Integrated Pest Management (IPM)

Integrated pest management (IPM) is an approach to managing pests that uses all available strategies to reduce populations below an economic injury level. IPM does not advocate a continuous pesticide spray program to eradicate pests. Instead, it promotes the integration of cultural, mechanical/physical, biological, behavioural and chemical control strategies. With IPM, adverse effects of pesticides are minimized, and economic returns are maintained.

An IPM program makes management decisions based on:

  • pest identification, biology and behaviour
  • pesticide resistance management strategies
  • beneficial organisms
  • monitoring techniques
  • use and timing of appropriate management tools
  • stage of crop growth
  • record keeping
  • sprayer calibration

Pest Management Tools

Cultural and Mechanical/Physical

Integrated pest management incorporates cultural and mechanical/physical practices to prevent or delay the development of pest outbreaks. Follow or use these cultural and mechanical/physical management practices or tools where applicable for your cropping system. The list is not exhaustive as it is highly dependent on crop and pest:

    • Site selection — Choose sites less favourable for pest development. Avoid planting in poorly drained locations. Plant rows to facilitate increased air movement through the crop based on the predominate wind direction in your area.
    • Resistant/tolerant cultivars — Select cultivars less susceptible to disease or insect pressure.
    • Clean, certified nursery stock or seed — Use nursery stock or seed tested and determined to be free from virus and bacteria, as well as grown according to guidelines that minimize the presence of other pests.
    • Sanitation — Chop and plow under or remove and properly dispose of all sources of pests, such as cull piles, dead/dying plants and plant parts, and mummified or dropped fruit from the crop or field. This can also include roguing out infested plants throughout the growing season.
    • Elimination of alternative hosts — Maintain good weed control and eliminate wild hosts from within and adjacent to the crop. They can act as alternate hosts for many pests. In some crops, good weed control can also promote air movement and facilitate drying of the leaves and fruit.
    • Encouraging natural enemies of crop pests — Modify insect habitat through the introduction of cover crops, border crops or naturalized hedgerows to promote beneficial organisms.
    • Pruning and Training — Remove infected plant material to reduce pest pressure. Manipulate the canopy to improve air movement within the canopy to facilitate drying and to improve spray coverage.
    • Water management — Timely irrigation can reduce plant stress during drought and increase plant tolerance to pests. Use trickle irrigation or schedule overhead irrigation so that plants are not wet overnight or for a prolonged period of time.
    • Nutrient management — Avoid excessively lush growth, which is more conducive to some diseases and more attractive to some insect pests.
    • Avoid crop injury — Minimize damage to the crop from equipment like cultivators or phytotoxicity from herbicides as these wounds may allow bacteria to gain entry to the crop.
  • Crop rotation – Between planting new crops, rotate to a non-host crop to break the pest cycle. This can help reduce the level of plant pathogens (e.g., fungi, oomycetes, nematodes) that remain in the soil or on crop residue left in the field. Rotation with non-susceptible (non-host) crops for 3 years usually allows enough time for infected plant material in the soil to completely decompose. In the absence of susceptible plant material, these soil-borne pathogens die off. For some soil-borne pathogens, such as the causal agent of clubroot, a rotation longer than 3 years may be required.
  • Inter-cropping – Use non-host crops planted in close proximity as a barrier to insects and diseases. Avoid inter-cropping plants with similar pest complexes.
  • Barriers – Barriers, such as row covers, screening and exclusion netting, are used in some crops to keep out certain insects and birds. It is important to maintain airflow in the crop in order to reduce the favourable environment for diseases.



Biological control uses beneficial organisms to help suppress pest populations. These biological control agents may be predatory insects, parasites, pathogens or nematodes. Many beneficials occur naturally in the environment (natural enemies); others may be introduced.

Beneficials may not completely eliminate damage by pests. However, once they are established, they can maintain pest populations at lower levels. They are generally effective against indirect pests such as aphids, leafhoppers and mites, but may be less effective at keeping populations of direct pests, which attack the harvested product, at levels acceptable for commercial production. Important insects and mites for biological control include ground beetles, mullein bugs, minute pirate bugs, lacewings, lady beetles and predatory mites.

Natural pathogens of insects and mites include bacteria, viruses, fungi and protozoa. Pathogens circulate naturally in insect populations. Under the right conditions, they can cause disease outbreaks in insects, which can significantly reduce insect populations. Aphids and caterpillars are routinely infected by cycles of viral or fungal disease, which thrive when the environment is moist.

Follow these practices to conserve and encourage beneficial insects in

fruit crops:

  • Avoid use of pesticides that are toxic to beneficials in a cropping system. Toxicity information regarding beneficial insects is available on some pest control product labels.
  • Encourage a diverse habitat within and/or around the perimeter of the crop where beneficial insects can live. Small flowering plants are an important food source for parasitic wasps.
  • Avoid ultra-clean cultivation. Crop residue, mulch or ground cover will encourage ground beetles and other important predators found at the soil surface.

For additional information on predators and parasitoids, see Ontario

CropIPM at, OMAFRA Publication 208, Predatory

Insects in Fruit Orchards or the Great Lakes Vegetable Working Group website at


Behavioural control uses a pest’s natural behaviour to suppress the population. Mating disruption, bait trap/crop and sterile insect release are types of behavioural control used in agriculture.

The most commonly used behavioural control in orchard and vineyard systems is mating disruption. Managing insects using mating disruption is very different from using insecticides. Mating disruption products are highly specific, targeting a single or few very closely related insect pests. These products release large quantities of synthetically produced sex pheromone into the cropping system, which confuses males and interferes with mate location. They do not kill the target pest, nor will they control immigration of mated females from untreated or poorly managed areas.

For more information on using mating disruption, see OMAFRA Factsheet

03—079, Mating Disruption for Management of Insect Pests. Mating disruption products are pest control products and must be registered by the Pest Management Regulatory Agency for use on a specific crop and insect combination.


Chemical controls include synthetic, inorganic, botanical and biological (biopesticides) pesticides. They kill/inhibit development of target pests and thus limit subsequent pest populations. Plant defence activators (e.g., phosphorous acid, Regalia Maxx) induce natural plant defences against crop pests, but do not directly impact the plant pathogen itself. Applications of plant defence activators to crops may “activate” the defence response of the plant, thus inhibiting infection.

Chemical controls are important tools for crop protection when used as part of an IPM program. Understand the pest’s life cycle and apply chemicals at the stage when the pest is most vulnerable or before the pathogen has infected the plant. Select the appropriate product for the target pests.

Use caution when using pest control products that may be toxic to bees, other insect pollinators and biological control (biocontrol) agents. Always read the most current pesticide label for guidance. Some pesticides cannot be used when bees are active in the crop.

To control insects and mites, monitor fields or blocks closely. Spray according to action thresholds, degree-day timing (see Degree-Day Modelling below) or at critical stages of crop development.

To control disease, apply fungicides prior to disease infection and development. Use factors such as weather conditions, crop stage and (where available) disease prediction models  (see Disease Prediction Models below) to assist in fungicide spray timing.


Consider incorporating biopesticides into your IPM program. When used as part of an IPM program, biopesticides can reduce the use of conventional pesticides.

Biopesticides are pesticides made from natural materials such as animals, plants, fungi, bacteria, viruses, and certain minerals. Generally, biopesticides:

  • are inherently less toxic than conventional pesticides
  • target specific crop pests, and
  • don’t persist in the environment.
Types of Biopesticides
  • Microbial biopesticides contain naturally occurring or genetically altered microorganisms such as bacteria, fungi, viruses, or protozoans. An example of a microbial biopesticide is Virosoft CP4 (PCPA Registration No. 26533), which contains the codling moth granulosis virus. It can be sprayed on apples to infect and kill codling moth larvae. Other examples of microbial biopesticides registered for use in various crops include Bacillus subtilis (e.g., Serenade SOIL) and the various subspecies and strains of Bacillus thuringiensis (e.g., Bioprotec).
  • Semiochemical biopesticides are chemicals that change pest behaviour. For example, insect sex pheromones are used to cause mating disruption of pests. One example is Semios OFM Plus Insect Sex Pheromone (PCPA Registration No. 31718). It causes mating disruption of oriental fruit moth in stone and pome fruits.

Non-conventional biopesticides are substances that are being used for other purposes, such as food or fertilizer. For example, canola oil is the active ingredient in Vegol Crop Oil, PCPA Reg. No. 32408, and is registered to control pests and diseases on various crops. Another example is Confine Extra Fungicide, PCPA Reg.

Organic Pest Control Products (Pesticides)

Organic pest control products are pesticides that are approved for use in organic production. For organic products, both the active ingredient and all additional ingredients must be derived from natural sources (typically biological or botanical).

All organic pest control products must be registered by the Pest Management Regulatory Agency (PMRA) for the pest and crop on which they are used; and, meet the requirements of the Canadian Organic Standards and any additional requirements of the local organic certification body.

While many biopesticides are used in organic production, it is important to be aware that not all biopesticides are organically acceptable and that not all organic products are biopesticides. In some cases, the active ingredient may be organic, but it may be formulated with other ingredients that are not acceptable for organic production (e.g., some formulations of the bacteria Bacillus thuringiensis). Similarly, there are organic pest control products that do not meet the definition of a biopesticide (e.g., copper is a mineral and not considered a biopesticide).

Several organic certification bodies serve Ontario farms and processors. Contact these organizations to get information on how to be certified. For more information on certification, as well as addresses and links to details of the organic regulations and standards, see the Organic Food and Farming Certification at

Degree-Day Modelling

Temperature, light and moisture affect the growth and development of plants and pests. Of these, temperature is the most important factor for insect and mite development. These pests need a certain amount of heat to move to the next development stage.

The amount of heat required for insect and mite development remains constant from year to year, but depending on weather conditions, the amount of actual time that it takes to complete development can vary.

Insects and mites have a minimum and maximum base temperature below or above which development does not occur. These base temperatures are different for each organism.

Degree-Days Celsius (DDC) are used to estimate the growth and development of pests in the growing season. Events such as egg-laying, egg hatch, movement of crawlers or the occurrence of disease infection can be predicted and used to schedule inspection and spray programs.

There are several methods used to calculate DDC, but the method commonly used with simple monitoring equipment is the averaging method or “max/min” method. DDC for a given organism are calculated as follows:

DDC = (Daily max °C) + (Daily min °C) / 2 – minimum base temperature


Degree-Days Celsius are accumulated daily. The averaging method works well in most years. However, the actual DDC accumulations may be underestimated in extended periods of cool weather or overestimated in hot weather.

An example of the averaging method on a relatively cool spring day:

For a given pest:

Lower base temperature = 10°C

Upper base temperature = 35°C

On a given day:

Minimum temperature = 5°C

Maximum temperature = 15°C

Degree-Days Celsius (DDC) for that day is = (maximum + minimum

temperature) / 2 – lower base temperature = (15+5) / 2 – 10 = 0 DDC

Note that the maximum temperature was higher than the base temperature for the insect, so growth and development were possible for at least part of the day. However, no DDC were accumulated. This illustrates how cool temperatures, especially over several days, could lead to an underestimation of insect development.

Degree-Days Celsius are either accumulated from a set start date, such as April 1, or from a specific event known as a biofix. A biofix is a biological event or indicator of a developmental event, that initiates the beginning of DDC calculations. A common biofix used for insects is the first sustained catch in pheromone traps. Using a biofix provides predictions that are more accurate and requires tracking temperatures over a shorter period.

There are several limitations to degree-days models:

  • Factors such as humidity, light intensity, leaf wetness and rainfall also affect pest development. As a result, DDC predictions are only estimates of pest development. Verify these predictions with field observations.
  • Temperatures used to determine DDC must represent the environment where organisms develop. Use weather data collected from within a mile or less of the actual orchard or field being monitored. Site specific information can be obtained by using data loggers. Ventilated heat shields should be used with data logger temperature sensors to ensure accurate air temperatures. Place data loggers at locations within the crop canopy where the pest is normally active.
  • DDC models have been developed and validated for only a few fruit pests in Ontario. Use precise temperature data measured on or very close to your farm for the best estimate of the development of these pests.
Table showing examples of degree day models used in fruit crops

Disease Prediction Models

Disease prediction models utilize environmental data collected from an onsite weather station (where available) and a network of weather stations across a specific growing area. Often, disease prediction models also require input on the crop stage since some diseases only occur at susceptible plant stages (ex. blossom fire blight in apples and pears). Depending on the disease, the weather variables include factors such as daily average temperature, precipitation, leaf wetness and relative humidity.

In some models such as TOMCAST, weather data is used to calculate disease severity values (DSVs) throughout the growing season. Growers are advised to spray when a critical number of DSVs have accumulated once the crop is susceptible or since the last fungicide application. The rate of DSV accumulation and the spray thresholds vary based on the crop and the specific model.

Some examples of disease prediction models that are applicable to Ontario growers are:

  • BEETCAST for Cercospora leaf spot in sugarbeets
  • BOTCAST for botrytis leaf blight onions
  • BREMCAST for downy mildew in lettuce
  • DOWNCAST for downy mildew in onions
  • TOMCAST for early blight, Septoria leaf spot and anthracnose in tomatoes
  • Cougar Blight for apples and pears
  • Maryblyt for apples and pears

A predictive model is also used for downy mildew in cucurbit crops across North America. This model tracks the development of the disease in the various cucurbit growing regions. It then uses weather forecasts to predict the spread of the disease from areas with known infections into other growing regions. For more information, visit the ipmPIPE website at:

In Southwestern Ontario, Weather Innovations Incorporated (WIN) offers TOMCAST and BEETCAST programs to tomato and sugarbeet growers. For more information contact WIN at 519-352-5334 or see their website at

The University of Guelph, Muck Crops Research Station also offers a number of disease prediction models for growers in the Holland Marsh region. For more information, visit their website at:

Growers are encouraged to establish and maintain their own on-farm weather station for the most accurate weather data. Software for many of the disease prediction models is often available for purchase from the manufacturers or distributors of weather monitoring equipment