Plans for 2023 and beyond: Growers share plans and highlights from 2022.
Growers across Canada share plans for the future as well as highlights and challenges from 2022. See page 8.
autonomous greenhouse growth 12 Koidra brings AI technology to Great Lakes Greenhouses
32 CO2 enrichment in controlled environment agriculture Is it always a good idea?
BY DR. FADI AL-DAOUD (OMAFRA) AND DR. XIUMING HAO (AAFC)
From organic waste to biogas How greenhouses help make renewable energy more sustainable
BY TOM FERENCEVIC
Sterile insect technique SIT for managing the pepper weevil and other challenging pests.
BY JACOB BASSO, CYNTHIA SCOTT- DUPREE AND ROSE LABBÉ
Taking over the reins and eager to learn
Change is afoot at Greenhouse Canada and as the publication’s new editor, I wanted to take this opportunity to tell you a little bit about myself.
I was born and raised in Hamilton, Ontario. I still live there with my husband and two wonderful and very energetic children, our senior cat and slightly younger dog. I am a beginner backyard gardener and household horticulturalist. My favourite plants are my various oxalis, my beloved lemon tree (from which I’ve grown THREE lemons in 2.5 years!) and pretty much anything that blooms in early spring – those first signs of life after our dreary winters are truly awe-inspiring.
Professionally, I’ve been a journalist in the news media for the past 16 years. I’ve worked in some very busy newsrooms, helping produce stories about many different subjects, issues and people.
While the first few weeks as Greenhouse Canada’s new editor have been a bit of a whirlwind, I’ve had the pleasure to meet some of you and
best practices and how everyone in the room can improve outcomes and save money. Several attendees that I spoke to following the discussion told this community, which involves all aspects of the greenhouse industry, feels like family, and that attending events like this feels like a reunion. That sense of community and the collective belief that we’re all in this together can be such a rarity in today’s world. It is inspiring to witness. I left news media in search of an opportunity where my skills could be used to help others do better, be better and feel valued. What I experienced at Mr. Sawaya’s assured me that I find myself in the right place. In my mind, whether it’s by putting food on a table or making the world a more beautiful place, helping you, the greenhouse community and its associated businesses and people, makes the world a better place.
In the near future, I hope to cross paths with many of you at Grower Day on June 20 in St. Catharines, or at Cultivate ’23 in Columbus, Ohio.
“In the near future, I hope to cross paths with many of you...”
attend my first industry event at Mel Sawaya’s Hydrangea workshop in April. While much of the technical discussion around hydrangea cultivation went over my head, I was struck by the spirit of camaraderie and collegiality of the group of close to 60 industry professionals in attendance.
As renowned hydrangea innovator, Sjaak van Schie, visiting from the Netherlands, fielded questions from the group, the presentation quickly evolved into a conversation about
If the opportunity arises, let’s talk about your insights, observations and concerns about the industry. Or even better, let’s talk about what’s working for you or others you know, and let’s find ways to share and celebrate that success.
I may be new to the world of greenhouses, but I am an eager student, and I am passionate about facilitating the conversations that will help us all navigate the challenges ahead.
uses
Ontario awards funding to bring alternative fertilizers to the market
International Zeolite will receive funding to lead commercialization projects to bring alternative fertilizer solutions to market. These projects will address the dependency of Ontario agriculture on imported fertilizers, as well as provide alternatives to traditional fertilizers to ensure a continuous and cost-effective supply of fertilizer products to Canadian agriculture.
The company is using the awarded grant funds to continue commercializing its zeolite infused products at its production plant in Jordan, Ont. These products have been designed to accelerate crop time, reduce up to 80% of fertilizer needed to produce crops and significantly contribute to the reduction of greenhouse gases.
START OF COLLABORATION BETWEEN B.C., NETHERLANDS ON DATA-DRIVEN HORTICULTURE
During a mission trip to B.C., a declaration of intent was announced between B.C.’s Windset Farms, B.C. Centre for Agritech Innovation (BCCAI), and Wageningen University & Research (WUR) to develop a research project around these topics.
Last week, members of Greenhouse Horticulture & Flower Bulbs, WUR, AgroFoodRobotics and the Ministry of Foreign Trade and Development Cooperation from the Netherlands visited Vancouver to discuss automation, robotization, and the use
of Artificial Intelligence (AI) in horticulture.
“Horticulture in B.C., faces challenges in the areas of labour, sustainability/circularity, food waste, quality, and earning capacity, much like in the Netherlands,” states a news release from WUR. It’s been
Canadian greenhouse grower opens new distribution centre
Nature Fresh Farms is expanding its operations to Delta, Ohio, adding 60,000 square feet to its footprint. The newly built distribution centre features high-tech fabrication and automation.
suggested that agtech can be part of the solution.
One of the events, organized by BCCAI, was to discuss “the co-creation of an innovation agenda for horticulture by Dutch and Canadian companies and research institutes.”
“With our new 45-acre organic strawberry facility set to come online this fall, our new distribution centre will help to accommodate the influx in product, providing climate regulation, monitoring [capabilities], and product protection measures,” stated Frank Neufeld, executive vice-president for Nature Fresh Farms.
BY THE NUMBERS
$132.8 MILLION
Combined total value of inflation-adjusted exports in Jan 2023 and Feb 2023.
UP 2.9% UP 45.5%
Exports were up by 2.9% over the same period last year (Mar 2021 to Feb 2022).
Looking at the situation through a COVID lens (from Mar to Feb, year-over-year), inflation adjusted exports from Mar 2022 to Feb 2023 were up 45.5% from the same period pre-COVID average.
Source: Export insights, Flowers Canada, Floriculture Stats Update (Data up to the end of February 2023).
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GROWER SURVEY 2023
Plans for 2023 and beyond: Growers share future plans as well as highlights and challenges from 2022
BY ANDREW SNOOK
Do you use social media (e.g. Facebook, Twitter, Instagram, Pinterest, etc.) to follow industry news and/or to market your products/services?
The Greenhouse Canada Grower Survey results are in, offering a snapshot of the greenhouse sector for 2022 and beyond.
WHO ANSWERED?
Growers across Canada answered the call for this year’s Grower Survey with 81 participants from the controlled environment agriculture sector. It is best to treat these results as informal and anecdotal, because some of the growers selected a mix of different growing spaces and/or crops, which will not necessarily add up to 100.
Of the growers that participated, 78 per cent were growing in greenhouses, 18 per cent identified as growing in an indoor, non-vertical farm (and not a greenhouse) or other, while 4 per cent were in vertical farming.
For the growers that identified themselves as ornamental and garden growers, the primary operations identified were led by wholesale growers (51 per cent) followed by young plant growers
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(44 per cent) and retail growers (39 per cent). For the growers that identified themselves as vegetable (produce) growers , the primary operations identified were led by retail growers (42 per cent), followed by wholesale growers (32 per cent) and young plant growers (24 per cent). When broken down by province, the majority of growers were located in Ontario (47 per cent), followed by B.C. (17 per cent), Alberta (10 per cent), and additional representation from Saskatchewan, Manitoba, Nova Scotia, New Brunswick and Quebec.
More than 54 per cent of respondents worked in operations measuring under 50,000 sq. ft., while 14 per cent worked in operations over 1,000,000 sq. ft., 9 per cent worked in operations 350,001 to 500,000 sq. ft., just over 7 per cent worked in operations 500,001 to 1,000,000 sq. ft., 6 per cent worked in operations 50,001 to 100,000 sq. ft., 5 per cent worked in operations 100,001 to 200,000 sq. ft., and the remining 5 per cent worked in operations 200,001 to 350,000 sq. ft.
Growers were also asked to identify the crops they primarily grow. The frontrunners (not exhaustive) were: garden vegetable plants (41 per cent); ornamental bedding plants (36 per cent); flowering potted plants (35 per cent); peppers (30 per cent); tomatoes (28 per cent); cucumbers (27 per cent); tropicals (22 per cent); perennials (20 per cent); leafy greens (19 per cent); herbs (17 per cent); plugs and propagation material (16 per cent); strawberries (10 per cent); cut flowers (10 per cent); eggplant (9 per cent); cannabis (7 per cent); trees and shrubs (7 per cent); microgreens (6 per cent); and woody ornamentals (5 per cent).
When asked who their customers are, 40 per cent of growers identified wholesalers, followed by mass merchandisers/box stores and grocery stores (35 per cent); other growers (32 per
cent); their own retail shops (27 per cent); and independent garden centres, independent retailers and florists (27 per cent).
SALES AND PROFITS IN 2022
When asked how sales compared in 2022 to 2021, 46 per cent of growers stated sales were stronger in 2022. More than 18 per cent of respondents stated they were up more than 10 per cent; 15 per cent stated they were up between 5 and 10 per cent; and 13 per cent stated they were up less than 5 per cent.
Another 14 per cent of growers stated no change in sales, while more than 15 per cent of growers stated they were down more than 10 per cent; followed by 8 per cent down between 5 and 10 per cent; and 4 per cent down less than 5 per cent. The remaining growers (13 per cent) stated they did not know if their sales were better or worse in 2022.
While sales were up with 46 per cent of growers, only 30 per cent of respondents stated that their profit margins were up, with 26 per cent up 10 per cent or less, and only 4 per cent up more than 10 per cent. Just over 28 per cent of growers stated there was no change in profit margins, while 15 per cent of growers’ profit margins were down more than 10 per cent; 11 per cent of growers’ profit margins were down 5 per cent or less; and 6 per cent of groers’ profit margins were down between 5 and 10 per cent.
FORECASTING
When looking at pricing in the near future, the majority of growers (56 per cent) were planning on increasing prices in 2023 with 21 per cent increasing prices between 5 to 9 per cent; 21 per cent increasing prices less than 5 per cent; and 14 per cent
raising prices more than 10 per cent. Approximately 25 per cent of respondents stated they would not change their prices, while 4 per cent stated they would be reducing prices.
In regards to sales forecasts, 41 per cent of respondents stated they were expecting higher sales compared to 2021, while 29 per cent of growers are expecting lower sales and another 29 per cent expecting no change.
INPUTS
Several input costs increased for growers in 2022. The most common were labour and wages (53 per cent); fertilizers and nutrients (45 per cent); heating (42 pre cent); electricity (34 per cent); pots, trays and containers (31 per cent); growing media (28 per cent); and plant material (23 per cent). Other input cost increases noted by some growers included biocontrols (13 per cent); marketing/sales (8 per cent); taxes (8 per cent); and conventional pesticides (5 per cent).
When it came to supplemental lighting, growers showed a significant increase in the use of LED lighting with 54 per cent of respondents stating they are currently using LED lighting (compared with 34 per cent in the 2021 Grower Survey). 40 per cent of growers stated they were currently using HPS. Another 16 per cent of growers stated they were planning on adopting LED lighting in the next three to five years.
LABOUR
Labour was the leading input cost in 2022 with 60 per cent of
growers stating the amount of labour they employed in 2022 compared to 2021 stayed about the same. 21 per cent of respondents stated their labour employed this year rose by up to 10 per cent, while 13 per cent stated their labour employed increased by more than 10 per cent.
When forecasting future labour needs, more than 63 per cent of growers stated they expect their labour needs to be about the same, while 19 per cent expect an increase of up to 10 per cent, and 11 per cent of respondents expect their labour needs to increase by more than 10 per cent. Just over 6 per cent of growers expect their labour needs to decrease by 10 per cent or less.
EXPANSION
Expansion was not in the plans for the majority of growers in 2022 with over 76 per cent stating no expansion. Just over 15 per cent of respondents stated they expanded less than 10,000 sq. ft.; while less than 5 per cent expanded between 25,001 and 50,000 sq. ft.; and 3 per cent stated they expanded between 10,001 and 25,000 sq. ft. This trend continued when asked about 2023 expansions plans with 76 per cent of growers stating they had no plans for expansion, followed by 17 per cent stating they are planning expansions of less than 10,000 sq. ft.
FUTURE INVESTMENT
When asked about investing in new equipment and technologies in 2022, 65 per cent stated they invested in new equipment with 8 per cent of growers investing more than $100,000 in their op
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What are your sales forecasts (volumes) for 2023 compared to 2022?
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erations; 13 per cent of growers investing $25,001 to $100,000; 10 per cent investing between $10,001 and $25,000; 11 per cent investing between $5001 and $10,000; 8 per cent investing between $1,000 and $5,000; and 15 per cent investing less than $1,000.
While the number of growers expecting to invest in new equipment and technologies in 2023 dropped to 56 per cent, 10 per cent are forecasting spending more than $100,000; while another 18 per cent are expecting to invest between $25,001 to $100,000.
BIOCONTROLS AND BIOPESTICIDES
When managing mites and insect pests, over 35 per cent of respondents stated their use of biocontrol agents and biopesticides increased, while 40 per cent of respondents had no change, 5 per cent identified a decrease in use, and 19 per cent stated they did not use them.
When managing disease, 25 per cent of respondents stated their use of biocontrol agents and biopesticides increased, while over 52 per cent of respondents had no change, and 22 per cent stated they did not use them.
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Driving autonomous greenhouse growth
Koidra
brings AI technology to Great Lakes Greenhouses Inc.
BY ANDREW SNOOK
In Leamington, Ont., another greenhouse operation has been embracing the world of artificial intelligence to enhance efficiency.
Great Lakes Greenhouses, one of the largest cucumber growers in North America, has been working with an intelligent automation company, Koidra Inc., to optimize its operations for increased yield and profitability for the past two years.
“Koidra was introduced to us by Dr. Xiuming Hao from the Harrow Research and Development Centre,” explains Mark Reimer, research and business development manager for Great Lakes Greenhouses. “One day, he came by with the founder, Kenneth Tran, and approached us with the idea that they were working on an artificial intelligence project. They were looking at a couple of different funding opportunities and looking for the right partner that would be willing to investigate this
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kind of innovative technology. We had a conversation and ultimately decided that the project and the technology had merit, and it was something that we were interested in pursuing.”
Koidra partnered with Agriculture and AgriFood Canada (AAFC) to develop and deploy an AI-powered autonomous grower to grow cucumbers and eggplants remotely and automatically to produce increased yields and improve efficiencies throughout Great Lakes Greenhouses. Koidra worked alongside Dr. Hao, research scientist with Harrow Research and Development Centre, AAFC, for the technology’s development and deployment.
“We have worked closely with Koidra on this project and the results so far are very promising,” Dr. Hao says. “The autonomous growing technology can transform the way we grow crops in greenhouses. By centralizing data from multiple
The first trial at Great Lakes Greenhouses was conducted on eggplant growing from April 19 to Oct. 25, 2022.
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sources and adjusting growing conditions in real-time, we are able to optimize plant growth, fruit production and improve energy efficiency. It’s exciting to witness how this technology is transforming the greenhouse industry. It holds a great potential for future greenhouse crop production.”
The project is supported by the Greenhouse Competitiveness and Innovation Initiative (GCII). Great Lakes Greenhouses also received funding through the Independent Electricity System Operator (IESO).
“Those are the two programs that we were able to kind of investigate and utilize for this program and develop a couple of different scopes starting in some non-traditional greenhouse crops, and then also looking at just the opportunities of this type of technology to create some energy savings and optimization,” Reimer says. “The timing was really good, because it was right when we were starting to investigate introducing LED lighting into the crops. So, the ability to use that extra input gave us the opportunity to really develop a product that could steer the crops, and the ultimate goal of increasing yield or getting yield at a lower energy input.”
Using a combination of expert knowledge and data centralized from a variety of sensors in the greenhouse, Koidra’s AI program is able to assist with autonomous adjustments of light levels, temperature, humidity, nutrient levels, water quality and carbon dioxide levels. Growers can switch anytime between inputting commands manually and autonomously. The technology was developed based on a principle that the AI system starts growing
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Growers can switch anytime between inputting commands manually and autonomously.
plants with the exact same parameters as the grower, ensuring that there is no deviation from what the grower would do.
“Great Lakes has always been forward focused. We’re always looking at trying to find the next innovation,” Reimer says.
TRIALS
The first trial at Great Lakes Greenhouses was conducted on eggplant growing from April 19 to Oct 25, 2022, with two zones of eggplant growers: one controlled by the growers, and the other managed by an autopilot system.
“Our autopilot controlled heating, CO2, and venting. The setpoints were changed every five minutes and data was monitored via Koidra’s dashboard and mobile app. During the trial, the autopilot system managed to increase the yield of eggplants by 28.5% compared to the controlled zone, which means that the autopilot system was able to produce a significantly higher amount of eggplants compared to the traditional growers’ practices,” Tran stated.
A second trial was conducted growing cucumbers from July 18 to Oct 18, 2022, using the same practices implemented during the growing of the eggplants. Again, the results were very positive.
“The trial with cucumber was conducted in the same manner as the eggplant trial, with two zones of cucumber growers: one controlled by traditional growers’ practices and the other managed by an AI-powered autopilot system. The results of the trial showed that the autopilot system was able to increase the yield of cucumbers by 19% compared to the controlled zone. This improvement in yield is significant and confirms the ability
of the autopilot system to increase the productivity of crop growth in commercial greenhouses,” Tran stated.
HELPING GROWERS
Reimer says Koidra’s technology assists with overseeing their operation, saving the growers time while potentially improving reaction times for responding to a variety of potential issues that could be taking place within the greenhouse.
“A big part of what Koidra has implemented is this network of sensors and cameras that extend to parts of the farm that normally a grower wouldn’t pass by – maybe every few days, especially on a large site like ours, which is 120 acres. So, this opportunity allows for us to keep an eye on everything all the time and report back on things that the AI can pick up or understand, maybe even before the grower has an opportunity to identify themselves,” Reimer says.
Reimer says Koidra has demonstrated an improvement in the yield of crops
Since the onset of the COVID-19 coronavirus pandemic, Great Lakes Greenhouses has been taking a hard look at efficient use of its labour force and sees technologies like Koidra’s to be extremely advantageous.
“The onset of COVID really gave us the opportunity to look at more efficient use of the labour force and being able to work in the greenhouse with less hands,” Reimer says, adding that a smaller labour force also reduces the potential for dangerous or destructive virus transmissions.
It has taken some time for the growers to become comfortable with the AI technology, but they have learned to embrace it.
“I think any grower is going to have a high degree of skepticism as they’re starting to look at this program. Every grower I’ve ever met has a passion for the industry, and they want to have a real strong understanding of what’s going on in their crops. The trusting of the technology and taking a step away is something that we’ve been able to alleviate by giving them
new confidence that the tools are working for them,” Reimer says. “But there’s always a little bit of an innate hesitancy to cede any of that direct control. Over the course of time and developing a program to monitor, understand and utilize the tools, they end up looking at it as more of a valuable tool than a competition.”
Reimer says Koidra has demonstrated an improvement in the yield of crops and has given Great Lakes Greenhouses greater insight on what’s going on in their crops.
“We can see different metrics that Koidra has put together and we can evaluate those and learn from that. With optimization we’re always a yield-first focus, but when we can add a percentage of yield increase, while not increasing our greenhouse footprint, that’s where we really benefit from this technology.”
Great Lakes Greenhouses has found this project to be very compelling and will continue to look for opportunities to optimize operations in the future.
CO2 enrichment in Controlled Environment Agriculture
Is it always a good idea?
BY DR. FADI AL-DAOUD (OMAFRA) AND DR. XIUMING HAO (AAFC)
When exposed to light, plants grow by converting carbon dioxide (CO2) and water into sugar and oxygen; this is a simple way to view photosynthesis. About half of the amount of CO2 that is fixed by plants during photosynthesis is released back into the atmosphere during respiration. This input and output of CO2 is a passive process that happens by diffusion through the leaf stomata where open stomata will facilitate this exchange and closed stomata will hinder it.
Pre-industrial levels of atmospheric CO2 gas were around 280 parts per million (ppm), but today’s levels are around 400 ppm. Atmospheric levels of CO2 gas also fluctuate with the seasons. They increase with warmer spring weather that promotes aerobic activity to breakdown dead organic material, and they peak in early summer when vegetation is in full bloom undergoing photosynthesis
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and consuming CO2. The consumption of CO2 continues as the growing season progresses until the atmospheric levels reach a low at the end of the season. The cycle begins again with the breakdown of dead organic matter in autumn and winter which releases CO2 back into the atmosphere.
Theoretically, if CO2 is required for photosynthesis and CO2 levels are increased, so too should the rate of photosynthesis, plant growth and food production. But is it possible to have too much of a good thing when it comes to CO2 and its effect on plants? And how do plants respond to CO2 enrichment under different environmental conditions?
This article aims to answer these questions by providing the latest scientific data on the effect of CO2 enrichment on plant growth and physiology, and its interaction with temperature, heat, and nutrition.
Theoretically, as CO2 levels are increased, so will rate of photosynthesis, plant growth and food production.
PHOTO
WHAT IS CO2?
CO2 is composed of one carbon (C) and two oxygen (O) atoms. It is a colourless and odourless gas at room temperature, but under higher pressure CO2 gas is converted into liquid. Solid CO2, better known as dry ice, is produced under high pressure and low temperatures. CO2 gas is soluble in water where it forms a weak acid known as carbonic acid (H2CO3). It is more dense than dry air, and it is transparent to visible light. However, CO2 gas absorbs and reemits infrared radiation. This allows it to trap heat and act as a greenhouse gas.
CO2 ENRICHMENT AND PLANT PHYSIOLOGY
Crops grown in controlled environment agriculture (CEA) production systems such as greenhouses and vertical farms in warehouses consume CO2 as they undergo photosynthesis when exposed to light. A typical greenhouse crop will use 4.8-9.6 kg per hour per acre. This process can drop the concentration of CO2 from ambient levels (around 400 ppm) to as
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CEA crops consume CO2 as they undergo photosynthesis when exposed to light.
low as 100 ppm if the production site is not ventilated. Such low levels of CO2 can cause significant plant health issues and losses in productivity. It is recommend-
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Current recommendations for greenhouses suggest that when vents are closed CO2 levels should be maintained at around 1,000 ppm on a sunny day and 600 to 700 ppm on a cloudy day.
ed to ventilate a vegetable greenhouse at a rate of 1 air exchange per hour to replenish the CO2 in the growing space. Enriching the air of vegetable greenhouses
with CO2, commonly referred to as CO2 fertilization, has also become common practice. It is typically done by using flue gas from boilers that burn natural gas to generate heat and CO2, or by purchasing liquid CO2 that is vaporized and pumped into the greenhouse. The quality of CO2 derived from flue gas must be monitored to ensure there are no harmful side effects from byproducts such as ethylene (C2H2), nitric oxide (NO), nitrogen dioxide (NO2), and carbon monoxide (CO).
Current recommendations for greenhouses suggest that when vents are closed CO2 levels should be maintained at around 1000 ppm on a sunny day and 600 to 700 ppm on a cloudy day, and when vents are open more than 10% CO2 levels should be maintained at 400 ppm or ambient levels. But what about other weather conditions like hot cloudy days or sunny cold days? To help answer these questions let’s first look at how CO2 affects crop physiology:
1. Photosynthesis – Plants uptake CO2 passively through their stomata by diffusion. Therefore, the higher the level
of CO2 is outside the leaf, the higher the level is inside the leaf. Higher levels of CO2 lead to more photosynthesis and are associated with a 15-30% increase in vegetable production, on average. Boosts in production as high as 50% have been observed in tomatoes and peppers and 73% yield increases have been observed in cucumbers. One study showed an increase of 72% in lettuce head mass when plants
were grown under 1000 ppm as compared to 200 ppm CO2. However, a growing environment with more than 1200 ppm of CO2 resulted in lower rates of photosynthesis and reduced yield for greenhouse cucumbers.
The level of CO2 in the growing environment is not the only factor to consider
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because the duration of the exposure of plants to CO2 enrichment also affects photosynthesis (dose = quantity + duration). If plants are exposed to elevated levels of CO2 for an extended period of time, they undergo a process called photosynthetic acclimation where the rate of photosynthesis drops, and the benefits of elevated levels of CO2 are not as pronounced as they were when the plants were first exposed to them. This drop in photosynthetic activity may be associated with a drop in chlorophyll content and a build-up of starch and other sugars in the leaves that may interfere with the function of chloroplasts. Furthermore, plant leaves may become chlorotic, deformed, rolled and brittle under prolonged CO2 enrichment. This is thought to be due to an imbalance in the ratio of carbon and nitrogen in the plant. One way to reduce photosynthetic acclimation in the crop is by feeding it high levels of nitrogen (N). Cucumbers that were grown with high N exhibited less photosynthetic acclimation than those that were grown with lower N levels.
2. Transpiration – When greenhouse
CO2 concentration is elevated above ambient levels it results in lower stomatal conductance and transpiration rates in plants, almost 10% less in some cases. This means that less water is evaporating from the leaves through the stomata, and less water is being taken up by the plant. This reduction in transpiration can increase the water use efficiency by up to 60% in plants and allows producers to reduce their water bill. However, lower rates of transpiration can be detrimental to
plants on a hot day because transpiration is one of the primary ways plants cool themselves when greenhouses reach high temperatures. The reduction in stomatal conductance and transpiration by CO2 enrichment is more severe under cloudy (low light) than under sunny (high light) conditions. This effect also varies with plant species and is more pronounced in eggplants compared to tomatoes, cucumbers, and peppers. Therefore, CO2 enrichment should be minimized during
hot days, especially on cloudy days and on eggplants, to allow plants to maximize their transpiration rate and their ability to cool down.
3. Food Quality – In general, elevated levels of CO2 increase sugar and antioxidant levels and decrease protein and mineral levels in vegetables. However, variability does exist between different crops and different varieties of the same crop depending on the concentration of CO2. Some tomato plants, for example, may produce higher quality and better tasting fruit under elevated CO2 conditions, whereas other tomato plants may have reduced levels of lycopene - the pigment that gives tomatoes their red colour. Also, some cucumbers grown under high CO2 levels have elevated levels of sugar but lower levels of dietary fiber.
The colour of some crops can change depending on the level of CO2
The colour of lettuce and strawberry crops can change depending on the level of CO2 they are grown in, and higher levels of healthy phenolic compounds have been observed in lettuce grown under CO2 enriched conditions. Overall, plants produce larger fruit that have lower nutrient concentrations when grown under elevated CO2 levels. This may be due to a dilution effect when plants increase their fruit size, but they don’t produce more nutrients to fill the larger fruit.
The effect of high levels of CO2 on sugar and protein levels in the fruit is also dependent on the availability of nutrients for the crop. This is similar to the effect of N on photosynthetic acclimation. Studies have shown that under low N and high CO2 concentrations cucumber quality improved, but no increase in yield was observed. In contrast, when cucumbers were grown under high N and high CO2 levels the concentration of sugar and dietary fiber in the fruit did not change while yield increased. Similarly in tomatoes, the effect of CO2 enrichment on the levels of sugars and lycopene can be positive or negative
depending on the nutrient levels available to the crop.
4. Improved Stress Tolerance – CO2 enrichment enhances the ability of plants to tolerate stresses like drought and heat because of elevated levels of soluble sugars and antioxidants. These compounds help protect plant cells from damage in stressful growing conditions. But this is counteracted by the associated reduction in transpiration rates that may be detrimental under hot conditions, as mentioned above.
HIGH LIGHT AND HEAT
The increase in photosynthesis when crops are grown under high CO2 levels is greater at higher light levels than at lower light levels, in general. Does that mean that increasing both CO2 and light levels is a good idea? Not necessarily. For example, it has been shown that CO2 enrichment increases antioxidant levels in lettuce when grown under high light conditions and when grown under a higher red to blue light ratio, but high light levels have the opposite effect on sugar levels because high light does not increase sugar levels in lettuce as lower light levels do under CO2 enriched conditions. Another study showed that CO2 enrichment reduced yield of marketable tomato fruit during bright and hot days of August in southwestern Ontario. Furthermore, tomato plants grown under high CO2 and high light conditions may suffer from short leaf syndrome (SLS) where plants develop short, thick, curled, and crisp, dark grey-green leaves. SLS has also been shown to be aggravated by not only high light but also high temperatures. One of the reasons for SLS is high tempera-
tures, especially high nighttime temperatures, that reduce tomato fruit setting and sink strength and cause an imbalance between sink and source. Less severe SLS was observed when plants were grown in high plant density because it may have resulted in more shade and lower light levels (lower source strength) in the crop canopy. Therefore, one practical solution to prevent SLS is to use high stem density by introducing additional stems in the spring.
IS IT ALWAYS A GOOD IDEA?
The current recommendations for greenhouses to maintain CO2 levels around 1000 ppm on sunny days and 600 to 700 ppm on a cloudy day when vents are closed, and 400 ppm when vents are open more than 10% still apply. However, greenhouse growers might also want to consider reducing CO2 levels during hot days, especially on cloudy days. Vertical farmers should also consider enriching with CO2, if they don’t already, and optimizing the levels depending on their light and nutrient recipes. Just like other environment parameters, proper control of greenhouse CO2 levels relies on properly functioning sensors. CO2 sensors should be calibrated on a regular basis according to manufacturers’ recommendations to ensure accurate measurements are taken. As greenhouse environment control systems becomes more dynamic with more sophisticated decision-making algorithms that optimize set points in real time, so too will CO2 control. In the near future, CO2 set points will be changing in real time to adjust to changing weather conditions (light and temperature), which will improve greenhouse efficiency overall.
FROM ORGANIC WASTE TO BIOGAS
How greenhouses help make renewable energy more sustainable
BY TOM FERENCEVIC
WHAT IS THE STATUS OF THE INDUSTRY?
Fifteen years after the Ontario government first announced incentives for renewable energy, Canada still counts fewer than 300 biogas plants. If wastewater treatment plants are excluded from this statistic, fewer than 100 facilities are in operation. Though incentive programs have come and gone, biogas simply hasn’t lived up to its supposed potential. This is not from lack of effort on the part of technology providers, all of whom have their roots in successful European companies. So, how can we explain this failure, and how can we transform it into becoming a thriving industry?
WHAT IS BIOGAS?
WHAT ARE THE BENEFITS?
Biogas is the fuel produced from the natural decomposition of organic matter. It is composed of 60 per cent biomethane, a very potent greenhouse gas when released into the atmosphere. But if this decomposition occurs in a closed vessel and the biogas is captured, it can be used as a natural fuel source. By using various methods, the biogas can be separated from other gases to make renewable natural gas fit for the natural gas pipeline or for use in natural gas-powered vehicles. Alternatively, the gas can be passed through a CHP (combined heat and power generator) to make electricity.
non-agricultural), permitting for renewable energy production, feedstock availability, and access to the electrical or natural gas grid. Biogas facilities also require skilled operators. Even though a good design will reduce the amount of work an operator has to do, the job still needs their full attention. Therefore, considering staffing costs in the economic model can help ensure a project’s success.
While having land, proper permitting, and access to the energy grid are factors that can be met fairly easily by most farms
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There are many benefits of biogas: it recovers organic waste and makes the most of our resources, fights climate change, supports local economies through energy production and job creation, and returns nutrients and organic matter to the land. Also, compared to other renewable energy sources, biogas can be seen as a baseload producer, since facilities run consistently 24 hours a day, seven days a week. This offsets the variability of wind and solar, which produce inconsistently or periodically.
A SUCCESSFUL PROJECT
Tom Ferencevic, CEO of Fitec, providing client support during the construction phase of a project.
and greenhouse operations, securing adequate and appropriate feedstock can be more of a challenge.
The key elements required for a successful biogas project include having appropriately zoned land, permitting for the receiving and handling of various types of organic waste (agricultural or
Dairy farms have the advantage of producing manure, which then serves as feedstock. Food waste produces more energy per tonne than manure and also generates revenue from tipping fees, but comes with its own set of biological and operational challenges. Despite sources claiming more than 35.5 million tonnes of food are wasted in Canada yearly, this food is only sometimes available in biogas facilities. Unless food is de-packaged or source-separated, the contamination with non-digestible materials makes it impossible to place in a digester. Also, most food
waste occurs in urban centres, while the majority of biogas operations are located at a distance from large cities, meaning trucking costs have to be factored into the business case. Additionally, since biogas facilities operate 24 hours a day, seven days a week, having reliable, long-term contracts delivering consistent waste is essential to a successful operation.
SUSTAINABILITY
From a sustainability standpoint, greenhouse operations stand to benefit a great deal from biogas. In addition, as hefty energy consumers, the appeal of generating electricity or natural gas on-site has tremendous appeal.
Biogas produced in an anaerobic digester is used in one of two ways: to power a combined heat and power generator (CHP) and convert the gas to electricity or to be cleaned and converted to renewable natural gas (RNG).
The advantage of a CHP is that excess heat can be recovered from the engine and directed to the greenhouse to reduce heating costs. The difficulty is that the CHP produces mostly electricity and smaller quantities of heat, which doesn’t match up with a greenhouse’s requirements primarily for heat and, to a lesser extent, light. Biogas plants don’t produce enough heat for large greenhouses (over 10 acres), but they can help small- to medium-sized greenhouses.
Regarding RNG production, biogas upgrading units are twice the cost of CHP units, making the business case more difficult. But rates are in flux, and the general trend for renewable natural gas rates seems to be rising. Effectively, largescale deployment of biogas in greenhouse operations has not materialized because the energy produced needs to offset more of their own energy use. Therefore, the investment cost is not justified, nor is the complexity of adding on what is effectively a separate business.
THE PATCHWORK OF RULES AND REGULATIONS
The main thing that is missing to make biogas technologies profitable for the greenhouse sector is incentives from the government. Existing programs are frequently revoked with changes in government. This lack of commitment to the
cause of climate change has resulted in a patchwork of rules and regulations that do not adequately support the renewable energy industry.
Recently, the Ontario government reduced the barrier to environmental permitting for farms to receive off-farm organic waste in quantities relative to the manure they produce. This barrier reduction favours the building of biogas plants in dairy operations. On the other hand, the federal government has been offering grants and
investment tax credits for renewable energy projects. These are more helpful for the biogas industry’s overall development and result from the federal government’s climate change policy.
The federal government wants more renewable energy resources and is trying to put pollution pricing into place to encourage development in this area, but they also want to keep the peace with the general population by keeping natural gas or electricity rates low.
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HOW CAN WE MAKE IT WORK?
As the oil and gas industry is subsidized, investment tax credits and subsidies are also required for renewable energy projects. The goal moving forward should be to level the playing field. However, until recently, the price of renewable energy has only been adequate to justify renewable energy projects for agricultural producers if they produce or have access to large quantities of organic waste. One way to address this problem is to use energy crops in biogas facilities.
The scale of the European industry was achieved through the government’s incentives for energy crops as feedstock. This decision was initially criticized for removing arable land from food production. But given the current political situation in Europe and the potential disruption of foreign fuel supplies, growing fuel crops and having access to local energy production suddenly seems more of a priority.
Other than localizing energy production, there are other advantages to using energy crops, such as corn silage,
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to produce renewable energy. One such advantage is a reduction in capital expenditures. For example, building a facility that produces 1000 m3/hr of biogas from energy crops would cost between $15 million to $20 million, as opposed to a more complex facility for food waste, which would require an investment of between $20 million to $25 million.
Canada’s population is quickly growing, and urban areas are expanding. The pressures on farmland are not new and are not looking to ease up anytime soon. Putting government incentives in place for energy crops may help to protect farmland from development. In addition, keeping land in production keeps the option open for returning that land to food production in the future, if required.
Biogas is a valuable investment. It contributes to increased sustainability in small- to medium-sized greenhouse operations, diversifying farm operations, and contributing an interesting element to an individual farm’s succession plan. All while making the most use out of our waste streams and protecting the environment. If it were economical for greenhouses to grow energy crops for biogas production, this would create an ecosystem for sustainability and growth in the biogas market.
Tom Ferencevic, CEO of Fitec and an environmental scientist at Fitec Environmental Technologies. Fitec is a Canadian company that provides environmental and biogas solutions all across North America.
Aerial view of Courthouse Hill Farm and Energy in Hants County, Nova Scotia where the Bloise Family Farm manages a dairy operation, a blueberry operation and a biogas facility.
UNDERSTANDING tomato plant signals and making decisions for better productivity
Part 2: Clusters and
flowers
A continuation of the series on understanding tomato plant signals
BY DR. MOHYUDDIN MIRZA
In part one of the article on tomato plant signals, it was mentioned that three leaves and one set of clusters is produced in greenhouse varieties and the speed of development depends on plant’s budget of energy produced and consumed. When a plant enters a generative state, then it channels more resources to clusters, individual flowers and fruits compared to leaves, roots and stems. All climate parameters are required to be at optimum level along with water, nutrients and other inputs. Some readers asked to include pictures from early and later stages of crop.
Picture 1 (left): Three leaves and one cluster example from a young crop with the very first cluster with fruit visible and second cluster opening up. It is worth mentioning that the shape and size of these flower cluster is pre-determined about 45 days earlier when buds were be-
ing formed and are affected by the climate conditions at that time. So, if you want to know more about these clusters then you must know what happened earlier. Temperature at the time of bud set is the biggest determining factor for cluster size, length and vigor of flowers.
Picture 2 (right): A mature crop and a cluster is seen, then two leaves and then one cluster. That can happen when plant is in a strong generative mode, good assimilates are bring formed and translocated.
ABOUT THE CLUSTERS?
Shapes, angle of appearance, and length tell a lot of things. Grape tomatoes have longer clusters, sometimes double and triple branching. One grower counted 70 fruits on one cluster. Large fruited varieties have smaller length clusters compared to grapes or cocktail-type tomatoes.
PHOTOS
ANGLE OF CLUSTER GROWTH FROM THE STEM
An angle of 45 degrees, like in pictures 1 and 2, is an indication of good balance between vegetative and vegetative growth and good climate parameters, especially the proper relative humidity. Clusters that are parallel to the stem is an indication of higher relative humidity, low transpiration, rapid growth under lower light levels, and likely will “kink” when fruit is set especially in large fruited varieties.
WHEN LEAVES OR SHOOTS COME OUT OF THE CLUSTERS
Picture 3 (P. 30, left) shows a thick stem, big flowers and leaves coming out of the cluster. It appears that the symmetry is lost. The flowers are pale yellow with thick calyx. Any fruit set on these clusters will show “catfacing” at the blossom end due to poor pollination. This is a very vegetative signal from the plant.
Picture 4 (P. 30, middle) shows a cluster was formed and then a strong shoot emerged out of that. The leaves can appear anywhere on the cluster, some-
times at the end of the cluster as well. This shows that plant is confused as to what the grower is trying to achieve. The plant became generative and then back to vegetative likely due to set points on temperature, relative humidity, irrigation volumes, more ammonium nitrogen and some others.
Picture 5 (P.30, right) is an example of a good cluster, set at proper angle, and brown spot-on flower anthers indicating that bumble bees visited it and pollinated it. Petals bent backward to attract pollinators and after that close and senesce and fall off and fruit is visible.
In order to understand these signals, we have to go back to the basic plant cycle. When seeds germinate, they develop roots and shoots and leaves and is part of what we call vegetative state. The plant’s priority is to produce leaves and support with adequate roots so that the process of food manufacturing (photosynthesis) can be started. Tomato plants ideally produce seven to nine leaves before first cluster appears, although the buds were formed almost 45 days ago. These flower buds
started forming when first set of true leaves start developing and growers use cooler temperatures to keep them from stretching. Once the flower buds start opening, plant signal is to start generative growth. The main thing is that the tomato plant has to keep a balance between vegetative and generative growth. The management approaches for keeping the balance requires in depth knowledge of the production cycles based on the sunlight. For example, tomato life span can be divided into: winter (Nov. to Dec.); early spring (Jan. to Feb.); mid spring (Feb. to April); summer (May to July) and summer/fall (Aug. to Nov.) As an example, for the summer cycle, radiation levels can exceed 2,000 joules/cm2/day. The focus should be on the quality of the flowering truss. Target fruit loads 80+/ m2 to ensure good leaf length. Control over the plant climate is reduced and is subject to daytime extreme. Here are few strategies growers use to maintain high production:
• Adjust day and night temperatures to obtain lower 24 hours averages.
• Reduce light intensity to close to 1,500
Lower humidity, save energy, and improve your climate.
Optimal humidity is vital for healthy crops. High humidity can lead to viruses, while low humidity can stunt crop growth. Canadian growers traditionally gap screens to reduce humidity, which results in heat loss and a higher energy bill. However, leveraging a vertical airflow system, such as Svensson’s ClimaFlow, can eliminate the need to gap screens by drawing cool, dry air from above the greenhouse and evenly distributing it to reduce humidity. With ClimaFlow, growers can also gain up to 10% more energy savings while enjoying a balanced, homogeneous climate. ludvigsvensson.com
joules by external shading and active use of screens. Very high Daily Light Integrals can reach during this production cycle and that can negatively stress the plant.
• Try to maintain CO2 levels around 800 ppm early in the morning when vents are not fully open. In summer below ambient CO2 levels can affect fruit sizing and reduced new leaf growth.
• Adjust feed EC based on light. Plants at this production cycle depend more on feed EC rather than slab EC. Adjust over drain percentage to keep the slab EC around 3.0.
• I recommend to introduce pH adjusted water under high transpiration demands when light is above 1,500 joules.
• With longer days, adjust irrigation practices and volumes so
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plants are not short of water. When this happens, the plants can draw water from the fruits resulting in poor quality.
• Pay particular attention to Vapor Pressure Deficit (VPD). Important to activate the plant early in the morning (VPD>3 grams/m3 of air) to condition high VPD in afternoon that can exceed 12 grams/m3
• Target 20 to 25 leaves for transpiration under high temperatures.
• In conclusion, I want to say pay attention to all the details in each production cycle to maintain a balance between vegetative and generative growth. Good growers are consistently achieving over 80 kg/ m2
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Mass-produce the weevil
SIT for managing the pepper weevil and other challenging pests
Applying the sterile insect technique
BY JACOB BASSO, CYNTHIA SCOTTDUPREE AND ROSE LABBÉ
The sterile insect technique (SIT) is an innova tive strategy to control insect pests without the use of insecticides that could one day be used for the control of routine and invasive greenhouse pests. It has historically been used to control a diversity of insect species that threaten not only humans and animals, but also crop health. Some examples are mosquitoes that vector malaria or dengue in tropical parts of the world, and tsetse flies that transmit parasites responsible for sleeping sickness in humans and cattle. Across the world, successful management programs for multiple Tephritid fruit fly species have incorporated the SIT, which reduces reliance on insecticides, and recently the sweet potato weevil was eradicated from two islands in Okinawa, Japan using this technique.
In Canada, two current and successful SIT programs have targeted field crop pests including the onion maggot (i.e., La Mouche Rose in Quebec)
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new research has explored applying the SIT for a problematic greenhouse pest, the pepper weevil.
WHAT IS THE STERILE INSECT TECHNIQUE AND HOW DOES IT WORK?
An SIT program essentially involves the release of large numbers of sterilized insects of the same species as a target pest. Following their release, sterile male insects will mate with wild, fertile females which are then unable to produce offspring. Following multiple rounds of sterile insect releases, the wild pest population will decrease to below an economic threshold, often within just a few generations. For the SIT to work, the target species must reproduce sexually, so species that undergo asexual reproduction (called parthenogenesis) are generally not suitable for this management tool.
For SIT to work, the target species must reproduce sexually.
Female
Sterile male No offspring
Release many sterile males into a greenhouse The weevil population will crash
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The SIT is also compatible, and in fact, most effective when used in combination with other management tools, such as biological control and conventional insecticides.
Insects are typically sterilized by irradiation using a radioactive source. It is important to note, though, that the irradiated insects themselves do not become radioactive and will not spread radiation once released. Crucially, the sterilized males must remain healthy and competitive against wild males so that they can seek out females and mate with them successfully.
Cost-efficient mass-rearing and accurate population monitoring techniques are also important for determining when, where, and how many sterile insects should be released, and how effective they are at reducing the pest population.
PROSPECTS OF THE STERILE INSECT TECHNIQUE FOR GREENHOUSE PEST MANAGEMENT
While the SIT has traditionally been used for outdoor agriculture over large management areas, applying the SIT in greenhouses has begun to receive attention in recent years. Greenhouse environments could potentially serve to enhance SIT efficacy relative to field releases by reducing emigration and thus maintaining high densities of sterile insects for longer periods of time. In fact, a number of key greenhouse pests are already being studied as targets for the SIT as coordinated by the International Atomic Energy Association (IAEA) and the Food and Agriculture Organization (FAO). These include spotted wing drosophila (Drosophila
Greenhouse
suzukii), the tomato leafminer moth Phthorimaea absoluta (formerly called Tuta absoluta), as well as armyworms in the Spodoptera and Helicoverpa genera. Earlier SIT research for control of Trialeurodes and Bemisia whiteflies as well as the serpentine and tomato leafminers (Liriomyza trifolii and L. bryoniae, respectively) have also been explored. With each study, we are steps closer to applying the SIT in protecting greenhouse crops.
DEVELOPING THE STERILE INSECT TECHNIQUE FOR CONTROL OF PEPPER WEEVIL
As a recent Master’s student, Jacob Basso and his research groups at the University of Guelph and Agriculture and Agri-Food Canada in Harrow Ont., have studied sterilizing the pepper weevil by irradiation to develop a pepper weevil SIT system, in collaboration with Bruce Power, Nordion Inc, and the Fruit and Vegetable Growers of Canada (FVGC). To this end, pepper weevils were first exposed to multiple doses of radiation as pupae, and the doses that ensured complete weevil sterility (i.e. a lack of offspring) were selected for further study. In this case, both male and female weevils were 100% sterile when exposed to a dose of 110 Grays of gamma radiation.
Irradiated weevils were next assessed for their lifespan and ability to fly. Sterile males have to live long enough to interact with wild females, and they also have to fly to reach them. In these trials, while sterile male flight and lifespan were negatively impacted by irradiation, they still managed to live long enough to mate, and a good proportion were still able to fly.
These irradiated weevils were also assessed for their sperm production and mating competitiveness relative to normal, unirradiated males. In controlled environment tests, sterile males produced much less sperm and mated at a lower rate compared to unirradiated weevils, suggesting that sterile males may be less competitive than their unirradiated counterparts in the crop.
OPTIMIZING SIT SYSTEMS AND FUTURE DIRECTIONS
Despite the limitations we observed in irradiated male pepper weevils, there are a number of ways such SIT systems can be optimized to improve overall sterile male health and competitiveness. The most evident way is by releasing of a greater total number of sterile individuals. Another strategy to consider is dose fractionation, whereby irradiated insects receive their total radiation dose as the sum of multiple lower doses.
Alternatively, pepper weevils could be sterilized as fully formed adults instead of pupae. This is because fully formed adults
chill and expose insects to a low-oxygen environment to slow their metabolism and protect them from unwanted tissue damage. Finally, since irradiated insects tend to have short lifespans owing to gut tissue damage which leads to their starvation, diets of insects such as the pepper weevil could be supplemented with additional nutrients to improve their survival and mating success with wild insects.
When a combination of these factors are applied to produce relatively healthy and competitive sterile insects, the SIT has a clear potential to manage challenging greenhouse pests such as the pepper weevil.
While there is still a need to conduct large-scale SIT trials in greenhouses, the prospect of developing this strategy for the sustainable and effective management of greenhouse pests is both exciting and promising.
are overall more resistant to radiation than undeveloped juveniles, resulting in improved sterile insect health. Other environmental factors to consider before and during the irradiation process are to
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INSIDE VIEW
GARY JONES | Gary.Jones@kpu.ca
A little bit of everything
“The owner of one of the U.K.'s biggest cucumber farms says the industry is facing a "triple threat" as he fights to keep his family business going. Tony Montalbano, who runs Green Acre Salads in Roydon in Essex, says U.K. salad growers are facing a threat to their business from spiralling energy bills, supermarket prices which do not reflect growers' costs and a shortage of workers. It was forced to stop production earlier this year because of the exorbitant cost of energy needed to grow the crop in the depths of winter.”1
While this is a prime-time news item to the U.K. public, the essence of such a story should come as no surprise to anyone in the greenhouse industry here in Canada. We’re all too well aware of the three ‘perfect storm’ issues mentioned (energy, returns and labour), and all face similar concerns to some extent. Growers have to be masters of simultaneously chipping away on all these fronts (and more). But for now, let’s look at a few energy-related items.
INTELLIGENT CROP MONITORING
mercial greenhouses. According to their literature, “The Solar Greenhouse of area 3,000m² will deliver approximately 0.25MWh of solar energy daily back to the grid (or to battery array for off grid installations). [This is] Equivalent to installing a solar farm rated at 60kWp, integrated into a transparent building structure. Enough energy to power 12 average residences. 250kWh production per day will offset over 1.3 tonnes of CO2 emissions each day.”3 While Australian growers enjoy much more sunshine than many here in Canada, if the capital investment is affordable, such technology may be worth investigating.
QUANTUM DOTS? HUH?
“We're all too well aware of the three 'perfect storm' issues...”
There has been much talk of Artificial Intelligence (A.I.) in the past couple of years, and the development of autonomous greenhouses. Even without going fully autonomous, new tech can help optimize greenhouse production. Swedish startup Ecobloom Technologies recently released EcoSense, “designed to help indoor farmers optimize their yield while reducing energy costs. By leveraging the power of artificial intelligence and machine learning, EcoSense provides real-time insights into plant health and growth, allowing farmers to make data-driven decisions and take corrective actions where necessary.”2 The aim is to optimize yield while reducing energy costs, and is being used by Kabbarps Trädgård AB, producers of fresh herbs and salad crops.
PHOTOVOLTAIC GLASS
Similarly, there has been research into photovoltaic glass for some time now. But this is now coming to commercial fruition. ClearVuePV is an Australian company with products ready for install in com-
Perhaps we ought consider options to fully utilize the one source of energy that is free – sunlight. Applying what might be considered space age technology, U.S. company UbiGro is developing its “luminescent greenhouse film that optimizes sunlight within your greenhouse. This layer of light uses clean nanotechnology known as quantum dots to improve the quality of light in the greenhouse. UbiGro’s layer of light leverages unused parts of the sun’s spectrum, UV and blue photons, and converts them into orange, red, and far-red, giving your plants more of what they need to thrive.”4 It's unlikely these developments will make a dramatic difference negating the energy issues growers face, but combining all these, and more, may reduce the “triple threat” to a double whammy. Already incorporated these utilities? Let us know, I’d love for us all to be able to learn from it. That just leaves the one issue – getting decent returns for all the hard work put into getting the industry’s incredible products to the supermarket shelves. I suspect that might take more work…
1 https://www.itv.com/news/anglia/2023-04-28/ cucumber-grower-giving-it-one-last-shot-tosave-his-family-firm, reported in www.HortiDaily.com, May 2023
2 http://www.ecobloom.se/ reported in www. HortiDaily.com,May 2023
3 https://www.clearvuepv.com/contact/ greenhouse brochure, accessed, May 2023
