Fundamentals of IPM
You may hear the term “IPM” used by a landscape professional and assume that it simply means choosing the right pesticide to apply for carefree pest control, but the concept of IPM is a much more nuanced approach that emphasizes pest prevention and prioritizes research-based practices to promote ecological health while managing a target pest population.
IPM is an abbreviation for Integrated Pest Management, which is defined by the United States Environmental Protection Agency as, “an effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices.” Pests are broadly defined as insects, plants, diseases and even animals that hinder the health and productivity of a plant. Humans often want to manage one or more pests in a particular setting to maximize our perception of health for that setting. For example, vegetable gardeners may find caterpillars undesirable on their cabbage and broccoli plants, fruit growers may want to keep tissue fungal diseases under control, and turf managers may want to prevent weed infestations in a lawn. Each of these examples involves different expectations and will require different strategies to diagnose, evaluate and control pests.
The first step in IPM is to understand the pest and its lifecycle. If you were to notice evergreen needles covered in small whitish ovals on your evergreen shrubs, how do you remedy the problem? How do you even know if you should address it? To do this you must identify the plant and the pest that is causing the symptoms you’re observing. Using knowledge as the foundation of IPM, you can determine that pine needle scale is invading your pine shrubs. From there, you can learn more about scale insects and anticipate how they will interact with your landscape.
Severe Scale Present on a Pine | Photo Dustin Wolff
Once identification of a pest is complete, a decision-making process comes next. How serious is the damage and is the problem getting worse? Is it worth treating and is it appropriate and cost-effective to do so at this stage in the pest’s life cycle? Depending on the preferences of the plant owner involved, the type of plant and its setting or use, and the resources available to manage the pest, the answers to these questions may vary greatly. A home vegetable gardener will probably tolerate cosmetic damage due to a pest differently than a commercial grower bringing products to market. The outcomes of decision making will inform how to begin controlling the pest effectively, if at all – many times no management is an option!
Apple Scab Lesion | Stock Photo
Control is the third stage of IPM and it can take different forms depending on the severity and life stage of the particular pest involved. The IPM philosophy implies that pest control minimizes hazards to people and the environment, so usually one or more non-chemical management tactics are used to prevent or exclude a pest issue before it rises to the action threshold established during the decision-making process. Each of the general control approaches is broken down below.
Cultural control: These tactics are actions that humans take on the landscape to encourage healthy plants and reduce pest establishment and survival. For example, dense stands of turf grass can prevent opportunistic weeds from establishing in lawns. Cultural strategies to boost the vigor of the lawn include irrigating, fertilizing, setting proper mower height, aerating and overseeding to encourage the growth of healthy desirable grasses.
Physical control: Also known as mechanical control, this method is time intensive and can be impractical for large spaces. Hand picking, traps, crop covers, fencing, pruning, water sprays, and hazing devices are all examples of physical management that can prevent or exclude pests from plants. To be effective, physical efforts require active monitoring so that intervention can occur at the first signs of the pest before it overwhelms the success of these strategies.
Biological control: Some pests can be managed by taking advantage of natural predators, parasites, or diseases that ordinarily occur in conjunction with the target pest. These natural enemies of pest species often hinder the pest from maturing or reproducing.
Chemical control: Sometimes all other management tools have been exhausted and chemicals are the last resort to deal with a pest problem. In those cases, herbicides, pesticides, fungicides or antibiotics can be judiciously applied following all product labeling to ensure effectiveness and safety. Proper care must be taken to make certain that the chemical(s) are labeled for the target pest and for the type of plant the product is to be used on. Finally, application at the right life stage of the target pest will produce the best results.
The process of IPM doesn’t end once a control measure has been applied. It is important to continue monitoring the landscape for signs and symptoms of a pest problem so that any recurrence or new invasions of other pests can be dealt with appropriately.
Citations and links
“Integrated Pest Management (IPM) Principles.” United States Environmental Protection Agency, 26 Aug. 2021