Controlling Pests in Cannabis Cultivation Using Integrated Pest Management

Learn about the four primary elements of IPM programs: defining action thresholds, monitoring and identification, prevention, and control; the numerous control approaches; and how climate control systems enable indoor cannabis growth while also managing pests like mold and mildew.

Learn about the four primary elements of IPM programs: defining action thresholds, monitoring and identification, prevention, and control; the numerous control approaches; and how climate control systems enable indoor cannabis growth while also managing pests like mold and mildew.

An integrated pest management (IPM) plan is required for pest monitoring, prevention, and control in cannabis growing. Pest scouting can be done by humans or by software. Plant productivity can be increased while pesticide treatment is reduced using a mix of eye inspection and computer vision. Furthermore, high-performance heating, ventilation, cooling, and dehumidification (HVACD) systems help keep insect populations at bay by maintaining target environmental conditions. To reduce outbreaks, you can utilize techniques like filtration, light treatments, and photocatalytic oxidation. IPM principles can benefit your crop regardless of how you farm, and HVACD solutions can be a part of your IPM plan.

Controlling Pests and Microbes: Strategies

Pest damage to crops is costly, but it may be avoided. You can keep pests out from the start and stop outbreaks in their tracks with good planning. Many pests have an impact on cannabis production facilities and must be managed in indoor, greenhouse, or outdoor settings. They are divided into three groups:

  1. Thrips, whiteflies, spider mites, and aphids are examples of insects and arachnids.
  2. Snails and slugs are mollusks.
  3. Bacteria, fungus, nematodes, and viruses are examples of microbial creatures.

To avoid and control pests, growers can employ a variety of measures, including cultural, physical, biological, and chemical methods. Integrated pest management (IPM) is a method of preventing or suppressing destructive insect pests by using a combination of control strategies in a coordinated and integrated manner.

There are four major components to integrated pest management (IPM) plans:

  1. Setting action thresholds
  2. Monitoring and identification
  3. Prevention
  4. Control

Operational efforts that create action levels and processes to follow kick off the “clean culture.” Consider the flow of your plant’s processes. Keep track of your progress in relation to your goals.

Set up quarantine procedures for sick plants. Prevent pest outbreaks by providing high-quality training and established methods, as well as risk mitigation through management strategies. Pest populations or environmental circumstances reach action thresholds, indicating that pest control action is required. For example, you must evaluate if seeing one or five spider mites necessitates taking action. Define the point at which pests become an economic danger in your standard operating procedures so that your team can make better pest control decisions in the future.

Identification and Monitoring

Determine which creatures must be controlled. Pesticide misuse is prevented by monitoring, and incorrect identification stops you from using the wrong pesticide. The sophistication of pest scouting methods varies. Growers can employ digital technologies to photograph plants and utilize computer vision to discover and report abnormalities, or they can use human staff to visually inspect plants.

Every grow operation should always do a visual examination by human workers to cross-check reports generated by digital systems. Inspect incoming plants, use indicator plants, and keep track of and evaluate scouting information with sticky cards on a regular basis.

Competitive growers use a combination of eye inspection and computer vision to maximize plant yield while reducing pesticide use. To be everywhere at once, computer vision combines artificial intelligence, robotics, and high-resolution photography. Using computer vision technology for indoor agriculture has three major advantages:

  1. Plant health – Artificial intelligence (AI) can detect diseases and measure photosynthetic health by comparing massive data sets of images against photographs of your plants day after day.
  1. Large data sets of parameters like CO2, fluid flow, fluid pressure, temperature, and others can be used to highlight defects in your systems in addition to direct sensor readings.
  1. Large data sets representing the plant’s life experience employing grow room settings such as light levels, temperatures, and humidity are used in system optimization. Growers can utilize this data to improve the system’s performance for any cultivar.

Methodologies for Pest Control

There are four main methods for prevention and control. Starting with cultural control, the IPM triangle moves from prevention to intervention, creating an environment where plants thrive and harmful bugs don’t.

For starters, cultural tactics can be profitable, cost-effective, and have no negative consequences for people or the environment. Cultural control is the core of any complete IPM plan, as it is environmental control. It is the oldest IPM technology, according to Jesse Porter of Inspire Transpiration Solutions, but it was mostly abandoned with the advent of chemical pesticides. However, there has been increasing interest in cultural control as a result of customer desire for more reliable, clean, pesticide-free cannabis.

Physical control tactics, on the other hand, include traps, obstacles, HVAC system operations such as filtration and ultraviolet (UV) light treatments, and farmers physically removing pests.

Third, biological control enlists the assistance of beneficial insects and bacteria. Trap plants can attract pests to your crops or serve as testing grounds for useful biological controls, while banker plants raise beneficial parasitic insects and habitat plants provide food for the natural enemies you use to combat pests. Guardian plants attract pests, feed beneficial insects, and allow pests to interact with the biological controls you use in your grow rooms.

Chemical treatments, as a final level of management, use agents that are toxic to insects but not to your plants.

Pest Management HVAC Systems

The transmission of infections can be slowed or sped up depending on the environmental conditions within each culture site. The impact you can have on microbial sporulation, pest mating cycles, and the efficacy of your IPM sprays is determined by the accuracy with which you can control temperature, humidity, and airflow. Sulfur, for instance, is more effective in high-humidity situations but becomes phytotoxic in high-temperature circumstances. Another example: colder temperature setpoints cause spider mite populations to enter diapause, which slows eating and reduces plant damage.

Indoor cannabis grow rooms are usually compact places with a lot of HVACD equipment. High-efficiency HVAC systems can help you implement your IPM plan’s preventive and control tactics. Pest control requires careful selection of HVACD system components, since HVACD equipment designed specifically for growing and drying can protect plants by maintaining ideal environmental conditions.

To sustain conditions during the difficult transition period between lights on and lights off, integrated machines with controls that track environmental variables to manage cooling, dehumidification, and heating demands simultaneously are crucial. For years, powdery mildew and botrytis (root rot) have plagued cannabis growers. Inconsistent maintenance of target environmental setpoints during the lights off time is a primary contributor to these outbreaks. Your cannabis continues to transpire at a high pace for 45–90 minutes after the 12-hour blooming lights on period ends.

Relative humidity is directly affected by air temperature, and when the lights are turned off, temperatures drop. Temperature spikes and pest vectors are formed in your grow rooms if proper heat is not given by HVACD equipment when the lights are turned off. These plant challenges will occur on a daily basis without quality controls, sensors, and HVACD components that can modulate to handle dynamic situations. Plant vitality, yield, and quality suffer as a result. Closely monitoring and managing supply air to zones ensures that your systems correctly harness the capacity of HVACD equipment to achieve IPM goals.

By properly constructing and maintaining your HVACD system, you may avoid it becoming a source of pests. “Anaerobic water can be a vector for water molds due to the amount of dehumidification required for cannabis growing.” “Evaluate drain pans, ducting, and HVACD system condensate lines on a regular basis to prevent the spread of fungal diseases that are harmful to cannabis cultivation,” Porter advised.

Consider effective, less dangerous pest controls initially, such as mechanical controls like traps or weeding, or highly targeted chemicals like pheromones to interrupt insect breeding, when picking control measures for your IPM plan. Additional pest management measures can be used if employees continue to monitor and detect pests and action thresholds suggest that less hazardous remedies aren’t functioning. Filtration, UV light treatments, and photocatalytic oxidation are the best mechanisms recommended by RII’s Technical Advisory Council for controlling insect outbreaks. For your IPM strategy, consider adopting multistage techniques.


Filters are a type of physical pest control that can keep pests and diseases out of your air streams and out of your grow rooms. The ANSI/ASHRAE Standard 52.2-2017, a testing procedure that assigns a number from 1 to 16, is used to rate filters. Cannabis growers are urged to use MERV 13 filters as the first line of defense against physical pests.

Light Treatments for Pest Management

UV light can be employed as an IPM technique in three different sections of mechanical systems that serve indoor cannabis facilities: cooling coils, air ducts, and the environment employing upper-air UVC lights.

When compared to other UV treatment procedures in the developing environment, cooling coil surface treatment may have fewer effects and focuses on the wetted coils within the HVAC equipment. “UV directed at the cooling coils offers an alternative to mechanical and chemical cleaning of the coils because the air moves swiftly within the cabinet and the effectiveness of UV lighting is reliant on both time and intensity,” said Craig Burg of Desert Aire. “The wetted coils are almost always chilly in indoor plant conditions, and there is a constant flow of condensate.” This prevents germs and biological pollutants from growing on coils.” Examine polymeric materials such as plastics in air-handling equipment and ducts for compatibility, as they may degrade when exposed to extreme temperatures.

In-duct UV disinfection cleans the air and increases the rate of airborne microorganism disinfection. To allow for more exposure time as the air travels through the lights, high-intensity UV tubes are often placed lengthwise down the duct.

Upper-air UVC fixtures are identical to in-duct UVC fixtures, but they are installed in the room, usually high on the walls. Because air travels slowly through the fixtures, germs are exposed for longer periods of time.

It is critical to take precautions to manage human exposure to UV radiation, both direct and reflected, for all three approaches. “Implement proper shielding to guarantee that both humans and plants are not exposed to UV radiation,” Burg advised, “and consider installation, servicing, and operation.” When humans are exposed to UV, it has serious health consequences.

MERV 13 captures pests with a diameter greater than 1 meter, however photocatalytic oxidation processes can kill smaller pests. Photocatalytic oxidation, which combines UVC irradiation with a titanium dioxide catalyst to react and shred malignant pollutants into water, carbon dioxide, and innocuous by-products, is another application of UV light therapy.

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