Integrated Pest Management or IPM can be thought of as the approach to control pest issues by identifying and understanding the pest, monitoring and when necessary, using a variety of methods to limit plant damage, meanwhile remaining economical and environmentally safe. IPM is used for controlling weeds, insects and diseases in plants and animals. The six elements to having an IPM strategy are prevention, identification, monitoring, action threshold, management options, and evaluation.
Prevention is the first element, although it is difficult to completely prevent most pests, using many of the management options can reduce the risk of having to control the pest.
Identification is the next element and is used once a pest has been noted. Identifying the pest occurs by examining the features. If the pest is an insect, you would identify the insect and its life stage. A couple of examples of insects include, the Colorado potato beetle in potatoes or cucumber beetle in cucurbits. Life stage and crop stage are important to knowing what may control the pest or if it needs to be controlled. This would be used in the action threshold element.
Action threshold (or economic threshold) would be identified by quantifying the pest (ex. number of insects per plant, number of infected leaves per plant and foliage area affected, number of weeds and weed size/stage) and when the management option is equal to or less than the damage that is occurring from the pest. Action potential also considers beneficial pests like ladybug beetles that will eat harmful insects.
Management options is the next step to a proper IPM strategy. Management options include cultural, mechanical or physical, biological, genetic, and lastly chemical control. Chemical control is considered the last option if all other methods cannot control the pest. Cultural methods we use are crop rotations, sanitization, mulching, plant density control to create shading, and purchasing disease free inspected seed. Mechanical and physical methods we use are cultivating, removing harmful pests by hand (hoeing, hand harvesting harmful insects), not walking or driving through plants unnecessarily when foliage is wet, and irrigating and fertilizing to reduce plant stress. Increased stress in plants can lead to easier pest damage. A great example is sugar content in plants, higher sugar contents deter most harmful insects from feeding and attract beneficial insects. Whereas a low plant sugar content will make feeding more enjoyable for harmful insects. Biological methods that we use for managing pests would be keeping an active count on beneficial insects to use those insects to our advantage to control unwanted pests. Another biological method we use is root inoculants to increase microbial activity in the soil to increase nutrient uptake and plant health. We commonly use genetic management tools to reduce disease pressure in plants. This is done by selecting varieties that have some level of resistance to certain diseases like Powdery Mildew, Bacterial Leaf Spot, Early Blight, Anthracnose, and many more. Many varieties are somewhat resistant to multiple diseases and we use this to our advantage. Lastly is chemical control, this is used when all other methods have failed to control the pest. Chemical controls can be organic and non-organic. By managing crop pests by using the other management tools often reduces or eliminates the use of pesticides. Diseases like cucurbit downy mildew (CDM) do not overwinter in Ontario, therefore it is not a disease issue early in the growing season. By utilizing online tracking of cucurbit downy mildew spread across the US, disease forecasts, and understanding weather patterns, fungal pesticide applications to prevent CDM can be eliminated until risk is evident. If pesticides are applied, they are done so in accordance with the label which is regulated by the Health Canada Pest Management Regulatory Agency (PMRA).
