What is IPM and why is it necessary?

IPM employs a range and combination of pest control practices and measures, including chemical, cultural, mechanical and biological applications. Pests include weeds, insects and diseases that may damage or compete with barley plants.

Using IPM along with an integrated crop management plan provides farmers with an opportunity to manage multiple crop issues. It can also prolong the usefulness of sources of disease resistance and lower the risk of herbicide/fungicide or insecticide resistance. 

The ultimate goal of IPM is to effectively reduce the impact of pests to ensure a crop is profitable. IPM is also important to the long-term sustainability of the agriculture industry. Overreliance on just one pest control method, such as resistant crop varieties, herbicides, or fungicides can cause pests to adapt and become resistant to that control method. This can be detrimental for all farmers. IPM can also have economic and environmental benefits for farmers, as it helps reduce the amount of pesticide use required.

When is IPM needed?

Although IPM refers to a more holistic approach than simply pesticide use, there are two calculations farmers can use to determine the level of pest presence you need to control to still have a profitable crop, and how much money you should spend on pest control before it’s no longer profitable. 

Determining the level of pest presence

Action threshold
The pest presence that must exist in your crop before control methods are required in order to avoid economic loss.
Economic threshold
The point at which the cost of pest control is equal to the value of yield loss if the pest is not controlled.

Employing effective IPM practices

Effective IPM begins with analysis of pest problems in your own crops. This requires regular monitoring in order to gauge the levels of weeds, diseases and insects that affect your crops and also levels of beneficial organisms such as bacteria, which can help with pest management. Take counts, samples and measurements while monitoring your crops, so that you have reliable data to work with and to keep on record for future years.

To effectively use IPM to target a crop production problem, it is critical to correctly identify the cause of these concerns. Unfortunately, misdiagnosis of a field issue can lead to the unnecessary use of inputs. Moreover, the true underlying cause of the crop production issue may not be resolved and it can continue to affect subsequent crops. To best analyze your crops, it’s also important to become familiar with the stages at which crops are susceptible to damage.

Weather monitoring is a good way to predict pest cycles and plan control methods. This information, combined with the outcome of your action threshold and economic threshold calculations, will help you plan some parts of your overall IPM approach. You should also talk to your agronomist, local Ministry of Agriculture office, and grain buyer for further direction. Once you have determined that action is needed, there are several options for pest control. IPM requires a combination of multiple types of these controls.

Chemical applications

This type of control method involves the use of pesticides and other chemicals for pest control. When using chemicals, it’s important to make sure that the product you are using is the correct treatment for your specific type of pest and will not harm any beneficial organisms in your crops. It’s also important to use the correct rate and timing, as per the label, and to follow the label instructions carefully. Also be aware that different countries have different rules for maximum residue limits (MRLs), therefore if your crop is intended for export, always talk to your buyer/exporter, chemical rep, before using any chemicals on your crop.

Finally, always ensure that you are not using just one chemical mode of action and control measure over the course of any one growing season. Also ensure that you are rotating your chemical active ingredients for fungicides, herbicides and insecticides. Avoiding the overuse of a single chemical mode of action is crucial in preventing or slowing the development of resistance. Research into the benefits of early fungicide applications on the Canadian Prairies is ongoing. However, the nature of the fungicides we use, the key parts of the plant in terms of grain filling and yield, and the shorter growing season can sometimes be barriers to their effectiveness. In contrast, early weed removal with herbicides is known to be an important part of an IPM strategy.

Cultural control

This type of control method begins with choosing good varieties.

Crop varieties are continually being bred for disease and insect resistance so stay on top of your knowledge of new options and choose varieties that have high levels of resistance. Cultural control methods also involve agronomic practices, including:

  • determining the best timing and environmental conditions for applying all your agronomic practices
  • in some cases, early application of herbicides and fungicides can be beneficial
  • using crop rotations to reduce favourable pest conditions and reduce pathogen levels within fields
  • using adequate seeding rates to ensure that crops are competitive against weeds
  • using proper seed row spacing for cereal crops, based on the soil disturbance, nitrogen placement, and seed bed utilization
  • employing sanitation methods such as using clean, treated and disease-free seed and cleaning all farming equipment thoroughly between fields, in order to prevent the spread of soil-borne pathogens and weed seeds