress really fast.
“I love farmers who question everything. They don’t understand why doing something is a risk. They tell me I’ve never killed anyone so what’s the problem. That’s the engagement that I need to get them to think about it. They need to get to where they understand all farms can have produce safety risks and admit that they need to learn something about food safety so that they can make adjustments within their operations and put practices in place to reduce the risks.”
Industry job opportunities
Bihn said she has been encouraging Cornell students majoring in horticulture to get a minor in food science. She has also been encouraging students majoring in food science who are interested in produce safety to get a minor in horticultural production.
“There are food science students who have no idea how farms operate,” she said. “Unfortunately this sometimes results in food science professionals offering ideas for problem solving that may not be doable.”
Bihn said that food safety has traditionally been housed with the food science departments and crop production has been housed with the horticulture department.
“It’s time for there to be some cross pollination between these two departments,” she said. “It has been slow to happen. We now have a Masters of Professional Studies degree at Cornell that merges horticulture and food science. There are jobs out there, but they are difficult to fill because there are people who know production or there are people who know food pathogens, but there are very few people who know both.”
Bihn said she has received requests from her horticulture colleagues at Cornell to give guest lectures on food safety and to collaborate on publications about incorporating food safety guidelines into field publications.
“The fruit and vegetable industry as a whole is certainly saying food safety is something that we need to be incorporating,” she said.
After four days of intense and strenuous riding through the Blue Ridge Mountains all the way to Atlanta, Ga., the Tour de Fresh is complete. As a result of the ride, many public schools across the country will have fresh salad bars installed in their cafeterias.
Thank you for your support and donations. A special thanks to Village Farms, Riococo, Houweling’s Tomatoes, Grodan, Age Old Organics, UrbanAgNews.com for their sponsorship of Hort Americas’ rider Chris Higgins, General Manager. All of our efforts will directly benefit the Earl Nance Sr. Elementary School in the St. Louis Public School system.
University of Arizona Controlled Environment Agriculture Center’s (CEAC) 2016 short course will focus on controlled environment agriculture (CEA) for food production within traditional rural and non-traditional urban farms. There will be a special focus on water issues, energy use and environmental stewardship.
The short course features a comprehensive program that will assist attendees to successfully produce crops within controlled environments and ensure those crops thrive and are marketable. Speakers and experts will be available to answer questions both during and after the short course. Included with the short course is an exhibitor room where attendees can talk with industry experts about their projects and multiple industry presentations where attendees can meet successful growers and discuss their ideas with them.
Webcast, DVD options
For people unable to travel to Tucson, the short course will feature a webcast option. Webcast attendees will have live access to three days (March 21-23) of short course lectures and materials. They will also be able to submit real-time questions for the speakers to answer. The program consists of six half-day sessions. Those interested in the webcast can register for individual half-day sessions. This allows attendees to choose those presentations they are specifically interested in viewing.
There is also an option to receive a DVD of the lectures if it is not possible to view the live lectures. All attendees have the option of purchasing a DVD of the speakers’ presentations with their registration. The presentations will be available to all paid attendees in an internet database for 90 days after the conclusion of the short course.
Hands-on workshops, optional greenhouse tour
Hands-on workshops are scheduled for March 24 at the University of Arizona’s CEAC research and educational facilities. Some workshops will focus on sensors, controls and fertigation. Other workshops will provide hydroponic production fundamentals for tomatoes, lettuce and strawberries grown in a controlled environment. The goal of the workshops is to connect theory and information with practical hands-on experience. On March 25, there will be an optional tour to a commercial greenhouse operation to tie together the short course presentations and workshops.
For more: Aaron Tevik, (520) 626-9566; atevik@cals.arizona.edu; http://ceac.arizona.edu/greenhouse-crop-production-engineering-design-short-course.
Growers can reduce the chance of disease infestation on greenhouse vegetable crops by incorporating a strict sanitation program and minimizing plant exposure to moisture.
Sanitation and moisture management are key factors in controlling diseases on greenhouse food crops, said Michigan State University plant pathologist Mary Hausbeck.
“Preventing greenhouse diseases starts with sanitation,” she said. “I can walk into a greenhouse head house and predict how many disease problems I’m going to find just by what I see in the head house area. Is it clean? Is it neat and orderly? Sanitation is a mindset. It either carries through from the head house to the growing areas or it doesn’t.”
Hausbeck said growers should try to do a thorough job of removing any plant debris that may be left in the greenhouse, including “pet” plants that may be left in hallways or in the corners of the greenhouse.
“When a grower is making a changeover to another crop there shouldn’t be any other plants left in the greenhouse,” she said. “That is the safest approach.”
Hausbeck said growers should also make sure there is a weed-free perimeter that goes all the way around the outside of the greenhouse.
“There should not be any weeds growing around the greenhouse,” she said. “Growers need to have a critical eye to make sure there is nothing around the greenhouses that can harbor pests or diseases. Ideally all of that needs to be removed.”
Moisture management
Hausbeck said growers should make every effort to limit plant exposure to moisture.
“This includes moisture in the air—relative humidity, moisture on the foliage—leaf wetness, and moisture in the growing medium,” she said. “Moisture is a big driver for disease prevention and control. Growers should limit the amount of moisture by decreasing the relative humidity, watering during the time of day when the foliage can dry rapidly or not getting the foliage wet at all and not overwatering the plant root system. These are things that are important when growing ornamentals and are helpful when growing vegetables. It’s moisture more than temperature. When the humidity is 85 percent and higher, growers should do what they can to reduce the moisture in the growing environment and be vigilant for moisture-loving diseases such as Botrytis to develop.”
Hausbeck said unlike ornamental crops, root rots on greenhouse vegetables are usually not major diseases that wipe out a crop. She said some ornamental crops can suffer considerable losses from the root pathogens Pythium and Phytophthora.
“Diseases that have tended to be major problems on vegetables in the greenhouse include the foliar pathogens downy mildew on cucumbers and cladosporium leaf mold on tomatoes,” she said. “Leaf mold can overwinter in plant debris and soil.
Diseases that tend to be major problems on greenhouse vegetables include cladosporium leaf mold on tomatoes. Photos courtesy of Mary Hausbeck, Mich. St. Univ.
“Vegetable pathogens tend to be crop specific. At the recent 29th Annual Tomato Disease Workshop I attended, most of the conversations centered around bacterial diseases on tomatoes. Those disease pathogens tend to be introduced via the seed. One disease that tomato producers talked about a lot is bacterial canker. This pathogen (Clavibacter michiganensis subsp. michiganensis) can move through hydroponic systems and from plant to plant through root grafting.”
Insect-vectored viruses
When it comes to viruses, ornamentals and vegetables are susceptible to some of the same viruses, including impatiens necrotic spot virus (INSV), tobacco mosaic virus (TMV), cucumber mosaic virus (CMV) and tomato spotted wilt virus (TSWV).
“These viruses have caused sporadic problems for ornamental growers and they can move onto vegetable crops with some devastating results,” Hausbeck said. “If thrips are a problem and there is a reservoir of INSV or TSWV in infected plants somewhere in the greenhouse, ornamental growers transitioning to vegetables need to know the symptoms on susceptible ornamental crops. They need to be especially vigilant since ornamentals can be infected without obvious symptoms.
“In the greenhouse, vegetables are susceptible to some of the same viruses that have caused problems with ornamental crops, including TMV. This means applying the same precautions such as employees not smoking and washing their hands after cigarette breaks. Ornamental growers need to be aware that they don’t get to walk away from these viruses just because they have switched to vegetables.”
Downy mildew is a foliar pathogen that can be a major problem on cucumbers.
Hausbeck said some of the viruses (INSV and TSWV) that attack ornamentals can be moved quite readily to food crops like lettuce via thrips.
“Pathologists don’t like to see the mixing of vegetables with greenhouse ornamentals,” she said. “That’s because INSV and TSWV can be brought into a greenhouse via infected cuttings or prefinished ornamentals. The virus can then be moved to vegetable crops by thrips. Growers need to monitor for thrips. If there are ornamentals growing in one part of the greenhouse, there is a risk that a virus may be moved from ornamentals to the vegetables.
“A virus such as TMV can also be introduced to greenhouse vegetables through infected ornamentals. The virus is easily spread among plants through physical contact such as grower handling.”
Chemical control limitations
Hausbeck said as ornamental growers move into food crop production they may not recognize that there are more limitations on fungicides that can be used on vegetables.
“Over years of production, ornamental growers are used to managing Pythium and Botrytis,” she said. “Those are some of the diseases that can also occur on greenhouse vegetable and herb crops. Growers may think that they can grab the same chemicals they are using on ornamentals like geraniums and poinsettias and use them on food crops. Depending on the product, this may not be legal.”
Hausbeck said on some ornamental fungicide labels the list of plants is very broad.
“Since these chemical labels may be broad in their application to ornamental plants, growers may mistakenly believe that the same product can be used on vegetables,” she said.
Clavibacter michinganesis subsp. michiganensis, which causes bacterial canker on tomatoes, can move through hydroponic systems and from plant to plant through root grafting.
Hausbeck said it is important for ornamental growers who are expanding into vegetables to recognize that they are growing food.
“Food is tightly regulated,” she said. “Growers cannot use a product that isn’t expressly allowed by label to be used on specific vegetable crops. If a crop is on the label, then the grower has to determine if the label allows the use of the product within as greenhouse setting. If there is no mention of a greenhouse on the label, then the product can be used as long as its use in the greenhouse is not restricted. This should be verified through state agencies or through the product registrant.
“Vegetable growers need to read and reread the label before applying any chemical. Growers can’t assume that they can use some of their trusted products to combat a disease like powdery mildew when it occurs on a food crop. And even though ornamental growers can use Truban for the control of Pythium, the fungicide is not labeled for greenhouse vegetable crops.”
Hausbeck said even though some of the pathogens will be similar on ornamentals and vegetables, greenhouse growers need to become educated about the products needed to manage diseases on food crops.
“Growers need to know the key disease threats for the specific crops that they want to produce,” she said. “Manage the greenhouse environment to keep it as clean and dry as possible. When a fungicide is needed, know which products are legal to use on vegetable crops within the greenhouse and know which tools work best.”
BEDFORD, Texas, Sept. 22, 2015 — Hort Americas is a proud sponsor (and rider participant) of the Tour de Fresh. This one-of-a-kind collaborative event unites the most significant brands and influencers in the fresh produce industry for a four-day cycling event that raises funds to benefit the Let’s Move Salad Bars to Schools campaign. The inaugural 2014 event raised over $142,000 and placed over 40 salads bars in communities in 11 states, including California, Colorado, Florida, Illinois, Michigan, Minnesota, Missouri, New York, Ohio, Texas, Wisconsin and the District of Columbia.
The goal of Tour de Fresh 2015 and its participants is to privately finance 100+ new salad bars in school districts across the country. At a cost of less than $3,000 per salad bar per school, sponsors and participants strongly believe that providing healthy eating opportunities for school children should be a requirement and is the foundation of creating positive change for our future.
This year Hort Americas efforts are also being supported by Village Farms, Riococo, Houweling’s Tomatoes, Grodan, Age Old Organics, UrbanAgNews.com as well countless other friends and family. All of our efforts will directly benefit the Earl Nance Sr. Elementary in the St. Louis Public School system.
Greenhouse ornamental plant growers adding edible crops to their product mix should consider incorporating biological controls into their integrated pest management program.
An increasing number of ornamental plant growers are looking to take advantage of the growing demand for locally produced edible crops. Whether it’s for sales in their own garden centers, roadside stands, farmers markets, grocery stores and restaurants, the demand for locally-grown produce continues to increase.
Dr. Frits Went and the Pursuit of the McCree Curve
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