Envisioning the microclimate How researchers are working towards a model of the microclimate. By Quade Digweed | Pg 28
Dr. Vojislava Grbic presents innovative new tools to manage the two-spotted spider mite. Pg. 40 | Photo credit: D. Pavicevic
BY CARA MCCREARY
DR. SARAH
DR. MICHAEL BROWNBRIDGE
Is COVID over yet? Far from it. In fact, when our Grower Day panelists shared their plans for ‘Moving Forward with COVID’, most were expecting a second wave in the Fall and another in early 2021. Here were some of the key takeaways:
Government COVID subsidies will start to wane, but panelists were positive that the high demand for plants this season will carry through into the Fall. Mum sales tripled in August for one panelist, foliage sales doubled for another. The demand for local produce has also been incredibly strong.
For two panelists who employ foreign workers, they are taking every precaution to keep their employees safe from COVID-19. One key area is contingency planning. If an outbreak were to happen among workers, what would be the plan? Is there a way to continue operating that would be safe for the workers and
strategy should help the business survive that hurdle, but this should be done strategically so it is not mistaken for price gouging.
This is also a good time to re-evaluate what’s selling and what’s not, then target orders accordingly. Rather than carrying 15 different colours of the same petunia, it’s time to reduce that number to something more manageable, particularly when juggling an online presence at the same time. Retail owners agreed that sizing up was a good move for appealing to inexperienced consumers who want larger, more “instant” items. Small fruits, vegetables and anything related to food growing saw a large uptake this season, continuing a previously established upward trend. Colourful items, as well as home and patio furnishings, were also big.
Orders should be submitted and confirmed now. Shortages observed so far include nursery stock on the
If an outbreak were to happen, what would be the plan?
still keep the business running?
For the two retail operators, both started online stores and curbside pickups this year. Both also noted that this ended up doubling the amount of work for roughly a third to a half of their usual return. The online storefront could continue to be a good fallback option.
FACTOR IN COSTS AND RISKS
Expenditure on personal protective equipment and efforts to create a safe working environment have increased production costs. Another factor to consider is risk. In the event where a crop doesn’t ship, a good pricing
West coast, as well as colourful items, perennials and home furnishings in Ontario. With interruptions in transport and less available airspace, there could be slowdowns in acquiring cuttings and starter items offshore.
Thank you to panelists who made this panel a reality: Bob & Carmen Mitchell (SunTech Greenhouses), Stan Vander Waal (Rainbow Greenhouses), Brian Minter (Minter Country Gardens) and Len Ferragine (Bradford Greenhouses Garden Gallery).
Look for a more detailed recap of this panel on greenhousecanada.com
and
Greenhouse Canada
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Like the greenhouse tomatoes launched in 2018, Wendy’s will be the first national brand in the Canadian quick service restaurant industry to serve 100 per cent greenhouse lettuce in all 384 of its restaurants across the country. All lettuce served will be grown in Canadian-sourced peat without pesticides. Whole Leaf, the grower of Inspired Leaves, will provide the lettuce to all of Wendy’s locations in
Canada. Located in Coaldale, Alta., Whole Leaf captures and reduces water consumption by over 90 per cent compared to field-grown lettuce. Their onsite process captures waste heat and CO2 at the same time, reducing greenhouse gas emissions and allowing it to be completely self-sufficient for electricity and heating.
SOURCE: WENDY’S RESTAURANTS OF CANADA
Ontario agricultural businesses, including greenhouses, can now access a free, government-funded consultation service to help choose the best options for protecting their workers from COVID-19. Carried out by experts at Workplace Safety & Prevention Services (WSPS) and backed by the Ontario Ministry of Agricul-
ture, Food and Rural Affairs (OMAFRA), the program provides each eligible agricultural operation with two days of personalized consulting and training services to help better manage the risks in their operation. The tailored program also offers a pandemic recovery toolkit on measures for managing the risk of exposure to COVID-19, awareness training, as well as
British Columbia is waiving minimum income requirements for existing B.C. farm operations, allowing them to maintain their current property tax farm status for 2021.
COVID-19 has been challenging for some B.C. farm operations, including smaller-scale farms that depend on roadside stands, farm markets and public interaction for sales revenue. New applications for farm class and retired farmer designations will be processed as usual. Any property subject to a legal change, including a change in ownership or subdivision, and any property with a change in use or where a lease is expiring, will be required to complete a self-reporting questionnaire and will not automatically be granted farm status for 2021.
SOURCE: BC MINISTRY OF AGRICULTURE
additional resources to support businesses as they implement measures to protect their employees.
Valued at $2,000, each two-day consultation is being funded entirely through the Agri-Food Workplace Protection Program There are 125 spots available for agricultural operators and they’re approved on a firstcome, first-served basis.
To enact some of the recommendations from WSPS, greenhouse operators can take advantage of another funding stream under the Enhanced Agri-food Workplace Protection Program. It can help cover 70 per cent of the costs, or up to $7,500 for implementing those measures.
Reach out directly to WSPS at 1-877-494WSPS (9777).
COVID sales and spend
SOURCE: STATSCAN, 2020
Total retail sales for Canada in May were 20% below levels in February
Most Canadians expect to spend about the same on groceries
Online sales in May were more than double the level observed in May of 2019
19% TO SPEND MORE 10% TO SPEND LESS
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Selected for its nestled branching, fuller, uniform habit and season-long flowering, this new brick red selection represents an advancement in heat-tolerant Osteospermum breeding, allowing for a longer sales window than most. Said to be some of the easiest Osteospermum to produce. Part sun to sun. 20-30 cm tall, 20-30 cm wide. provenwinners.com
A thorough clean out can reduce carryover of pests and pathogens. Have you covered every nook and cranny?
BY CARA McCREARY
As many greenhouse vegetable crops start to wind down, it is critical to conduct a thorough clean out between crops. Not only can this reduce carryover of arthropod pests and plant pathogens, it also improves the success of integrated pest management (IPM) programs in the next crop.
Here are three critical steps to a thorough cleaning:
1. Remove organic matter (OM): Why? Because OM protects pests and can neutralize/inactivate disinfectants.
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2. Wash with detergent, rinse, dry: Why? Because washing/scrubbing with detergent first can eliminate more OM and begin to break down pathogens.
3. Disinfect, rinse, dry: Why? Because this final step can catch what was missed in steps 1 and 2.
Tips to keep in mind during clean out :
• Maintain warm temperatures to starve pests and increase efficacy of disinfectants
• Monitor for residual pests
• Maintain sanitation and hygiene (e.g. foot -
Start with a clean greenhouse before planting to help set up your IPM program for success.
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Apply disinfectant with a power washer or specialised equipment on low pressure.
baths, hand sanitizers, freshly laundered clothes, clean footwear, etc.)
• Heat and vent to rid greenhouse of pesticide residues after clean out to avoid phytotoxicity in your next crop
Keep this checklist handy to make sure you’ve covered all your clean out tasks.
Crop disposal
Treat crop before removal to kill active pests
Remove and properly dispose of:
• Old crop – do not pile or spread infected plant material behind your greenhouse
• Other materials (clips, slabs, strings, etc.)
Remove remaining plant residues; sweep and vacuum focusing on gaps in floor covering, walkways, corners, ledges, etc.
Clean irrigation system
Remove drippers from media; keep lines slightly charged to maintain moisture
Disconnect pH and EC sensors
Remove filters
Flush lines:
1. Flush with water
2. Flush with acid (e.g. nitric acid, sulfuric acid, hydrochloric/muriatic acid); check the emitter manufacturer for pH requirements
3. Pulse several times at 1-hour intervals for 24 hours
4. Flush with clean water
5. Flush with disinfectant
6. Flush again with clean water when specified by the product label
Clean and disinfect:
• Stock tanks, return/dirty leach tanks, freshwater tanks
• Pump sets
• Emitters stakes (soak in acid solution for up to 48 hours, rinse well, disinfect, rinse well when specified by the product label)
Replace emitters and other parts when necessary
Washing and disinfection
When washing and disinfecting different parts of the greenhouse, be sure to let soak (wet) for a minimum of 15 minutes up to 60 minutes. Though
longer contact time is generally more effective, be mindful of corrosiveness of disinfectants. Rinse well with water and let dry completely between steps. Do not forget door handles, keyboards and other surfaces touched by employees.
Wash and disinfect structure
• Use a power washer or some specialized equipment on low pressure with large opening tip
• Start at the point of the roof and work down
• Replace old floor covering when necessary
Wash and disinfect all horizontal surfaces, including:
• Rafters
• Pipes
• Troughs
• Concrete walkways
Wash and disinfect all tools and equipment, including:
• Scissor carts
• Picking crates
• Wires
• Machinery
• Vehicles
• Fork lifts (including forks)
• Pallets
• Knives and scissors
Wash and disinfect other common areas, including:
• Offices
• Washrooms
• Lunch rooms
• Packing lines
• Boiler room
Gone through the checklist above? Now you are ready for planting!
Disclaimer: Always check federal, provincial and municipal regulations when choosing pesticides and disinfectants. It is critical to store, handle, apply and dispose in a proper manner to avoid or eliminate negative impacts on personal health and safety and the environment. Always check safety data sheets (SDS) recommendations before using any product. Check warning labels for required personal protective equipment (PPE).
Cara McCreary, MSc., is the greenhouse vegetable IPM specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs. She can be reached at cara. mccreary@ontario.ca .
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From nerve-racking to bestselling, growers banded together for one of the best seasons yet.
BY GRETA CHIU
The Canadian ornamental sector will forever remember 2020 as one of the bestselling seasons to date.
“I sold 30 per cent more than I did any other year,” says Michiel Verheul, owner and operator of High Q Greenhouses in Sturgeon County, Alta. Of the 400 independent garden centres (IGC) that he supplies, only three cancelled or reduced their orders at first, he says, grateful for his customers’ support. But the three soon uncancelled and repurchased, and at higher quantities than before, as IGCs in Alberta reopened and stock started flying off the shelves.
It was the second half of the business that had him questioning their financial stability. Supplying contract-grown material to municipalities, Verheul often goes through great lengths to source the exact colours, varieties and sizes requested and some selections were started months in advance. When the COVID wave arrived, several towns and
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cities reduced their orders by half or cancelled them outright due to reduced or diverted seasonal staff. This left Verheul with a large fraction of highly specialized material, uncommon for the normal consumer crowd.
Upon hearing his predicament, close friend and customer Debbie Foisy, immediately reached out to her social media following. While Deb’s Greenhouse doesn’t normally bring in bedding plants, gardening materials were in high demand as interest surged in home gardening. She identified Verheul’s products, encouraging customers to support a local grower who had suffered losses due to COVID, with High Q receiving almost 100 per cent of the proceeds. “It helped me move [product] in a way that I couldn’t on my own, getting it into the hands of people who really desperately needed it,” says Verheul.
Fellow growers, including those who had never ordered from High Q before, also came forward
Michiel Verheul (center) is looking forward to the next season as new gardeners return for more. Also pictured: Ina Verheul (left) and Bronwen (right) of High Q Greenhouses at 2018 GISC.
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Visual Characteristics
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Growth Characteristics
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• Good truss and fruit quality throughout cycle
• Premium plant vigor
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Disease Resistance
• Very good disease resistance package, including intermediate resistance to powdery mildew
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in his time of need, moving 80 to 85 per cent of Verheul’s more unusual material. “And they’re not $2 items,” he adds. Grateful for their support and foreseeing an emerging gap in supply, Verheul immediately began seeding and planting leftover material from prior seasons to help other growers.
“Nobody really knew how much we were going to sell, but based on European markets and what we saw in other places in Canada, we heard reports where the growers couldn’t bring them fast enough to the garden centre. The garden centres were running out.” Verheul’s team filled trays of popular ornamentals by the hundreds and grew tens of thousands of tomato and pepper plants in fourinch containers, all finished and ready for retail.
“We fought very hard as an association to get essential status,” says Verheul, who also serves on the Board of Directors of the Alberta Greenhouse Growers’ Association (AGGA). But once IGCs were allowed to open, Foisy says the response
was overwhelming. Evidence of a new audience emerged as 83 per cent of her online sales were from new visitors to her web store, some brand new to her IGC and others purely brick-and-mortar customers before.
Because one of the long-time
greenhouses in the area recently retired, Foisy had already increased their seedling and young plant orders this year. “Then when COVID hit, we anticipated demand to be even greater and we upped it again.”
For growers and IGCs that remained open, it was their busiest July yet. Foisy extended her retail season by two more weeks and lengthened their store hours to accommodate more customers. She also hired three staff full-time, in part to enforce strict COVID regulations so both staff and customers felt safe, as well as handle curbside and in-store pickup of web orders. But for growers who ran out of plant material and didn’t source more, Verheul says they missed out. “Long-time customers that have carried you through the wet years, the cold years, and the dry years – those customers that came to a closed door – are they going to support you next year or are they going to support a local grower that has continued to try and get product in from elsewhere?”
Receiving inquiring calls on everything from peat moss to garden supplies, he’s gladly referred them to other businesses
even though he didn’t supply them. “You would never get that kind of service from a box store.” Many garden centre departments of large supply chains closed a month early in their area. “People who normally shop at box stores have been forced to use the independent route,” says Verheul.
“I think that the pandemic has really opened our eyes, not just in our industry, but to what joy we can provide [to the public],” says Foisy. Seeing the initial unease in her community over COVID-19, she created how-to videos on food gardening and other fun projects over social media, while offering her greenhouse as a garden oasis for private bookings back in April.
For her next project, Foisy is planning a large outdoor display garden with multiple uses. Not only will it house every perennial in their catalogue, the garden will also double as an educational space and foster connections between plants and consumers. It’s also family friendly. The garden will feature a number of small doors and hidden pathways
reminiscent of Alice in Wonderland and the Secret Garden. “Thinking about the pandemic, people don’t want to feel congested when they’re shopping and it’s never been more apparent than this year,” she says.
Moving forward, Verheul believes that IGCs will continue to enforce appointment bookings. “You can get in, because this is your time, your spot and it gives the customer a really privileged feeling… It’s like having somebody lift the ribbon when you’re
at a famous nightclub,” he says. While a box store may offer the opposite of a VIP shopping experience with unpredictable wait times, IGCs have created a positive atmosphere albeit the personal protective equipment and physical distancing in place. “You’re with 15 other people instead of 300… It almost feels like you have the greenhouse to yourself.”
Even if COVID lockdowns are lifted by next season, Verheul predicts that 50 per cent of this year’s first-time gardeners will return and continue for the next four years. He advises IGCs to pre-sell online before they open in April. “Generate some cashflow. Even if it’s not picked up or delivered right away,” he says. “We can train our customers to avoid disappointment when they phone on June 15.”
In the constant tug-of-war between box stores and independents, it seems that COVID may have put IGCs ahead
How to sample and choose the right tests to find out.
BY DR. SARAH JANDRICIC AND DR. CHEVONNE DAYBOLL
After reading the previous articles in this series, you’re now aware of which pathogens can be spread through your irrigation water, where they can accumulate, and why that’s important.
So what can you do about it? This third article in the water sanitation series will walk you through how to sample water sources on your farm, and which tests you can run to determine if your water is helping – or hurting – your crop.
Several labs in Ontario will process water samples and check for everything from nutrient levels and pesticide residues, to fungal and bacterial loads. Most sample for pathogens using a “DNA multiscan”, which looks for bits of DNA from a wide range of known pathogenic species. But part of
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getting useful results from these labs is knowing where and how to properly sample. Here’s a compiled list of do’s and don’ts to help you get started.
Checking your water for pathogens isn’t something you should do only when you think you have a disease problem. Just like monitoring for insect pests in your IPM program, checking your water should be part of your regular integrated disease management (IDM) program.
You’ll also want to look at different points along your irrigation system to determine which water sources are potentially contaminated and how this is flowing through your greenhouse.
When it comes to when, where and how to
Whether it’s a boom, spaghetti or flood bench irrigation system, be sure to sample the water being delivered to the crop to determine if there are pathogens coming from it.
sample, consider the following do’s.
1. DO monitor at frequencies that relate to the level of risk. These include: Different points in the production cycle (especially before a new crop goes in); when changes in source water quality occur (e.g. switching from roof water to water stored in a cistern), when sensitive crops are present (based on crop type and/or stage – this is why knowing your crop’s susceptibility to diseases before planting is important); when labour is available (no one will likely be sampling water in the middle of the Mother’s Day rush).
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2. DO sample from all sources of water, and from various points along your irrigation system. This can reveal potential sources of contamination, and give you a picture of how pathogens are spreading throughout your farm. Testing along your irrigation system can also reveal issues with water pressure and distribution which may be causing wet or dry spots in the crop that can also lead to disease problems. Try to sample from locations that are close to where the water enters the production area (e.g. in
3M yeast and mold Petrifilm growing various fungi. These films can be used to help quantify the amount of fungal pathogens in your irrigation water, and are a useful component of regular water testing.
the first few rows or benches) and those that are near the end of the line to gain a better idea of the problems you might be facing.
3. DO sample recirculating water before and after water treatment. This tells you if your chosen water treatment strategy is working like
it’s supposed to. Never assume that it’s functioning properly. All systems need maintenance, and some need proper levels of active ingredient(s) to work, which can change frequently depending on the amount of organic matter in the system. Be safe not sorry, and follow a regular testing schedule to maintain your investment.
4. DO follow guidelines suggested by your chosen lab. There may be specific guidelines for collecting water samples and for general shipping and handling to make sure you get the best results. Read over these thoroughly before collecting and sending out samples. In a pinch, you can use disposable water bottles to collect samples, but ensure they’re rinsed with your source water well before taking a sample. Never use vessels that were used for another purpose (e.g. scoops for mixing fertilizer, your morning coffee cup of choice) to grab samples as they may leave residue that can affect your results.
5. DO have a consultant or specialist help you interpret the results of any tests. They can help you figure out which pathogens are
There are various points along your irrigation system that should be sampled regularly. To truly understand your water quality throughout the farm, it’s better to sample from multiple points at once than from one point frequently.
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pests for concern, and what to do about them. Stay tuned for a future article on the interpretation of various tests on ONfloriculture.com
What not to do can be as important as what to do. Consider these don’ts and make sure to come up with others that may apply to your own farm.
1. DON’T leave sampling until the last minute. Sampling should be a proactive activity, not a reactive one. But if you’re like many of us, a lack of time and having too much on your plate can mean that your water samples are taken after crops have gone in or after you spot something that isn’t quite right. Schedule regular water sampling into your calendar (or a trusted employee’s calendar) and make sure it gets done ahead of sensitive crop cycles or your big spring season.
2. DON’T be afraid to send in several samples at once, despite the cost. Whether you like to do a more thorough check of your irrigation systems twice a year, or you are facing
a problem and don’t know where to start, having more samples can help you more accurately pinpoint a problem in the greenhouse, saving you time and headaches.
3. DON’T forget to factor in costs of regular sampling into your pest management budget. DNA multiscan tests (that sample for all potential pathogens down to the species) cost around $250 per sample. A supply of 50 Petrifilms (used for general counts of unspecified fungi in water) cost $135. This is a drop in the bucket compared to possible crop losses of 10 to 50 per cent due to pathogens in recirculating water, so make room for them in your pest control budget. If you’re an Ontario producer experiencing an active pathogen issue and aren’t sure of its source or options for treatment, OMAFRA specialists may be able to cover some of the testing costs to help you figure out the problem.
As a complement to lab testing, on-
farm testing protocols have also been developed by the Soil Resource Group, as part of a Canadian Agriculture Partnership-funded project. These methods use adapted Petri dishes, called “Petrifilms” to grow fungi that may be in your water. Although more labourintensive and less specific than lab testing, the Petrifilm method is relatively cheap and allows for rapid results and repeat testing.
This article is the third in a series from ONfloriculture.com about water sanitation. The series is meant to have you reflecting on your own irrigation system before you are faced with a problem.
Sarah Jandricic, PhD, is the greenhouse floriculture IPM specialist and Chevonne Dayboll, PhD, is the greenhouse floriculture specialist for the Ontario Ministry of Agriculture, Food and Rural Affairs. They can be reached at sarah.jandricic@ontario. ca and chevonne.dayboll@ontario.ca.
Perhaps not the first vegetable that comes to mind, greenhouse eggplants garner a premium over their field-grown counterparts.
BY MICHAEL YOUNG
While popular as an emoticon, the humble aubergine may not be the first Ontario-grown vegetable that comes to mind. And yet, approximately 16 per cent of eggplants sold in the province are grown locally. While competition from foreign growers with lower price points presents challenges, the Greenbelt Foundation has released its Plant the Seeds: Opportunities to Grow Southern Ontario’s Fruit and Vegetable Sector report that outlines how Greenbelt-area growers could increase production, providing over 18 per cent of all eggplants sold in Ontario.
The eggplant is an example of a “world food” that, when grown in southern Ontario, competes with imports from the US, Mexico, Central America, and some Caribbean countries. Given that it is a warm-climate crop, there is particular opportunity for production expansion among Ontario greenhouse growers who can achieve a longer, uninterrupted growing season than field growers. Whereas most field-grown eggplant can only be transplanted to the field after May 24th, greenhouse growers or those who use high tunnels to prevent frost damage, can bring plants to maturity more quickly and capture higher, early-market prices.
The highest price for Ontario-grown eggplants is achieved through direct sales to food retailers, with the Ontario Food Terminal (OFT) offering slightly lower returns. In 2019, prices for Ontario field-grown eggplant ranged between $0.64/lb and $0.95/lb in the September to early November period. In 2018, prices at the OFT ranged between $0.90/lb and $1.50/lb for sales starting in July. Greenhouse-grown eggplant, on the other hand, garners significantly higher prices that range between $2.50/lb to $3.50/lb.
a well-established premium over field-grown eggplant. Consequently, greenhouse-grown eggplant may be sold competitively at a higher price-point.
Major food retailers prefer to work with one or two suppliers to achieve necessary volume requirements throughout the year. With field-grown eggplant available for up to three months and greenhouse-grown product available longer term, growers and industry associations can work together to assemble a critical mass that meets retailer’s needs.
Additionally, to supply major retailers, growers may be required to be part of a North American supply chain that fulfills accounts in Canada and the US from a number of sources. Alternatively, Ontario field growers could align with greenhouse growers to be part of a 12-month local supply offering. Which-
ever the case, a critical mass of product is required to supply individual retail accounts. Smaller growers must aggregate with others to reach this necessary critical mass.
Ontario growers are competing with US operations that have a longer growing season and lower labour costs, resulting in lower per unit costs. The USDA reports farmgate values of eggplant at approximately $0.55/lb in Canadian dollars. These figures suggest that Ontario growers should strive for a more competitive cost structure. With that said, greenhouse-grown eggplant has
With 450,000 acres of Canada’s most productive farmland and in close proximity to the province’s biggest market, the GTA, any significant expansion in eggplants would likely happen within the Greenbelt. As a result, the Greenbelt Foundation is supporting agri-food producers in collaboration and knowledge-sharing to achieve expansion opportunities.
Michael Young is the communications advisor for the Greenbelt Foundation.
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Gaining control of the greenhouse climate isn’t as simple as deciding on minimum and maximum setpoints.
BY QUADE DIGWEED
One of the most well-known benefits of controlled environment agriculture is in the name – the control, manipulation, and optimization of the growing environment. Good control, however, is dependent on more than keeping the greenhouse air temperature and humidity between set minimum and maximum values. If we define the greenhouse climate as the ‘macroclimate,’ then the immediate climate surrounding the crop is known as the plant ‘microclimate.’ Think of the microclimate as a bubble around the plant, a blanket of still air surrounding it. This microclimate can vary across the greenhouse and is strongly influenced by crop structure (geometry) and greenhouse management. Uniform control of the greenhouse macroclimate does not guarantee a uniform microclimate. By predicting this variation in the canopy and the impact of control variables (e.g. temperature, humidity) on the microclimate, we can identify areas that may be prone to disease, better predict yield, and understand the influence of new technologies on the microclimate before they’re installed. Past work at the Harrow Research and Development Centre in Ontario focused on modeling the microclimate in greenhouse cucumber, while current work at Harrow is now focused on the impact of supplemental lighting on the greenhouse microclimate, specifically in greenhouse peppers. A model to predict these effects is currently under development, along with new measurement methods and technologies to directly observe the impact of lighting on the greenhouse microclimate.
commercial production. Eventually greenhouse operators will be able to apply their own measured control variables to the model, creating more accurate predictions about the microclimate in their greenhouses. The challenge is overcoming relatively sparse measurements in commercial greenhouses and the variations between them. We are at least three years out from this being feasible, although the more sensors a commercial grower is willing to add, the easier this would be to do.
METHOD: FROM MACRO TO MICRO
Researchers at Harrow have begun the design of the new greenhouse microclimate model by assessing existing models. There are strong solar radiation and supplemental lighting models, as well as greenhouse macroclimate predictive models, currently in use around the world. Rather than redesign these existing models, our plan is to collect their inputs, combine them with
Just as air temperatures can vary across a greenhouse, the plant microclimate is heavily impacted by plant structure, varying between plants and vertically within the crop. While the greenhouse microclimate could be directly measured with enough sensors, the cost of measuring essential greenhouse microclimate variables (e.g. leaf and fruit temperature, wetness, light transmission, vapour pressure deficit, CO2) at the density required for meaningful predictions would be prohibitive for most growers. By first developing a model in a research greenhouse equipped with the required sensors, predictions can be made and applied to
Figure 1. Researchers are taking a step-wise progression to modeling, first beginning with plant structure and moving towards validation.
microclimate and plant growth data from Harrow, and develop a model to assess the impacts of new greenhouse technologies on the microclimate.
Our approach to this model is a step-wise process (Fig. 1). We start with plant structure, observing how the crop changes over time in leaf area index, plant density, and vertical and horizontal growth. This is an important starting point because the shape and location of leaves and fruits can change where and how energy
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Harrow. This methodology still requires several new inputs: namely, a definition of the plant structure, relationships linking microclimate to macroclimate, and new sensors or ways of collecting data to efficiently and accurately validate the newly developed model.
well-defined physical relationships that can be calculated
and mass are exchanged. Once we have those values measured and recorded, we move on to radiation, greenhouse macroclimate and finally plant microclimate. Each variable is dependent on the one before it, and linked by layered equations, hence the order of our workflow. Once this model is developed, it will be verified by comparing predictions to ongoing microclimate measurements taken at
Greenhouse climate control focuses on achieving a steadystate relationship – a balance. The amount of energy and mass entering the system is equal to the amount leaving the system, but at a specific setpoint that is best for the plant. In our case, energy enters as heat and light, and leaves as heat. Mass entering the system can be water uptake through the roots, humidity through fans/vents under poor control, misting systems, for instance, though most models do not account for the water and sugar assimilated by the plant because it is such a small percentage. Ideally, this balance is achieved with as little energy leaving the system as possible. This energy and mass balance follows
The challenge arises due to the rate of change and variation across the greenhouse. Any change in the input variables, such as increased sunlight, leads to a change in this balance. Just as there is a balance between the greenhouse macroclimate and the outside climate, there is a balance between the plant microclimate and the greenhouse macroclimate, which is impacted by the same laws of physics. As mentioned, there is significant variation in the microclimate throughout the greenhouse: this leads to the flow of heat and water vapour in many directions at the same time, and all these flows are interrelated and influence each other. With all these interactions, how can we begin to solve any of the individual balances?
To begin creating a solution, we first have to define how specific it needs to be. Do we simulate the balance across every single leaf, so that we can predict the exact amount of energy each plant is converting to biomass for us? Or can we just pretend that there is one great big leaf in the mid-
dle of the greenhouse, equal to the area of all the leaves put together?
There are advantages and disadvantages to either approach. While modeling every single leaf would provide the most accuracy, a single simulation run through this model would likely take years to finish a single prediction, if it were even possible to define the location of every single leaf. With only one balance calculation required, the second option of simulating one great big leaf would certainly be faster, but we know that the climate can vary significantly across a greenhouse so the “average” we predict might be too general to be valid anywhere.
At Harrow, we have the benefit of possessing large historical datasets, containing plant growth measurements across entire growing seasons. These measurements include leaf dimensions and light distribution, both between rows, and vertically within the canopy. By feeding all this data into a computer, we can create what’s known as a density function, a mathematical formula that provides a probability of a leaf being in a specific area of the greenhouse as a function of time.
Looking to Figure 2, we use a combination of two approaches. The opaque “big leaf” model on the left represents
separate rows, while the translucent “medium leaves” on the right, represent the leaf distribution within each row. The graphics simply represent the probability of there being a leaf at a given height in the canopy. Each of these leaf density estimations can represent a row and a height in the greenhouse crop, or in modeling terms, a “node” of the model. Instead of assuming that the node intercepts all the light that hits it, we can treat each node as a filter that lets through some light to the nodes below it based on the leaf density function, with each node receiving less light than the ones above. Because we can’t yet reliably measure where we would find leaves in the canopy, instead of trying to guess where real opaque leaves would be, we treat each node as a location containing a large translucent leaf. If, from measurement, we know that there is a 30 per cent chance of a leaf being in a particular spot, we treat the translucent leaf as a filter that blocks 30 per cent of the light, and allows 70 per cent through to lower layers. Once we know how much light reaches each layer, the remaining microclimate variables can be calculated. Of course, no model is per-
Phil Tiemstra
Gull Valley Greenhouses, Blackfalds, Alberta
“The tomatoes and lettuces we grow are favorites at local farmers markets. And after learning of the revenue potential of winter production to capitalize on year-round demand, we decided to install Philips LED interlighting and toplighting in our tomato greenhouses, and Philips LED toplighting over our lettuce crop. Because our greenhouses are not very tall, Philips LED was the best option because we can place the LEDs closer to the crop; HPS lights would burn the tops of the head. Since making the switch to LEDs in 2017, they have proven to be a big bank for the buck.”
fect, and the tradeoff with this approach is less accurate simulation of air movement in the canopy
One of the major challenges of mathematical modeling is interpreting the results. The output will be large datasets full of temperature, vapour pressure deficit, transpiration, and light values at each node of the model. In addition to interpretation, it is also essential to ensure
that the model is producing accurate results. Previous work at Harrow has developed microclimate monitoring towers, consisting of temperature, humidity and radiation sensors located at each modeled node to monitor the plant microclimate. With the addition of LED lights to the greenhouse, we also need to consider the spectrum of light, not just the quantity, reaching each node. The spectrum can significantly impact crop development, and certain spectra of light are more likely to reach the bottom of the canopy.
Future monitoring towers will need to be equipped for measuring spectrum to develop a more complete understanding of the greenhouse microclimate. Different light sources also produce different amounts and types of heat. HPS lights produce more radiant heat, which directly warms up the crop canopy, whereas LED lights produce more convective heat, which is mixed with the greenhouse air. The effects on the microclimate can be directly observed with the use of an infrared camera. Figure 3 shows the growing head of a pepper plant under HPS on the left, and under LED light on the right. Both plants were grown in identical greenhouse compartments, maintained at identical climate control settings. Only the type of lighting was varied between the two pictures. The growing head under HPS varies from 21°C at the leaf tip, to 25°C at the stem, while the growing head under LED is a uniform 23°C. The crop under HPS light will have a warmer, drier microclimate at the same setpoint, but also have an increased rate of transpiration, shown by the cool leaf tip. The increased amount of water vapour exiting the plant causes a local cooling effect, as the evaporation of water requires a significant amount of energy absorbed from the surrounding area in the form of heat. While the drier climate with increased transpiration may lead to faster growth, it may also lead to increased stress, chlorosis, or vulnerability to disease.
So the question is, how do we find the correct balancing point for all these climate variables that would lead to faster crop growth without causing undue stress to the plant? The exact answer isn’t yet known, and leads to a limitation of microclimate modeling and measurement. Part of the challenge is that it varies significantly from greenhouse to greenhouse and crop to crop, especially with different light sources. While these models and datasets can be tremendously valuable, without the input, expertise, and observations from growers and researchers, the model results are just a large matrix of numbers. The continued optimization of greenhouse climate control will take coordinated efforts from researchers, growers, modelers, and control engineers to fully solve the complex puzzle before us.
Quade Digweed is a greenhouse engineer at Agriculture and Agri-Food Canada (AAFC). He can be reached at quade.
By Glenna Cairnie CGC Program, Marketing and Event Coordinator
After 40 years of conferences, one would think we had seen it all but a pandemic shutting down business and events around the world? “Unexpected” is an understatement. Over the past months, we have witnessed remarkable adaptations as people and industry have had to navigate new territory in every facet of their lives. The importance of technology became even more significant as traditional interactions were restricted.
The Canadian Greenhouse Conference, too, has adapted and embraced technology to fulfill its mandate. The fun and energy of the physical conference will be missed this year, but the CGC has prepared an excellent virtual speaker program and maintained important conference components to support growers and the sector.
The 2020 program, consisting of four webinars over two days, will highlight new ideas, methods, and research with an accomplished line-up of speakers. Live presentations will allow for audience interaction and questions. The webinars will be recorded, and registration allows for post-show access to these recordings for a limited time.
The conference theme, “Beyond 2020” was developed long before COVID-19 came on the scene but as we enter the last half of 2020, it is all the more appropriate as we look forward to better days ahead and embrace the lessons learned and ideas created.
WEDNESDAY, OCTOBER 7
Sponsors:
Wednesday morning kicks off the 2020 Canadian Greenhouse Conference with a focus on lighting.
Xiuming Hao (Agriculture & Agri-Food Canada) launches the program, updating growers on his ground-breaking LED lighting research. While it is economically advantageous to use long photoperiod, low-intensity lighting, it has been found that lighting longer than 17 hours can cause significant injury to greenhouse fruit vegetable.
Hao will discuss newly developed LED lighting strategies which allow for injury-free production of greenhouse tomatoes and cucumbers with 24-h (continuous) lighting. These strategies also have a great potential to reduce peak power demand and electricity costs, in addition to the benefits of reducing light fixture capital costs, light pollution, and improving energy efficiency in year-round greenhouse vegetable production.
David Llewellyn (University of Guelph) will present results of a recent trial that tested whether supplemental lighting with similar end-of-day (EOD) spectrum treatments could influence flowering in greenhousegrown potted floriculture crops from different photoperiod response groups. Common crops including chrysanthemum (short day), geranium (day neutral), gerbera (facultative short day) and calibrachoa (long day) were tested. Discover the commercial implications of this research and related trials from the University of Guelph
Canada’s northerly latitude means that less than half of the solar radiation reaching crops at the peak of summer is delivered in the depths of winter. This difference has clear implications for greenhouse crop production and, along with the increasing number of vertical farms, is one of the main drivers of today’s use of HPS and LED lights for protected crop production. Despite this, little research to date has systematically examined how these new light environments can impact greenhouse crop protection – both the good bugs and the bad. We know light is important to arthropods, such as when moths are drawn to flames. But how important is it really to greenhouse pest management? In this session, Rose Labbé, (Agriculture & Agri-Food Canada) will discuss how light quality, quantity and duration can all affect individual insects as well as their populations and sometimes tip the balance towards achieving successful greenhouse pest management.
Wednesday afternoon speakers turn the attention to crop protection. Biosecurity specialist, Dave Van Walleghem (Vetoquinol
Canada) is emphatic that proper cleaning and disinfecting between crops is vital; allowing the new crop to save their resources for growth rather than challenging previous pathogens. Don’t miss this opportunity to find out how cleanliness has a measurable payback.
Vojislava (Vava) Grbic and her Western University team are working on developing a commercially viable Integrated Pest Management Response Service (IPM-RS) to help growers improve pesticide selection, reduce sprays, save money, and reduce worker and environmental exposure. Grbic will present strategies and current progress and will identify specific needs, support roles for IPM specialists and individual growers to help create sustainable, secure, environmentally friendly, and economically competitive greenhouse production.
Issues surrounding workplace safety and seasonal worker housing were front and centre in Ontario this summer. The contagious COVID-19 virus revealed systematic issues that caused great concern in the industry, the public and government. Justine Taylor (Ontario Greenhouse Vegetable Growers) has worked closely with all stakeholders in developing policy to protect the health and well-being of greenhouse workers. Taylor shares best practices that have proven to be successful for both employers and employees.
THURSDAY, OCTOBER 8
Sponsors:
Our collective experience over the last few months has provided evidence as to how quickly businesses (and conferences!) can adapt to a virtual world. The public learned very quickly to use online platforms and apps to ensure their needs were met, and the average person’s comfort level with the use of technology increased greatly over a short period of time. This is good news for our sector which will require heightened use and acceptance of technology from workers and customers to achieve success. You will find innovation and inspiration with Thursday’s series of presentations as advances in artificial intelligence (AI) hold the promise of the future.
The growing world population needs access to safe and healthy food. Protected agriculture can provide a large portion of this increasing demand. Greenhouse acreage is growing, but there is a shortage of qualified workers to manage these farms. Projections indicate that this issue will become more of a problem in the next five to 10 years. While smart algorithms can provide solid solutions to this issue, their implementation demands a shift of minds and social innovation. Has the pandemic prepared us for this advanced technology? Are we ready for a new era in food production?
Ron Hoek (Blue Radix) explains how algorithms and smart data can provide growers with a “digital brain”. Not only can this brain optimize climate, irrigation and
energy in the greenhouse, but it can actually steer these installations. Find out AI’s potential for your greenhouse, how it can impact your day-to-day tasks and bring value to your operation.
Can AI help cultivate cherry tomatoes in a greenhouse? This challenge was faced by the international teams that participated in the Autonomous Greenhouse Challenge hosted by Wageningen University & Research and Tencent. An ever-growing world population has given rise to an increased demand for fresh and healthy food. Greenhouse horticulture will need to make increased use of technology to meet the demands of production while challenged with a lack of skilled workers. Silke Hemming (WUR) reports on the outcomes of the 2019/2020 Autonomous Greenhouse Challenge, the advances realized and how artificial intelligence may hold the answer to feeding a hungry world.
According to the World Bank, agriculture accounts on average for 70 per cent of all freshwater withdrawals globally. The FAO projects that irrigated food production will increase by more than 50 percent by 2050.1 Today over 240 hours/acre/year is spent on irrigation by growers that is not data driven or coordinated. This traditional approach results in inconsistent application due to the human element: different staff with different habits. This results in poor application, the wasting of resources and increased labour costs for training and retraining. Since most greenhouses already use a climate computer to monitor temperature, the opportunity to automate this process is already within reach. A collaboration between Vineland Research and Innovation Centre and LetsGrow. com has led to the development of just such automation. LetsGrow’s world-leading AI data platform provides growers with a holistic view of their greenhouse through data generated from the greenhouse and based on plant physiology. Vineland’s decision-making software integrated into LetsGrow’s data platform will provide irrigation advice through the use of machine learning. Hussam Haroun (Vineland Research & Innovation Centre) and Ton van Dijk (LetsGrow) will walk you through the development and benefits of the new platform.
Greenhouse strawberry production around the world has increased as the demand for high quality, high flavour and low pesticide strawberries continues to grow. Growing greenhouse crops is a complex task as all aspects of production (light, temperature, water and humidity, air movements, etc.) and their interactions must be considered. If the greenhouse is too hot, what is the best way to cool it without impacting all the other factors such as plant growth and water use? Luis Trujillo (Hoogendoorn) will talk about strawberry production using the basic principles of plant empowerment to efficiently produce highly flavoured berries.
Selecting the ideal substrate for your cannabis production and managing it correctly can be very challenging. PierreMarc de Champlain (Berger) will help growers understand
1 Food and Agriculture Organization of the United Nations (FAO). Water at a Glance: the relationship between water, agriculture, food security and poverty. Rome. 15pp. available at http://www.fao.org/nr/water/docs/waterataglance.pdf)
the role of each component that can be included in your growing mix and the factors that will influence your decisions throughout the production process.
In addition to the virtual speakers program, two important components of the CGC have been maintained and moved to our website.
The very popular Research Updates session has been converted to a Poster Session featuring a diverse selection of research projects, authored by both established and student researchers. Sponsored by the Ontario Agricultural College at the University of Guelph, the posters will be displayed on the CGC website and available for viewing at your convenience.
A New Variety Showcase will feature videos and information from breeders promoting their latest cultivars. This new feature will provide centralized, curated content for growers to access throughout the season. Thank you to our showcase sponsors: Ball Seed, Dümmen Orange, Syngenta Flowers, Enza Zaden, Rijk Zwaan and Syngenta Seeds for making this idea a reality.
On the subject of sponsors, a special thanks to all the 2020 sponsors who recognize the value of the CGC and its grower community with continued financial support. Sponsor funding is integral to the success of the conference, and the CGC is proud to partner with these companies to support Canadian growers and the industry as a whole.
There is no doubt that technology is changing how we interact, learn and work. Each year sees a progression and it is exciting to be part of an industry that is at the forefront of change. In addition to its importance in the scientific arena, horticulture is unique as it provides for two vastly different, yet valuable, human needs: sustenance for our bodies (food) and sustenance for our souls (beauty). In this unparalleled year, let us celebrate the innovation that keeps this sector moving forward and pause to reflect on the beauty it bestows.
Be sure to explore the virtual poster session for the latest in research, as well as new varieties for the Canadian market in the virtual showcase.
Assessing the Cold Tolerance of Pepper Weevil (Anthonomus eugenii) in Southern Ontario
Diana Catalina Fernandez, Agriculture & Agri-Food Canada/University of Windsor
What’s the Deal with Onion Thrips in Greenhouse Floriculture?
Ashley Summerfield, Vineland Research & Innovation Centre, ON
Assessing the Predatory Capacity of Nabis americoferus Expressed Through a Functional Response on Tomato Pest Species
Andrew LaFlair, AAFC/University of Windsor
Next-Gen Amplified Sustainable Agriculture (NASA) – It’s About Space!
Rupp Carriveau, Professor, Environmental Energy Institute, University of Windsor, ON
Demonstration of Energy-Saving Dehumidification in Ontario Greenhouses
Jingjing Han, Research Engineer, Flowers Canada (Ontario)
Optimizing Light Recipes for Improving Ornamental Plant Propagation in Controlled Environments
Devdutt Kamath, University of Guelph, School of Environmental Sciences, ON
Low-level Blue LED Light During Night-time Improves the Growth and Quality of Indoor and Greenhouse Grown Microgreens
Quinglu Ying, University of Guelph, ON
Hydroponic and Aquaponic Cannabis Production
Brandon Yep, University of Guelph, ON
Production of Specialty Crops Using Efficient & Sustainable Controlled Environment Systems
Yun Kong, University of Guelph, ON
Biological Control of the Pepper Weevil Using the Parasitoid Wasp, Jaliscoa hunteri
Serena Leo, University of Guelph, AAFC
Collaborating with industry, this researcher is working to extend the lifetime of current TSSM management tools and create a brand new biopesticide for the grower’s toolbox.
By Greta Chiu
Growers who have encountered the two-spotted spider mite (TSSM) before may be all-too familiar with its uncanny ability to survive a number of different pesticides. The good news is, a new set of tools are being developed to target pesticide resistance in TSSM – one to prolong the lifespan of existing pesticides and another to bring a completely new type of pest control into play.
“It feeds on more than 1,100 plant species including more than 150 crops, which is an extraordinary ability,” explains Dr. Vojislava Grbic, associate professor and plant geneticist at Western University. Collaborating with her husband Miodrag, an entomologist who led a global sequencing project that mapped out the TSSM genome in 2011, both Western researchers have devoted the last 15 years of their work to understanding the biology of this generalist pest. With documented resistance to over 95 different active ingredients, TSSM’s ability to reprogram itself to overcome initially toxic pesticides is likely linked to its highly adaptable nature.
ADAPTABILITY
When under attack, plants attempt to protect themselves by generating a shield of chemicals meant to deter or poison their attackers. Generalist pests can typically metabolize common
defence compounds produced by most plants and survive to a large degree. In contrast, specialist pests have honed their craft to efficiently counter defences put up by their primary host, but these pests tend to be less successful when placed on an unfamiliar crop.
Albeit being a generalist, what makes TSSM so remarkable is its ability to adapt and specialize to new hosts. For example, a mite blown into a tomato greenhouse from a nearby soybean field might not be a problem at first, says Grbic. The tomato crop would be able to defend itself initially. But should the mite establish a sizeable population, particularly in a warm environment like the greenhouse, it can adapt, proliferate and cause a lot of damage in a short timeframe. Research has shown that TSSM can adapt to a new host after just 20 to 25 generations – equivalent to about six months.
“The mite has evolved the ability to detoxify a lot of plant defence compounds. As a result, what we’re seeing in agriculture is that biological property allows them to develop resistance to manmade chemicals – resistance to pesticides,” says Grbic. Populations of TSSM can also be resistant to multiple pesticides at once. In one extreme case, Grbic worked with a grower who tried five different pesticides, one after another, before succeeding with the sixth. “But by that time, the mite population had exploded, so he lost the part of the crop in that part of the greenhouse.”
Because of pesticide resistance, TSSM control can be highly inefficient for crops without effective biocontrol methods. To help reduce the current hit-and-miss method of TSSM management, Grbic’s team has been working on an IPM resistance management service (IPM-RS) that could help growers tailor TSSM control methods to specific populations in the greenhouse.
Similar to human genealogy kits, growers would collect plant samples containing different TSSM populations from the greenhouse, package them in the provided containers and send them off to Grbic’s lab. There, researchers would look for clues in the mite’s DNA, such as the frequency of resistant mutations occurring and height-
ened expression of suspect genes, then run models to predict the level of resistance or susceptibility of the mite population to different pesticides. After a few days, the grower would receive a report with details on which pesticides to avoid and a list of recommended pesticides that have a high probability of being effective and to what extent. “The grower or IPM specialist can then prioritize which pesticides they would use,” she says.
Having developed the system for abamectin and etoxazole, Grbic is working with Agriculture and Agri-Food Canada (AAFC), Ontario Greenhouse Vegetable Growers (OGVG), the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and Plant Products to confirm their models in commercial greenhouses before moving on to other pesticides. They hope to have a prototype ready in the next two to three years.
“We have to focus on extending the useful half-life of existing pesticides because it takes a long time to develop new technology,” says Grbic. “Because spider mites develop resistance so readily, the utility of these pesticides becomes somewhat limited once they are launched on the market.”
While lengthening the use of existing pesticides, Grbic’s team has also been working on a completely different type of tool against TSSM – a biopesticide that uses a process known as ‘RNA-interference’ (RNAi) or ‘reverse genetics.’
Rather than applying a chemical that could potentially be detoxified and rendered useless by TSSM, the proposed biopesticide uses a type of genetic material known as double-stranded RNA (dsRNA). Because RNA normally exists
in a single-stranded format and not double, the TSSM cell flags this dsRNA as being potentially dangerous, such as the result of a cellular error or strange viral RNA that must be eliminated. The cell then initiates a number of processes that then set out to dismantle, or ‘silence,’ any matching single-stranded RNA, including its own. By leveraging this natural form of self-policing in the cell, researchers simply have to introduce a piece of dsRNA that matches the code for critical enzymes in TSSM, and nature will take care of the rest.
Grbic’s team recently published a paper that demonstrates almost 100 per cent mortality of adult TSSM using RNAi-based biopesticides. Once applied, it can take five to six days for TSSM adults to perish, but they also cease egg-laying during that time, leading to a dramatic decline in numbers. While the technology looks promising, she says there’s still a lot of research to be done. “The goal is to not only find a target that is going to lead to fatality or at least reduce the mite population, it’s also important to find target sequences which are not variable in field populations of mites.” Because of the method’s specificity, the biopesticide may need
to include multiple dsRNA fragments to account for genetic variability between different TSSM populations.
“RNAi is not a universal tool for all pests,” says Grbic, explaining how some other agricultural pests have naturally high gut pH or enzymes that degrade the RNA molecules before they can start the process. “But for mites, it works like a charm.” Because the biopesticide has to be ingested by TSSM and absorbed by the cells to work, her team is now collaborating with industry to develop a stable formulation that can sustain UV exposure and other environmental factors, ensure that RNA molecules reach their target, and degrade over time without harmful residues.
While their research has been successful in a controlled, laboratory environment, Grbic wonders if they might find something different in a real-world setting. “There are other factors that may influence mite responses that we’re not aware of, and we’re not including [them] in our experiments.”
Grbic’s team is looking to put their technology to the test and inviting interested growers to take part. With limited biological control options in greenhouse tomatoes and a shrinking array of TSSM pesticides available, she hopes to finetune both IPM-RS and RNAi-based biopesticides in this crop before moving onto others.
“It’s had a very long evolutionary time to evolve these unique features that we are just starting to understand,” Grbic says of TSSM. “It’s amazing how much we don’t know.”
Don’t miss Dr. Vojislava Grbic’s talk on October 7 at 1pm; part of the 2020 Canadian Greenhouse Conference virtual program.
The 2020 speaker program brings an impressive list of guest speakers, covering issues that apply to a wide range of crops under cover.
Berger
Pierre-Marc graduated from the University of Sherbrooke with a Bachelor’s Degree in Biotechnological Engineering, developing an integrated knowledge of biological sciences. Thanks to the university’s revolutionary practices in cooperative training and problem-based learning, Pierre-Marc is attuned to the fast-paced evolutions in the industry and how suppliers are applying them in the field. Prior to working at Berger, PierreMarc worked at Lang 2000; working to improve practices in the treatment of polluted water. Before that, he worked in the Université de Sherbrooke’s Biology Department, performing soil ecology research. He began his career as a research assistant at Agriculture and Agri-Food Canada’s Food Research and Development Center, performing work to help preserve food quality and ensure safe food processing. Pierre-Marc considers Berger’s horticultural niche extremely captivating; its direct impact in the field enables him to use his extensive background in research to the benefit of growers worldwide.
VOJISLAVA (VAVA)
GRBIC
Western University, ON Dr. Vojislava Grbic holds a PhD (Genetics) from the University of Wisconsin, a MSc (Plant Genetics) from the University of Novi Sad, Serbia and a BS (Plant Breeding) from the University of Novi Sad, Serbia. Her interests lie in the genomics of plant-pest interaction and her studies currently focus on RNAibased pest control for the spider mite and development of spider mite silk as a natural bio nanomaterial. The overall goal of her work is to exploit fundamental knowledge to develop novel tools for sustainable agriculture.
Agriculture & Agri-Food Canada, Harrow, ON Dr. Xiuming Hao is a senior research scientist with Agriculture and Agri-Food Canada (AAFC) at Harrow Research and Development Centre in Harrow, Ontario. He holds a PhD in plant physiology from University of Guelph and an MSc in computer control systems from Wayne State University. Dr. Hao has been involved in the greenhouse research at the research centre since 1995. The focus of his research program is on greenhouse environmental physiology and energy efficiency. He has conducted numerous projects on greenhouse crop management, climate control, and energy conservation, including highwire cucumber production systems, new greenhouse insulation technology, heat placement in greenhouse vegetable production on raised-troughs, new greenhouse cover materials and dynamic temperature, CO2 , humidity and fertigation control strategies. Dr. Hao has led the AAFC national research project on dynamic plant-based environment control to improve energy efficiency in greenhouse vegetable production. He has conducted extensive research in the last 18 years and is leading the national AAFC lighting projects on greenhouse vegetables to improve light and energy use efficiency in year-round greenhouse vegetable production.
Vineland Research & Innovation Centre, ON Hussam Haroun, M.Eng., M.E.E.I., P.Eng. joined Vineland Research and Innovation Centre in 2020 as Director, Automation. Haroun oversees Vineland’s Automation Program with the goals of developing and integrating robots, automation technologies and AI-based tools for the management
of crop production, packaging and processing and optimizing crops and production systems to improve efficiency and facilitate the adoption of automation technologies.
Wageningen University & Research, NL
Dr. Silke Hemming studied Horticultural Sciences at the University of Hanover, Germany. She received her PhD at the University of Hanover in 1998, completing a thesis with the title “The effect of photoselective greenhouse covering materials on ornamental plants”. Since 1999 she has worked at Wageningen University and Research Centre in various capacities. Hemming is an expert in the field of novel greenhouse design concepts and modern greenhouse coverings and has worked on several projects related to increasing light transmission, changing light spectrum, the effect of diffuse light, the possibilities of NIR-reflecting coverings and the development of modern coatings for glass coverings. The WUR LightLab is a unique facility with the most modern measurement equipment for optical properties of greenhouse materials. She recently initiated research in the field of artificial intelligence and greenhouse controls and led the first and second international challenges on autonomous greenhouses. Her team has expertise on the field of energy saving, greenhouse climate, water saving, modelling, data science, computer vision, sensors and robotics for greenhouse and indoor farming applications.
Blue Radix, The Netherlands
Ronald Hoek graduated cum laude in Marketing (MSc) and holds a bachelor degree in Commercial Economics
from Nyenrode Business University, NL and TIAS. He has worked more than 15 years on energy transition and data-driven solutions in the international greenhouse industry, with broad experience in marketing, product development, operations and technology at C-level. Hoek combines smart technology with business challenges, applying the principles to agrifood and energy/sustainability as these are domains with global and societal impact. His passion is to translate innovations into robust new business models with a purpose.
Agriculture & Agri-Food Canada, Harrow, ON
Dr. Roselyne Labbé leads the greenhouse entomology research program based at Agriculture and AgriFood Canada’s Harrow Research and Development Centre (HRDC). Her group rigorously compares and contrasts the many new and old tools and agents used for crop protection, with an emphasis on the integration of new agents and technologies. Recently, the greenhouse entomology program at Harrow has focused on better understanding the impacts of artificial lights on biological control agents and crop pests, as well as on the discovery, assessment and potential commercialization of new biological control agents, including some native to North America. The research program ultimately aims to identify both the most effective and yet sustainable ways to manage the diversity of pests present within Canada’s greenhouse and vertically farmed crops.
University of Guelph
David Llewellyn holds a M.Sc. in Horticulture and is a research associate in Dr. Youbin Zheng’s lab, at the University of Guelph. He has been working in the horticulture industry for the past 20 years with broad experience including: field vegetables, nursery crops, landscaping, tender fruits, woodlot management, and greenhouse production. In the last two decades, he has specialized in controlled environment horticulture research including: greenhouse floriculture production, indoor and greenhouse cannabis
production, and engineered interior landscapes for improving air quality in occupied spaces. His main goal is to serve the horticulture industry by performing grower-relevant research that will improve production efficiency while reducing the industry’s environmental footprint.
Ontario Greenhouse
Vegetable Growers
Justine received her PhD in analytical chemistry from the University of Alberta and has been working in the greenhouse sector since 2011. She currently manages all matters related to science and government relations for Ontario’s greenhouse vegetable farmers.
Hoogendoorn
With more than 25 years of experience in markets and a strong focus on innovation and technology, it is no surprise Luis Trujillo ended up in horticulture. After years of working in various countries providing high technology solutions for indoor farming, Trujillo joined Hoogendoorn in 2019. His international experience has allowed him broad understanding as to the importance of using technology in covered agriculture to achieve outstanding results. He now brings that knowledge into practice within Hoogendoorn America. His daily job is to support growers and partners in choosing the best-fitting automation solution for their business, whether it is a greenhouse or an indoor farm.
LetsGrow.com
As Global Head of Sales and Operations at online data platform LetsGrow.com, Ton is responsible for the overall customer experience. His background as a former grower helps him to understand the needs of growers and enables him to work together with clients to create optimal solutions. Ton states “It is not just the collection, analysis and display of correct cultivation data that enables growers, crop advisors and investors to optimize their yield, but knowledge transfer also plays an important role. This is what we do via the principles of Growing by Plant Empowerment.”
Vetoquinol Canada Ltd.
Dave graduated with a Bachelor of Science in Agriculture from the University of Manitoba and continues to enhance his industry knowledge through ongoing education. He has spent his career working in various production animals’ units in a variety of roles; from hands-on, to managing units, to service representative, to veterinarian assistant. Dave is currently the National Biosecurity Specialist for Vetoquinol Canada where his education, practical knowledge and hands-on approach allow him to bring a unique perspective to biosecurity that is easy to understand.
RUPP CARRIVEAU
University of Windsor
Dr. Rupp Carriveau is the Director of the Environmental Energy Institute and CoDirector of the Turbulence and Energy Lab at the University of Windsor. His research activities focus on energy systems futures. Dr. Carriveau serves on the Editorial Boards of Wind Engineering, Advances in Energy Research, and the International Journal of Sustainable Energy. He recently guestedited special editions of Energies and The Journal of Energy Storage. Professor Carriveau was a recent recipient of the University Scholar Award and has acted as a Research Ambassador for the Council of Ontario Universities. Dr. Carriveau is a Founder of the Offshore Energy and Storage Society (OSES) and recently Co-Chaired OSES2018 Ningbo China, and OSES2019 Brest France. Professor Carriveau is Chair of the IEEE Ocean Energy Technology Committee and was just named to Canada’s Clean50 2020 for his contributions to clean capitalism.
Agriculture & Agri-Food Canada, University of Windsor
Diana is a PhD candidate co-supervised by Dr. Roselyne Labbé from AAFC and Dr. Sherah VanLaerhoven from University of Windsor. Her interests revolve around how
insects interact with their surroundings, other organisms, and especially with plants and other insects. Currently, Diana is working on the ecology of the pepper weevil, a pest of field and greenhouse peppers. The goal of this research is to provide a better understanding of this insect in a temperate climate that can be applied in management programs to control this pest.
Flowers Canada (Ontario)
Dr. Jingjing Han is a research engineer working for Flowers Canada (Ontario) Inc. since 2018, where she provides engineering expertise. She holds bachelor’s and master’s degrees from China Agricultural University in Beijing where she majored in Agricultural Bio-environment and Energy Engineering, and obtained her doctorate in mechanical engineering at the University of Saskatchewan. Over the last ten years, Dr. Han has acquired a great deal of experience in evaluating energy consumption and savings from various greenhouse dehumidification systems. Recently, she has worked on an energy-saving dehumidification project funded by the Ontario government since 2018 for Flowers Canada (Ontario) Inc. Currently, Dr. Han is looking for new projects regarding energy savings in greenhouses to help the sector reduce fossil fuel consumption.
University of Guelph, ON Devdutt Kamath is a MSc candidate at the University of Guelph under the direction of Dr. Youbin Zheng. His research focuses on using LED lights and different light qualities to improve ornamental plant propagation, specifically seed germination and seedling growth, in a controlled environment.
University of Guelph
Dr. Yun Kong is a postdoctoral research associate working in Dr. Youbin Zheng’s lab at the University of Guelph. He has many years of experience in horticulture, especially in greenhouse production. His research interests include environmental
physiology of greenhouse plants and greenhouse environment adjustment technologies. In the past decade, he has focused his research on the interaction between light environment and horticultural plants.
University of Windsor
Andrew LaFlair is a second-year student at the University of Windsor in the Integrative Biology Master’s Program. Previously he earned a bachelor’s in Honours Biological Sciences with distinction at the University of Windsor in 2019. LaFlair is currently working under the supervision of Dr. Sherah Vanlaerhoven at the University of Windsor and Dr. Roselyne Labbé (AAFC). LaFlair’s research is focused on the development of native biological controls and the diversity of predatory bugs locally. He has a desire to see his work impact local communities and industries and aspires to play a part in the greenhouse and biological control industries that are found locally within Greater Essex County, Ontario, Canada.
University of Guelph, AAFC
Serena Leo completed her B.Sc. in Biology with a specialization in animal physiology at the University of Ottawa. As an undergraduate student she completed an undergraduate Honours project with Dr. Emily Standen and Dr. Jeremy Kerr studying the flight muscle in bumblebees. The objective of this study was to develop a procedure to surgically remove their intact dorsal-longitudinal muscle and test its contraction properties in the Aurora muscle physiology machine. During her time in Ottawa, Leo also had the opportunity to work at the AAFC Experimental Farm in both the Biocontrol and Winter Wheat labs. Time spent working at the farm improved her understanding of the importance and intricacies of agriculture. To combine her love of studying insects with this newfound love for agriculture, she began to investigate innovative ideas to create sustainable solutions that are both beneficial to the environment and to the growers. Leo is now working on
her M.Sc. co-supervised by Dr. Cynthia Scott-Dupree at the University of Guelph, and Dr. Rose Labbé at Agriculture and Agri-Food Canada’s Harrow Research and Development Centre.
University of Guelph
Ashley grew up in a small farming community in the Ottawa Valley prior to studying Zoology at the University of Western Ontario. She has had a wide variety of research experiences involving amphibian and reptile conservation, management of invasive plants, and community ecology of insects. Ashley has been involved in IPM research for the past six years at Vineland Research & Innovation Centre in Dr. Rose Buitenhuis’ biocontrol lab. She recently began her Master’s degree at the University of Guelph in Dr. Cynthia ScottDupree’s lab where she is conducting research on IPM of onion thrips in floriculture crops.
University of Guelph
Brandon Yep is an Extension Agronomist at Canopy Growth Corporation and holds a master’s degree in Environmental Horticulture Science and a bachelor’s degree in Agriculture Science from the University of Guelph. During Brandon’s graduate studies he conducted cannabis research at Green Relief Inc., focusing on the improvement of aquaponics for cannabis cultivation. Under the advisement of Dr. Youbin Zheng and in collaboration with other industry experts, Brandon has published in numerous peer-reviewed scientific journals on cannabis and aquaponic research.
University of Guelph
Qinglu Ying is a Ph.D. candidate under the supervision of Dr. Youbin Zheng at the University of Guelph. She is focusing on using LED light strategies to improve the production of microgreens in controlled environments. Her research found that light quality from LED light has profound effects on plant growth and secondary metabolites in both growth chamber and greenhouse.
With heating costs becoming an issue yet again, growers cannot afford to not have this resource.
After reviewing the principles behind heat loss, Dr. Bartok discusses greenhouse siting, construction materials, insulation, fuels and heating, ventilation and cooling, space utilization, utilities, trucking costs, and management.
Appendices include an Energy Conservation Checklist, Heat Loss Calculations, Useful Conversions, and Selected Product Manufacturers and Distributors.
Tables and diagrams throughout.
$23.95 Item #0935817743
These greenhouse operators pulled out all the stops, communicated with their workers about COVID-19, and it’s paid off.
BY GRETA CHIU
It’s been over six months since provinces across Canada declared a state of emergency due to COVID-19. But as businesses shut their doors, temporarily laid off workers and asked employees to work from home, essential services like greenhouse vegetable production never stopped. To keep Canadians nourished, greenhouse operators had to find ways to keep their employees safe and their operations in business.
For a small family farm just outside of Leamington, Ont., their first hurdle was receiving additional migrant workers from Mexico on time. Recruited through the eightmonth Seasonal Agricultural Workers
Program (SAWP), their workers were delayed by three weeks during the initial height of the pandemic as flights were cancelled or seconded for Canadians stranded abroad.
“We’ve had all essentials brought onto the farm,” says the owner, who runs a cucumber greenhouse operation. Save for a few emergencies that couldn’t be handled on the farm, their workers had chosen not to leave the property since midMarch. “We started grocery shopping for them right away.” Minimizing trips into town as much as possible, their family took care of the workers’ groceries and essentials and arranged for a mobile banking unit to make bi-weekly onsite visits so workers could wire money back home to their families.
Rijk Zwaan has been active in North America for over 25 years with continous R&D investment and dedicated crop specialists. Since 2013, we have used our demonstration greenhouse in Leamington, Ontario. This local approach enables us to test our newest varieties under local climate and market conditions. We look forward to discussing your variety choices with you!
Kivu RZ
Beef Tomato
• Nice round fruit shape with slight shoulder
• Much less susceptible to dropping fruits than current standard in the market
• Good setting and high production potential
• Consistent fruit shape with uniform ripening
• Stable large average fruit weight throughout the season
Santiana RZ
Large TOV
• Jointless
• Slower starter compared to others but one of the highest finishers
• Good shelf life
• Consistent high average fruit weight especially in the second part of the season
• Performs well under high temperatures
The owners have since set up a business account at a local grocery chain which allows them to pick up online orders for their workers. When requested, a Mexican grocery truck visits with comforting items such as pop, chips and tortillas that remind the workers of home.
As for their living quarters, the workers stay in the owner’s old family farm house – the one that the operating family grew up in. “Our house is approved for 15 workers, and we have 10 living there,” she says. On average, there are two workers per room with beds that are, at a minimum, two meters apart.
“We know it’s tough,” she says. “They want to get out and be social.” To liven up the atmosphere, the owners have been providing food and meals on site and hosting fun nights. Even before the pandemic, employers and employees would host dinners to share food and culture with each other – a melding of different worlds under one roof. “They really are like family to us,” she says, voice breaking.
In June, their entire farm was tested for COVID-19. Results came back negative for everyone – owners, local employees and migrant workers, alike.
“There was some apprehension of wanting to get tested,” she recalls. Not wanting to force the decision on any member of her team, every employee made their own choice about whether to be tested. “We were fortunate that all workers were on board,” she says. They wanted to do their part and confirm that their workplace protocols were working.
But even after receiving negative test results, the owners didn’t let down their guard or lighten up on sanitation procedures. “We’ve been screening every morning – checking for fever, asking every one of them if they’re ok or feeling any symptoms.” They’ve also hired dedicated staff to sanitize all frequently touched surfaces twice a day or sometimes more. Their workers are equipped with facemasks, gloves, sanitizer, wipes and other
personal protective equipment, and they’ve installed plexi-glass on their packing line where a two-meter distance can’t be maintained.
“As long as we’re openly communicating with everybody, I think things are going smoothly,” she says, emphasizing the importance of staying on top of new developments and communicating with the entire workforce, not just migrant workers. “We just want them to know … If you’re experiencing anything, we’ll be able to get a better handle on it if that’s dealt with in the early stages,” she says, adding, “We’re all in this together, which might be clichéd, but we really are.”
While news of COVID cases surfaced among a few larger greenhouse operations over the past few months, the picture being painted has been largely skewed with reports of mistreated workers.
“The reality is, greenhouse owners more than anybody are concerned about the health and welfare of their workers,” says a Leamington-based tomato greenhouse grower. “Without healthy workers, we really don’t have much of a business.”
His operations are spread out over three greenhouses – one location has over a hundred migrant workers, while two others have under 50 each. Wanting to keep their peers safe, both local and migrant staff all agreed to be tested for COVID-19 and the results came back negative.
“My guys have been spectacular,” he says. Since the pandemic, he’s invested in full-time staff to bring in all food and basic necessities and turned away any visiting street vendors. Staff inspect bunk beds for cleanliness and they’ve installed infrared scanning systems that automatically check workers’ temperatures every morning as they enter through the door. Plexi glass separates close working conditions on the packing line and workers have their own acres in the greenhouse, along with access to hand sanitizers, gloves and other forms of PPE.
“Every time somebody isn’t feeling well, we make them go down to the doctor to check. We have no interest in having someone in the greenhouse who’s not feeling well or infecting others.”
Though they’ve all been minor cases of typical colds or flus – he’s not letting his guard down.
Since workers were screened before getting onto the plane, and again after arrival in Canada, he surmises that cases of COVID-19 among greenhouse workers likely stem from their interactions with locals rather than their living or working conditions. But as the months wear on, he feels that it will become increasingly hard to keep workers penned up on farm grounds.
“It seems like we’ve gone from being concerned about overrunning the hospital to having a zero infection rate,” he says. “One is completely impossible.”
Since the introduction of SAWP in the 60s, bunkhouses have grown in size and comfort. For this greenhouse operation, each room is built to house 10 workers, but they’ve only allowed for eight, giving workers more room than what government regulations call for. All houses are centrally heated, air conditioned and equipped with refrigerators, freezers and pallets of water. “They’re all inspected multiple times by multiple agencies in the government.” To improve the quality of life for his workers, their latest facility even has a built-in basketball court and a game room. “Short of me developing our own vaccine, what more can we do?” he asks.
Migrant workers in his employ have returned year after year, and for some, they’ve been employed at this operation for over 15 years. “In Jamaica, if you can find a job, you’re making six to seven thousand a year,” he says. “You work for us, you’re making 30 thousand and in better working conditions.” As a result, some workers have made enough to own multiple houses in their native countries and their children can afford to attend college in Canada or the United States.
“There’s zero chance that Canadians are going to come do this work,” he says. Their business has tried hiring domestic workers before, and many tend to give up on the laborious work by lunch time. With migrant workers, he says, they want to be there. Taking into account the cost of flights, domestic transportation and medical insurance, the greenhouse operation already spends more than the Ontario minimum wage on each migrant worker. Now with COVID, average expenses may have risen, but it’s worth the cost for skilled, dedicated labour.
“Bottom line is, these guys are needed. We need to treat them right.”
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Novel developments in delivery systems are allowing us to push the boundaries of what’s possible in biological control.
OBY DR. MICHAEL BROWNBRIDGE
f the number of innovative methods used to apply natural enemies and microbial control agents in the past few years, some have been rapidly adopted, others are just starting to become mainstream. Here’s a selection of new and notable developments in delivery systems, and how they could make life better for the greenhouse sector.
MINI-SACHETS AND BLISTER PACKS
About 10 years ago, introduction of the mini breeder sachet for predatory mites revolutionized biocontrol programs in greenhouse crops. They rapidly became the preferred method for releasing predatory mites, and several species are now available in this format (e.g. cucumeris, swirskii, californicus, andersoni). Use of sachets provides many advantages over bulk carrier, particularly in later stages of crop production. When placed correctly into the crop, these self-contained rearing systems produce mites for four to six weeks, making them very economical to use. No carrier residues are left on leaves, mites are released where they are needed and product is not wasted on the floor. However, mini sachets have to be hung in the plant canopy for optimal performance, which is not feasible with young plants.
The biocontrol companies came up with a neat solution, by attaching a stick to the sachets allowing placement alongside vegetable seedlings, in spring bedding plants, among plugs, hanging baskets, and other young crops. While broadcasting remains an option in propagation, the steady supply of predators from a breeder sachet avoids having to make repeat (weekly) applications, and in many cases, sprays can be avoided so that plants arrive from the propagators with no chemical residues that could adversely affect biocontrol agents introduced later into the crop.
contents dry quickly and negatively affect production of both feeder and predator mites. To overcome these constraints, Koppert constructed a new type of breeder sachet from material that maintains optimal conditions inside for the production of feeder and predatory mites, even at low ambient humidity. More predatory mites can be released from the sachet over time, leading to improved control of pests. What’s more, the sachet is biodegradable. Swirski Ulti-Mite (for thrips and whitefly) was first released in North America in 2017, and has been successfully used in outdoor pepper production in California, demonstrating the robustness of this system. The manufacturers recently introduced another version for N. californicus: Spical Ulti-Mite
Commercially managed bees can be used to deliver beneficial microorganisms.
for control of two-spotted spider mite. Small changes to an innovative concept have produced breeder sachets for almost any occasion, increasing opportunities to use predatory mites across a broader range of crops and growing conditions.
The original paper construction limits their use in some settings. For example, when used in very dry environments, the
Blister packs? Sounds like something used in a medical emergency but it is the latest evolution in packaging for parasitic wasps used for whitefly control. Most growers will be familiar with the cardboard strips carrying parasitized whitefly pupae used to introduce Encarsia formosa. The same approach has
Ridder
been used for Eretmocerus eremicus which provides better control of Bemisia whitefly. However, unlike Encarsia which can emerge from either side of the parasitized pupa, Eretmocerus only emerges from one side. Consequently, with the pupae being glued to the card, you have a 50:50 chance of an adult wasp emerging (or not) from the parasitized pupa. Enter the blister pack. These contain parasitized pupae together with a carrier inside a plastic ‘blister’, allowing the adult wasps to emerge unimpeded. A simple, yet effective way to improve emergence rates.
Drones are very hot right now, particularly for applying predatory mites in high-value, large-acre crops where use of biocontrol agents has traditionally been limited by cost and time with dissemination by hand. Enter technology.
Use of unmanned aerial vehicles (UAVs) to carry and disperse biocontrol agents is not a new concept, but services utilizing UAVs have only recently become commercially available. Salinas-based company Parabug has developed UAV technology for the delivery of predators
such as Phytoseiulus persimilis, Amblyseius cucumeris, Orius insidiosus, and parasitoids to control thrips, spider mites and other pests. The technology is being used in southern and northwestern US states to deploy predators in field-grown strawberries, almonds, fruit trees and in outdoor ornamentals. AmericanHort’s Plug and Cutting Conference last year included a live demonstration of UAVs dispersing persimilis in garden mums at Metrolina Greenhouses.
The precision and efficiency of UAVs
seems to improve daily, and the technology is being adapted for delivery of other pest management products, including pesticides, enabling spot treatments with pesticides or beneficials using GPS coordinates. Christian Nansen at UC Davis sees UAVs as being part of an integrated crop management system. His work focuses on the use of hyperspectral cameras mounted on drones to detect differences in light reflected from leaves which are indicative of a plant stress response. The ultimate goal is to enable the use of image analysis techniques to differentiate among different stress factors, even down to the pest level, so that the right solution can be chosen then distributed by drones into affected areas of the crop only.
Will UAVs ever make it into greenhouses? Maybe, maybe not. But other unmanned autonomous vehicles are already in use. Think robotic sprayers in greenhouse vegetables – that technology only became commercially available relatively recently. This is a new frontier combining high tech with biocontrol, and the future awaits those with a foot in each camp!
Spraying is the default method of application for most microbial biopesticides. While better spray practices can significantly enhance deposition rates and subsequent efficacy, spraying is still a relatively untargeted and inefficient method of treating plants. Previous articles have already addressed the use of low-volume misting (LVM) systems and other methods for improved spray application of microbials, so here are some alternative delivery methods to watch for.
Bee Vectoring Technologies (BVT) in Ontario has developed a patented system that uses commercially-managed bees to deliver beneficial microorganisms to flowers. Bumblebees are preferred for green-
Maureno
• High yielding
• Uniform fruit shape and quality
• Fast coloring
• High resistance: TM:0-3
Florate (E23B.0308)
• High yielding
• Uniform fruit shape
• Consistent quality
• Early season production
• High resistance: TM:0-3
• High yielding
• E xcellent fruit quality
• Easy setting
• Fast coloring
• High resistance: TM:0-3
• Intermediate resistance: TSWV:0
house, select outdoor and some specialty crops, while honeybees are best for open fields. Active at lower temperatures than honeybees, bumbles can also be used in early spring or winter crops. Their larger size carries more microbes as well.
BVT’s dispenser system is incorporated into the lid of the commercial hive. The system includes a removable tray (the Vectorpak) that is pre-charged with Vectorite powder plus the beneficial microbe. The powder sticks to the bees as they leave the hive through the dispenser, and it is carried to and deposited into the flower. Flowers are a common entry point for a range of disease-causing organisms and a preferred habitat for many pests (like thrips), so this targeted delivery of disease-suppressive or insect-active microorganisms can be highly effective.
Currently, BVT utilizes a strain of Clonostachys rosea (BVT-CR7) as the primary ‘active’ in their system. A known antagonist and mycoparasite of several plant diseases, the fungus can also grow endophytically within plants and activates the plant’s own defense mechanisms. This can significantly reduce the incidence of Botrytis on fruit (comparable to synthetic fungicides), enhance productivity in
greenhouse tomatoes and field-grown strawberries, and improve the shelf-life of harvested fruits. The fungus also suppresses other necrotrophic diseases such as Sclerotinia and Monilinia, and is effective against pathogens such as Alternaria, Phomopsis and Anthracnose
The first commercial iteration of BVT’s technology is already being embraced by strawberry growers in Florida, and the company is considering application of other microorganisms, including the insect pathogen Beauveria bassiana Research at Agriculture Canada showed that bees could efficiently deliver the fungus to control thrips, whitefly, greenpeach aphid and tarnished plant bug in greenhouse tomato and sweet pepper (Note: BotaniGard is already approved in Canada for application by bees). This would be a timely and useful application, enabling delivery of both insect- and disease-controlling organisms to traditional greenhouse vegetable crops, as well as strawberries and raspberries which are increasingly grown in protected systems. Bacillus thuringiensis (Bt), can also be vectored by bees and could potentially provide protection against flower-feeding caterpillars. Lastly, the company is
Note the clear plastic ‘blister’ of this Eretmocerus blister pack containing the parasitized pupae, a carrier facing the pot and the rear open ‘flap’ which allows adult wasps to emerge.
investigating use of the system to deliver streptomycin to combat bacterial and fungal diseases of fruit, vegetables and seed. Currently, the antibiotic is widely used to control fire blight on apple and pear trees and is applied by spraying. Delivery by bees would mean virtually no contamination of the surrounding environment and would ensure continual delivery of the protectant throughout the bloom period, something which cannot be guaranteed by spraying.
Bee vectoring is a highly targeted delivery system that uses no water and saves growers from repeated spray applications of pesticides. BVT self-describes their technology as a “natural precision agriculture system.” Can’t argue with that. No batteries required!
In commercial greenhouses, use of bumblebees as pollinators is largely restricted to tomatoes, eggplant and, on a limited scale, peppers. This technology is not applicable to other edible crops such as cucumbers and herbs, or in floriculture, but other arthropods could be used as vehicles to transport beneficial microorganisms. Work at the Université de Montréal by Gongyu Lin assessed the susceptibility of predatory mites to B. bassiana strain ANT-03 (BioCeres), and their capacity to acquire spores, which would then be transported into thrips-infested areas. Results showed that all mites could carry
B. bassiana spores, and while active against western flower thrips, strain ANT-03 was benign to Amblyseius swirskii and Stratiolaelaps scimitus, with low virulence towards Neoseiulus cucumeris B. bassiana GHA strain (BotaniGard) is also compatible with those microorganisms.
The beauty of this approach is that foraging mites can transport fungi to parts of the plant where pests like thrips (which like to live in tight, concealed places on the plant) are very difficult to reach using conventional spraying techniques. Furthermore, predators preferentially consume young thrips larvae, while older larvae and adult thrips are more susceptible to the fungus. Consequently, use of the two biocontrol agents together could provide a very elegant means of targeting all foliar stages of the pest.
In small ‘proof of concept’ greenhouse studies carried out by Anatis, thrips control was better on plants receiving the mite-fungus treatment than those treated with the mite or fungus alone. Greenhouse trials completed in China showed that this approach can work in practice, and N. cucumeris and A. swirskii were used to disseminate B. bassiana which infected Asian citrus psyllid, Diaphorina citri, on potted citrus plants. As with bee-vectoring of beneficial microbes, this method has the potential to deliver savings by reducing or eliminating direct costs associated with spray applications (skilled labour), reducing the amount of ‘active ingredient’ required to obtain control, and eliminate disruptions to production associated with chemical applications.
New delivery techniques are changing and expanding opportunities to use biological control on a large scale. Just as a good formulation is essential to the survival, stability, ease of use and efficient application of any biological product (microbial pesticide or biocontrol agent), the application method has a direct impact on efficacy and cost-effectiveness. Continued development and improvement of delivery systems will allow us to push the boundaries of biological control, enabling earlier and more targeted interventions, while also bringing associated health and safety benefits, and improving sustainability.
Michael Brownbridge, PhD, is a biological program manager at BioWorks Inc. Email him at mbrownbridge@bioworksinc.com.
As growers of high quality young plants from seed and vegetative materials, we’re uniquely positioned to accommodate the needs of small to mid-sized operations. Here’s why...
we sell direct: Since we sell our plants directly, we take full responsibility for the quality of each order.
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Philips GreenPower LED toplighting compact (TLC) grow light from Signify is the easy, energy efficient 1-to-1 replacement for high pressure sodium (HPS) lighting. The TLC delivers the right light levels for light-loving crops while helping growers easily manage greenhouse climate. The Philips TLC allows greenhouse growers to easily switch from HPS to LED lighting, using existing HPS set-up and trellis construction. The high light output of up to 1800 µmol/s and high efficacy of up to 3.0 µmol/J helps growers effectively optimize crop growth, enhance crop quality, and reduce operational costs. www.philips.com/horti
The NEW Sol Collection is a unique new foliage celosia from our Fantastic Foliage® collection which expands the options for consumers looking for sun-loving foliage accent plants for patio planters with a different texture and look, as well as for quick-growing, low, shrub-like plants that look great at the front of the border. It has a relatively fast production time and holds well at retail. Purple foliage develops and intensifies once planted outside. Available in two colourvarying varieties, NEW Gekko Green, a Fleuroselect Gold Medal winner, and NEW Lizzard Leaf.
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This high-quality growing medium enriched with cutting-edge active ingredients provides an ideal growth environment for plant roots. Active ingredients work together to enhance plant performance, quality and yield, by expanding the root system. Combined, Mycorrhizae and Bacillus enhance nutrient and water uptake, reduce transplant shock and increase tolerance to stresses. With unique chunk coir reducing soil compaction and carefully selected peat moss, this formulation provides ideal balance between air porosity, drainage capacity and water retention. It also offers growers what they need to optimize the quality of their hanging baskets, large containers and longterm crops. www.pthorticulture.com/
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Available in 12- and 14-inch diameters, our FiberGrow® WaxTough WaterSaver Hanging Basket w/ Grommets offers a timeless, earthy design. Molded using a slurry of fibers and binding agents in order to increase their strength and durability, the addition of a wax coating (impervious to moisture) increases the containers longevity for use on municipal lamp posts along main streets or in backyards and front porches. https://hc-companies.com/product/ waxtough-fiber-hanging-basket/
DLI HORTI-Series with 5 year
Following the introduction of the LED TopLight fixture, now Dutch Lighting Innovations introduces the improved DLI HORTI fixture. A major focal point is the cooling of the critical components on the electronic ballast. By placing the critical parts of the ballast at the top of the housing, the air flowing over the housing ensures an optimal cooling of the electronics. Independent tests show that this results in the coolest fixture on the market, which result in great reliability and a long service life. pete@dutchlightinginnovations.com +1 289 407-6420 https://dutchlightinginnovations.com/
In this new economic landscape, there are challenges we are facing. As your business reopens, Wellmaster is here to Make a Difference. Our Hand Sanitizer Pump is an ideal solution for agricultural, industrial or outdoor environments. It has a durable all steel design and can be self-standing or floor and wall mounted for additional security and stability. It also features a protective nozzle hood to prevent overspray as well as an adjustable tray for various sized containers. Its springloaded foot pedal ensures hands-free contact. In these challenging times, Wellmaster Hand Sanitizer Pumps are a low maintenance, high value investment to keep you safe. www.wellmaster.ca
Ridder HortOS offers largescale horticultural enterprises a centralized environment for working collaboratively towards shared goals. It not only gives you access to financial and operational data from multiple crops, greenhouses and locations, but also transforms that data into actionable information and clear insights – so you can make the right decisions yourself or have HortOS make them for you fully automatically. 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. www.ridder.com/hortos
• High yielding
• Uniform fruit shape
• Consistent quality
• Early season production
• High resistance: TM:0-3 https://www.enzazaden.com/
The Nursery Mix is an excellent alternative to the common bulk products available on the market. This coarse mix is perfect for your trees & shrub production in large containers, 3 gallons and wider. The structure of this mix allows excellent drainage of excess water but maintains appropriate water retention at the same time. The perfect ratio! Because of the components, you will experience a very minimal shrinkage of the media in the container and packaging will assure you receive the exact amount of material you pay for!
www.lambertpeatmoss.com/products/ the-nursery-mix-high-porosity/
Moxie!™ is the only compact interspecific geranium series perfectly suited for space-efficient production for small pots and with unique brilliant colors. Plants have excellent branching and good heat tolerance. They flower all season long and are ideal for medium-size containers. New colors for 2020-2021 season are Moxie! Orange (pictured), Violet, and White Improved. www.syngentaflowers-us.com/moxie
Who said organic growing is exclusive to greenhouses? The ON7 professional soil mix is designed for organic growing at nurseries for perennials, trees and shrubs. Composed of aged bark, coarse peat, compost, and sand, it is an excellent base for an organic fertilization regimen. This product is available in bulk and in bags. www.fafardpro.ca
Thanks to its high average fruit weight combined with good endurance right through to the end of the growing season, this large tomato on the vine produces an above-average yield. It is an open and generative crop, particularly in the summer, so it is easy to work with. Moreover, the sturdy fruits have a long shelf life, which makes this tomato popular with retailers and consumers alike. www.rijkzwaanusa.com
CAST, formerly the California Spring Trials, is set to return in 2021, only this time it will be the California Summer Trials. Scheduled dates for the event are Wednesday, June 23 through Sunday, June 27, 2021.
Seeking to help stimulate attendance of brokers, growers and retailers, the change in date was a direct response to requests from the broker community. Many felt that a June event would be more aligned with their travel schedules for learning about new plants and programs. Previous spring dates fell on the busiest time of the year for their customers, both growers and retailers.
Source: Press Release
$3.3 million for Ontario
The Ontario government is committing $3.3 million in cost-share funding to 58 projects through the updated Rural Economic Development Program (RED) to help rural and Indigenous communities diversify their economies, retain skilled workers, invest in local infrastructure and create jobs. Municipalities, not-for-profit entities, Ontario Indigenous communities/organizations or local services boards are eligible for the Rural Economic Development program and costs are shared according to which of the two streams under which the project may fall:
Economic Diversification and Competitiveness: Projects that remove barriers to business and job growth, attract investment, attract or retain a skilled workforce, strengthen sector and regional partnerships and diversify regional economies.
Strategic Economic Infrastructure: Minor capital projects that advance economic development and investment opportunities.
For the Economic Diversification and Competitiveness Stream, the province will contribute up to 50 per cent of eligible project costs to a maximum of $150,000.
For the Strategic Economic Infrastructure Stream, the province invests up to 30 per cent of eligible project costs to a maximum of $250,000.
Source: Government of Ontario
CLASSIFIED RATES: Minimum order $75.00 or 84¢ per word, word ads must be pre-paid. CLASSIFIED DISPLAYS: $72.00 per column inch, or $5.14 per agate line. GENERAL INFORMATION: Payment must accompany order. Copy required by the 1st of the month preceding publication. All advertising copy subject to the approval of the publisher. Send order and remittance to: Classified Dept., Greenhouse Canada, P.O. Box 530, 105 Donly Dr. S., Simcoe, ON N3Y 4N5
GARY JONES | Gary.Jones@kpu.ca
The theme of ‘pests’ for this issue seems very appropriate given the long balmy summer days, ideal for multiple generations of sap-sucking, leaf-curling, stem-cutting bugs. Oh the joys of growing plants. So I reflected on some past ‘Inside View’ columns.
In May, we talked about Dr. Zamir Punja’s (SFU) interesting work on the genetics of cannabis, and whether we ‘really know the authenticity of existing strains’? We then linked that idea to the work of Dr. Mathias Schuetz at KPU, testing the genetics of hops to conclusively identify different hops (Humulus lupulus) cultivars, documenting the impact of environmental factors and genetic differences on flavour and aroma profiles when grown on different farms. The idea was that if similar techniques were used on cannabis, Schuetz’s work on hops could possibly enable growers to actually know the authenticity of cannabis stock they’re buying.
So, I was wondering about pest management, and I don’t know if this holds true, but could we do the same for biocontrols? I ask, because we know that the glandular hairs on the leaves and stems of tomatoes hinder the distribution ability of some biocontrol agents, for example Phytoseiulus persimilis finds it difficult to get around on tomato leaves. But some ‘strains’ of ‘Persimilis’ do
Suffice to say he’d just found his first infestation of aphids. He was mortified. But further delving around among the leaves he unearthed “some other grubs!” I explained we’d found not more damaging pests but a bunch of beneficial friends chowing down on their prey. The sudden change in Ross’ attitude from one of despair to discovery was a joy to behold. I explained to him a little of the pest-prey lifecycles and what was going on in this fabulous new ecosystem he is now stewarding. I also told him he’d just learned his first major lesson through his garden – humility. Don’t think you can simply beat Mother Nature. Sure, look forward to and enjoy the delicious fresh produce that will be the reward of one’s labours, but don’t get so self-congratulatory that pride takes over – you’re sure to be headed for a fall. In this instance, aphids had gotten the better of my friend.
Later, his conversation turned to how slowly things were growing. I gently explained that the fantastic soil and amendments he’d invested into his new boxes had produced plants that were actually growing like Jack’s fabled beanstalk. Nonetheless, I encouraged him to take to heart a second lesson from his garden: patience. He’d also learn this while waiting for the beneficial insects to kick in, since they’re not the instant solutions he’d expect from chemical sprays.
better than others, apparently. If we can identify those early on, could we breed adapted systems more quickly? Could genetic profiling unlock some such ‘spidey-sense’ of certain biocontrol agents which could then be bred up into populations suitable for ‘customised’ applications?
In the June issue, I mentioned my neighbour and his COVID-induced adventure, building some raised beds in his backyard to grow food for the family. Let’s call him Ross. Because that’s his name. He’s really enjoying his new, all-consuming pastime. Which is fantastic, of course. And it means he and I connect more than we did pre-COVID because he’s always looking for a second opinion as to what’s going on among the lush greenery of his food patch. The other day he asked with some urgency if I’d go check over the cabbage, and his tone of absolute panic made me wonder what on earth I’d find.
So, I wonder, is there merit in seed companies selling varieties bred from a particular geographical region (‘provenance’) to amateur growers? Like forestry tree seed is. Such ‘authenticity’ of seed might even provide some local resistance to pests like those my neighbour is dealing with.
Ross is doing great. And I sense he’s already on his way to a third lesson from the garden: determination. He’s going to have to fight weeds – even the most benevolent and optimistic gardener would be hard-pressed to enjoy the horsetail and convolvulus in his manicured garden. I’ve decided to let him learn that lesson in his own time.
Gary Jones is a faculty member of the School of Horticulture at Kwantlen Polytechnic University, Langley, BC. He sits on several industry committees and welcomes comments at Gary.Jones@kpu.ca.
