Researchers divulge preventative practices for biocontrol success.
By: Dr. Rose Buitenhuis, Ashley Summerfield and Dr. Michael Brownbridge | 14
Editorial 4
Industry News 6
Grower Day 7
New Varieties 8
Business Issues 10
The retail experience
Technology Issues 11 Solar powered greenhouses
Ventilation Strategies 18
Are your preset controls right for your crop?
Smart Farming 28
First Nations community grows functional foods
Inside View 46 Perpetual energy
A Yukon producer fuels new state-of-the-art greenhouse using biomass technology.
| 34
Cool shades How to make use of energy screens in the summer sun
BY DUANE VAN ALSTINE
They call it ‘the rugose’ What you should know about the new tomato virus
BY GRETA CHIU
The fine print on big data
Is your greenhouse data as private as it seems?
BY DR. JASON BEHRMANN
Photo by: Yukon Gardens
In with the tax, what about the gas?
Last October, the federal government announced a federal carbonpricing backstop for Ontario, New Brunswick, Manitoba and Saskatchewan – four provinces without carbon pollution pricing in place deemed acceptable by Ottawa.
The national goal was to reduce emissions to 30 per cent below 2005 levels by the year 2030, and it was up to the provinces and territories to figure out how. They could either put a direct price on carbon pollution or adopt a cap-and-trade system. For the direct cost option, the price would start at a minimum of $10 per tonne in 2018 and rise by $10 per year to reach $50 per tonne in 2022. For the cap-and-trade option, the number of greenhouse gas emission permits for businesses would be reduced each year, encouraging them to adopt cleaner technologies.
90 per cent of the collected revenue will reportedly be returned to households in their respective provinces. However, Dan Kelly, CEO of the Canadian Federation for Independent Business, tells Global
the recently deposed provincial NDP government.
Perhaps biomass will make a comeback. Our cover story (pg. 34) features a Yukon grower who recently added a hydroponic vegetable greenhouse to his operation, and it’s powered by an automated biomass boiler. Though some will argue that burning trees isn’t carbon neutral due to the time it takes to re-establish a mature forest, the released carbon is largely made up of what was sequestered during the growing process. In the case of our cover story, this grower makes use of trees infested by insects and, in the future, may look towards trees removed for wildfire prevention.
For biomass to succeed, Natural Resources Canada (NRC) notes the importance of supplying it at a competitive cost, with minimal environmental impact and of suitable quality for energy conversion. Enter the forest biomass energy plantation, a designated area for growing biomass meant for bioenergy production. Where natural forests take about 40
...could biomass boilers become a more enticing investment...?
News that there’s no real information on the rebate for small business owners, even though more than half a million businesses will be impacted by the carbon tax.
April 1 has now come and gone. Since then, each of the four provinces have appealed the federal decision through their respective courts without success. The Saskatchewan Court of Appeal recently ruled that the federal carbon tax is indeed constitutional. Alberta may soon become a fifth member of this disgruntled group, once newly minted premier Jason Kenney repeals the provincial carbon levy enacted by
to 100 years to mature, plantations can produce suitable biomass in three to 15 years. Plus, plantations can be established by farmers with extra land and placed near the location of the end user(s). With advancements in multiple aspects of forest biomass production, these plantations can now produce 10 to 15 oven-dry tonnes of biomass per hectare per year.
In the end, it all comes down to cost. Given the changes in carbon taxation, could biomass boilers become a more enticing investment in the near future? Perhaps it could help supplement areas of Canada that are prone to natural gas interruptions.
Greenhouse crops affected in neonic decision
In re-evaluating the effects of clothianidin, imidacloprid and thiamethoxam on bees and other pollinators, Health Canada has cancelled some uses and changed use restrictions on others. Actions will be implemented over the next two to three years.
Thiamethoxam: Cancelled foliar- and soilapplied methods for both outdoor and greenhouse ornamentals that will be planted outside and are attractive to pollinators.
Imidacloprid: Cancelled soil-applied methods for both outdoor and greenhouse ornamentals that will be planted outside and are attractive to pollinators
Clothianidin: Cancelled soil-applied method for greenhouse pepper transplant drench used for transplant outdoors
Health Canada says their re-evaluations were based on “hundreds of scientific studies, from both manufacturers and published literature.”
AI AGRI-TECH COMPANY RECEIVES $3M
Sustainable Development Technology Canada (SDTC) has announced a $3 million investment in an AI-based platform for pest management and yield prediction. The recipient is Ecoation Innovation Solutions, a B.C. company that combines robotics, machine learning and measurements of plant health and biochemistry to create automated solutions for detecting
early signs of stress in greenhouse crops.
“Our platform captures and digitizes the knowledge of growers and translates the signals of stressed plants before symptoms become visible,” says Saber Miresmailli, founder and CEO of Ecoation. “We use robotics and AI to expand growers’ presence and push their knowledge beyond the boundaries of time and geography. Through
this platform, we can pinpoint issues at the earliest stages and eliminate the need for pesticide applications. Ecoation merges the art and science of food production. We are extremely honoured to receive this investment, which will enable us to take our Canadian technology to the global stage while creating more jobs and opportunities here in Canada.”
SDTC funds are used
to help Canadian entrepreneurs “accelerate the development and deployment of globally competitive clean technology solutions,” according to the release.
“The information gathered by the Ecoation robot would be extremely helpful for increasing efficiency and reducing risks within our operations in Delta,” says Casey Houweling, of Houweling Greenhouses.
BY THE NUMBERS - Canada’s natural gas use in January 2019
Grower Day to cover new greenhouse technology
Greenhouse Canada magazine’s annual Grower Day has expanded into a two-day event. Running from June 18 to 19 at the Holiday Inn in St. Catharines, Ont., the event is joined by sister publications Grow Opportunity, Canadian Security and Canadian Packaging.
For greenhouse ornamental and vegetable production, learn about ‘flourishing in the technological age’, featuring leading-edge technology and innovative solutions from researchers and industry experts. Interested growers should register for day 1 of the event on June 18.
DAY GROWER
Biofungicides: Managing plant diseases with microbes
Use of specific beneficial microbes for managing plant diseases has grown steadily over the past 20 years. The keys to success with microbial biofungicides are knowing what they are and are not, what they do, and best-use practices.
Speaker: Dr. Matthew Krause, BioWorks
Managing pests in the digital age
Don’t wait to act. Mobile apps can now help identify greenhouse pests and diseases and even provide best management tips.
Speaker: Dr. Sarah Jandricic, OMAFRA
Clean water: Filter by design
Clean water is one of the most important elements of a successful operation.
Hear about case studies of different biofiltration technologies and wetland designs.
Speakers: Albert Grimm, Jeffery’s Greenhouses; Lloyd Rozema, Aqua Treatment Technologies
Grounds for a DIY mix
From machinery costs to ingredients, this grower shares the highs and lows of using their newly installed mix line for creating their own growing substrate.
Speaker: Brandon Koole, Creekside Greenhouses
Here comes the data crunch
From big data to artificial intelligence, software solutions are rising to the forefront of greenhouse automation. How could they help streamline your operations while lightening your labour needs and improving your business process?
Speaker: Scott Holmes, Extreme Technology
The payback on mechanization:
A tale of two growers
With the continued shortage in labour, automated solutions are at the top of many wish lists. But is the payback worth the initial pain? Two growers tell all.
Speakers: Rodd Gibson, Jeffery’s Greenhouses; Aron Hoff, Meyers Fruit Farms and Greenhouses
Lighting & plant science: A deep dive into using smart LED lighting
New lighting strategies with smart LED fixtures are redefining horticultural lighting. Recent findings demonstrate several growth-promoting advantages: longer photoperiods with relatively low-intensity irradiation can increase leafy green production; specific wavelengths of light at strategic times during the day can benefit both leafy green and vine crop growth and may control THC levels in cannabis; and varying light intensity during the day impacts leafy green development. Additionally, smart LED fixtures with light sensors can work with a DLI predictive algorithm to reduce variability in lighting between days, and use fixture dimmability to reduce electrical usage.
Speaker: Dr. Melanie Yelton, LumiGrow
How to co-exist with your cannabisgrowing neighbour
With lighting and odour issues coming from cannabis greenhouses, how can a flower or vegetable operation peacefully co-exist with their cannabis growing neighbours?
Speaker: Vicki Hilborn, OMAFRA
Winners of the Top 4 Under 40 and new Grower of the Year awards will also be revealed on June 18, presented by Greenhouse Canada .
For growers interested in cannabis, attendees can sign up for June 19 (Day 2). Programme topics include innovation, safety, organic production, outdoor growth, hemp, hiring and more.
GROWER DAY will be running June 18 to 19 at the Holiday Inn in St. Catharines, Ont.
To register, visit growerday.com
Capella Neon Pink Petunia
This compact petunia’s captivating colour literally glows with a luminescent pink hue. For growers, it performs well in propagation, blooms early and creates a tidy quart with minimal PGRs. Works beautifully in baskets and mixes well in combos, while continuing to grow and perform in the home garden. New colours include neon pink, baby pink and ruby pink. danzigeronline.com
Eventide Dark Bronze
Eventide Dark Bronze garden mum features improved shape, timing and uniformity. Rich, dark orange colour with gold in the back of the petals. Suitable for black cloth with a seven-week response time. Fits into three-quart and larger production programs. dummenorange.com
Hydrangea Kanmara Blue
A new generation of hydrangea with large, majestic blooms, Kanmara Blue radiates glamour and is sure to steal the show. Use these patio hydrangeas on the terrace, doorstep or balcony. Flowers well into late-summer or fall. Supplied as dormant, 23-cm pots with eight-plus canes. 51-61cm tall, 86-91 cm wide. ballingenuity.com
Nemesia Momento
Rose Pretty Polly
Featuring all new blue-white and lavender-yellow colours, this series breaks the mold of nemesia with the ability to continually initiate blooms, even under the hottest conditions. Compact habit is ideal for quart production as well as combinations. Finish times range from five to eight weeks, depending on pot size. green-fuse.com
Available in lavender, pink and white, this polyantha rose has very good disease resistance and excellent flowering from spring through fall. It maintains a very pleasing compact habit in the landscape and is nearly thornless. Cuplike, semi-double flowers produce a light, sweet fragrance. Bushy growth, zones 4 to 10. 0.76 m tall, 0.91 wide. starrosesandplants.com
Imara XDR Impatiens
Little Lady Lilac
Little Lady combines the beautifully fragrant flowers of Miss Kim with a more compact, restrained plant that is nearly half the size. In late spring, the dark pink buds open to lilac pink, with a heady fragrance that will tickle your nose! As it matures through the summer, the fresh green leaves will cup upwards as if they were hands
The first Impatiens walleriana with a high degree of resistance to downy mildew, confirmed in independent trials in North America and Europe. Proven landscape performance that fights back with reliable flowering all season long. An easy and economical-to-produce series, ideal for high-density growing in packs and pots. Mounded habit. 25-30 cm high, 25-30 cm wide. syngentaflowers-us.com
praying. The smaller size makes this shrub perfect for foundation plantings, but it can also be used en masse, or as an informal hedge where you don’t need a lot of height. Rock solid hardy, it was bred on the northern plains of North America and will thrive even in zone 2.
Developed in Canada. 1.5m tall, 1.5m wide. jeffriesnurseries.com
Price, convenience or experience
Lessons learned from FICO Eataly World.
Retail is changing and it’s changing rapidly. The key to success is to identify where your business fits into the retail model of the future.
With consumers changing their shopping habits, today’s retailers must identify which of the following three key areas in the market they want to position themselves in:
1. Price: which tends to be led by everyday lowprice retailers rather than discount stores
2. Convenience: which is being slowly dominated by online retailing and especially by Amazon
3. Experience: where the consumer visits a brickand-mortar retailer on a journey of discovery
The majority of brick-and-mortar retailers need to own the experience market where customers come on their journey of discovery. It means no longer “processing” customers but spending more time talking to them. It also means that many retailers will fail due to not being able to develop an experience for their customers, often because they are too product-driven rather than focusing sufficiently on the customer experience. Retailing in the future will require a blend between the two.
With this in mind, I visited FICO a privately-owned ‘edutainment’ park, located in Bologna, Italy. It’s also the world’s largest agri-food park, covering two hectares, with 40 farming factories, 45 restaurants/eating locations and 150 retailers selling and promoting local produce.
developing the in-store experience. Experiences have to change constantly. When I visited FICO one February, the theme of the month was apples. This changes each month, guaranteeing a different experience for the visitor. Education is now part of the new rules in retailing. FICO produces an “Experience Catalogue” that promotes short courses, never more than one hour long, on local crafts including “How to Make Cheese”, “Farm to Steak”, “Making Pasta”, “Passion for Rice” and “Fruit becomes Sorbet”. All are topics that would be of interest to their target consumer. Keep to your values. FICO has very strong values around being local and promoting local stories. 149 of the exhibitors I saw lived the journey. However, one retailer was selling pineapples and bananas from Costa Rica. In discussions with FICO’s senior management, we agreed that this was not part of their values statement. The lesson is, do not let one individual alter the team’s values as it will affect the brand of the entire organization. Include children and ensure you are providing an interactive experience for them. At FICO, children are encouraged to place seeds in a rockwool cube and place them in a hydroponic growing zone. They can take a photo and place it on the FICOdesignated phone app so they can follow their individual seed to harvest. This engages them in the whole experience and again encourages them to return to FICO.
Garden centres have an important role in the new retail scene.
The park is designed so local farmers and artisans can promote, educate and sell. Not every business can invest the same amount of money and time that has gone into this experience, but every business can learn from it and adapt it to their own business model.
Today’s consumer is looking for a local expert in-store as they become more inclined to be “discovery” shoppers rather than “mission” shoppers. This means that the stories and solutions offered by the retailer are important to the overall development of their business. What impressed me was the knowledge of their ambassadors. The ambassador who took us around knew the local stories and could explain how to prepare meals based on the ingredients on offer. Your team members are your business’ ambassadors, and they are important in
Garden centres have an important role to play in the new retail scene.
They are one of the few retail environments that can provide an experience for the whole family and appeal to all generations – few other retailers have this opportunity. To be successful they must develop the experience for the consumer. This often means more consumer gathering places and less product space in-store.
I believe we are going to see more interactive garden centres in the coming years. This is already happening and companies such as Terra in Toronto, Chladek’s in Prague and Aster Garden Centre in Russia have already identified these opportunities. John Stanley is a retail business coach, consultant, speaker and author. His expertise is in customer-focused layout, merchandising, marketing and branding, and customer-focused selling and service. Visit his website at www.johnstanley.com.au.
Windsor researchers study solar-powered greenhouses
University of Windsor researchers have teamed up with local produce growers to improve greenhouse energy efficiency and decrease operating costs.
The two-year project led by Dr. Rupp Carriveau, director of UWindsor’s Environmental Energy Institute and co-director of the Turbulence and Energy Lab, is examining the technical
ABOVE
Dr. Rupp Carriveau (L) and Lucas Semple (R) are pictured at an Under Sun Acres greenhouse in Leamington, Ont. The university has teamed up with the produce grower to examine the feasibility of a solar energy system.
and economic feasibility of a solar energy system designed to reduce dependency on carbon-based fuels for heating and grid-connected power for electricity.
“We’re focusing on energy from the sun,” says Dr. Carriveau, who is working on the project with UWindsor’s Dr. David Ting, co-director of the Turbulence and Energy Laboratory. “The advantage here is that we can offset some of the dependence on natural gas, which of course we know has a carbon footprint and has a notable water footprint as well.”
The innovative system harvests solar energy to bolster both greenhouse heating and power requirements. Carriveau says a defining system feature is its ability to store the solar energy for use in times when the sun is not shining. Advanced
chemical batteries will store the electricity, and water tanks that contain a strategic phase change material (PCM) store the heat.
As Carriveau explains, PCMs can often offer greater heat storage capacity. The water they’re using carries special self-contained “beads” made from a material that will also change phase (say from liquid to gas) as the water heats up. This requires additional heat energy, known as latent heat, beyond the usual amount of energy needed to heat just the water itself (sensible heat).
Funded by the Greenhouse Renewable Energy Technologies R&D Initiative, the project is one of only three projects approved in Ontario and the only led by a university. UWindsor received $98,000 to conduct the comprehensive technoeconomic study.
Chris Del Greco, owner of Under Sun Acres and Rising Sun Acres Greenhouses, is leading the industrial side of the project alongside Lucas Semple, the greenhouse operations engineer and UWindsor Engineering alumnus. The greenhouses produce sweet bell peppers and are located in Leamington, Ont., which is home to North America’s largest concentration of greenhouses.
“From crop production and pest management to heating demands, climate control, ventilation, energy curtains and right into our irrigation recirculation system and packing house, we are always trying to stay ahead and streamline to be more efficient,” Semple says. “Making this whole process more efficient from an energy perspective and from a labour perspective is very important for the whole community.”
The project is now entering final design stages. More granular design details will be added through collaboration with other industrial partners, including Green Sun Rising, Baird Architects and Engineers, and BDK Engineering.
“Behind-the-meter solutions like ours enable growers to reduce their dependency on grid connected energy,” says Carriveau. “This can be welcomed by grid operators who often look for novel ways to meet increasing energy demand without major public infrastructure investments. There are so many possibilities here, including the potential of linking multiple operations in a greenhouse microgrid. It’s exciting work – we’re thrilled to be doing it.”
18 & 19,
DAY GROWER
... IS GROWING!
LEARN MORE AND REGISTER ONLINE AT:
JUNE 18TH
Flourishing in the technological age
Topics include:
• Biofungicides: Microbe vs. microbe
• Managing pests in the digital age
• Clean water: Filter by design
• Grounds for a DIY mix
• Software solutions for greenhouse automation
• The payback on mechanization: A tale of two growers
• Lighting & plant science: A deep dive into using smart LED lighting
• How to co-exist with your cannabisgrowing neighbour
JUNE 19TH
Cultivating your cannabis enterprise
Topics include:
• Innovation in cannabis cultivation
• Safety in cannabis product
• Going organic
• The business case for outdoor grow
• All about hemp
• Procedures and protocols
• Business briefs
• Product packaging
• KEYNOTE: Security and Risk Management for your Cannabis Business
MOVING FORWARD with preventative strategies
To get the most out of your greenhouse biocontrol program, start with preventative strategies.
BY DR. ROSE BUITENHUIS, ASHLEY SUMMERFIELD, AND DR. MICHAEL BROWNBRIDGE
Every IPM strategy emphasizes prevention. This includes starting clean and maintaining a resilient pest management program thereafter. The basic principles to achieve this are minimizing pest entry, maximizing plant resistance and using biocontrol to manage the residual pest populations.
STARTING CLEAN
Cutting dips are becoming common practice. According to the latest floriculture grower survey, 74 per cent of Ontario growers who start from cuttings will dip them first. Research conducted at Vineland Research and Innovation Centre (Vineland) focused on dipping unrooted cuttings in reducedrisk products (e.g. insecticidal soap or oil, biopesticides) and developed methods to control Bemisia whiteflies on poinsettias, as well as western flower thrips on chrysanthemum and bedding plants.
For many of the tested products, efficacy had to be balanced against the risk of phytotoxicity. Consequently, the recommended dip rates are lower than spray rates, in particular for soap and oils. The best rates and product combinations were tested on a larger scale in research greenhouse and commercial greenhouse trials. In all cases, the value of adding dips to the IPM program was clearly demonstrated: dipping not only lowered pest numbers on the cuttings, but also improved subsequent biocontrol of both Bemisia whiteflies and western flower thrips. Dip efficacy against two-spotted spider mites was discovered through an accidental infestation in one of the thrips trials. Subsequent laboratory trials confirmed that both Landscape oil and SuffOil-X are good dipping options against this pest, which is often found on chrysanthemum cuttings and together with thrips. Table 1 summarizes the best performing dips against
1
pests in our research trials. Note that some of these products are still undergoing label expansion to include dipping as an application method, so make sure to check the label. Also, try dips on a small batch of cuttings first, to ensure these products and rates work for you and do not cause any phytotoxicity.
Growers are experimenting to see if dips can help control other pests such as scales, mealybugs, broad mites and aphids. Another possibility is to dip rooted cuttings or liners/ plugs. This type of plant material was not included in the Vineland trials, but growers are seeing positive results from this technique. Some people even double dip, once as unrooted
Model to illustrate how a clean start and optimized plant nutrition can reduce pest population development, as compared to conventional methods.
cuttings and again when the cuttings have rooted. There are many possibilities and every grower should figure out what works for them.
INCREASING PLANT RESISTANCE
There is a growing realization that pest control must evolve beyond the simple application of control products to include
FIGURE
strategies that reduce plant susceptibility to pests and diseases. The systems approach addresses underlying causes of pest outbreaks and considers how mitigation strategies can be integrated with other crop production practices.
One potential approach that is receiving more and more attention is to increase plant resistance to pests by optimizing (i.e. reducing) fertilizer rates. There is no Canadian Food Guide for pests, but they generally need the same kind of nutrients as we do, including carbohydrates, proteins, lipids and minerals. The fertilizer we use to grow our crops will have a direct effect on the plants’ suitability as food for pests. Research has shown that nitrogen is one of the most important nutrients affecting plant-insect interactions and that pests like aphids, thrips and whiteflies flourish on plants grown under high-nitrogen regimes.
In January 2019, Ontario researchers published an article in Greenhouse Canada1 where they demonstrated that the concentration of nitrogen used in chrysanthemum production could be lowered by 75 per cent without affecting plant quality. Other studies at the University of Guelph2 indicate that floriculture crops like gerbera and mini-roses are also likely over-fertilized.
So the question becomes, if we lower nitrogen, will we also lower the risk of pest outbreaks? This is the subject of a joint research project by Vineland and Ontario floriculture specialists Dr. Sarah Jandricic and Dr. Chevonne Carlow at the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).
Funded by the Canadian Ornamental Horticulture Alliance (COHA) research cluster, the goal is to identify nutrient levels that reduce western flower thrips and greenhouse whitefly population growth, on chrysanthemum and gerbera
Best performing dips for controlling pests on unrooted cuttings. *Rate depends on the sensitivity of the crop.
respectively, without negatively affecting the production period or the quality of the finished plant. In addition, this project will determine if biostimulants can play a role in this system by helping plants cope with reduced nutrients, improving general plant health or even inducing plant defences against pests. The next step will be to investigate if reduced fertilizer rates will improve the efficacy of biocontrol agents and how. For example, lower nutrient levels may slow down pest population growth and make it easier for biocontrol agents to ‘catch up’, or perhaps change pest susceptibility to biocontrol agents. Ultimately, commercial greenhouse trials will demonstrate the benefits of integrated nutrient and pest management strategies.
IMPROVING BIOCONTROL SUCCESS
Early intervention tactics, such as starting clean and growing resistant plants, address some of the major causes of pest outbreaks. Dipping reduces pest populations right at the start and buys time for biocontrol agents to start working. We predict that optimized plant nutrition will slow down pest population growth, which makes it easier for biocontrol agents to manage residual pest populations. This makes biocontrol programs much more stable and resilient, less about chasing after outbreaks and more about maintaining low pest numbers.
REFERENCES
1Shelp, B.J. et al. https://www.greenhousecanada.com/ inputs/fertilizer/moving-towards-low-input-floriculturaloperations-32713
2Zheng, Y. et al. (2004). HortScience, 39(6), 1283–1286; Zheng, Y. et al. (2010). HortScience, 45(9), 1378–1383.
ACKNOWLEDGMENTS
Thanks to Wonhyo Lee for technical assistance. This research is supported by the American Floral Endowment (AFE) and the Canadian Ornamental Horticulture Alliance (COHA) in collaboration with BioWorks, Neudorff, Dümmen Orange, Concentric, Premier Tech, l’Institut québécois du développement de l’horticulture ornementale (IQDHO) and Flowers Canada (Ontario).
Rose Buitenhuis, PhD, is the research scientist in biological control, Ashley Summerfield is the research technician in biological control, and Michael Brownbridge, PhD, is research director of horticultural production systems at Vineland Research and Innovation Centre. Contact rose.buitenhuis@vinelandresearch.com.
Fafard O series regroups our best selection of high performance soil mixes approved for organic culture.
Organic grower, we’ve got you covered.
EMPOWER PLANTS through well-balanced ventilation
Rather than aiming for a preset greenhouse temperature, ventilation should be used to support the plant’s water and CO2 needs.
BY JAN VOOGT
In January’s issue of Greenhouse Canada, readers were introduced to the concept of ‘Growing by Plant Empowerment’ (GPE). Combining grower experience and knowledge of plant physiology, the goal of GPE is to optimize the behaviour of plants in the greenhouse environment by maintaining critical balances involving energy, water, CO2 and assimilates within the plant.
These balances can be monitored by sensors, combined with crop measurements, then interpreted in the context of plant physiology and physics to help finetune and improve the crop.
In the first article of this multi-part series on GPE, the importance of a greenhouse’s irrigation strategy, in relation to the water balance of the plant, was explained (see March/April 2019 issue of Greenhouse Canada).
In this second article, we will explore the importance of GPE in a greenhouse’s ventilation strategy, focusing on the relationship between ventilation and plant evaporation, and eventually how a wellbalanced ventilation strategy can promote photosynthesis and light use efficiency (LUE).
WELL-BALANCED VENTILATION
Typically, a ventilation strategy consists of a mixture of different methods. First, there may be a minimum window opening needed to avoid a build-up of adverse gases like NOx, ethylene, etc. The release of moisture may be another reason to increase the angle of the window opening, which also depends on weather conditions. Typically, the main driver for large window openings is temperature control. It is often believed that temperature is the key to plant development, and that a too-high temperature reading must be avoided at all times.
CO2 uptake for photosynthesis by keeping the stomata open under high radiation conditions. This maximizes LUE and production of assimilates for growth and development. Therefore, ventilation should be used to achieve the right combination of climate conditions, rather than simply reaching a specified temperature.
THE ENERGY BALANCE OF THE GREENHOUSE
First of all, a few words need to be said about the energy balance and the moisture balance of the greenhouse. Figure 1 shows the different energy flows that, together, form the energy balance. The Law of Conservation of Energy
The ultimate goal of the ventilation strategy, however, should be to support the plant’s water balance and to ensure
says that the output must equal the input. It is essential to note that the energy balance is largely influenced by greenhouse temperature relative to the temperature outside. If the temperature outside increases or decreases, the greenhouse temperature will rise or drop accordingly because different elements of the balance are determined by the difference in temperature between indoor and outdoor, rather than its absolute value. As a result, the greenhouse climate is strongly
FIGURE 1. The energy balance of the greenhouse
affected by weather conditions. Moreover, the energy balance is linked to moisture balance, as will be explained in the next section.
THE MOISTURE BALANCE OF THE GREENHOUSE
Figure 2 shows the different input and output moisture fluxes that, together, form the moisture balance of the greenhouse. The Law of Conservation of Mass requires that, again, the output must equal the input. The moisture balance influences the absolute humidity of the greenhouse air, measured in grams/kg dry air, or grams/m3 air. Taken together with air temperature, this allows us to calculate the relative humidity (RH).
The relationship between absolute humidity and air temperature is described by the well-known psychrometric chart. It is beyond the length and scope of this article to elaborate too much on the characteristics of humid air that can be found on this chart. For those who are interested, there is an online version of the psychrometric chart available at http://gpe.letsgrow.com/psychro.
Typically, a large part of the energy from solar radiation is “absorbed” by the crop and “converted” to water vapour (latent heat) by evaporation. This is why the energy balance and moisture balance of the greenhouse are closely linked. The greenhouse climate is a result of the interaction between greenhouse conditions and crop activity. The same goes for the greenhouse’s energy balance, moisture balance, and CO2 balance.
Now, let’s look at how we can optimize photosynthesis using greenhouse climate control, with particular emphasis on ventilation strategy.
EVAPORATION OF THE PLANT
Plant evaporation is driven by energy supplied by both radiation and convection. Radiation is, in principle, independent of the conditions of the air. Neither air temperature nor humidity will
influence this. Convection, however, depends on air movement and the temperature difference between the leaves and the air. When leaf temperature is lower than air temperature, convection energy contributes to plant evaporation by moving heat towards the leaves. If, however, the plant temperature is higher than air temperature, convection helps keep the plant cool by moving heat away, and decreases the need for evaporation.
FIGURE 2. The moisture balance of the greenhouse
THE ROLE OF AIR HUMIDITY
It is well-known that a low relative humidity (RH in %) or a high humidity deficit (HD in grams/m 3) promotes plant evaporation. The latter can also be expressed as vapour pressure deficit (VPD in kPa). Unfortunately, there are some misunderstandings around VPD because this abbreviation can have two different meanings, namely vapour pressure deficit or vapour pressure difference.
Vapour pressure deficit depends only on the condition of the air and is just another way to express HD. Vapour pressure difference is the difference between the water vapour pressure inside the plant’s leaves and the vapour pressure in the air. This VPD can only be calculated if the plant’s leaf temperature is being measured, for instance with an infrared sensor. Our previous article mentions how VPD should not exceed 1.5 – 2.0 kPa for most types of crops, because this indicates water stress.
In general, a low RH, and hence a high HD and vapour pressure deficit, leads to a lower leaf temperature in relation to air temperature. This doesn’t necessarily imply a high vapour pressure difference, as long as water availability inside the plant is sufficient and stomata are open enough to let in CO 2. As a result, total plant evaporation is high, because convection contributes to the input energy supplied. Under high radiation conditions, however, the total evaporation rate may be faster than the plant’s rate of water uptake, and stomata will start closing in order to maintain water balance and avoid dehydration.
The first direct result of stomatal closure is an increase in leaf temperature. Evaporation is hampered, and as a result, the energy balance has to shift to a new equilibrium state. This is found at the point where the lower evaporation rate matches the lower influx of convective energy. This way, the energy and water balances are restored, but at the cost of a lower CO 2 influx because the intake through the stomata has been reduced.
This problem becomes even more severe if RH is lowered further. To reduce the evaporation rate, the stomata now have to close even more and CO 2 uptake is restricted even further. In contrast, if the RH were higher, the degree of stomatal closure would be less, and the plant would be able to control its water balance more easily without affecting CO 2 uptake too much. In other words, a high RH allows the plant to keep its stomata more open, even if it has to restrict evaporation to some degree.
THE EFFECTS OF THE COMMON VENTILATION STRATEGY
The usual ventilation strategy focuses mainly on moisture exhaust and air temperature. Let us now take a look at this from the perspective of LUE.
Under high-radiation conditions, greenhouse temperatures tend to reach 30 °C or higher. For most growers, this is one reason to open the windows further. As a result, the exhaust of moisture and, in the case of CO2 enrichment, the loss of CO 2 through the vents is accelerated. The decreasing RH, however, increases plant evaporation which, most likely, leads to further closing of the stomata. At the same time, in the case of CO 2 enrichment, the CO 2 concentration in the greenhouse decreases. Together, this leads to greater plant stress and poor photosynthesis.
FIGURE 3
Energy fluxes and plant evaporation (1A=solar radiation; 4B= Convection energy towards the plant; 2A = Evaporation as a result of radiation energy; 2B = Evaporation caused by convective energy.) Leaf temperature must be lower than air temperature in this diagram because convective energy is moving towards the plant (4B).
AN IMPROVED STRATEGY BASED ON PLANT EMPOWERMENT
Now let us think of a different strategy that aims to support the plant balances.
Under high radiation conditions, we would like to maintain LUE at a high level. This means that the stomata must be kept open as much as possible to let CO2 in, so the plant can benefit optimally from the available PAR light. In the previous section, we explained that this can be achieved by increasing the RH, closing the vents further instead of opening them further. This also restricts CO2 loss by ventilation. Both effects promote photosynthesis and LUE.
The commonly expected steep rise in greenhouse temperature does not occur due to two reasons. First, warm moist air can contain much more energy (also called enthalpy) per m3 than dry air. So if RH is higher, the same cooling capacity can be achieved by a much lower ventilation rate in m3/m2·hour. This can be easily derived from the online ventilation simulation model provided by LetsGrow.com (http://gpe.letsgrow.com)
Second, when the crop is less stressed, plant evaporation is kept going and more solar energy is absorbed by the crop, resulting in better cooling of the greenhouse.
WHAT IF CROP EVAPORATION CAPACITY IS TOO LOW?
Depending on the type of crop, as well as the crop stage, there may be an imbalance between radiation intensity (W/ m2) and crop evaporation capacity (grams/m2·hour). In that case, keeping a high RH within the greenhouse may require extra instruments such as a high-pressure misting system or something similar.
As an alternative or additional measure, white wash could be applied or a retractable shading screen, preferably a diffuse
While the crop he’s built a business around may be teeny, tiny, Greenbelt Microgreens owner Ian Adamson’s big-picture thinking is yielding impressive results. When it was time to replace their greenhouse’s cloudy double polyethylene covering, Canada’s largest producer of organic microgreens put quality first. After investing in ACRYLITE® Alltop high impact UV transmitting acrylic multi-skin sheet, Adamson estimates that crop yields have improved by 40% and the growth cycle has been reduced by 20%. Macro thinking can truly take a company’s crop to new heights. Call us today to learn more. 1.800.631.5384. www.acrylite.net
FIGURE 4
This graph shows the climate conditions on consecutive days. The green bars indicate to what extent the climate is considered “optimal”. If the score is below 100 per cent, the grower is urged to further analyze the situation and seek out the factor restricting optimal growth.
type of screen, could be used above the crop.
It must also be mentioned that the photosynthetic capacity of the crop, expressed in a maximum PAR (photosynthetically active radiation) level in micromoles/m2·s, can require the application of white wash or shading screens. The history of ‘Next Generation Growing’ in The Netherlands has shown, however, that what was believed to be light stress in many crops actually appeared to be water stress. Thanks to this new insight, a higher PAR light level can now be tolerated in combination with a higher RH level under high radiation conditions. As a result, higher growth rates and better production and quality can be achieved.
THE LETSGROW CLIMATE MONITOR MODULE
LUE is mainly determined by four climate factors: PAR level, CO2 concentration, humidity (RH and VPD), and temperature. Now the question is, how do we continuously monitor all of these factors in order to know which factor is the limiting one that should be improved to push LUE to the max? For this purpose, the LetsGrow.com online climate monitor was developed. This climate monitor module provides growers with a very powerful tool to assess the realized growth conditions at a glance.
parameters. If all are within the predefined range for the given irradiation/PAR level, the score is 100 per cent. If one or more are out of range, the score is lowered depending on the degree of deviation.
SUMMARY
Ventilation should be aimed at allowing the plant to optimally benefit from the available light for photosynthesis. In practice, different strategies can lead to reasonably good results. The best ventilation method, however, takes the energy and water balances of the plant as a starting point, and strives towards the best combination of PAR light level, CO2 concentration, humidity (RH and VPD) and temperature, thus optimizing photosynthesis and LUE. In many cases, this can be achieved by just keeping the vents more closed under high radiation conditions.
Ventilation should be aimed at allowing the plant to benefit optimally from the light.
LEARN MORE ABOUT PLANT EMPOWERMENT
The starting point is that optimal growth can be achieved by aligning air temperature, humidity and CO2 concentrations with the actual radiation or PAR light level.
The grower can enter the desired climate conditions depending on the irradiation/PAR level. For each condition, a minimum and maximum value can be defined, where the range in values is considered “optimal”. The grower defines, for instance, that at a PAR level of 300 micromoles/m2·s, the temperature should be 24 to 25 °C, RH should be between 60 to 70 per cent, and CO2 should be between 450 – 500 ppm.
The climate monitor continuously scans all of the
GPE is based on the same principles as ‘Next Generation Growing’ (NGG), developed in the Netherlands over the last 15 years. It has been shown that this approach can deliver significant advantages regarding production and quality, plant health and energy savings for many different crops. For the most part, this can be achieved without extra investments in greenhouse equipment.
The basic principles have been further developed, refined and extended, focusing on optimal growth in a sustainable way and going by the new name ‘Growing by Plant Empowerment’. For more on GPE and the book Plant Empowerment: The Basic Principles, visit plantempowerment.com. Copyrights of text and illustrations: LetsGrow.com, 2019.
Jan Voogt is a senior researcher at Hoogendoorn Growth Management and is one of the authors of Plant Empowerment: The Basic Principles.
Putting on your summer shades
A properly installed curtain system could help maintain an ideal climate inside your greenhouse.
BY DUANE VAN ALSTINE
As energy and production costs continue to rise for the horticulture sector, commercial greenhouse growers need to do all they can to operate more efficiently. One way growers are doing this is by installing energy curtain systems in their greenhouses.
Many growers have already seen, or heard of, the benefits that energy curtains can provide during the winter when heating costs are high. However, growers are also beginning to realize the benefits that curtains can provide during the summer, acting as shade to their crops when the days are longer and sunlight levels are significantly higher. It doesn’t take long for the radiant heat from the summer sun to send the temperature inside the greenhouse soaring far beyond what’s desired, but a properly installed curtain system can help to maintain an ideal climate inside.
Energy curtains, also referred to as energy
screens, are retractable components made from composite materials. Curtains are installed above or below the trusses, but most often above to accommodate supplemental lighting. They can be installed to open and close across the greenhouse, from gutter to gutter, or can cover and retract across the length of the greenhouse. A flat curtain system is typically the most cost-efficient choice, but how your curtains are installed depends on the needs of your crops.
The three most common categories of curtain materials are nonporous, porous, and semiporous. Nonporous materials, such as poly film, are generally not ideal for greenhouse curtains as they don’t allow for condensation from the roof to penetrate. A semi-porous material is generally the most practical choice for both heat retention and shading. Typically made from alternating pieces of aluminized and clear polyester or acrylic fabric
woven tightly together, semi-porous curtains allow condensation to pass through with little air exchange between the upper and lower sides of the curtains when they are closed.
USE IN THE SUMMER
When installed and used correctly, your energy curtains will help to create and maintain an ideal growing environment for your plants. Curtains should be closed when they can improve conditions inside the greenhouse, but they can be opened when outside conditions are more favourable.
In the winter, curtains can help keep heat inside the greenhouse. For example, when the sun goes down in the winter, your curtains will likely need to be closed completely to ensure the heat doesn’t escape. But in the summer, curtains are also used to keep the heat out of the greenhouse. When daytime temperatures rise, curtains can help reduce indoor temperatures and provide shade for your crops. Orchids, for example, are an extremely sensitive plant that can burn quickly if too much sunlight is allowed in their growing area. Having shade
curtains can help to reduce and disperse sunlight so plants are protected. On summer nights, slightly or completely open curtains will allow the cooler air to hit your crops.
Your curtains can also be used in conjunction with your roof vents to help manage the humidity in the greenhouse. Having your vents open while the curtains are closed, or nearly closed, will allow fresh, cooler air inside the greenhouse while still having a barrier that prevents too much colder air from hitting the crop. If the humidity is too high inside the greenhouse, the curtains can be opened slightly along with the vents to lower the humidity inside. Your curtains can also be used in conjunction with your heating system to reduce humidity. You may find that humidity buildup can be problematic on summer mornings, but turning up your under-bench heat while opening shading and vents will get rid of the humidity quickly. Once the humidity is manageable, the shading and venting can be returned to automatic settings. Using your shade curtains in conjunction with your roof vents and your heating system will help ensure your crops are
benefiting from an ideal environment while saving on energy costs.
Curtains also have the potential to decrease your water use during the summer. When your curtain system is working in conjunction with your irrigation system, it will reduce your crops’ needs for water uptake. Strict water regulations and drought control takes effect in many areas during the summer months, so growers should do all they can to obtain maximum value from their water resources. Be sure to talk to an expert to see how a shade curtain system can reduce your irrigation costs.
AUTOMATE ENERGY CURTAINS FOR MAXIMUM EFFICIENCY
Your crops will see the most benefit from your curtains during the spring and summer months if they’re controlled by a central environmental computer. Automating your shade curtains is important, not only because they control the amount of natural sunlight that’s allowed into the greenhouse, but because they affect other environmental conditions including lighting, temperature, airflow and humidity. All of these factors can be a lot to keep track of if you’re only using a manual or semi-automatic system. Full automation will provide peace of mind that your curtains are providing your plants with their ideal environment. We recommend that you review your controls over as many past seasons as possible, using this information to help improve them for the current season. An automated system will make things easier but it’s equally important that you avoid becoming complacent with the parameters you have set. A day in June can be drastically different from a day in July, so it’s important that you’re paying constant attention to your controls and making the necessary changes to avoid negative effects on your crops and minimize energy wasted.
The type of curtain system and material you have installed in your greenhouse will depend on various factors including the regional climate, the style of greenhouse and the crop environment. There are numerous options available, so work with knowledgeable experts who will ensure you’re getting the best curtains at the best value for your plants.
Duane Van Alstine works on special projects for GGS Structures Inc. For more on energy curtains, visit ggsstructures.com.
Farming smart in northern Manitoba
Food accessibility has long been an issue in more remote regions of Canada. This northern initiative puts new indoor farming technology to good use in the OCN community.
Q&A WITH JOAN NIQUANICAPPO AND STEPHANIE COOK OF OCN SMART FARM
For the Opaskwayak Cree Nation (OCN) in northern Manitoba, new smart farming technology is improving their access to fresh, healthy food in a big way.
Presented at the Canadian Greenhouse Conference (CGC) last fall, operations manager Stephanie Cook and general manager Joan Niquanicappo of the OCN have been heading a vertical farming pilot project that offers affordable, fresh produce to those living in remote regions.
According to the presentation, a study by the Opaskwayak Health Authority showed that close to 50 per cent of the OCN community suffered from diabetes – an alarmingly high rate.
In partnering with the University of Manitoba, they hoped to conduct a health research study to explore whether functional produce from the smart farm, along with the right educational resources, could help lead to change in the community – all while ensuring that the farm could be a viable business in its own right.
ABOVE
Partnering with technical specialists from Korea Agriculture System & Technology (KAST), the first seeds were planted on the smart farm in February of 2016. Over 70 different varieties of plants have been successfully grown since.
Following their presentation at the CGC, Greenhouse Canada magazine followed up with Cook and Niquanicappo on their smart farming journey.
Q: What prompted you to begin a vertical farming operation?
Niquanicappo: The concept of a year-round produce growing facility was intriguing. For the OCN to initiate a project of this scope, the ability to produce fresh vegetables – and functional vegetables at that – this was exciting. It was astounding to find that vegetables could help combat chronic illnesses, such as diabetes and its complications. A hydroponic system, utilizing recyclable water, no soil, no pesticides/chemicals, independent of weather,
Since the first seeds were planted in 2016, members say the OCN Smart Farm has successfully grown over 70 different varieties of vegetables, flowers and fruits.
THINKING ABOUT INSECT PROTECTION FOR YOUR GREENHOUSE? THINK FMC.
Choosing the right insecticide makes all the difference to your production and profitability. FMC has you covered, with three proven control products to protect your high-value crops.
Use Exirel® insecticide early to give cucumber, pepper, tomato and eggplant foliage the protection it needs during the most critical stage of development. Translaminar and locally systemic movement, plus rapid absorption ensures the product moves through the plant quickly to control cabbage looper, whiteflies, pepper maggot, pepper weevil1 and thrips1
Coragen® insecticide is a unique broad-spectrum, Group 28 active that controls pests resistant to other insecticides. It quickly stops insects feeding and delivers control at all growth stages. Protect your cucumbers, tomatoes, eggplant and pepper plants from cabbage looper and lepidoptera leafminers.
Beleaf® 50SG insecticide, a Group 29 product, targets piercing and sucking pests effectively. Protect your strawberries, cucumbers, peppers and tomatoes from thrip, aphid, lygus bug and whitefly feeding damage.
and all using smart technology – the opportunities were endless.
Q: What problems did you enounter during the initial set-up?
Niquanicappo: Beside the initial stage fright, the main problem was to have all the equipment CSA approved. There were growing pains in that short period of time from December 2015 to March 2016, but we were able to overcome them. The logistics of preparing the equipment to Canadian standards was time-consuming, and the cost of utilizing tradespeople was very high. The training of local people to assemble, maintain and operate the smart farm was not a problem, but it was still very new, so there was a bit of uncertainty on our part. We have since successfully grown 70 different types of vegetables, flowers and fruits.
Q: How do you control or prevent diseases and insect pests?
Cook: We follow strict sanitation procedures, including Hazard And Critical Control Points (HACCP) developed by KAST and adapted to our
Smart Farm for caring for the plants personally and procedurally. We ensure that our Smart Farm is sanitized regularly. As our Smart Farm operates in our community hall, whenever an event is held, we wait two days before entering the farm. Our pest control consists of natural remedies such as lemon juice with water or vinegar and water to help with arachnids, arthropods, dipterans, aphids and other pests.
Q: How do pricing and freshness compare to imported products?
Cook: When we started selling our produce, it was being distributed to community members who had been coming back for the freshness, so the price remained constant throughout the year. Unlike imported vegetables, our produce is grown locally for freshness, and available all year round.
Q: Since the farm’s inception, how has the community responded?
Cook: The community members cannot wait for each harvest. They welcome the produce with curiosity, both to newly
introduced varieties and to common produce such as lettuce and herbs.
Q: What’s next for the smart farm? Niquanicappo: We will be using the smart farm to combat diabetes. We are going to conduct a research study with community members living with diabetes or preexisting diabetic conditions. We also want to explore ways in which we can make our operations sustainable through the sale of the smart farm equipment, service and maintenance packages, as well as supply sales.
From members of the OCN Smart Farm: On November 9, 2018, the OCN lost a close and valued colleague, Isaac Jung. Jung was instrumental in forming the relationship between the OCN and KAST, which resulted in the creation of the OCN Smart Farm. Isaac will always be remembered as a true partner of the OCN. He will be missed.
Editor’s note: Responses were edited for length and clarity. Thank you to all the participants from the initial phone call, as well as those who replied over email.
Growing is your business. Protecting it is ours!
Since 1963 we have been providing high quality insurance protection to our clients from coast to coast. Experienced, local service is available through our national network of offices. For a quality product, local service and very competitive pricing give us a call today.
Spotting the rugose virus
Vegetable greenhouses urged to practise strict hygiene protocols as studies on virus continue.
BY GRETA CHIU
Canadian greenhouse vegetable growers have adopted strict sanitation protocols as a new tomato and pepper virus continues to emerge in different parts of the world, including North America.
“There were a number of detections in Mexico,” says Niki Bennett, science coordinator at Ontario Greenhouse Vegetable Growers (OGVG). Known as the tomato brown rugose fruit virus (‘TBRFV/ToBRFV’ or ‘the rugose’ for short), the disease has been detected in approximately 100 cases across 20 states in Mexico. It was detected in Belgium and the Netherlands earlier this year.
“All you really need is one bad seed in a bunch,” says Bennett. Able to survive months to years outside of a plant host, the viral disease is highly contagious and can be transferred via seed, human contact, clothing, tools, containers and other surfaces such as string, poly and troughs.
According to the Cultivation Insight fact sheet provided by De Ruiter, symptoms of the rugose were first spotted in Israel in 2014 on tomato varieties with the Tm22 gene, which provides resistance to the tobacco mosaic virus (TMV)
ABOVE
and tomato mosaic virus (ToMV).1 The virus was then detected in Germany,2 southern Italy2 and California in 2018. With all of the infected plants destroyed, the disease was presumed to be eradicated in California.
While there are no confirmed cases in Canada, Bennett says growers should take the necessary precautions as trade pathways are highly integrated within North America. All commercial tomato varieties are suspected to be susceptible.
“The host range is still being established,” Bennett adds. Many of its known hosts exist across the country, including petunias, nightshade weeds, goosefoot weeds and tobacco. Potatoes and eggplants are not known to be affected.
FAMILIAR SYMPTOMS
Symptoms are similar to other tobamoviruses such as TMV and ToMV, says both OGVG and De Ruiter. On tomato and pepper leaves, this includes mosaic discolouration, yellowing of leaf veins and occasional narrowing of leaf blades. On the fruit, yellow spots and brown
Symptoms show a rugose fruit surface with brown streaking and calyx necrosis.
rugose (wrinkled) patches can appear. Necrotic lesions can sometimes form on peduncles, pedicels and on the calyx.
It’s easy to mistake the virus for others, since symptoms are very similar, says Marcin Widecki, technical sales representative at De Ruiter.
The Cultivation Insight fact sheet states that symptoms of the virus appear within 12 to 18 days of infection. Infection at a young age will lead to more severe symptoms, and plant stress tends to exacerbate it. Other factors such as variety, growing conditions and nutrition will affect it as well. The impact on production can be substantial, losing as much as 30 to 70 per cent yield.
TAKE PRECAUTIONS
De Ruiter representatives say many of their customers are taking precautions, ensuring updated hygiene protocols, closing greenhouses to visitors and limiting the movement of workers from one greenhouse to another.
As Bianca Jamieson, spokesperson for the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) explains, “all recommended biosecurity measures are good practice for prevention and management of any pest or disease that has potential to spread to new locations.”
General preventative measures include strict sanitation and thorough clean-outs between crops, as well as regular disinfection of surfaces that receive heavy traffic or contact with plants or people (e.g. tools, carts, crates, pallets, packing lines, door handles, fork lifts, walkways, irrigation systems). Workers should wear freshly laundered clothes with clean boots that remain in the greenhouse. Disposable coveralls and boot covers are advised. Thorough handwashing and disinfection are critical.
If the disease is suspected or found, OMAFRA is advising growers to send samples to a diagnostics lab, remove infected plants promptly by placing them in sturdy garbage bags, block off rows and restrict access, and rotate crops if possible.
FUTURE EFFORTS
De Ruiter has accelerated their breeding efforts to combat the rugose, but it’s not ready yet. “We recognize the importance of this, and we’ve prioritized looking into a breeding solution for it,” says Emily Hackstadt, North America marketing
manager for De Ruiter. “While there’s nothing commercial on the market yet, it’s something that our team is focusing our efforts on.”
The vegetable seed company is also taking precautions against the virus and other pathogens. “De Ruiter ensures that strict hygiene protocols are put in place through the Good Seed and Plant Practices (GSPP) Certification to prevent spread of harmful infections like ToBRFV and many other viruses,” says Hackstadt. In the meantime, awareness and
education are top priorities. “Growers should train their team to not only take the right precautions, but to also understand the symptoms and how things spread,” she adds.
REFERENCES FROM CULTIVATION INSIGHT FACT SHEET
1 Luria, N., et al. 2017. A new Israeli Tobamovirus isolate infects tomato plants haboring TM-2(2) resistance genes.
2 EPPO Global Database. https://gd.eppo. int/taxon/tobrfv
heavy soils conditioning improvement used in potting soil mixes odorless mixes with peat moss
natural soil conditioner for lawns, gardens and plants improves soil aeration neutral PH
quantity and size available upon request
increases water and fertilizer retention in soil
preserves bulbs and roots germinating seeds and rooting cuttings improves potting and transplanting
natural soil conditioner for lawns, gardens and plants improves soil aeration neutral PH
GREENHOUSE HEATS UP IN NORTHERN
LEFT
Yukon Gardens’ new hydroponic vegetable greenhouse runs on a new automated biomass boiler.
Armed with the latest greenhouse technology, this Yukon grower is bringing fresh vegetables to Canada’s northern climates.
“The learning curve is pretty steep,” admits Lorne Metropolit, owner and operator of Yukon Gardens in Whitehorse, Yukon. Like many other experienced greenhouse growers, he was used to doing most tasks manually before. With the help of his friend and experienced greenhouse consultant, Dr. Mohyuddin Mirza, as well as other experts in the horticultural trades, Metropolit was able to make his state-of-the-art greenhouse a reality.
Completed last spring, their new 30,000 sq. ft hydroponic vegetable greenhouse is climate-controlled through a new computer system. But unlike many other greenhouses in more southern climates, Metropolit’s latest expansion runs on an automated biomass boiler.
Log firewood burning is a very common way to heat homes in this region, he says, and they’ve been using outside boilers for the past 30 years. “The novelty wears off when you get up at four o’clock every morning to feed the boilers.”
Now with the new boiler system from Europe, fuel is delivered to Metropolit’s operation in the form of wood chips, which are kept in a storage bin and automatically fed into the new boiler through an auger. The heating system is phenomenal, he says, with a nice, even and constant flow. The manufacturer and distributor both
monitor the performance of the boiler, and are available by phone to assist with any issues 24/7.
As for the source of fuel, Metropolit’s operation is making use of standing dead trees in the Haines Junction area, approximately 90 miles from his operation. “Many years ago, we had a huge infestation of spruce beetle,” he explains. Rather than letting the trees rot and release greenhouse gases during the process, the wood is processed into wood chips, which are then purchased by Metropolit.
There’s another source of biomass that may soon emerge for the greenhouse. It’s part of an approach called Firesmart, he explains. Enacted by the Yukon government, the program clears and thins out spruce and pine around populated communities to reduce the possibility of a wildfire.
According to the 2016 Yukon Biomass Energy Strategy document, close to $60 million is spent annually on fuel and electricity to generate heat in the territory, where three-quarters is made up of imported fossil fuels. With this biomass strategy in place, the territory plans to reduce its dependence on imported fossil fuels, and instead, meet their heating needs using wood harvested in the Yukon.
However, the report also notes the challenges involved in growing a biomass energy industry. For one, older woodstoves and outdoor boilers can be inefficient, releasing
Yukon Gardens’ latest addition makes use of a growing biomass economy.
BY GRETA CHIU
NORTHERN CANADA
particulate matter into the surrounding air. The territorial biomass strategy would require modern, more efficient biomass systems that burn more cleanly and are equipped with automated fuel feeds – much like Metropolit’s.
Second, the process of harvesting would need to be managed from a sustainability standpoint, while minimizing social and environmental impacts. According to the territory’s report, 112,000 hectares of forest in the Yukon are consumed by forest fires each year. “This represents nearly 200 times more wood than is currently harvested for energy use in the territory.” That would open up opportunities for salvaging wood previously damaged in burned areas, infected by insects, produced by sawmill waste or discarded from tree thinning or clearing FireSmart activities.
LOCAL PRODUCTION COSTS ARE HIGH
“The majority of the vegetable production up here is outdoors, and that doesn’t come on stream until mid-tolate June,” says Metropolit. The territory depends on food, fuel and other supplies transported by truck, but it’s a trip that can be hampered by Mother Nature, including spring washouts on the Alaska highway or forest fires.
With new horticultural technology on the market, locally produced vegetables are becoming more feasible. It’s also more environmentally friendly compared to hauling food over long distances by diesel-fuelled trucks. But running a greenhouse isn’t exactly cheap. For Metropolit, the costs of building the greenhouse and keeping it heated make up some of his highest expenses. Because of this, it’s more costly to produce vegetable up north than it is to import them by truck, he says.
Although his products are priced about five to 15 per cent more, the ‘buy local’ movement has been a gamechanger for them. “If you want a high-quality tasting tomato, you try to harvest it as late as possible and still be acceptable to the market,” says Metropolit. “We’ll harvest in the morning [and] it’ll be in the grocery store by noon.” Produce from southern climates such as California, Mexico or Ontario are more likely to be picked pink to ensure their survival during the shipping process. “They taste green
ABOVE
Lorne Metropolit and his daughter Kelsey supply local markets in the Yukon, reducing the need for produce transported by truck from southern latitudes.
[and] they don’t have the sweetness [or] the flavour,” he explains, “which is to the benefit of local producers.”
With the high costs of building the greenhouse, Metropolit decided to forego supplemental lighting. “A lot of places in Alberta will grow year-round without lights,” he explains. Production during the darker months may not be as optimal as the summer months – they receive close to 22 hours of daylight on June 21 – but they’ve also found that there is enough natural light by midFebruary to grow without electrical help. With the high costs of installing the lights and running them, other areas took precedence for the high-tech operation.
The cost of obtaining his plant material, for instance, isn’t small.
Metropolit’s seeds are sourced from the Netherlands, and while the majority of the plants are started at their greenhouse, about one-third of the plants come from a propagator in the Lower Mainland area of British Columbia. Even with all of the proper precautions taken, Metropolit says about 10 to 60 per cent of his plants were lost during the shipping process due to cold weather conditions last year. This year, it was 10 to 20 per cent. He has to send twice as many seeds to the propagator to ensure that he receives the number of plants that he needs. But still, it’s worth contracting out the work to ensure it’s done with the right expertise.
Another problem complicated by the Yukon climate is humidity control within the greenhouse. “It’s difficult for
Licensed Producers (LPs) know that when it comes to controlling and monitoring their growing environment, a simple, flexible, and sustainable control system is crucial. This is why proactive LPs are turning to Reliable Controls. Our nation-wide network of factory-certified Authorized Dealers will design, install, and commission a comprehensive control system paired with an intuitive, custom-tailored graphical interface. Take command of your precisely-controlled environment. Generate tracking reports and analytics. Reduce your carbon footprint while improving productivity, quality, and serviceability.
Licensed Producers (LPs) know that when it comes to and their growingenvironment,asimple,flexible,andsustainablecontrolsystemiscrucial.Thisiswhy
To learn more about this cost-effective and Canadian-made solution, please contact a local Reliable Controls
Authorized Dealer near you.
us to open our vents in the middle of winter,” says Metropolit, so he brought in dehumidifiers from Israel, distributed through Envirotech in the U.S. “They do cost a little to operate,” he explains, but it’s a small cost compared to the heat lost through open vents. Not only that, but the amount of snow on the vents makes them dangerous to open up, he adds.
FROM FLOWER BED TO FOOD GARDEN
First started as a botanical show
With the high influx of tourists and gold miners in the summer, the transient rise in population drives up demand for fresh produce
garden in 1985, Yukon Gardens began growing and selling flowers over the years, eventually getting into vegetable production about 25 years ago.
“Older people like the flowers and walking through gardens,” Metropolit says. “The younger crowd nowadays aren’t into it as much, and as a result, many botanical gardens are now either closing or changing.”
SunPatiens®
IMPATIEN S
SunPatiens® is the original and trusted name in sun- loving impatiens! Loved by growers, r etai l ers, l an d scapers an d consumers— SunPatiens deliver value—three seasons of of color in both sun and shade! New colors include Comp act Orchid Blush and V igorous Lavender S plash.
In addition to running one of the largest garden centres in northern Canada, Yukon Gardens can now produce vegetables for 10 months of the year. “Back then, we didn’t have this philosophy of buying local,” he adds. “If you couldn’t match or beat Mexican tomatoes, you didn’t sell any.” Now, Metropolit finds that his use of biological controls resonates with his customers who are looking for pesticide-free produce.
Viking & Viking XL
T he all-weather begonia for landscaping and lar ge containers. Available in green, bronze and dee p chocolate leaf colors— no other be gonia series in this class offers chocolate. Available in two sizes— L ar ge and XL!
With the high influx of tourists and gold miners in the summer, the transient rise in population drives up demand for fresh produce. “The grocery stores depend on us,” says Metropolit, but their orders are cut by half during the offseason, leaving the greenhouse operation with excess produce. “We could find other markets, but when our initial markets start to heat up, we would have to cut [the new markets] off.” The excess produce doesn’t go to waste either. Yukon Gardens donates two to three times per week to a local food bank.
Profusion
ZINNIA
T his eye-catching, non-fading color blooms w it h a kiss of brigh t c herry and becomes more intense as the flower ages. Cherry B icolor matc hes t he proven performance a nd uniformit y of the Profusion series— offering easy care and disease resistance.
Bloom!
www.sakataornamentals.com
To get the word out about their locally grown produce, marketing has become an integral part of the business. “It’s a totally different horticultural world now,” says Metropolit. For someone who is used to putting in 14 to 16 hours per day planting, watering and digging, he leaves the social media and website maintenance to his daughter Kelsey, who returned to the family business following a horticultural program at Olds College in Alberta.
A Saskatchewan-native from a town called Cudworth, just south of Prince Albert, Metropolit eventually moved up to the Yukon for “hunting, fishing and adventure,” he says. Working as a teacher during the winter while dabbling in horticulture in the summer, he eventually opened up Yukon Gardens with the support of his wife. As for his inspiration, Metropolit says one of his earliest photographs was of himself in a stroller, parked on a narrow sidewalk, as his green-thumbed grandmother worked on a perennial flower bed. “I learned my trade by eating pansies,” he laughs.
Big data: The devil is in the details
Collecting big data on your greenhouse? Know the fine print.
BY DR. JASON BEHRMANN
Your greenhouse contains a wealth of a prized commodity that recently skyrocketed in importance – and you can’t even hold it in your hands. It’s big data, and growers should take notice.
Big data is essentially ‘a lot of information’ in a digital format that technology companies use to develop cutting-edge innovations. From records of your packaging materials and electricity bills, to tracking the steps your workers take during a harvest cycle, we can use this information to gain detailed insights into greenhouse farming practices. Knowing the ins-and-outs of your greenhouse enables us to develop high-tech services that keep your farm efficient and profitable. It would be foolhardy to turn one’s back to opportunities made possible by big data, especially since overlooking progress could leave your business in the dust of more tech-savvy competitors.
That said, is it always in your best interest to share your greenhouse data? Sometimes. Greater sharing of data is necessary to spur faster innovation and provide broader benefits to growers. This is why leading organizations and initiatives, such as the Open Ag Data Alliance and the Open AgTech Consortium, strive to promote
mass sharing and use of agricultural data along with stringent privacy, property and security safeguards. If the latter part of that sentence raises your eyebrows, you are not alone.
With sensational headlines of hacking, cyberattacks and data security breaches around the world, farming representatives and regulators like Agriculture Canada are highlighting the importance of protection against cybercriminals. Concerns about privacy, security and data ownership are becoming mainstream amongst the greenhouse farming community. Working at an agriculture technology company, we are alltoo-familiar with these concerns. We collect data from greenhouses to develop artificial intelligence (AI) services on a routine basis. With each new greenhouse customer, we often hear the same questions about what technology companies do with their data, where it goes and what benefits the data ought to provide and to whom. These repeated questions demonstrate that greenhouse farmers as a group could use further guidance on this topic, and we will do our best to provide it here. To begin, let’s clarify different uses and categories of data ownership within greenhouse farming. Armed with this information, you can
better determine which data sharing initiatives best support your needs and personal values.
FOR THE COMMON GOOD
The adage “a rising tide raises all boats” rings true for collaborative data projects in agriculture. Alone, any given farmer may have little data available for technology development. But by pooling data from growers around the globe, we can amass vast amounts of information then used to make a positive impact on
Enbridge Smart Savings
farming. Projects spearheaded by notfor-profits and charities are particularly noble, especially since most of the products from these initiatives are made free to the world.
Being of particular importance to greenhouse farmers, one example pertains to crop pest and disease diagnosis by AI and machine vision. With support from companies and philanthropic organizations, the global farming community built a vast databank of images of diseased and infested crops.
Growing is Energy Intensive
By analysing the spots and wilts on plants, sophisticated software learned the characteristic fingerprints for a slew of crop diseases. You can now download a free app for a smartphone. With it, anyone can take a picture of a spotted leaf in your greenhouse and get an instant diagnosis of a growing list of parasites.
Offering everyone the ability to diagnose crop diseases and pests at the push of a button is a monumental feat. Farmers in more isolated areas with fewer resources can draw from this expertise.
Should you join the bandwagon and share your data? The benefits may be indirect...
Enbridge can help you use less energy and save money!
Audits, assessments and engineering analysis
The purchase and installation of energy efficient technologies
The implementation of operational improvements to reduce energy requirements
Paul Morrison, P.Eng., CEM
Enbridge Energy Solutions Consultant
We offer financial incentives for: (416) 495-5010
On our home turf, this technology enables any greenhouse worker to identify and sound the alarm right away when pests appear; this includes identifying unknown crop parasites recently introduced to a farming region. Imagine if we had this technology at the onset of the thrips epidemic. Through early detection, we might have been able to stop its spread throughout Canada. With this technology, the greenhouse industry would gain better means to quash the next new crop disease or pest that inevitably will arrive at our shores.
Pooling images of sickly crops is but one example of a growing number of collaborative data-sharing projects in greenhouse farming. Should you join the bandwagon and share your data? The benefits to your greenhouse may be indirect but could contribute to strengthening agriculture as a whole. That seems like a worthwhile endeavour.
JUST FOR YOU
Not all data is pooled. When building custom-made technology, data from your greenhouse alone is often necessary, but data from neighbouring greenhouses may very well be useless. Each greenhouse has unique attributes given differences in geography, growing equipment, chosen crop varieties and more. For instance, when devising high-tech means to optimize your heating, lighting, irrigation and whatnot, data from your greenhouse is most pertinent. For the most part,
Vegetatively propagated varieties are the hottest plants in the market today, with more introductions and research than with seed varieties. By far, the majority of these vegetative crops are propagated by cuttings.
From these general subjects, the book focuses in on specifics for specialty bedding plants, perennials, specialty cut flowers, and foliage plants. More than 60 important floriculture crops are covered in detail, allowing propagators and growers can provide high-quality cuttings and young plants to the market.
$87.95 Item #1883052485
the same is true for building unique AI software to automate common tasks in your greenhouse. Your data used to train that smart software will produce a tool that will understand tasks in your greenhouse alone.
This category of greenhouse data sharing has notable particularities. First, the data is either collected onsite by using cameras and sensors you typically purchase or is available in your private records (for example, records of past harvest yields). You make the investment
in acquiring the data and pay for the final technological product born from this information. It thus makes sense that you should remain the owner of that unadulterated – or “raw” – data and be the primary benefactor from sharing it with technology companies. Being specific to your greenhouse, you should voice your values on privacy standards, data ownership and whether any part of that data is used for other purposes. If any of these issues are unclear, ask the technology company for a plain-
Experience ultimate control of your greenhouse with iSii
Hoogendoorn’s next generation iSii monitors and controls all climate, irrigation and energy equipment in all types of greenhouses. The iSii is equipped with advanced controls that work according to the principles of Plant Empowerment, which resulted from Next Generation Growing (NGG) research. This way light, temperature, humidity and CO2 are aligned with each other for a maximum photosynthesis. In addition, to prevent water stress, irrigation is driven by the evaporation energy and water balance of the crop. With the iSii process computer, you set the base for high quality production.
language explanation. Though you may remain the owner of your raw data, know that technology companies often need to invest time and resources to transform data into something useable by anonymizing it, compressing it and so on. Given their investment, expect technology companies to have some claim to ownership over the transformed data. Be sure to ask what happens to your data should you no longer be a customer; can you request that the company delete it? You should have that option, and indeed, this standard was set in the European Union and may soon become the norm in Canada.
DATA AS PAYMENT
There’s no such thing as a free lunch. Yet we take for granted many free online platforms and software tools from private companies. How do these companies make money? By selling you, or more specifically, your data.
Worldwide innovator
in horticultural automation
info@hoogendoorn.ca www.hoogendoorn.ca
From farmer dating apps to posting the bounty of your greenhouse on social media, every profile entry, click, swipe and photo uploaded to these free services become valuable sources of data – and the property of that service provider. For the most part, mass data collection and its sale by these service providers remain unseen. Why is this so?
Tracking your activities enables service providers to know how best to design customized and practical digital tools we adore. On the flip side, it is common to sell information about you and your greenhouse to unknown others. Most of the time this makes it easy for companies
to target you and your greenhouse with relevant advertisements; by merging data from many greenhouses, companies also obtain valuable information on market trends, regional cultivation practices and the demographics of greenhouse professionals.
Having your data sold in exchange for free services might be a fair trade; however, this category of data use and collection is fraught with concerns. Recent sensational cases where social media data enabled the targeting of thousands of people with political propaganda is but one example of the risks we face. To date, the malicious use of big data in agriculture and related cybersecurity risks remain uncommon for the most part. An arguably more pertinent concern today is that bad press may mislead the greenhouse community into painting all data acquisition and sharing with a broad—negative—brush.
The last thing we want is for greenhouse growers to delay technological adoption due to ascribing risks with one form of data sharing to another. This is a real concern. Conversations with our customers indicate that growers have few resources to explain all the nuances of big data in greenhouse farming. Without question, tech companies have a duty to explain the benefits and risks to the greenhouse community. We are eager to have this conversation, so never hesitate to reach out.
Jason Behrmann, PhD, is the senior marketing communications manager at Motorleaf. He can be reached at jason. behrmann@motorleaf.com
CANADA CLASSIFIEDS
T: (519) 429-3966 • F: (519) 428-3327
CLASSIFIED RATES: Minimum order $75.00 or 84¢ per word, word ads must be pre-paid. CLASSIFIED DISPLAYS: $72.00 per column inch. GENERAL INFORMATION: Payment must accom- pany order. Copy required on publication close date. All advertising copy subject to the approval of the publisher. Send order and remittance to: Classified Dept., Greenhouse Canada, P.O. Box 530, Donly Dr. S., Simcoe, ON N3Y 4N5 Canada
ADVERTISERS INDEX
A.M.A. Horticulture Inc. ............................43
Top 4 Under 40 .......................................25
Grower and Wholesaler
GARY JONES | Gary.Jones@kpu.ca
Perpetual energy
As a school student, did you ever wonder ‘why am I learning this stuff?’ Apart from ‘integration’ and ‘differentiation’ math that is, which, unless you’re a civil engineer, you’ve likely never used again. As much as I enjoyed school, I wondered this too often.
I was recently chatting with a group of greenhouse growers/owners about topics for workshops or study days. Inevitably, we got around to talking ‘energy’ and then the serious issue in BC of the fractured northern gas pipeline. While testing pipe integrity along its length, it’s still only at 85 per cent capacity and likely won’t be 100 per cent for a long time.
This means crazy gas prices. Commonly $200/ GJ for one February weekend, and $220 the highest I’ve heard. At the same time, north of the fracture, I understand prices are as low as $1/GJ. Imagine.
Reduced gas flow through this (only) pipeline means less capacity to fill storage, which is running low. At the same time, it appears that some of the gas is being sold to the US. Compounding this, BC is experiencing a lower than normal snow pack, with consequently reduced water run-off and less capacity for hydroelectric generation. It’s a perfect energy storm.
Dependency on the northern BC pipeline has sparked (no pun intended) discussion of a ‘virtual pipeline’. Trucking it in. A full trailer is left behind at the customer and the empty trailer taken away. Think Danish carts for bedding plants.
Some have said that the industry is in love
(usually nickel) to produce methane and water. Today, technology can improve on the process in ways unknown by Sabatier back in 1897. “It has been seen in a renewable-energy-dominated energy system to use the excess electricity generated by wind, solar photovoltaic, hydro, marine current, etc. to make hydrogen via water electrolysis and the subsequent application of the Sabatier reaction to make methane.”1 So, electrolysis of water using renewable electricity to create hydrogen (which can partly be used directly in fuel cells) and the addition of carbon dioxide CO2 (via Sabatier process) to create methane. Winwin. If sufficient artificial methane were produced, it could be put back into the gas pipeline, and used like we do to generate electricity and heat (combined heat and power), overcoming low points of renewable energy production.
Scientists at Paris Diderot University believe they’ve found a more efficient catalyst to turn CO2 into methane. “The catalyst the researchers discovered is similar to the chlorophyll in a plant, only instead of turning CO2 into oxygen it turns it into methane. The molecule uses energy from the sun to break up the CO2 molecule into carbon and oxygen atoms, which then combine with hydrogen to form methane and water.”2
“The researchers still have a long way to go before their new catalyst is used commercially.” “If this catalyst can become even slightly more efficient, in the near future we could be producing cheap methane literally out of thin air.”2
Some have said that the industry is in love with the pipeline.
with the pipeline. Actually, it’s the gas we love, not the pipeline. The pipe is a means to an end. Maybe we should go ‘off-grid’ for gas. I was doodling about ways to suck carbon out of the air (great for doing our part to reduce atmospheric CO2) and combine it with hydrogen to make methane (CH4, the major component of natural gas). A whip around the internet, and up pops the Sabatier Reaction.
This process was discovered by “the French chemist Paul Sabatier and Senderens in 1897”1–the underlying process for the manufacturing of synthetic natural gas. The Sabatier process involves the reaction of hydrogen with carbon dioxide. But there is a little downside, since it requires elevated temperatures (300–400°C) and high pressures in the presence of a catalyst
Here’s my concept. Combine Sabatier’s process with highly efficient catalysts, modern renewable energy and compact engineering, to build a shipping container-sized ‘plug-and-play’ system to be dropped off at a greenhouse to provide renewable gas, electricity, heat and reduce atmospheric CO2 I’ll take 10 per cent of the royalties. I knew I should have listened at school.
REFERENCES
1 https://en.wikipedia.org/wiki/Sabatier_reaction
2 Ars Technica, referenced in Popular Mechanics, June 2017, at: https://www.popularmechanics.com/science/ green-tech/news/a27412/catalyst-turn-co2-into-methane/
Gary Jones is co-chair of Horticulture at Kwantlen Polytechnic University, Langley, BC. He sits on several industry committees and welcomes comments at Gary.Jones@kpu.ca.
Growing Your Business
GROUNDBREAKING ROOTING TECHNOLOGY
Now available for annuals and perennials from Dümmen Orange
Basewell™ is an innovative new product form that combines the benefits of unrooted cuttings and rooted cuttings. With visible root development, Basewell™ is more mature than a URC, making it possible to plant directly into a finish container.
