Pesticide Risk Reduction Strategy for Greenhouse Floriculture

June 2017

For inquiries regarding the content of the strategy, please contact:
Pest Management Centre, Agriculture and Agri-Food Canada


Pesticide risk reduction strategies are developed under Pesticide Risk Reduction (PRR) of Agriculture and Agri-Food Canada's (AAFC) Pest Management Centre. To reduce undesirable impact of the use of pesticides in agriculture, PRR works with grower groups, industry, provinces, researchers and regulators to identify gaps in pest management and opportunities to develop and implement strategies to address these.

A pesticide risk reduction strategy is a detailed plan that aims to address grower needs for reduced-risk management tools and practices for specific pest issues. The strategies are developed through extensive consultation with stakeholders. The strategy document presented here summarizes the framework and activities supported by PRR. It is intended to provide information about the development and implementation of the strategy and new tools and practices made available through this process.

For more information, please visit the Pest Management Centre.


Pesticide Risk Reduction acknowledges all participating stakeholders for their contribution and collaboration in the development and implementation of a reduced-risk strategy for greenhouse floriculture. In particular PRR recognizes the contributions of the Greenhouse Floriculture Working group including:

  • Cary Gates – Working group co-chair, Flowers Canada Growers;
  • Garry Watson – ret., Flowers Canada Growers;
  • Dean Shoemaker – previously Flowers Canada Growers;
  • Graeme Murphy – ret., Ontario Ministry of Agriculture, Food and Rural Affairs
  • Wayne Brown – ret., Ontario Ministry of Agriculture, Food and Rural Affairs
  • David Woodske – British Columbia Ministry of Agriculture Food and Fisheries;
  • Regis Larouche – previously Quebec Institute for the Development of Ornamental Horticulture;
  • Cynthia Scott-Dupree – University of Guelph;
  • Deborah Henderson – Kwantlen Polytechnic University;
  • Albert Grimm – Jeffery’s Greenhouses;
  • Michael Brownbridge – Vineland Research and Innovation Centre;
  • Rose Buitenhuis – Vineland Research and Innovation Centre.

Executive summary

Greenhouse floriculture is a growing industry in Canada, and comprises a tremendous diversity of crops and production systems including cut flowers, potted flowers, potted plants, propagative stock and bedding plants. The variety of crops grown, in addition to the greenhouse growing environment itself, lead to unique pest management challenges for growers. This report describes the collaborative framework developed and activities supported by PRR in implementing a national Pesticide Risk Reduction Strategy for Greenhouse Floriculture.

This strategy was developed through consultations and collaboration with industry stakeholders including grower groups, provincial crop specialists, researchers and AAFC scientists. Knowledge gaps, potential risk reduction solutions and barriers to the adoption of certain reduced risk management approaches were identified and developed into a strategic approach for pesticide risk reduction. The three main goals targeted for the greenhouse floriculture strategy are: improved access to new lower risk pest control products; development of new reduced risk pest management tools, technologies and integrated systems, and; promotion, facilitation, and adoption of reduced risk techniques.

Since 2003 PRR funded 12 projects covering a range of reduced risk approaches including biopesticides, alternative cultural controls and knowledge transfer projects. Some key outputs from these projects include:

  • A baseline of pest management issues and practices within the industry and defined research, development and technology transfer priorities;
  • New information regarding the compatibility of specific biological control agents with conventional pest management products, and; consolidated knowledge on reduced risk treatment options for the management of insects on propagative stock;
  • Management of western flower thrips through the placement of chrysanthemums as trap crops;
  • The registration of sulphur for use in greenhouse vaporizers and of the biopesticide Met52; and regulatory submissions related to several other reduced risk pest management products;
  • Hands-on integrated pest management (IPM) workshops, as well as an online platform to access a suite of web-based IPM resources.

More details about the solutions resulting from this strategy are provided in Table 2 at the end of this document.

Pest management and pesticide risk reduction issues

Greenhouse floriculture production is an important industry in Canada. In 2015, flowers and ornamental plants accounted for 53% of sales in the greenhouse sector, with a total value of $1.5 billion. In this same year there were 1,855 greenhouses in Canada specializing in floriculture, with a total of more than 7.9 million square meters dedicated to greenhouse flowers and plants.

Pest management issues in the floriculture greenhouse environment are complicated, as growers face unique regulatory issues, and must balance an extremely diverse number of crops, each often with their own pest issues. In addition, as a result of re-evaluations of older chemistries by the national regulator – the Pest Management Regulatory Agency (PMRA) - some pest control products have been voluntarily discontinued by the registrant, some have had ornamental uses removed from the label, and some active ingredients are being phased out of use, leaving growers with limited conventional options for pest control.

The enclosed nature of the greenhouse leads to additional challenges such as year round production and the swift spread of pest problems. At the same time it provides an environment where biological control can be used as an effective, low risk management approach. Greenhouse growers have shown themselves to be early adopters of these strategies. However, despite a demonstrated eagerness to use these approaches growers indicate that it can be difficult to implement and maintain a biological control system without support. These systems also require knowledge of and access to products that are compatible with the living biological control agents.

Strategy development

The preliminary work for the development of this strategy was conducted through an industry led project with funding provided by Pesticide Risk Reduction (PRR). Flowers Canada Growers (the national organization representing the interests of floriculture growers), consulted with stakeholders across the country through face to face meetings, teleconferences and surveys. These consultations provided an important benchmark of current pest management issues and practices within the industry and identified opportunities for pesticide risk reduction in floriculture. After project completion, a floriculture expert working group was established to refine goals for risk reduction.

Working group consultations

A national floriculture pesticide risk reduction working group was established by PRR in the fall of 2010. The working group included growers and grower representatives, researchers, provincial extension experts and federal regulators. Through teleconference meetings the strategic goals and action plan were discussed and potential projects to reach the goals were identified. These consultations also provided an important platform for collaboration among stakeholders.

Priority issues and gaps

A number of pest management issues were identified through stakeholder consultations, some of which were outside the scope of PRR. Those key issues identified for work under the strategy are the following:

Lack of reduced risk pest control products

Many of the current products registered for greenhouse floriculture uses are older chemistries, and results of the survey by Flowers Canada Growers indicated that some growers no longer feel these work well due to resistance development within pest populations. More effective, lower risk products such as biopesticides are needed to replace the lost uses and to develop sound resistance management strategies for products which are registered and available.

Need for improved availability and accessibility of biological controls

Biological control is an important pest management alternative and an integral component of IPM for greenhouse growers. This approach is already well accepted by the industry with 90% of the surveyed growers indicating they use these methods to some degree in their operation. There is an opportunity for more biological control systems to be developed, implemented or improved which will increase the use of biological control overall. To do this, new knowledge about beneficial arthropods and rearing capacities, as well as information about biocompatibility of various products with beneficial arthropods, are required.

Lack of alternative pest management practices and technologies

Pests can often enter the greenhouse on propagative material. Technologies and practices to mitigate the introduction of pests at the point of entry could drastically reduce the need for other interventions such as conventional products, at a later date. Pesticide application methods can significantly affect how much actual product is applied and the degree of plant coverage achieved in a greenhouse. More efficient methods of pesticide application are needed which can reduce the total amount of pesticide used, while providing a higher degree of targeted control. There is also a need for more accessible and practical tools for pest monitoring and identification to be used by greenhouse staff.

Insufficient communication and extension support across growing regions

IPM strategies are often complicated and require a high level of commitment and know-how from the grower to be successfully implemented. Growers make good use of what information is available; however growers across the country have different access to extension personnel and technical support, and information needs to be consolidated, kept up-to-date, and made accessible to all growers in Canada. In addition, more opportunities for face to face interactions with researchers, extension experts and other greenhouse floriculture growers, as well as opportunities for demonstration trials could help to increase uptake of reduced risk, integrated techniques.

Action Plan

Based on these issues and proposed solutions, an action plan was developed to implement the greenhouse floriculture strategy (Table 1). This action plan includes goals, milestones and implementation activities, as well as describing progress on research and development activities undertaken by PRR.

Strategy Goals

The three goals defined in this strategy are:

  1. Improve access to new lower risk pest control products;
  2. Develop new reduced risk pest management tools, technologies and integrated systems;
  3. Promote and facilitate adoption of reduced risk techniques.

Table 1 - Action plan to implement a reduced-risk strategy for greenhouse floriculture production in Canada

Goal 1. Improve access to new lower risk pest control products
Milestones Implementation Activities Completion Date
Identify key pest management issues and potential reduced risk solutions PRR09-060Pesticide Risk Reduction Strategy Development for Floriculture in Canada – Through this project, extensive consultations with growers and extension specialists were held across Canada to discuss and identify priority pest management issues and potential for pesticide risk reduction. A snapshot of current pest management and issues for the floriculture industry was captured to be used as benchmark to track future progress. May 2010
Improve availability of biopesticides and other lower risk products by evaluating efficacy and providing registration support for new products that fit into integrated management programs BPI06-010 – Efficacy trials to demonstrate the performance of Facin™ on ornamentals in greenhouses – This project generated inconclusive data against the target pests, and no regulatory submission was made as a result. March 2007
BPI06-120 – Essential oils formulations for the control of mites, insects, and diseases on greenhouse ornamental and vegetable crops– EcoTrol was shown to offer some protection against aphids and mites. May 2007
PRR provided support to the ornamental team at the Minor Use and Risk Reduction Strategies Division at PMRA towards obtaining label expansion for sulphur to be used in sulphur vaporizers. The registrant submitted a registration package to the PMRA in September 2010; the use is now on the label. September 2010
BPR11 – 060 Evaluation of Met52 for the management of thrips on greenhouse ornamentals – Through greenhouse trials efficacy and crop tolerance data were developed in support of a regulatory submission for Met52 (Metarhizium anisopliae strain F52) for the control of thrips in greenhouse ornamentals (Chrysanthemum spp). This use has been added to the label. Fall 2012
BPR12-070 – Evaluation of SuffOil-X (paraffinic oil) for the management of thrips in greenhouse ornamentals – Trials were conducted to develop efficacy and crop tolerance data in support of a regulatory submission for SuffOil-X for the management of thrips in greenhouse ornamentals. A first time registration package was submitted to the PMRA in November 2015. November 2015
BPR13-070 – Registration support for Grandevo for the management of whiteflies in in Poinsettia – A value package prepared by PRR in support of this use, was provided to the registrant, and submitted in November 2014. (Sub no. 014-5332, 2014-5441). The regulatory package was subsequently withdrawn by the registrant and PRR project was terminated as a result. March 2014
BPR14-070 – Screening of biopesticides and risk-reduced products for the management of powdery mildew in cut gerbera – Through this project several products were screened to identify a suitable solution for the control of powdery mildew in cut gerbera. Promising products were identified, and efficacy data generated with one of these (Cyclone, citric and lactic acids) was used in support of an URMULE, and the use was added to the label in 2016. March 2015
Goal 2. Develop new reduced risks pest management technologies and tools for integrated systems
Milestones Implementation Activities Completion Date
Improve knowledge on biocompatibility of conventional products currently registered for use in greenhouse production MUR06-080 – Potential side-effects of fungicides on natural enemies and pollinators used in greenhouse vegetable production – This study examined the toxicity of reduced risk insecticides (imidacloprid, abamectin, metaflumizone, and chlorantraniliprole) and fungicides (myclobutanil, potassium bicarbonate, and cyprodinil + fludioxonil) used or with promise for use in Canadian greenhouse vegetable production on three species of arthropod biological control agents (Orius insidiosus [Say], Amblyseius swirskii [Athias-Henriot], and Eretmocerus eremicus [Rose & Zolnerowich] and bumble bees Bombus impatiens [Cresson]). It was found that chlorantraniliprole, myclobutanil, potassium bicarbonate, or cyprodinil + fludioxonil can be applied for greenhouse pest management with minimal harm to bumble bees and biological control agents. September 2009
Investigate potential of trap plants to reduce pest populations on greenhouse floriculture crops MUR06-090 – Use of trap plants as a risk reduction control option for thrips on greenhouses ornamentals – This study investigated the use of trap plants for the control of western flower thrips (WFT) on potted chrysanthemum. The study showed yellow flowering chrysanthemum to be more successful at attracting adult WFT than gerbera or eggplants. Placement of trap plants should be near vents and doorways as well as between flowering and non-flowering crops to attract dispersing thrips before residential thrips become established. The use of trap plants was shown to be as effective as pesticide sprays (spinosad) at controlling WFTs. Employing a trap plant strategy could potentially reduce greenhouse sprays of insecticides against WFT by 85-100% in ornamentals production. March 2007
Investigate insect pest control methods in propagative stock PRR11-040 – Review of status of management issues surrounding propagative pests in Canadian greenhouse floriculture industry – Through a literature review solutions that could be investigated for the control of thrips, mites, aphids, whitefly, mealybug, moths and scales on cuttings in ornamental greenhouses were identified. Some treatment options with a probability for success included: hot water treatments, reduced risk pesticides dips and biopesticides such as Beauvaria bassiana. The type of treatment will depend on the plant material, target pests and affordability. The main limiting factor to be considered for all treatments is phytotoxicity. October 2011
Goal 3. Promote and facilitate adoption of new reduced risk techniques and systems
Milestones Implementation Activities Completion Date
Support development of multimedia tools to facilitate knowledge and technology transfer to growers PRR10-230 – Development of an Integrated Pest Management/Biocontrol Internet Portal for Greenhouse Grower Educational Purposes – Through this project a website ( was developed and launched to provide growers with a comprehensive and consolidated package of information on implementing integrated pest management (IPM) systems and biological control tools into their production practices. Whitefly was chosen as an appropriate model on which to design the website interface. The site was updated in September 2015 through external funding. July 2011
PRR13-050 – Dissemination of information on biological control of whitefly to poinsettia growers through educational videos – Through this project a three part video series demonstrating an integrated pest management approach emphasizing biological control of whitefly on poinsettia was produced and made available to growers through under the Whitefly Management Section ( March 2014
Support hands on, face-to-face workshops to facilitate knowledge and technology transfer to growers PRR11-020 – Dissemination of information on integrated pest management techniques in greenhouse floriculture through workshops – Through this project two workshops were held, one in conjunction with the Canadian Greenhouse Conference in Niagara Falls, and the other in Langley, British Columbia. Both workshops included presentations by keynote speakers specializing in entomology and pathology, respectively, as well as hands on, rotating workshops. Subject areas covered included: integrated pest management of whitefly; invasive pests – keeping them out of the greenhouse; effective scouting in floriculture crops; the use of biological control agents; and disease detection and management in ornamentals. March 2012
PRR05-280 – Biocontrol and IPM workshop for greenhouse vegetable, floriculture and nursery growers in BC – This event was held with Kwantlen Polytechnic University College to provide a forum for learning and exchange of new ideas. Post seminar survey results indicated a high likelihood of adoption of some of the presented techniques. March 2006

Strategy impact – then and now

Pesticide Risk Reduction has provided support to the greenhouse floriculture industry in several key areas, with funded project work starting in 2006. Issues identified at the beginning of the official strategy in 2009 centered around:

  • lack of pest control products;
  • need for improved availability and accessibility of biological controls;
  • lack of pest management tools and technologies and insufficient communication and
  • extension support across growing regions.

Seven of the 26 products registered in 2006 have been either discontinued, phased out or proposed for phase out for use on greenhouse ornamentals. These include organophosphate such as: endosulfan, acephate, and the carbamate bendiocarb. Through Minor Use Pesticides, four new products have been registered for use, and through Pesticide Risk Reduction, 3 new biopesticides were made available to Canadian growers. In 2006, just two biopesticides (Bt products) were available. There are now 6 available, of which 2 were supported through this strategy. Labels overall have become more general, with more labels listing “greenhouse ornamentals”, increasing the numbers of registered uses included with new registrations.

Growers now have increased access to biopesticide products and some non-chemical management approaches. Growers also have increased support for implementing biological control and integrated pest management through training resources such as grower workshops, and an integrated pest management website. Specific tools and solutions supported under this strategy are summarized in Table 2.

Challenges remain for the industry, including many outside the scope of Pesticide Risk Reduction. Products, both conventional and biological, can cease to be available to Canadian growers as a result of de-registration (seven products are currently under re-evaluation), a lack of support by the registrant, changes in ownership, or no availability of source material. Current application technologies still need to be improved and new invasive pests continue to threaten the industry. While online resources can provide timely and widely accessible information to growers, they only remain useful if a long term financial commitment is made to maintain and update the content.

Strategy outcomes

The major outcomes from the implementation of the reduced-risk strategy for greenhouse floriculture include:

  • Priority pest management issues identified by the GH floriculture industry and defined areas of research and priorities for the sector to pursue.
  • Improved access to more reduced risk products for the control of pests in greenhouse floriculture production.
  • New and consolidated knowledge on reduced risk approaches such as treatments for propagative stock and compatibility of biological control agents and pollinators with chemical modes of management
  • Improved access to high quality IPM information, resulting in an increased number of growers informed about integrated pest management, including biological methods, via targeted workshops for crop-pest management and online resources.

It is anticipated that in combination, these outcomes will help greenhouse floriculture growers reduce reliance on chemical pesticides while remaining an economically competitive industry.

Table 2 - Solutions developed through the strategy

Solutions Pesticide risk reduction mechanism Applicable Greenhouse crops and pests Potential for adoption: Total crop area or total number of plants Additional benefits/comments
Contact and residual toxicity data of fungicides on greenhouse beneficial insects and mites Protection of beneficial/biocontrol organisms All greenhouse crops and relevant pest issues greater than 7,833,000 square meters of greenhouse area This project’s results are applicable for both greenhouse vegetable and greenhouse floriculture.
Information on potential methods of controlling pests in a reduced risk method on greenhouse floriculture cuttings Avoidance of pest pressure and reduction in chemical pesticide use Pests of propagative stock (including: thrips, aphids, scales, mealybugs, leafminers, mites, and lepidoptera) greater than 99,044,000 cuttings grown in Canada, and any additional imported Information from this literature review provided a baseline of information to pursue reduced risk methods of mitigating pest introductions into the greenhouse.
Registration of Met52 Granular Bioinsecticide, submitted use of for SuffOil-X Reduction in chemical pesticide use Thrips in container grown ornamentals greater than 7,833,000 square meters of greenhouse area, where plants are grown in containers Met52 granular is currently unavailable.
A trap plant system for the control of western flower thrips in chrysanthemum greenhouses Avoidance of pest damage Western flower thrips on chrysanthemum greater than 33,562,000 cut chrysanthemum Trap plant systems, and related banker plant systems are now being used across Canada in both ornamental and floriculture production.
A website containing up to date information regarding IPM systems in floriculture greenhouses Increased likelihood of IPM being adopted All greenhouse crops with whitefly issues greater than 7,833,000 square meters of greenhouse area This website was updated through external funding in 2015 to include IPM information on thrips, in addition to information previously available for whitefly.
IPM Workshops for Greenhouse Floriculture in Ontario and British Columbia Increased likelihood of IPM being adopted All greenhouse crops and relevant pest issues greater than 5,451,000 square meters of greenhouse area (BC and Ontario) These one-time workshops provided an opportunity for growers to interact directly with pest management researchers and professionals.
Three videos demonstrating biological techniques for the control of whitefly in the greenhouse Increased likelihood of IPM being adopted Whitefly on poinsettia greater than 7,222,000 potted poinsettia These videos are available on the website: