A matter of perception LEDs change how pests see sticky cards
BY DR. SARAH JANDRICIC
Hot for houseplants
Why houseplants are about more than just esthetics BY
TREENA HEIN
Expanding sights
Hyperspectral technology pushes the boundaries of plant monitoring BY DR.
MICHAEL
TASCHUK, NICHOLAS KALOGIROU AND HAL FRIESEN
Garnering insight
2022 has been designated the Year of the Garden in Canada.
At time of writing, executive director of the Canadian Garden Council, Michel Gauthier, tell us that things are progressing nicely and that they are on track to launch their public campaign.
According to the website, there will be live activities, celebrations, and special events planned throughout the year. This is a sharp contrast from more than a year ago when public gardens were not able to open, either due to COVID restrictions or a lack of funding to hire thousands of full-time and seasonal labour positions, many of whom maintain the grounds.
Though subsidized through different levels of government funding, the majority of the revenue stems from public admission and tourism. With gardens closed and no tourism to speak of, the pandemic was a tremendous blow to their operating budgets. “A lot of the gardens have members and donors,” Gauthier said, but with the financial
commissioned by the Canadian Garden Council and carried out in November 2020, more than four in five Canadians expect to spend the same or more time gardening in 2021 compared to 2020. Whether that came true remains to be seen. Anecdotally, conversations with others in the sector were very positive, with either higher volumes sold or sold earlier than in 2020.
Other interesting highlights from the Nanos poll can be found on the bottom right corner of pg. 6. See what gardening means to Canadians, when it comes to climate change, and mental and physical health. By now, you’ve probably heard the term “Plant Parents” many times over, pointing to a generation of still-childless individuals who have adopted plants instead. But what’s interesting is the emotional connection that comes from being part of an online plant community. Dr. Bridget Behe divulges more on this topic in our houseplant merchandizing feature on pg. 20. The feature also includes a short
situation being what it was, relying on donations was not something they could count on.
What’s more, the Canadian Garden Council says public gardens contribute millions of dollars to the local economy across the country each year. While some grow their own plant material, many gardens also source from local greenhouses and horticultural suppliers, impacting that relationship.
Clearly, their voices were heard as the federal government officially designated 2022 as the Year of the Garden back in March of this year. According to a Nanos poll
profile on Solar Gardens, a succulent specialist in Saskatchewan whose engaging classes and diverse array of unique product has garnered much success.
The other major theme in this issue is lighting – not just in the visible sense, but across the entire unseen spectrum. Check out whether LEDs change how greenhouse pests perceive sticky cards (pg. 12), how optical radiation can help manage disease (pg. 8), and opportunities to use hyperspectral imaging to capture the first signs of plant distress unseen by the human eye (pg. 26).
Until next time.
Westmoreland to eliminate single-use plastics
Westmoreland and Apeel Sciences have joined forces to eliminate single-use plastics (SUPs) from Long English cucumber packaging.
According to the release, this is U.S.-based Apeel’s first relationship with a Canadian supplier. In the first year of this partnership, Westmoreland expects to curb 185,000 pounds of plastic – which is the equivalent of 200 million plastic straws, or enough shrink wrap to cover 485 football fields.
Based in Ontario, Westmoreland’s greenhousegrown Long English cucumber currently uses a plastic film to maintain the shelf life of each product but uses an estimated 90 tons of plastic to do so each year.
Apeel’s plant-based protection creates an edible barrier, an extra “peel” that can’t be seen, felt, or tasted. This unique coating maintains shelf life by keeping moisture in and keeping oxygen out; two factors that lead to spoiled vegetables. Source: Westmoreland
QUÉBEC URBAN FARM TO USE HORIZONTAL ROTARY GROWING TECHNOLOGY
Gigrow Urban Farms is about to construct its first urban operation using horizontal rotary growing technology.
Based in Québec, the company announced an investment of $13 million for the venture. Located in the Varennes industrial park, this initial 24,000-squarefoot facility is said to become one of Québec’s largest urban agriculture projects.
With partner Gigrow’s Québec-developed technology based on horizontal rotary cultivation, Gigrow Urban Farms estimates they will produce up to four million heads of lettuce a year, plus other plants. The system reduces water use and produces a contaminantfree and consistent crop year-round.
According to a company spokesperson,
Mastronardi Produce, AppHarvest form FarmCo
Mastronardi Produce Ltd. and AppHarvest announced the formation of FarmCo, a joint agtech venture to develop a portfolio of controlled environment agriculture (CEA) facilities.
The partnership will expand the supply of fruits and vegetables, including leafy greens, to Mastronardi’s existing fresh produce marketing and distribution business in the U.S.
“We have seen the demand for locally grown produce skyrocket...” says Paul Mastronardi, president and CEO of Mastronardi Produce Ltd.
FarmCo is slated to have its own leadership team. The two partners are to contribute equity and assets of over $100 million. The combined equity will be used to raise additional capital to fund Farmco’s growth, with a build target of over 750 acres of CEA facilities in the U.S.
Source: Mastronardi Produce & AppHarvest
the technology can be stacked vertically. “It is one of the most efficient technologies by square footage of production,” shares the company. Durability was a key component to the design. The estimated lifetime of the stainless steel system is 25 years minimum.
With this new infrastructure, Gigrow Urban Farms aims to support efforts to achieve food self-sufficiency through consistent local production. This initial urban farm is a first milestone for the company, which aims to build three to four other similar facilities across Québec within the next five years.
The first facility should be in operation by March 2022, reaching full production by the final quarter of the year.
Source: Gigrow Urban Farms
BY THE NUMBERS
2022 is the Year of the Garden
8 in 10
Canadians agree or somewhat agree that gardening can have a positive impact on climate change
96% agree or somewhat agree that gardening can improve mental and physical well-being
Over 3 in 10 like gardening as a side hobby
81% agree or somewhat agree that students should be taught gardening skills in schools
95% agree or somewhat agree that gardens improve quality of life
1 in 6 describe themselves as an avid gardener
OPTICAL RADIATION shows promise against disease
Research in Europe shines a light on possibilities for Canada
BY PETER MITHAM
Ultraviolet light from the sun is widely recognized in field production as one of the best natural controls for mildew that exists. Many growers who face the issue open up the canopy of their plants to facilitate light penetration as well as air circulation to keep moisture levels low.
For greenhouses, light exposure is one of many variables that growers actively manage. While plant development is the usual target when manipulating this variable, Norwegian scientist Aruppillai Suthaparan has been studying the potential of certain wavelengths of light to manage disease.
“It’s not always easy to prevent pathogen entry into our crop pro-
ABOVE
duction systems,” said Suthaparan, a researcher in the Faculty of Biosciences at the Norwegian University of Life Sciences (NMBU) in Ås, Norway.
Chemicals have been the primary way for managing disease, but there are increasing concerns about their environmental and human health impacts. Resistance is also a concern. Powdery mildew, a particular focus of Suthaparan’s work, is a case in point. “The use of the fungicides against powdery mildew is not a sustainable solution because these pathogens always develop fungicideresistant isolates so they can tolerate and survive,” he said. “So most of the fungicides that are available in the market right now are very, very
PHOTO
CREDIT: SAGA ROBOTICS, K. SKARSGÅRD
ABOVE
inefficient against fungal diseases, including powdery mildew.”
This is where the use of optical radiation is attracting interest among researchers and growers. Specific segments of the spectrum – ultraviolet, visible and infrared regions – all have different effects on the plant. A difference in light quality (wavelength) and quantity (intensity and duration) perceived by the plant will affect photosynthesis, development and photoperiodism.
For fungi, optical radiation influences its developmental behaviour along with its relationship with the plant host. Finding the right spectrum of light, the right length of exposure and the right time of day becomes important. The right mix has been a focus of Suthaparan’s research, the results of which he discussed with growers at the Lower Mainland Horticultural Improvement Association virtual short course earlier this year.
Since light exposure has a cleansing effect, the first step was to see if day length made a difference to disease rates. Tomatoes and roses were subjected to four different day lengths, and the incidence of powdery mildew was lowest among those exposed to continuous lighting. But most plants don’t want continuous lighting, which also boosts energy costs. Suthaparan’s team therefore started looking at different wavelengths to see if they could be effective. The target pathogen was Oidium neolycopersici, which causes powdery mildew in tomatoes.
Researchers first tested the effect of various spectra of optical radiation. Within the tested ultraviolet (UV) range, wavelengths from 250-290 nm were found to suppress all powdery mildew. In the visible range (400-750 nm), red light achieved the most effective control. But red light also resulted in plants that appeared
highly stressed, suggesting that red light wasn’t sufficient by itself. While blue light could deliver healthier-looking plants, it had no significant effect on powdery mildew alone. “However, [a] combination of red and blue light with red light proportion ≥50% showed significant suppression of powdery mildew with compact tomato plants [in a] controlled environment experiment,” he said, based on unpublished data.
This prompted a look into combinations of wavelengths, including blue light and UV, to see if powdery mildew control was possible while still giving plants exposure to a healthy range of light. The trials indicated that a longer dose, up to four minutes of short wavelength UV between 254-284 nm, was most effective when used simultaneously with red or green light. “You have very, very efficient suppression of disease,” Suthaparan said.
While glazing materials, shading, lighting and other tools in modern greenhouses and vertical farms can change the spectrum of optical radiation that plants receive, this is more difficult in traditional greenhouses, high tunnels or field settings. This fact led researchers to look at timing. Trials indicated that exposing the plants to UV light at night, when they’re able to avoid exposure to other hindering forms of light for at least four hours, and ideally six to eight hours, was key.
“UV-A, blue and infrared minimize the disease suppressive effect of short wavelength UV and red,” Suthaparan explained. “If you have UV treatment, you need to have a certain lapse time before the next perception of UV-A and blue light.”
The more regular the treatment, the better the suppression of disease. Ideally, growers should treat plants on alternate days as a way to mitigate disease. Since other frequencies of light can affect
Pictured here is Thorvald by Saga Robotics. The company has been collaborating with researchers, including Aruppillai Suthaparan’s team at the Norwegian University of Life Sciences as well as Cornell University in the U.S., among others.
PHOTO
ABOVE
Suthaparan captures an untreated strawberry plant [left] compared to another that was treated with a short dose of UV [right].
other pathogens, the light treatments can be delivered in rotation. Blue and orange-red (600-660 nm), for example, can be efficient against gray mold.
Suthaparan tested the use of optical radiation against powdery mildew in a variety of settings, including cropping systems for strawberries, tomatoes, asters, rosemary and cucumber. “In all the cases you could see very clear disease suppression,” he said.
But deploying the technology at a large scale is a challenge. Since greenhouses employ cropping systems tailored to the specific crop being produced, the system for dosing the plants with light also needs to be customized to ensure thorough coverage and effective disease suppression.
“You can use optical radiation in the control of diseases, but you have to design it properly, considering the kind of crop production system, other environmental conditions conducive to disease, and the level of disease pressure you have,” Suthaparan explained.
Working with Saga Robotics, a Norwegian company that makes the autonomous Thorvald platform for field and polytunnel environments, the supplier is rolling out with claims that it’s 80 to 95 per cent effective against powdery mildew.
“But still there are some challenges,” Suthaparan said, noting that indoor and outdoor environments will result in different levels of control. Sensors need to be calibrated properly, to ensure that optical radiation is being applied effectively. Disease pressure also has to be taken into account, so that plants aren’t being dosed needlessly.
With ongoing research projects funded by the National Research Council of Norway, Suthaparan and his team are working on a system that can automatically detect the presence of pathogens and quantify the pathogen inoculum in the production system. It will send an alert regarding the risk of a disease outbreak based on environmental conditions.
“[It] has sensors that will log environmental data [and be] combined together with disease modelling so we can treat the plants selectively, wherever we have disease pressure,” he says. Their other collaborative projects will work on exploiting plant genetic resources to prime the plant’s immune system by treating them with selective wavelengths of optical radiation.
Thorvald is distributed in the U.S., U.K., Italy and Norway through their farming-as-a-service (FaaS) model. “No capital investment for early customers is required, and maintenance costs are included, meaning low risk and high flexibility for
the grower,” says Pål Johan From, CEO at Saga Robotics. “Light treatment is offered through the season as a complete service with field mapping, treatment deployment and maintenance performed by us.” Partnering with Cornell University in the U.S., Saga has completed trials for greenhouse crops, but is currently focusing their commercial start-up efforts on strawberries and grapevines
While crop monitoring systems have been developed in Canada with a view to help growers stay on top of disease, the targeted use of optical radiation to control and suppress disease has yet to attract significant research or investment here, at least of those that are publicly divulged.
Dr. Geneviève Marchand, plant pathologist at Agriculture and Agri-food Canada’s Harrow Research and Development Centre, said the use of optical radiation to control disease “is certainly a promising area for research.” Structured trials have yet to be undertaken, however, meaning researchers have circumstantial evidence and observations on what could be possible.
“The relationship between plants, lights, and pathogens is a complex system,” she says.
In addition to the direct effects of light on the plant, the pathogen and the relationship between the plant and the pathogen, there may be indirect effects depending on the kind of light used. This shouldn’t discourage researchers from exploring what will work best for growers in Canada, but it does mean there is plenty of work to be done.
“There is enough to keep researchers busy for a very long time,” she says.
Peter Mitham is a freelance writer based in B.C.
Editor’s note: A 2019 article by Cornell University noted that eight years prior to writing, Aruppillai Suthaparan’s team had discovered that the powdery mildew fungus shuts down its innate system for repairing damage caused by UV light at night A nighttime dose of UV takes advantage of this weakness. Since then, researchers from Cornell, the University of Florida, Rensselaer Polytechnic Institute, the USDA Agricultural Research Service Grape Genetics Research unit, the Norwegian University of Life Sciences, along with the Norwegian Institute of Bioeconomy Research (NIBIO), have formed the Light and Plant Health research group to adapt the findings for different crops and field conditions.
Efforts to include mention of CleanLight, a UV tech supplier with a presence in Canada, were declined at time of print.
WHAT LED lighting means for pest monitoring
Have you ever wondered whether monitoring and mass trapping cards look different to pests under different types of lighting?
BY DR. SARAH JANDRICIC
Comparing the performance of yellow and blue mass trapping cards under HPS light [left] to the same cards under LED lights using a red:blue mix of 50:50 [right].
Let’s face it – Canada’s greenhouse industry is eager to embrace new technologies. A key example is the use of LEDs in the greenhouse industry, going from preliminary research tests to widespread use for supplemental lighting in less than 20 years. The use of LED lights over conventional lighting comes with all sorts of gains – from production yields to energy savings. But are we sure we aren’t leaving something behind?
When technology has the capacity to be a game changer, we tend to focus our efforts on studying its direct effects, such as growth time and crop quality. But we often don’t stop to study what the indirect effects could be, both positive and negative.
With LEDs, the key indirect effects we need to consider are on insect and mite pests that infest the crops we are lighting, and the IPM strategies we use to control them.
Previous articles in Greenhouse Canada have covered some interesting preliminary results on the effects of LEDs on natural enemy biology and behaviour (see Arthropods and Greenhouse Lighting: Like Moths to a Flame by Dr. Rose Labbé and Cara McCreary, Greenhouse Canada , October 2020 edition). Today’s article asks an even more basic question – do we know how LED lighting will affect something as simple (and as critical for IPM decision-making) as pest monitoring using sticky cards?
A MATTER OF PERCEPTION
Sticky cards used for monitoring and mass trapping are generally yellow or blue, for a good reason. These wavelengths are two parts of the visual light spectrum that insects most respond to. Thrips, especially, respond to blue, which is why this colour of trap is sometimes used in vegetable and floriculture greenhouses (visit ONfloriculture.com for more on thrips and optimal trap colours).
But what happens when we shine what is essentially a purple light (i.e. an LED with a red/blue mix) on a yellow or blue trap card? To the human eye, at least, this certainly seems to have a significant effect on trap colour. But what colours do the insects perceive? Does this make the cards less – or more – attractive to pests?
GETTING ANSWERS
To answer these questions, we set up a trial in research greenhouses looking at the efficacy of monitoring cards under traditional HPS lights compared to red/ blue LEDs. Here’s a summary of our set-up.
Insects and plants chrysanthemums as a model crop. They don’t need supplemental lighting, but they do host a variety of pests. 30 thrips per bench were released into the crop and allowed to reproduce for two weeks. The fungus gnats came free!
Lights: We hung a single light (LED or HPS) above the centre of each bench filled with 100 pots of 6-inch mum plants. We used a 50:50 red-to-blue light ratio for the LED.
registered significantly lower readings with a light meter. This was so we could see how cards responded in the “bleed zones” of the lights, as well as directly under them.
Benches were also split into two sections (A & B) with equal numbers of
WHAT DO I SPY WITH MY LITTLE EYE?
between the benches and along walls shared with other greenhouse compartments to prevent interference
pairs of yellow and blue sticky cards at the focal points of the lights and at various distances down the bench that
After all this work setting up our trial, what did we find with our pest insects of interest? Well, the answer depends on what day you might have asked us… Our first trial was run over two A SYSTEM DEVELOPED WITH 40 YEARS OF EXPERIENCE, DESIGNED BY OUR ENGINEERING TEAM, SEWN IN CANADA USING THE BEST FABRICS AND INSTALLED BY VRE EXPERTS.
ABOVE
Insect light sensitivity differs from humans and plants. Plant absorption of light peaks in the red and blue wavelengths, while insects respond best to green/yellow, blue and UV wavelengths.
in commercial greenhouse production using supplemental lighting.
We know from previous research in Southern Ontario, that over two-week periods, yellow cards catch more thrips than blue cards at a ratio of 70:30 under ambient lighting. In our first lit trial, this held true for thrips caught under both HPS and LED lights. If there were no perceived differences in our card colours when it came to attracting pests, you would expect around 50 per cent of the insects to be caught on each colour – but we saw 68 per cent of thrips going to yellow, on average. This was also seen in fungus gnats, which preferred yellow cards at a similar ratio.
Overall, this is good news for growers in traditional greenhouse production facilities. They can continue the practice of using yellow monitoring and mass trapping cards – which effectively catch a variety of flying pests –regardless of their lighting type.
Although the proportion of thrips and fungus gnats caught on yellow versus blue cards were similar across both lighting types and lighting areas, the actual number of thrips caught in the different lighting areas varied in a way we didn’t expect. Under HPS lights, the highest number of thrips (1,072) was caught in the focal area, compared to just 236 thrips in bleed zone 2. This trend was reversed under the LED lights – most thrips were caught in the farthest bleed zone, with the fewest under the focal point.
ABOVE
A diagram of the trial set-up investigating lighting effects on mass trapping/monitoring cards. Each bench contained 12 sticky cards placed directly above the crop. Light intensity directly under the light (i.e the focal point of each light, represented by the darkest circle) was 350 μmol/m2/s for both types of lights. In the first bleed zone, light intensity was ca. 215 μmol/m2/s. This was reduced to 150 μmol/m2/s in “bleed zone 2” for the LED lights. However, the HPS light had less range; light intensity in bleed zone 2 was similar to ambient lighting conditions at around 115 μmol/ m2/s.
FIGURE
ABOVE
Proportion of thrips caught on yellow or blue trap cards under supplemental lighting from A) HPS lights or B) LED lights over a two-week period. The dashed line at 0.5 represents where we would expect the bars to be if thrips had no preference for card colour. An “*” indicates that the data significantly differed from the expected ratio of 50:50 at P ≤ 0.10, meaning the colour with the taller bar was preferred.
We don’t know why this is yet, but it certainly warrants further investigation, as optimal placement of monitoring or trap cards under HPS versus LED lights might differ.
We also ran a second trial over a 24-hour period of extremely overcast weather. This was intentional (what we call a “worst-case scenario” trial), so we could see what happens when most of the light comes from supplemental lighting. These conditions more closely mimic warehouse-style cannabis or microgreen production, or greenhouse conditions at latitudes with little natural light in the winter.
As you can see from the graphs to the right, we got some interesting results. Although overcast conditions did not change how thrips or fungus gnats responded to card colour under HPS lights, it did under the LED lights. In the bleed areas, the purple light from the mix of red:blue LEDs seemed to cancel out the effect of card colour – both yellow and blue were equally effective!
It’s unclear, exactly, why we didn’t see this effect at the focal point of the LED light – perhaps the vertical position of the cards directly under the light protected them from drastic colour changes on the sides of the cards; we just aren’t sure yet.
But this certainly suggests that when LEDs are the only light source, the light recipe chosen can drastically affect what we think we know about something as simple as optimal monitoring card colour. Further testing is needed in systems like warehouse production and vertical farming to see how lighting types affect the usefulness and optimization of traps for monitoring and pest management.
Until IPM researchers have a little more time to play catch up with greenhouse lighting’s
ABOVE
Proportion of thrips (A-B) or fungus gnats (C-D) caught on yellow or blue mass trapping cards under HPS or LED lights. The purple highlight indicates areas where LED lights changed the attractiveness of the cards tested. The dashed line at 0.5 represents where we would expect the bars to be if insects had no preference for card colour. An “*” indicates that the data significantly differed from the expected ratio of 50:50 at P ≤ 0.10, meaning the colour with the taller bar was preferred.
effects on insects, it’s a good idea to test trap colours and types in your own facility to get the answers you need. A quick two-week trial with pairs of cards set up at various distances from your light source (at least four pairs) is all you need to shed some “light” on the subject!
Sarah Jandricic, PhD, is the greenhouse floriculture IPM specialist for the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). She runs the ONFloriculture blog (ONfloriculture.com), which provides timely pest management information to floriculture growers. Reach her at sarah.jandricic@ontario.ca.
Pepper weevil studies bring new products to light
New research reveals surprising results using kaolin clay and mineral oil against the pest.
BY DR. ROSELYNE LABBÉ, CARA MCCREARY AND MATTHEW BRAZIL
The pepper weevil is a native North American pest with origins in Mexico. While it does not overwinter outdoors in Canada, it is routinely reintroduced with pepper imports from regions where the pest is prevalent.
Beginning in 2009, pepper weevil has periodically appeared in Ontario, but only in 2016 was it considered a major crop pest when it incurred significant greenhouse and field pepper crop losses. These economically damaging pepper weevil populations were linked to mild winters and hot summers during 2015-16, which enabled early and rapid pest population growth and spread. Since then, Ontario’s greenhouse pepper industry has made many transformational changes which have greatly mitigated the reoccurrence of pepper weevil in Canada. But the threat posed by this pest remains.
Some of the challenges related to pepper weevil management are that most life stages – including the egg, larvae and pupae – occur inside buds and
ABOVE
pepper fruit. Coupled with the adult’s instinct to hide in and around crops, these behaviours make it difficult to effectively monitor and control this pest. As a result, the mostly hidden pepper weevil easily persists in crops, where it is protected from insecticide treatment and can trigger premature fruit loss through egg laying and larval feeding.
In addition, the pepper weevil is challenging to control through many conventional insecticides. Research in Mexico and the US indicates that some populations are becoming resistant to conventional products including carbamates, organophosphates, organochlorines and pyrethroids. Given this resistance, and the fact that Canada already has a limited toolkit available for managing pepper weevil, the entomology research team at Harrow Research and Development Centre, supported by Ontario Greenhouse Vegetable Growers and the Canadian Horticultural Council, set out to identify new solutions for pepper weevil management in
The pepper weevil can be a difficult pest to control. Research in parts of North America show signs of populations becoming resistant to conventional pesticide products.
Canadian greenhouses.
We conducted extensive product screening to assess multiple new insecticide products labelled as reducedrisk (biorational), conventional, and biopesticides. In total, our team completed five rounds of insecticide testing in laboratory and greenhouse crop settings. We assessed 16 different compounds at up to three different doses each and observed whether they could lead to adult pepper weevil mortality and reduced crop injury.
KAOLIN CLAY AND MINERAL OIL PROVEN EFFECTIVE
Testing a range of different potential insecticides in the greenhouse, two in particular were among the most effective against pepper weevil and offered unique mechanisms of action: kaolin clay (Surround) and mineral oil (Pure Spray Green Spray Oil). Kaolin clay led to 70 per cent adult weevil mortality and reduced offspring emergence by 59 per cent. Mineral oil led to 55 per cent adult weevil mortality and 54 per cent reduction in offspring emergence.
Surround works through two relatively unique mechanisms. It is both a potent
irritant to the insect itself and also deters feeding and egg laying when applied to crops. As such, researchers observed both a direct mortality of adult weevils following Surround applications, the greatest reduction in premature fruit loss, and the lowest number of weevil offspring emergence measured among the different pesticides tested on greenhouse crops. In other words, this product could ultimately help protect crop yield.
Pure Spray Green also worked well to control adult pepper weevil, to minimize fruit loss and was the next best product for reducing weevil offspring emergence. This input suffocates all exposed stages of the pest, damaging their cuticles and acting as a repellent.
Other benefits of both Surround and Pure Spray Green include reducing the risk of resistance development in either pepper weevil or other pests and their potential compatibility with organic production.
One challenge however is that Surround leaves a residue on pepper fruit
ABOVE
Kaolin clay led to 70 per cent mortality among pepper weevil adults.
sale. Alternatively, treatments can be made after last harvest when residue is no longer a concern. Using this strategy, a superior crop clean out can be achieved, limiting the carryover of pest populations between crop cycles.
PRODUCT LABELLING AND REGISTRATION IN PROGRESS
Data from this research is being used in the pursuit of label expansions through the User Requested Minor Use Label Expansion (URMULE) program at the Pest Management Regulatory Agency (PMRA). Requests will include product uses for management of pepper weevil on greenhouse and field pepper crops in Canada.
To date, kaolin clay has been submitted to the PMRA for use against pepper weevil in greenhouse peppers.
To growers who have known and suffered the wrath of this destructive pest, it’s worth knowing that new effective products have been identified with the potential to improve pepper weevil management in Canada. This is particularly important for organic greenhouse producers as otherwise, there is no insecticidal product currently available for use on pepper crops. Furthermore, these products with novel mechanisms will be useful for resistance management, representing potentially more compatible complements to existing biological control organisms routinely used on greenhouse pepper crops. More information on use patterns will become available as products are registered for use on greenhouse pepper crops.
This article is based on research originally published in the Journal of
ABOVE
Researchers tested 16 different compounds, studying pepper weevil mortality and crop health in both laboratory and greenhouse settings.
Economic Entomology and available online at: https://doi.org/10.1093/jee/toaa092
Full reference: Labbé, R., Gagnier, D., Rizzato, R., Tracey, A. and McCreary C. 2020. Assessing new tools for management of the pepper weevil (Coleoptera: Curculionidae) in greenhouse and field pepper crops. Journal of Economic Entomology. 113: 1903-1912.
ACKNOWLEDGEMENTS:
The research team involved in this work includes Dana Gagnier, Rebecca Rizzato, and Hannah Thibault of AAFC; Amanda Tracey of OMAFRA who provided technical assistance and collected trial data; as well as Jim Chaput (retired) and Hannah Fraser of OMAFRA who
contributed to label expansion and new registration packages submitted to PMRA. This research was made possible through the Canadian Agri-Science Cluster for Horticulture 3, in cooperation with Agriculture and Agri-Food Canada’s Agri-Science Program, a Canadian Agricultural Partnership initiative, the Canadian Horticultural Council with industry contributors, as well as through Collaborative Framework project 2117 funded by Ontario Greenhouse Vegetable Growers (OGVG).
Roselyne Labbé, PhD, is a research scientist in greenhouse entomology at AAFC’s Harrow Research and Development Centre. Cara McCreary is the greenhouse vegetable IPM specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Matthew Brazil is a student in the Horticultural Technician Program at Niagara College.
This is one in a series of research updates, written in collaboration with students in the Hort1346 Greenhouse Production Course at Niagara College and initiated by instructor Sebastien Jacob.
HOT FOR houseplants
The lowly houseplant has reached new heights due to the availability of unusual species, the impact of online influencers and the pandemic.
BY TREENA HEIN BELOW
For West Coast Gardens, they’ve found that simplicity can be best for their displays.
Houseplants are feeling the love like never before. From the fiddle leaf fig to succulents, consumers are scooping them up at unprecedented rates.
“More recently, our customers have been people aged 30s to late 40s and they have really gravitated to the 4” to 6” tropicals,” notes Bryan Moffatt, retail operations manager at West Coast Gardens in Surrey, BC. “The plant sizes seem to be what they can fit into their homes. A lot of people wish that they could have larger tropicals but unfortunately they may not have the space.” Moffatt adds that plants with variegated leaves are always popular, along with plants having other unique leaf patterns, colours and shapes – Alocasias, for example.
Tropical plants with unique foliage are also in constant demand at The Watering Can, which has two locations near Niagara, Ont. “Our most popular are the succulents, fiddleleaf figs, snake plants, philodendrons and ZZ plants,” says Manager Sue Dodd. She adds that “any plant that has a variegation of white and green will remain in high demand as we enter 2022.”
There are a variety of reasons behind the booming desire for houseplants, notes Professor Bridget Behe at Michigan State University, who has conducted decades of research on garden centre retail trends. One clear reason is to allow a bit of the natural world into the living space. Another is for the fresh herbs and vegetables to use in cooking and baking. But Behe and her colleagues have found there are many more benefits – emotional ones.
“Some of the Millennials and many of the Gen
Z in particular want to nurture something,” says Behe. “They may not yet have pets or human children, and being a ‘plant parent’ is a very rewarding experience. They enjoy caring for the plants, but from the research that we’ve done last year and this year, we’ve found there is a lot of emotional reward in the social connection benefits.”
LEFT
The Watering Can changes up their displays to reflect current trends.
By sharing stories and images, houseplant owners derive a strong sense of belonging.
In short, social media platforms are gathering places for much of the social interaction among new houseplant owners, allowing likeminded individuals to discuss their plants’ needs but mainly to take their plant enjoyment to the next level. By sharing stories and images with each other, houseplant owners derive a strong sense of belonging.
Behe also explains that many social media influencers have built interest in plants and are another focus for the ongoing social connection. She adds that there can be a vying for status in the community, and status can be attained if one can manage to acquire a rare or unusual plant that an influencer or someone in their social group already possesses. And in addition, “part of the fun,” says Behe, “can be the quest.”
Moffatt agrees that online plant
groups seem to set the tone for ‘musthave’ plants. He adds, “Hoyas are very popular, but only certain types. When we brought in Hoya Sunrise, they sold out very quickly while Hoya Carnosa didn’t have the same draw. Plants seem to have their moment of fame and then, in a month, are not as desired anymore as the market is flooded.”
Overall, tropical plant supply at West Coast Gardens remains tight. “When plants do appear on availability lists, there are limits to the amount you can purchase,” Moffatt reports. “Unique items are not commonly found on availability lists. Many large growers will only sell to their larger purchasers, which makes it even harder to source unique plants.”
Behe confirms that huge demand from Millennials and GenZ in particular – who are very active on social media and are constantly on the lookout for new offerings – have led to sellouts over the past two years and contributed to some species being sold for exorbitant prices.
“As a result, we are also seeing some theft [at] retailers,” says Behe, “and in some cases, it’s the employees who are taking plants and selling them.”
ENCOURAGE DEMAND
Aside from the need to perhaps boost their security, garden centres can benefit from the huge demand for houseplants if they are willing to put in the work.
Behe explains that smart retailers are developing a strong online presence to make themselves a hub for social network activity. “This will encourage sales,” she says, “but you need to watch the trends. Online platforms are always changing, and right now short videos are becoming more ‘in’ to compete with static photos. The social media interaction needs to be a consistent conversation, whether it’s about plant care or how to use herbs, and not a sales pitch. You want to keep people engaged and not turn them off.”
Retailers should also look at how they sell. “The pandemic has led to further development of the ‘culture of convenience’ and people are used to picking up prepackaged groceries without having to visit the store,” says Behe. “Amazon is selling plants, plant pots and more. So, retailers should offer some conveniences, but of course they still have to make money. It’s great to give traditional classes if you have the space, but you can value-add in other ways. There are virtual ‘home’ classes or parties being offered where kits are picked up or delivered ahead of time, and people who know each other log on together or get together at one person’s home. But again, we have to make sure events are profitable.”
RULES FOR DISPLAY
At West Coast Gardens, a few rules are followed in displaying house plants to ensure sales stay strong. One of them is simplicity. “Plants will truly shine when kept in a simple display,” says Moffatt. “We like to group our displays by type of plant, instead of having a variety found in multiple places. We also utilize height, ensuring our displays work from floor to ceiling. Too many items in a display will
ABOVE
Displays at West Coast Gardens have three colours at most and avoid overwhelming the customer with too much product at once.
The best of nature
At Rijk Zwaan, we apply state-of-the-art techniques to the rich genetic diversity nature offers us. Within the grape tomato segment, there is a wide range of products varying in taste, shape and colour including red, orange, yellow, green, pink, brown and many more colours! We are constantly developing our range to include good, tasty and profitable varieties that stand out from the crowd while offering the grower positive plant characteristics. We look forward to discussing your variety choices with you!
Together with our partners we want to actively contribute to the world’s food supply and stimulate vegetable consumption by laying the foundation for healthy and appealing vegetables.
For more information, contact: Tomato Crop Specialist Marleen van der Torre m.van.der.torre@rijkzwaan.com
Sharing a healthy future
confuse a customer.” Moffatt adds that displays should have three colours at most, and that “colour blocking will draw the eye and allow dimension.”
West Coast Gardens has found signage and themes to be very important. “We don’t want the customer to have any guess work in regards to questions they have,” says Moffatt. “Displays should
Lastly, displays at West Coast always have an inspirational angle to highlight the potential of a plant. “The goal,” says Moffatt, “is to help the person visualize the plant in their own space.”
Inspiration and connection are also a strong focus at The Watering Can, along with freshness. “All displays are an experience,” says Dodd. “Everything in that
Succulent Savvy
For Roger Valliere, owner of Solar Gardens in Saskatoon, Sask., their class offerings, succulent specialization, and huge varietal inventory have been key to their outstanding success.
You work hard. Your water should, too
Available in liquid or granular formulations, H2Pro Greenhouse and Nursery Surfactant optimizes the moisture penetration and holding capacity of soilless growing media. The uniform moisture distribution it provides reduces wilting and its effectiveness can last up to a year. Maximum hydration from less irrigation—that’s the power of H2Pro.
Valliere has always focused on succulents. He started growing them 35 years ago from specimens collected under import licences from all over the world. At his 50-acre site with six greenhouses, Valliere grows over 1,700 succulent types which usually reach saleable size in three or four years. Nowadays, he also buys some rare succulents that are grown in large volumes from seed by U.S. companies. He notes that “when we first started taking succulents to trade shows in 1996, people didn’t even think they were real, but now they are very popular.” Valliere says the success that they’ve had would not be possible if his huge array of succulents didn’t possess a certain characteristic. “Here, we get lots of Prairie sun and that makes for colourful plants and it’s the colourful plants that are in demand,” he explains. “And in terms of growing, you don’t want to give them very much nitrogen or phosphorus. We have orange, pinks, vibrant greens and yellows, and there is no comparison with imports. Imported plants are mostly a dark blue hue and also lose colour during transport.”
While Valliere sells wholesale to 170 gardening businesses in Canada (mostly in Alberta, B.C. and Manitoba and he’s looking for more), he also sells large amounts to consumers – pre-made pots full of succulents, small ‘wedding favour’ pots and as mentioned, through classes.
Prior to COVID, he had 1,800 students a week of all ages come to classes at his greenhouse site, selecting from about 400 varieties to fill their selected pots with approximately 30 plants each. Classes were not possible during the pandemic, but wholesale purchases went up 300 per cent, Valliere reports.
Starting in September 2021, Valliere will hold classes at a new store location in one of Saskatoon’s malls. He already has a sales outlet at another strip mall in the city. These plants are displayed under LED grow lights, under which he says they do very well.
EXPANDING SIGHT: Plant health beyond the naked eye
Hyperspectral imaging takes plant health monitoring to a whole new level. Here’s how it works.
TBY DR. MICHAEL TASCHUK, NICHOLAS KALOGIROU AND HAL FRIESEN
he human eye evolved to see light from blue to red, but reflected light from plants conveys significant information outside of these wavelengths. By looking outside the visible spectrum, new technology can induce a paradigm shift for plant health monitoring and reach beyond common environmental variables like temperature, humidity, and CO2 content.
This technology is known as hyperspectral imaging. To understand how it works, let’s use your phone as an example.
The digital camera records a red, green and blue image for every photograph you take. These three images combine into the colours that humans can see with the naked eye. When applied to plants, each image pixel has three values that can quantify plant or leaf properties. However, much more information can be obtained if more colours (or wavelengths beyond red, green and blue) are measured – a technique referred to as spectroscopy.
Hyperspectral imaging technology combines imaging and spectroscopy to grant data-based insight into the world of what we see, as well as beyond what we can’t see. A good visual summary of the information provided by a hyperspectral imager is in the “hypercube,” a stack of images taken at different colours, shown in Figure 1. By probing, for example, a single pixel as a function of colour, a lot of information and insight can be gleaned. In the example here, the percent reflection of a single pixel is plotted as a function of wavelength, and as we’ll see later in this article, there’s a plethora of information in a single pixel of this “hypercube.”
drought, unfavourable temperatures and other factors. Most importantly, hyperspectral imaging provides early detection of these signals. This article will introduce how this is done and highlight some of the potential opportunities that hyperspectral imaging can offer crop growers.
A BRIEF HISTORY OF PLANT HYPERSPECTRAL IMAGING
Hyperspectral imaging has its roots in precision agriculture
FIGURE 1
A typical “hypercube” of data gathered by a hyperspectral imager, where we have a stack of images with slight variations as a function of colour (or wavelength). Looking at a single pixel in the cube (plotted on the right) for example, can provide a lot of insight into plant health. (Reflectance plot generated using sample data from Riedell and Blackmer, 1999.)
Hyperspectral imaging provides data suitable for monitoring a wide range of plant conditions such as nitrogen status, infections, maturity index, and plant stress as a result of
and climate monitoring, going back to as early as the 1980s [Mulla, 2013]. Early hyperspectral imagers were so expensive that having a single camera monitor a wide area was all that was feasible. The camera resolution and number of spectral bins (the most familiar of which are the three red, green and blue bins of
A visual representation of the scale and timeline of hyperspectral imaging development. Satellite surveys of land areas with hyperspectral imagers have gradually transitioned to aerial surveys, drone surveys, camera monitoring, and finally into singlecrop sensing as hyperspectral technology has advanced and dropped in cost.
RGB cameras) determined how much insight you could really get into any plant characteristic.
As hyperspectral imaging technology advanced, its cost decreased so it could be used first in aerial monitoring, then in hand-held applications. Today, hyperspectral imaging technology is comparatively more affordable than it used to be. Though its capital costs are still largely out of reach for the majority of greenhouse operations, continued research offers the potential for its use within sensors to monitor plants affordably. Outside of scale and cost, imagers and analytical capabilities have advanced significantly. Spatial and spectral resolution have improved, and knowledge of crop response to specific chemicals, behaviours, and stresses has enhanced the technique’s usefulness. This insight is obtained without invasive tests, making it very attractive for crop growers monitoring living plants.
Expanding operations can scale their sensor-to-grower ratio, augmenting human skills and expertise across a larger greenhouse area. This is important both in remote and indoor farm operations. Sensors can also give you more unbiased, continuous, and permanently stored data.
To really appreciate the benefits of modern hyperspectral imaging, though, we need to understand the different plant features that allow this technology to provide deep insights.
VISIBLE PLANT SIGNATURES
Plants use visible light for photosynthesis; it’s also what growers rely on to inspect crops. By eye, growers can identify many damaged or diseased plants, but not all. Images in the visible spectral region offer many insights that growers may not be able to immediately identify, such as the presence of nutrient deficiencies, diseases and pests [Zubler and Yoon, 2020].
Wavelength Ranges (nm) Plant Bio-Traits
420–440 Chlorophyll-a absorption
420–480 Chlorophyll absorption
450–470 Chlorophyll-b absorption
490–550 Pigment reflected peak
510–570 Green reflected peak
630–650 Chlorophyll-b absorption
630–690 Plant species discrimination
650–670 Chlorophyll-a absorption
640–700 Chlorophyll absorption
673–683 Chlorophyll fluorescence
680–700 Chlorophyll fluorescence
720–740 Chlorophyll fluorescence
700–750 Leaf health and shape
760–800 Cell structure reflectance peak
760–900 Discrimination between plant species
800–960 Species biochemical traits
900–920 Proteins
920–940 Oil
960–980 Starch content, water
980–1000 Starch content
Wavelength ranges for specific plant traits, reproduced from Peng et al., 2019.
FIGURE 2
FIGURE 3
The human eye is good at telling the difference between a healthy and a damaged plant, but it can’t always identify a stressed plant. For visible wavelengths, most light is absorbed aside from green, but that absorption changes depending on a plant’s health. For the NIR and IR images, the solid arrows in the figure indicate reflected light, and the dotted lines indicate transmitted light. Because hyperspectral imagers see beyond the visible light range, they can identify stressed plants early. The reflectivity/transmission values are examples, and in reality will depend on crop species, type of stress, and observation wavelength.
The chlorophyll pigments, key molecules involved in photosynthesis, absorb blue and red light [Peng et al., 2019], but reflect green light, causing the plant’s green appearance. Chlorophyll is also where most leaf nitrogen is stored, and so provides an indirect way to estimate a plant’s nutrient status [Blackburn, 2007]. Chlorophyll concentration generally decreases as a plant is stressed, and so measuring it can indicate how a plant is interacting with its environment.
Chlorophyll fluoresces in the red to near-infrared region [Peng et al., 2019]. Fluorescence refers to a material absorbing light at one colour, and re-emitting at another colour. A familiar example is fluorescent safety clothing. Chlorophyll fluorescence indicates how much chlorophyll pigment is present, but requires information outside the visible wavelength range.
Many other molecules besides chlorophyll interact with visible light. One example is anthocyanins, a pigment type that can regulate photosynthesis, protect the plant from overly intense light, and adjust osmosis to protect it during freezing or drought periods [Blackburn, 2007]. Anthocyanins are still being studied to determine the roles they play in a plant’s function. In the past, they were only detectable through chemical analysis, but improvements to hyperspectral imaging have allowed scientists to detect it through the pigment’s absorption in the red-green region [Blackburn, 2007]
RED-EDGE PLANT SIGNATURES
Chlorophyll pigments have a sharp cutoff at the visible spectrum’s red end, where they no longer absorb but instead reflect light. The exact “red-edge” wavelength shift can indicate chlorophyll concentration in plants and canopies [Blackburn, 2007].
By comparing the red-edge location to the wavelength where the reflectance shows the smallest change, we can also calculate the concentration of oxidized compounds in stressed leaves [Guan et al., 2005]. Extending a bit beyond red wavelengths grants access to far more plant information. What if we go even further into the infrared?
INFRARED PLANT SIGNATURES
The electromagnetic spectrum’s infrared portion is what we feel as heat. Wavelengths from 700 nm to 2,000 nm are known as near-infrared.
Inside plants, their water, proteins, cellulose and lignin all determine how much near-infrared light is reflected [Elvidge, 1990]. Beyond providing molecular signatures, infrared reflection provides insight into structural changes in the leaf, and therefore can detect damage from pests such as leaf miners [Xu et al., 2007]. When a healthy plant is stressed, diseased or infected, its reflectivity and scattering of infrared light will change in a measurable way.
SiLICON ENRICHED
MANAGING PLANT STRESS EARLY: FILLING THE GAP OF WHAT WE CAN’T SEE
Humans are really good at spotting the differences between a healthy plant and a damaged one. Skilled growers build up a depth of expertise and experience in detecting changes that indicate when a plant’s on its last leaves, so to speak. However, humans aren’t as good at spotting the differences between a healthy plant and a lightly stressed plant. The visual cues are subtle and may not be in the visible range.
Here is where hyperspectral imaging really comes into play. It gives us plant signatures in the near-infrared and beyond, outside of what our eyes can detect. Hyperspectral imagers can differentiate between healthy, stressed and damaged plants, as shown in Figure 3.
Hyperspectral imaging empowers early stress detection so growers can react to unfavourable conditions and optimize growth outcomes. If you only react once you see a damaged plant, you’ve arguably lost considerable yield, and it’s uncertain whether or not the plant will fully recover. Through recognizable plant-stress signatures, growers can make rapid corrections to approach optimal growth.
AN EXAMPLE OF HYPERSPECTRAL IMAGING
FIGURE 4
Salt stress in Arabidopsis thaliana seedlings was detectable using a hyperspectral NDVI within 15 minutes as compared to 8 hours for the human eye (generated using data from Beisel et al., 2018).
REFERENCES
One of the challenges with hyperspectral imaging is its vast amount of measured data. Scientists reduce the complexity using ‘vegetation indices’ which focus on key parts of the hypercube to bring important information to the surface. One common hyperspectral imaging index class is called normalized difference vegetation index, or NDVI, which measures the relative reflectance of near-infrared light [Beisel et al., 2018]. A group of researchers was able to demonstrate early detection of salt stress in a plant within 15 minutes, when it was only visible 8 hours later by the human eye [Beisel et al., 2018].
There are many more examples of hyperspectral imaging’s power to inform crop growth, and scientists are only scratching the surface of what’s possible.
HOW WILL HYPERSPECTRAL IMAGING DEVELOP IN THE FUTURE?
Just as your phone and computer get faster every year, cameras and detectors continue to get cheaper and better. What once was too expensive for anywhere but space is now routinely used for field agriculture. We are seeing the beginnings of more cost-effective monitoring, detection, and analysis of plants through hyperspectral imaging, and soon it will become more readily available in greenhouses. Researchers and companies are building out the technologies and algorithms to bring many of the mentioned capabilities into greenhouses in a more cost-effective way.
There’s a broad, collaborative effort to expand humanity’s perspective beyond what we observe with our eyes so we can see from a plant’s point of view. As we learn more from and about this perspective, we glimpse the dawn of a colourful future for agriculture.
[1] J. S. Boyer, “Plant productivity and environment.,” Science, vol. 218, no. 4571, pp. 443–448, Oct. 1982, doi: 10.1126/science.218.4571.443.
[2] W. E. Riedell and T. M. Blackmer, “Leaf reflectance spectra of cereal aphid-damaged wheat,” Crop Sci., vol. 39, no. 6, pp. 1835–1840, 1999, doi: 10.2135/cropsci1999.3961835x.
[3 D. J. Mulla, “Twenty five years of remote sensing in precision agriculture: Key advances and remaining knowledge gaps,” Biosyst. Eng., vol. 114, no. 4, pp. 358–371, 2013, doi: https://doi.org/10.1016/j.biosystemseng.2012.08.009.
[4] Y. Peng et al., “Identification of the best hyperspectral indices in estimating plant species richness in sandy grasslands,” Remote Sens., vol. 11, no. 5, 2019, doi: 10.3390/rs11050588.
[5] A. V. Zubler and J. Y. Yoon, “Proximal Methods for Plant Stress Detection Using Optical Sensors and Machine Learning,” Biosensors, vol. 10, no. 12, 2020, doi: 10.3390/bios10120193.
[6] G. A. Blackburn, “Hyperspectral remote sensing of plant pigments,” J. Exp. Bot., vol. 58, no. 4, pp. 855–867, 2007, doi: 10.1093/jxb/erl123.
[7] Y. Guan, S. Guo, J. Liu, and X. Zhang, “Algorithms for the Estimation of the Concentrations of Chlorophyll A and Carotenoids in Rice Leaves from Airborne Hyperspectral Data,” in Computational Science -- ICCS 2005, 2005, pp. 908–915.
[8] C. D. Elvidge, “Visible and near infrared reflectance characteristics of dry plant materials,” Int. J. Remote Sens., vol. 11, no. 10, pp. 1775–1795, Oct. 1990, doi: 10.1080/01431169008955129.
[9] H. R. Xu, Y. B. Ying, X. P. Fu, and S. P. Zhu, “Near-infrared Spectroscopy in detecting Leaf Miner Damage on Tomato Leaf,” Biosyst. Eng., vol. 96, no. 4, pp. 447–454, 2007, doi: 10.1016/j.biosystemseng.2007.01.008.
[10] N. S. Beisel, J. B. Callaham, N. J. Sng, D. J. Taylor, A. L. Paul, and R. J. Ferl, “Utilization of single-image normalized difference vegetation index (SI-NDVI) for early plant stress detection,” Appl. Plant Sci., vol. 6, no. 10, pp. 1–10, 2018, doi: 10.1002/aps3.1186.
Michael Taschuk, PhD, P.Eng, is founder and CTO; Nicholas Kalogirou, P.Eng, is the AI product manager; and Hal Friesen, M.Sc, is the R&D team lead and technical communications specialist at G2V Optics based in Edmonton, Alta. G2V supplies commercially available lighting and monitoring products for a range of renewable energy, aerospace, and controlled-environment agriculture applications. They can be reached at info@g2voptics.com.
GARDEN EDIBLES: New for 2021/2022
As summer neared its end in many parts of Canada, Greenhouse Canada reached out to sector representatives for their thoughts on new garden edibles and highlighted some promising selections in the process.
BY GRETA CHIU
High temperatures and extreme drought severely impacted gardens in parts of Canada and the U.S this year, making it hard to pick favourites. Here were the highlights.
PANAMERICAN SEED
Connecting with both Duayne Friesen in Manitoba and Dustin Morton in Alberta on separate occasions, both representatives for Ball Seed placed the same two frontrunners at the top of their garden edibles list – which clearly says something about the performance of these genetics.
[1] Jalapeno Pot-a-peno: “This little guy delivers,” says Friesen. “I have mine growing in a 10” hanging basket and it is not anywhere near
outgrowing the pot.” Its small habit makes it a great fit for smallscape gardens, balconies and patios. The early maturing and prolific variety brings a bounty of fruit through the season amid glossy dark green foliage. “Only planted in mid-June we have harvested twice, taking off more than 40 hot peppers in total to can up, [while] still picking a couple for fresh use when needed,” continues Friesen. “It’s very likely we’ll get another 30 or more off of it before the weather sours.”
Green fruit offer a hearty spiciness, while a ripened red lowers the zing and allows more sweetness to come through. “The flavour it great,” says Morton. “It’s got a fantastic trailing habit (as advertised) and it’s prolific.” Even
in late August, one of his customers still had the plant in a 6-inch on their bench, while picking and selling the peppers.
“It’s a must-have alongside an HB tomato program.”
[2] Basil Everleaf Thai Towers: Described as having the same tall habit as Emerald Towers Basil, Morton says the leaves on Thai Towers are small like those of a Thai basil, but the plant flowers much later, preserving the warm anise flavour of the variety. Also like the original Emerald Towers, it takes time to reach the full effect. “You’re going to want to do some ‘consumer education’ with this item as the goal isn’t to grow and harvest once like a lot of basil,” advises Morton. “This is meant to grow and keep coming back to, thanks to the late flowering.”
“It really does grow as pictured, tall and narrow,” says Friesen. At time of writing in late August, his Thai basil had not flowered either. “Also, there were no issues with downy mildew that lays to waste many a basil plant these days.” Among his basil collection in the yard, he says, “Emerald Thai Towers is easily the best of the bunch.”
SYNGENTA FLOWERS, VEGETALIS
“My summer trials have been ravaged by wildlife due to extreme drought conditions,” says Jeannine Bogard, business lead on home and garden for Syngenta Flowers. Knowing the Canadian market however, here were her recommendations.
[3] Sunsugar Watermelon: “The Sunsugar watermelon is pretty darn good,” says Bogard. “Visitors to the trials are really
surprised at how sweet and juicy it is. It has good crisp texture, too.” Described as a “very productive all-sweet type,” the plant is said to produce blockier fruits weighing in at 18 to 21 lb. along with vigorous vines that can reach more than 6 ft. in length, which help shield developing fruit from sunburn. The fruit is described as being “juicy with a rich sweetness,” with medium-sized seeds. Good tolerance to rind necrosis. 85 days to harvest from transplant.
[4] Snow Max Snow Pea
The Snow Max Snow Pea is said to produce an abundance of sweet, flat pods measuring 3.5 inches in length. Semi-stringless, the pods are described as crisp, yet tender. An easy-to-grow variety in the garden, it offers resistance to downy mildew, powdery mildew and fusarium. The self-trellising plant is a semi-leafless Afila type that makes it easy for gardeners to spot the pods. “The Snow Pea Snow Max is the first snow pea Syngenta has introduced in quite a while,” says Bogard. 70 days to harvest from transplant.
[5] Clementine Cauliflower
“Brassicas are pretty popular in Canada,” notes Bogard, who highlights two from this genus. The vigorous, hybrid cauliflower Clementine offers eye-catching orange curds from its
7-inch head, The colour is said to hold well even after being cooked, as the carotenoid pigments are not watersoluble nor heat-sensitive. The taste is described as mild, sweet and nutty. 70 to 75 days to harvest from transplant.
hybrid storage type cabbage, Zenon. Meant for long storage periods over the winter, the 7.9-inch heads average at 6.6 lb and are said to hold their colour well. The plant itself is described as highyielding with resistance to Fusarium. 145 days to harvest from transplant.
PROVEN WINNERS
It wasn’t easy evaluating edibles this year as high temperatures and extreme drought severely impacted parts of Canada and the U.S.
Proven Winners introduced two new varieties to their Proven Harvest line. Note that they also carry additional vegetables sold only as seed products, some with their new compostable seedstarting eco-pots which offer nutrients built into the container.
[6] Crave Sweet Corn
“Sweet corn Crave is the bicolour version of last year’s introduction, Glacial,” says Bogard. This hybrid sweet corn is said to offer excellent eating quality with good crunch and flavour whether roasted, grilled, boiled or steamed. Ears reach 8 inches in length, accompanied by great husk length, colour and flags. 78 days to harvest from transplant.
[7] Zenon Cabbage
Bogard’s second choice of Brassica is the
[8] AlliYUM Garlic Chives: Serving as a cooking herb and an ornamental perennial, AlliYUM (Allium) is a new flat leaf chive that is said to offer both onion and soft garlic flavours. “Succulent foliage is topped with lavender purple flowers in midsummer.” Zones 5 to 9. 10 to 16” high, 12 to 18” spread in garden.
[9] Pesto Besto Sweet Italian Basil: According to Proven Winners, this is the best seed-grown sweet basil they’ve trialled. Originating from the same breeder of Amazel Basil with similar vigour and taste, this downy mildewresistant variety is another high foliage yielder. 18 to 30” high, 12 to 24” spread in the garden.
Reduce Single Use Plastic!
INTRODUCING THE NEW ECO+ GRANDE™ CONTAINER
100% MADE FROM PLANTS
• COMPOSTABLE
• NO MORE PLASTIC WASTE!
PLANT NUTRIENTS BUILT INTO THE WALLS OF THE CONTAINER
• NUTRIENTS ARE SUPPLIED TO THE PLANT DIRECTLY FROM THE CONTAINER
• HELPS CONSUMERS TO BE SUCCESSFUL ALL SEASON
CAN BE PLANTED OR COMPOSTED
• CAN BE PLANTED DIRECTLY INTO THE SOIL
• EASE OF PLANTING IMPROVES CONSUMER EXPERIENCE
ECO+ GRANDE CONTAINER
A GAME-CHANGING COMPOSTABLE* POT MADE FROM PLANTS.
CONTACT YOUR PREFERRED BROKER OR PROVEN WINNERS ANNUALS PROPAGATOR TO LEARN MORE TODAY!
PULL TABS
• REMOVABLE TABS FACILITATE STRONG ROOT DEVELOPMENT
• CONTAINERS BREAK DOWN AND BECOME INERT, ORGANIC COMPOUNDS
• NO MICRO-PLASTICS OR ADDITIONAL WASTE BY-PRODUCTS
ALBERTA STRAWBERRY grower goes vertical
In a small greenhouse on a U-pick farm north of Calgary, visitors fill up on pails of strawberries plucked from DIY towers.
BY JOHN DIETZ
BELOW
Phil Trenholm of Saskberry Ranch tends to U-pick strawberry towers in the greenhouse.
It’s an Alberta work-in-progress for sure, but it’s looking hopeful.
This year, the little homemade greenhouse located an hour northwest of Calgary held about 5,280 strawberry plants. ‘Amazing!’ was the most frequent remark as U-pick customers came through the entrance.
At eye-level, they were staring at towering, vertical rows of fat, bright-red berries and green leaves under the polymer roof. If any stopped to count, there were five rows of 24 towers. Each tower was stacked eleven containers high, with four plants per container, also known as pods.
During the first week of the season, picking was at shoulder level and above. By the end of the season, pickers were reaching down to collect strawberries at knee level or ankle level. Visitors could fill a pail on a single walkthrough in about five to eight minutes without putting a knee to the ground.
Business was booming at Saskaberry Ranch, a rare source of pick-your-own strawberries north of Calgary.
Operated by Phil and Christine Trenholm along with their four children, the mixed farm and U-pick ranch is on a 140-acre site they first planted in 1999. Phil is just three miles from where he grew up.
“We wanted something sustainable on a quarter-section for a family,” Phil says.
They started planting orchards of Saskatoons
and raspberries, started raising a few small animals for meat and built a pair of greenhouses.
In July and August, streams of customers arrived with pails for U-pick and shopping bags for other products. Some fresh produce is available in September and October, including a second crop of strawberries, then the gates close for another season. Phil delivers about twice a month after that to designated locations.
LEFT
Each growing pod is 13 inches wide and is shaped like a four-leaf clover. One strawberry plant goes into each cup-shaped leaf.
They needed to devise a vertical system for intense greenhouse strawberry production.
“We have Saskatoons, raspberries, strawberries, sour cherries, cherry tomatoes, some rhubarb and a few cucumbers. We also sell pasturebased chicken and eggs, grass-fed finished Angus beef and grass-fed finished sheep,” he says.
FILLING A DEMAND
At Saskaberry, most U-pick is outdoors. It has about nine acres of Saskatoon production and a new orchard of raspberries is about to come into production.
Phil and Christine planted their first strawberries about ten years ago. On the website, Phil writes, “Initially we did not intend to grow strawberries, due to the labour
involved, but because of numerous requests we started growing strawberries.”
At first, they provided elevated strawberry beds on four-foot-tall straw bales. The berries grew in soil-filled frames on top of the bales. It was low-density, vulnerable to hail and “too much work.”
That was when the Trenholm family decided to try vertical strawberry production. One 28x56 ft. greenhouse was available. It was covered with woven poly to protect the tender fruit and tall enough for vertical production.
Woven poly, Phil explained, is heavy, resists hail and diffuses the sunlight. The plants wouldn’t scald and would have light from all directions.
Phil needed to devise a vertical system for intense greenhouse strawberry production on the farm. He couldn’t find a Canadian system although two American companies were offering a possible option using pods of foam or plastic to hold the plants.
With more searching, he found stacking pods of UV-treated plastic available on Alibaba, the Chinesebased, ebay-type service. A shipping broker in Calgary worked with him to verify the transaction and eventually placed an order for enough pods to fill his greenhouse. The shipment arrived during the 2018 growing season. Afterwards, they emptied and refurbished the chosen greenhouse. The A-frame structure has a pony wall on each side, about 5-feet tall. The triangular roof, with joists on eight-foot spacing, is attached to the pony walls. The steep angle minimizes hail damage.
As they set up for vertical production, they awaited the arrival of about 6,000 living, day-neutral Seascape strawberry plants from Nova Scotia. It came in April 2019. They ordered through the Alberta
Farm Fresh Producers Association, a voluntary non-profit organization of direct marketing growers.
PRODUCTION BEGAN IN 2019
Phil decided to divide the greenhouse interior into five rows and seven walkways. The rows are 48 feet long. Walkways are about 38 inches between rows.
Growing pods are 13 inches wide and shaped like a four-leaf clover, with one strawberry plant in each cup-shaped
leaf. A hole in the centre enables pods to be attached to a pole.
The entrepreneur attached 12 pods to seven-foot metal rods, on six-inch spacing. The towers are tied into a network (top and bottom) that supports itself but still has some ‘give’ as pickers work down the rows.
“We have the rods attached to guy wires across the top. That holds them all in line, so nothing gets knocked over,” he says.
ABOVE
Strawberries grow in pods that are attached by metal rods and tied into a vertical system in the greenhouse.
NUTRIENTS & WATER
Phil roots his seedling strawberries in a solid growing medium, a mix of peat moss and compost, differing from a liquids-only hydroponic system.
The compost is generated from sheep manure and bedding material that, a year earlier, was piled in spring and intensively worked so that the materials would rot down. He says, “We go from fresh manure to beautiful black soil in about a year, and it has no odour.”
Water for the greenhouse is collected in an outdoor storage tank. The family built an elevated framework of irrigation pipe and hose, hanging from the ceiling, to water the strawberry towers. Two emitters serve each tower, dripping into the top two pods of each column. The remaining pods are watered by top-down percolation.
The seedling shipment arrives in April and is planted by the Trenholm family in
about two days. Labour for harvesting at least is not an issue. Their U-pick customers provide the labour, harvesting without the usual worries an employer faces.
Phil says, “With the U-pick scenario, you are going to take some losses. I have some damage with broken plants, some spoiled fruit, but I’m not having to pay labour. From what I hear from other growers, labour is their biggest headache and biggest expense. I’m willing to take a hit on production if I can avoid that [from] happening.”
FINETUNING PRODUCTION
Phil made some modifications to improve 2021 production. “The first two years (2019-2020) we tried growing with just a peat moss/compost blend. It started good but it seemed like there weren’t enough nutrients in the compost to keep it growing all season,” he says.
The water volume required for sustaining good growing conditions in the lower pods meant that an oversupply of water was delivered to the top pods. And, he needed to compensate for the excess leaching in the top pods. Now, he injects some liquid organic nutrients.
“The biggest challenge for us would be more even irrigation,” he says. “The top has been almost over-wet. This winter (2021-22) I’m going to try modifying some pods so that I can get more water down into the lower levels without overly soaking the top. I’m hoping to achieve more even fertility with the organic fertilizer we drip through.”
As well, weeds were a challenge in 2021.
He says, “Somehow my compost was loaded with clover seed this year. Any wild grasses, like quack grass, do not survive.” This winter they plan to steam the compost before filling the pods to see if that makes a difference in weed germination.
WORK IN PROGRESS
While their work increased on the small farm in the early years, Phil and Christine also raised four children. Today, the oldest is married and they have up to five helpers for the busiest times.
“We’re all involved. My kids help with planting, weeds and harvesting,” Phil says. “We are a fully functioning family farm. For the most part, everybody can do everything on here.”
The crew includes Cydnie and her husband Sam Klassen, brother Jakob, 18 and Lucas, 16 and sister Andreya, age 13.
Phil and his family foresee bigger things ahead.
“My kids want to get another greenhouse up,” he says. “I don’t think we have the time and energy for that now, so it’s likely that we’ll start expanding in 2022. I have a 30x70 greenhouse that’s all crated up and ready to go. I want to get the bugs out of the system I have, then we’re going to hit it and go.”
The vertical strawberry system is a work in progress. “We haven’t got it down to a science yet,” he says. “This year we’re a whole lot better than we were in 2020, so we are definitely improving our system.”
He adds, “Wherever you are, people seem to love strawberries. There are no other large U-pick strawberries operators around Calgary, so I have all the market I could possibly imagine. I believe this will work once we get the bugs out.”
John Dietz is a freelance writer based in Alberta.
Heat wave puts new varieties to the test at New Blooms
Organizers welcome growers to annual event in Alberta and Saskatchewan.
BY GRETA CHIU
Not even record-breaking temperatures could prevent the fourth edition of New Blooms from returning to Canada’s Prairies.
Held on July 15, the event at Deb’s Greenhouse in Morinville, Alta. drew 65 attendees from 45 greenhouse businesses. Organizers then took the show on the road, travelling to Humboldt, Sask. for the New Blooms Roadshow at Misty Gardens on July 22, hosted by Paul and Diane Kneeshaw.
“It was so much fun,” says Debbie Foisy, owner of Deb’s Greenhouse. “Last year, everyone was more reserved because of COVID, but this year it felt normal again. It was great.”
The annual event was first started four years ago by Chris Berg, marketing director of Dümmen Orange North America, who continues to choose the genetics being trialled. The plants are then grown by Michiel Verheul of High Q
ABOVE
Greenhouses who collaborates with Foisy in displaying the varieties and running the event, including the speakers program.
Last year, she and Verheul added the roadshow to Humboldt. Back by popular demand, this second day welcomed 37 registrations and close to 30 greenhouses this year.
“Some came from far away. A three- to fourhour drive to get to this event was not unusual,” says Verheul of both days.
Adding to the challenge of COVID, Western Canada had been hit by intense, dry heat this summer, reaching temperatures in the low to mid 40s.
“There were some begonias in the trials and in the greenhouse, [and] it got so hot that even with shade, those begonias did not fare very well. They cooked,” Verheul recalls.
Debbie Foisy, co-organizer of New Blooms holds Durabloom Pink Orchid petunia [left]. Michiel Verheul, co-organizer of the event presents a new selection from the Main Street coleus collection [right].
New Blooms display in Alberta.
Unfortunately, this meant a few varieties didn’t make it to New Blooms. As for the rest of the varieties, many required an extra bit of watering and sprinkling on the leaves to help relieve the heat.
“We generally choose varieties that do really well in the Prairies, like petunias, calibrachoa, salvia,” he explains. “We didn’t choose ones that could potentially do better in the heat, because they’re not popular in the Prairies. Most of the time it rains in the summer.” According to organizers, both locations for New Blooms are rated at Zone 3, receive plenty of light and are prone to harsh winters.
This year, they received 100 cuttings from Dümmen Orange. Verheul grew them as individual varieties, using eight to nine cuttings per 12” to 14” pot. All containers were donated by Gabcor, a planter supplier based in Ontario.
As COVID restrictions began easing up on masking and indoor gatherings, New Blooms was able to bring back their speakers program. This year, the roster included greenhouse consultant Dr. Mohyuddin Mirza, retired greenhouse owner John Bouw, as well as pre-recorded presentations from Berg and Robert Brett of Plant Haven filmed during the California Summer Trials in late June. Berg also brought back the tradition of concocting and serving a signature drink, this time a lavender-infused cocktail called “Drink like a Diva.”
In terms of varieties, Foisy and Verheul highlight three
particular entries that performed well and were wellreceived by the events’ attendees.
The first was Hummingbird Falls Salvia, which was uniquely compact for its class, not to mention being “pollinator positive” for bees, hummingbirds, butterflies and others.
The second was the Main Street coleus series, which included Bourbon Street, Orchard Road, Venice Boulevard and Yonge Street. “Some have scalloped edges, some are serrated, some are straight, wide or narrow,” says Foisy. Whether sun or shade, indoors or outdoors, the collection offers versatile options for a range of growing conditions.
The third was the Durabloom petunia, which was described as having big flower power and a promising future ahead. “I think they’re going to compete with Supertunias,” says Foisy.
Though organizers have yet to set dates for next year, this year’s experience has opened their eyes to new possibilities. Because New Blooms used to take place a few days after the Cultivate show in Ohio, U.S., it was always logistically trying for organizers to put together the final touches and coordinate out-of-province speakers within a few days of their return. This year, Foisy’s garden centre kept their doors open all summer.
“Going forward, having a pre-recorded session will be much more beneficial than getting people to fly out,” says Verheul. “The whole dynamic has changed.”
PHOTO CREDIT:
M. VERHEUL
ROCKWOOL WASTE could open new markets
A non-biodegradable medium, rockwool could generate additional value through secondary use.
BY TANYA HVILIVITSKY
Researchers from Niagara College’s Agriculture & Environmental Technologies Innovation Centre (AETIC) are investigating uses for a waste product from the greenhouse industry.
With students from the Greenhouse Technician program, the research team worked on a course-based growing trial project with Walker Environmental Group (WEG) to explore recycling possibilities and beneficial secondary uses of rockwool, a nonbiodegradable mineral wool product often manufactured as a soilless growing medium for hydroponic production.
“This type of media, which comes wrapped in plastic bags, allows growers to precisely dose fertilizers, water and other components necessary for the most optimal growth of the plants,” says Marin Dujmovic, process specialist at WEG. “Once crops are harvested, this media is not reusable for growing and needs to be disposed of.”
Walker’s machinery shreds the material, separating plastic bags from the reusable rockwool. “Once separated, plastic is disposed at the landfill (even though we are looking into reusing this plastic in [the] manufacture of low-carbon fuels etc.) and shredded rockwool material is used as a bulking agent in compost production,” adds Dujmovic.
bulking agent, but also as a compost quality enhancer.
“If there’s no impact with the highest percentage, that means they can get rid of tons of rockwool, and the plants grow just fine,” says Schulze, who’s also the coordinator for NC’s Greenhouse Technician program.
If the used rockwool media is successfully incorporated into compost production, it may mean new markets for WEG as they will be “able to recycle new material (used rockwool media) on an ongoing basis with good use of the end product,” adds Dujmovic.
As a result of these growing trials, WEG is now advancing development of its rockwool growing media recycling program. The company has since received funding under the Greenhouse Competitiveness and Innovation Initiative from the Agricultural Adaptation Council to study the market development of rockwool recycling services.
With its history of offering environmental waste solutions, WEG partnered with AETIC, part of the college’s Research & Innovation division, to investigate the possible benefits of using rockwool as more than just a bulking agent.
“In theory, this bulking agent will increase compost’s moisture content (since we receive rockwool at high moisture levels, with some nutrient leftovers as well), water holding capacity, porosity and nutrients, which all have a beneficial effect on the growth of the plants,” explains Dujmovic.
Led by NC faculty research lead Derek Schulze, the growing trial with basil used varying percentages of the rockwool/ compost blends, compared with a control, to quantify how the plants grow. Results of this phase will determine if it’s possible and/or beneficial to use the rockwool in compost, not only as a
Walker is also working with Ontario Greenhouse Vegetable Growers to validate composting as a means for effectively destroying pathogens affecting greenhouse-grown plants.
“The work previously conducted at Niagara College has been instrumental in helping us develop this program as we work to find a suitable means for treating, recycling and creating valuable products from waste growing media,” said Greg Robles, manager of innovation & optimization resource recovery at Walker Industries.
The AETIC growing trial received funding from the Ontario Centre of Innovation (OCI) through their College Voucher for Technology Adoption (CVTA) program and the NC-led Greenhouse Technology Network (GTN).
Tanya Hvilivitsky works with the Greenhouse Technology Network (GTN) to capture its research-industry collaborations. The GTN is a consortium of research-focused centres led out of Niagara College that help small and medium-sized businesses in southern Ontario extend their R&D capabilities and solve technology challenges. Learn more at greenhousetechnetwork.ca
PHOTO CREDIT: NIAGARA COLLEGE
Growers know that when it comes to controlling and monitoring a production environment, a simple, flexible, sustainable control system is crucial. This is why you can depend on Reliable Controls. Our nationwide network of factory-certified Authorized Dealers will help you 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.
To learn more about this cost-effective, Canadian-made solution, please contact a Reliable Controls
Authorized Dealer near you.
Western Canada: 403.561.4148
Eastern Canada: 647.982.7412
2022 is the Year of the Verbena
In the August issue, National Garden Bureau profiled the new houseplant category in the ‘Year of’ program. Now, we turn our attention to one of the original categories: annuals.
BY DIANE BLAZEK
Which annual will be trending in the spotlight for 2022? Why, it’s the verbena. While there are perennial types of verbena on the market, for the purposes of this program we will focus on annual types, many of which are known as Verbena x hybrida
The original species were native to the Americas and Asia but have since been refined and bred for today’s gardening consumer. National Garden Bureau (NGB) members chose to highlight the verbena because of the many different colours and types that are available. When grown in the right conditions (full sun with good air circulation), these plants need little extra care to thrive and produce blooms all summer long,
ABOVE
making them a great choice for home gardeners. Given the range of colours that verbena come in, there is surely something for everyone’s décor and tastes.
Plan ahead for the 2022 season by selecting some of these popular verbena series:
Cadet – An upright verbena that flowers one week earlier than other uprights. Very uniform with good heat tolerance.
EnduraScape – The first verbena that’s hardy through the hottest days of summer but can take the cold down to the low teens, and still rebloom, bringing lasting colour to landscapes all season long.
Firehouse – This medium-vigour verbena
In the annuals category, 2022 has been deemed the Year of the Verbena thanks to the many colours and types available and little extra care needed to keep plants blooming. Pictured: Lanai Candycane.
has a beautiful mounded habit perfect for hanging baskets and landscapes. They have superior powdery mildew tolerance and prolonged summer flowering.
Lanai – A semi-trailing verbena characterized by disease resistance, bold patterns, bright colours, and contrasting eyes. It spreads up to 2 feet and has a long bloom season. Compact versions with mounded habits are also available.
Obsession – With colours that will mesmerize, Obsession is perfect for packs and small pots with strong branching and high uniformity that make production a breeze.
Quartz – An all-season verbena that makes a great choice for spring and fall temperatures but also tolerates heat and humidity.
Superbena: These verbena hybrids were developed to be more robust, more mildew resistant, and more resilient than older varieties. They also produce larger flowers in many colours, including bicoloured striped patterns.
Tapien: A trailing verbena characterized by a multibranching growth habit, spreading up to 3 feet to create a dense low-growing carpet of blooms. Highly mildew-resistant and thrives under a wide range of weather conditions.
Temari - Temari trailing is a range of broad-leaved verbena, which are centrally branched, produce vigorous branches which quickly form mounds of colour.
Vanessa – Vanessa has a controlled, well-branched habit that was selected for mildew tolerance. It holds its colour into the heat of summer.
ABOVE
Cadet Upright Purple flowers earlier than most other verbenas and offers good heat tolerance.
‘YEAR OF’ PROGRAM
By November 1 of this year, photos of these varieties will be available on the NGB website. NGB also provides multiple marketing materials that can be downloaded at no charge from the NGB website. If you need the logo prior to November 1, simply contact NGB at info@ngb.org.
Growers and garden centres are encouraged to take advantage of the publicity generated by this program by using the marketing collateral NGB can provide for your 2022 catalogues, websites, advertisements, presentations, trade show booths, event exhibits and other materials.
Need another reason to use this program? NGB does extensive work on creating marketing content, such as social media graphics, which makes it much easier for you to post information about the “Year of” plants on your own social media platforms. Our work on this helps save you time and money, especially during the busy spring season!
Consumer publicity for the 2022 Year of crops will begin in January 2022.
Stay tuned to this space for the next 2022 ‘Year of’ crop.
Diane Blazek is executive director of All-America Selections and National Garden Bureau. NGB is a North American non-profit organization and marketing arm of the gardening industry. It exists to educate, inspire, and motivate the use of plants in homes, gardens, and workplaces. NGB members come from around the world and are experts in the field of horticulture. Find out more at ngb.org. ABOVE EnduraScape withstands a wide range of temperatures.
Automation Compatible Containers
If
DEHUMIDIFICATION under closed screens
Opening a gap in the screen could disrupt climate uniformity in the greenhouse. Could a fan system be part of the solution?
IBY JAN LUYENDIJK
t’s a challenge for many growers: maintaining an optimum, uniform, growing climate under a closed screen. If humidity and temperature move too far out of line, a gap will often be opened in the screen. But opening the screen to remove moisture and heat causes undesirable climate differences in the greenhouse. Also, recent changes in legislation, causing restrictions regarding light emission, need to be taken into account.
The lighting systems require solutions to keep temperature and humidity under control. If the temperature or humidity rises too high, one of the solutions could be drawing in drier air into the greenhouse by using a ventilation system.
Jeroen de Wit, international sales manager for horticulture at Van der Ende Groep, is well aware that extreme climate differences are an urgent issue, not only in his home country, the Netherlands, but also worldwide, including Canada.
“Many growers choose the least bad solution: just opening the screen to create a small [gap] to allow moisture and heat to escape. But then you get a cold downdraught under the screen, which creates irregularities in the greenhouse climate. A non-uniform climate can in turn lead to production differences. And yet another problem is that opening the screen during blackout periods [can] cause light emission.”
and supplier has been working to solve.
As de Wit explains, applying a fan system that draws in cold, dry air from above the closed screen, mixing it with the warmer, more moist air in the greenhouse and then distributing it evenly in the growing space under the screen, provides a solution that allows for a more horizontally and vertically uniform climate. Particular models offer modulating valves that regulate the amount of air that’s drawn in from above the screen and from the greenhouse, allowing controlled cooling and dehumidification.
Use of measuring boxes outside and inside the greenhouse –both above and below the screen – are necessary to control the ventilation system. For products connected to the greenhouse climate computer, the fan system automatically kicks in once measured levels move out of line. This also helps determine the right settings, maintaining the right ratio between air intake from above and below the screen.
Some hortizontal fan systems are designed to ensure that the screen fits closely to the fan and no energy is lost. Pictured: Airmix Model T.
With the global introduction of the Principles of Plant Empowerment, an integrated approach to cultivation based on crop balance, plant physiology and physics, de Wit sees this as a perfect fit for ventilation systems. They allow growers to keep their screens closed as much as possible, in the interests of an optimum plant empowerment strategy. And keeping the screens closed for a longer time will result in savings of heat, energy and CO2
The issue of dehumidification with a closed screen first received serious attention over five years ago. This is an issue that the Netherlands-based greenhouse technology producer
The possibility of cooling even during blackout periods without light pollution can be an important addition to a grower’s toolbox for controlling the climate. It helps maintain climate uniformity in all applications, and without suffering energy losses with an open screen. The favourable effect can also be seen in the reduced disease burden in the greenhouse: a consequence of optimum ventilation.
Every greenhouse is unique and the best solution depends on the crop, type of greenhouse and location, to name a few. A custom-made fan plan should be drawn, taking into account these various factors as well as natural forms of ventilation.
Van der Ende Groep in Maasdijk, the Netherlands, has been developing solutions for modern greenhouse horticulture for nearly 40 years, focusing on water and climate technology. For more information, visit vanderendegroep.com or contact Jeroen de Wit at jdw@vanderendegroep.nl
Effects of broad-spectrum white light on crops revealed
Studies show advantages to wavelengths beyond typical narrow-band lighting.
BY FLUENCE BY OSRAM
Results from a series of multi-year studies have shown that wavelengths outside of the red and far-red regions can lead to improved crop yield and performance.
Fluence by OSRAM announced the results of studies conducted with partners worldwide, analyzing the effects of broad-spectrum white light on plant yield, morphology, development and quality in cannabis, Merlice tomato and bell pepper crops.
The studies found that while spectrum sensitivity is cultivar-dependent, broadspectrum lighting strategies — which include green light and other wavelengths largely absent in narrow-band spectra — improved crop yield, morphology and overall performance in selected cultivars when compared to narrowband spectra with high ratios of red and far-red wavelengths.
“The results from our global studies show
ABOVE
how effective broad-spectrum white light can be in improving crop performance for many cultivators around the world,” said Dr. David Hawley, principal scientist at Fluence. “Broadspectrum strategies are about balance and flexibility in the spectrum itself as well as the overall cultivation approach. While there are certain scenarios in which narrow-band spectra, or pink light, may make sense from an energy efficiency or crop production perspective, we’ve found that many cultivars simply perform better under broad spectra across the KPIs cultivators care about most: yield, morphology and overall quality.”
MERLICE TOMATOES
A collaborative study with Wageningen University and Research (WUR)—led by researchers Leo Marcelis and Ep Heuvelink— evaluated differences in yield, morphology,
A series of multiyear studies analyzed the effects of broad-spectrum white light on plant yield, morphology, development and quality in cannabis, Merlice tomato and bell pepper crops.
HortOS knows
Is the moisture content in the growing substrate too high?
Ridder HortOS Grower is the online tool that brings together all the relevant climate, production, cultivation and crop data from the various crops and greenhouse locations, and presents this in one place. The Grower Module is available within the HortOS platform and provides direct insight into the progress of the crop in relation to set long-term goals. In the presentation of these data, the emphasis is on monitoring yields and efficiency. So whether it involves day-to-day greenhouse operations or long-term strategic decisions, HortOS enables the entire organization to work together to drive growth and profitability. RIDDER.COM/HORTOS
development and quality for Merlice tomatoes grown with the VYPR top light series under four light spectra: PhysioSpec BROAD R4, PhysioSpec BROAD R6, PhysioSpec BROAD R8 and PhysioSpec DUAL R9B. BROAD R4, R6 and R8 all contain significant fractions of green light and other photosynthetically active wavelengths, while DUAL R9B is a narrow-band spectrum that contains almost no green light.
As researchers increased the ratio of red light in the overall spectrum, they recorded a linear decrease in yield. Compared to spectra with higher blue, red and far-red wavelengths, Merlice grown under broader spectrum lights yielded increases in fruit weight of as high as 13 per cent. Other tomato cultivars grown under broad-spectrum saw yield increases of up to 14 per cent.
CANNABIS
Fluence conducted individual studies with WUR and Texas Original Compassionate Cultivation (TOCC).
In the TOCC study, researchers studied Type I, Type II and Type III cannabis responses to broad-spectrum R4, R6 and R8 under high PPFD. In each case, broad-spectrum R4 generated the most dry weight per plant. In Type I cannabis, PhysioSpec BROAD R4 generated 17 per cent higher yields than the next highest yielding spectral solution, R6. Cannabis grown under broad-spectrum R4 also significantly improved morphology compared to plants cultivated under R6 or R8. Plants grown under broad-spectrum R4 were free of photobleaching in their upper buds, a development that typically occurs in plants grown with a higher fraction of red light.
ABOVE
Cannabis grown under broad spectrum R4 were free of photobleaching in their upper buds.
In the WUR study, researchers found that in some cultivars, monoterpene and cannabinoid content, including THC, CBD and CBG, is significantly inversely proportional to the fraction of red light in the production spectrum. With these cultivars, R4 induced a 20 per cent increase in cannabinoid compounds compared to spectra with red light ratios as high as 90 per cent or more.
“The results of the TOCC and WUR intensity and spectrum
CONTAINER GARDENING
Container gardening provides boundless, exciting opportunities for both novice and experienced gardeners.
In this stunning book, Kathy Brown gives expert advice and shares her latest ideas on how to transform patios, walls, courtyards and doorsteps. In addition, step-by-step recipes guide the reader through the process of both planting and aftercare, either for short-term seasonal schemes or for longer-term projects.
$29.95 Item #1847972750
Scan to Buy Book
studies are important for cannabis cultivators for two reasons,”
Hawley says. “First, there is rarely a scenario in which they should grow cannabis under low PPFD. Our research continues to emphasize how much more beneficial it is to grow cannabis under higher PPFDs. Second, watch your red light ratio. There are a couple [of] very specific cultivars and production situations that could benefit from narrowband or high red/far-red and blue wavelengths. But it can also have detrimental effects on cannabinoid content, terpene ratios, yield and morphology, and would raise the risk of significant photobleaching of the canopy. That’s why we generally recommend growing cannabis with broad-spectrum under high PPFD.”
BELL PEPPER
Fluence also conducted studies with bell peppers at the Harrow Research and Development Centre in Ontario, led by Dr. Xiuming Hao and Dr. Jason Lanoue. The collaborative research on bell pepper found that fruit quality significantly increased in Gina and Eurix cultivars under broadspectrum lighting. Peppers grown under broader spectrum light increased average fruit size by up to 15 per cent compared to others with higher blue and red wavelengths. An increase in the dry matter content — which is largely associated with fruit quality — also rose with increasing greenlight.It was also found that broad-spectrum lighting strategies improved the consistency of week-to-week production by levelling out a traditionally flush-prone crop cycle.
Only
Educational/Government Extension
Manufacturer/Distributor
Other ____________________________
Please Specify
YOUR JOB TITLE (Please Check One:)
Owner/President Head Grower
Manager/Supervisor Sales Representative
Other _____________________________
Please Specify
Payment Enclosed
(Payable to Annex Publishing & Printing Inc.)
to:
“Time and time again, our research with leading institutions around the world is proving that there is no universal spectral strategy for cultivators,” says David Cohen, CEO at Fluence. “For many crops and cultivars, however, it’s also showing the holistic benefits of broad-spectrum white light not just for the crop, but for a cultivator’s entire operation.”
CANADA CLASSIFIEDS
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
Fluence’s ongoing global research initiatives include additional studies on strawberry, lettuce and cucumber cultivation.
INSIDE VIEW
GARY JONES | Gary.Jones@kpu.ca
The Answer is Yes
“To think green is to be green.” I saw this on the back of a garbage truck doing the rounds one morning. We’re bombarded with ‘green’ or ‘sustainable’ messages every day. But is there any substance behind this ‘marketing’ message?
As I write, “The European Union has announced a raft of climate change proposals aimed at pushing it towards its goal of becoming carbon neutral by 2050.”1 According to the same source, “They include plans to tax jet fuel and effectively ban the sale of petrol and diesel powered cars within 20 years.” These goals are being referred to as the “Fit for 55 package because they would put the bloc [EU] on track to meet its 2030 goal of reducing emissions by 55% from 1990 levels.” Sweeping, drastic changes ahead for European colleagues perhaps. But what if we’re faced with similar taxes and bans to those in Europe? Such regulation may not be far away…
B.C. has just announced changes to the Greenhouse Gas Reduction (Clean Energy) Regulation to increase the production and use of renewable gas, as well as green and waste hydrogen. “‘A key part of our CleanBC strategy is increasing the use of hydrogen and other renewable gases in place of fossil fuels in vehicles, buildings and industry,’ said Bruce Ralston, Minister of Energy, Mines and Low Carbon Innovation.”2
“B.C. is the first province in Canada to make these kinds of changes allowing for the increased production of renewable gas, including hydrogen. The amendments support the Province’s upcoming hydrogen strategy, which will include ambitious
renewable energy, heat recovery, innovative glazing materials and transformation of organic waste.”3
The ‘Opening Remarks and Panel Discussion on Energy Matters’, of ‘Grower Day’ in June mirrored Dr. Dorais’ ideas. Growers from four provinces/territories and Dr. Rupp Carriveau from U. of Windsor discussed current energy sources, (primarily biomass and natural gas), and suggested what they may use in the near future. All are keen to use energy as efficiently as possible, as this simply makes economic sense. Some are looking at possible alternatives such as geothermal (if drilling costs can be managed), PAR transmissible PV panels (agrivoltaics), and more accurate energy accounting. One grower highlighted the need to consider changes in greenhouse design, proper (better) use of thermal screens and energy walls for storage/release of radiant energy.
Green energy is not only an idea for marketing purposes.
goals to increase the production and use of renewable and low-carbon hydrogen to help achieve climate targets under CleanBC ...”2
“We’re committed to finding new solutions that significantly cut climate-harming pollution in all sectors and power a clean economy for people and businesses,” said George Heyman, Minister of Environment and Climate Change Strategy.2
The pandemic put food security right in the centre of a focussed societal searchlight. Quebec has plans to increase the volume of its greenhouseproduced food supplies. Dr. Martine Dorais (Laval University) reported to a webinar hosted by Zone Agtech that this will not be without challenges which include “achieving a balance between productivity and sustainability.”3 “She explains that sustainability can be improved through use of
There are many options to explore for our energy requirements: Hybrid greenhouses (vertical farm and ‘traditional’ greenhouse), wind, solar, passive systems. Partnering with neighbouring industry for waste heat recovery. Use of artificial intelligence to squeeze every last drop of energy (and CO2 and electricity) out of fuel input. Lower temperature regime production methods and breeding of cultivars that thrive with less energy input. Converting food waste into ‘natural’ energy. We must continue exploring all these (and more) as we inevitably head towards a carbon-neutral society (whether we like it or not). As one member of the Grower Day panel responded to a question, ‘The Answer is Yes’. When looking at the issues around fuel sources and energy use, and whether we ought to be interested, the answer must be yes.
‘Green energy’ is not only an idea for marketing purposes. It’s also simple economic sense. And now it’s part of a real political movement. It’s not just a slogan on the back of a garbage truck, even if that truck is heading to a local greenhouse to fuel their burner. Now is the time to be prepared.
1 BBC News, at: https://www.bbc.com/news/world-europe-57833807
2 BC Gov News, at https://news.gov.bc.ca/releases/2021EMLI0046-001286
3 ‘Quebec’s goal is to double greenhouse acres by 2025’, Grower, June 2021.
Gary Jones is a faculty member in the School of Horticulture at Kwantlen Polytechnic University, Langley, BC. He sits on several industry committees and welcomes comments at Gary.Jones@kpu.ca.
LED BACKED BY BY SCIENCE INNOVATION
Cultivate at scale with the precise and versatile NEW RAZR Modular System
Market-leading efficacy in broad white light
Purpose-built for any size vertical farm
Easy configuration on any vertical rack
Enhanced light uniformity for Danish Trolleys
Plug-and-play mounting and field-replaceable parts
Contact us to see how the RAZR Modular System can increase productivity and consistency on your farm. Visit, www.fluence.science/products/razr-series
