Integrated pest management

Understanding how to manage pests with decreased chemical options is becoming important. Deregulation and insecticide resistance is growing, but few new nodes of actions to tackle these issues are on the horizon.

Using Integrated Pest Management (IPM), the comprehensive approach to controlling pests while minimising environmental impact, is essential for food producers. Insecticides will continue to play a role, but we will need to be used more strategically for the benefit of the environment, food safety, and maximising 
crop returns.

Key IPM principles include:

• cultural practice
• mechanical control
• companion planting
• biological control
• targeted chemical control.

Implementing practices that do not rely on insecticides, puts you in a better position to manage the chemical options more effectively. For example, flowering lucerne can be a food source for white butterflies that may lay more eggs on nearby brassica crops. Timing lucerne cuts and flowering events to avoid peak butterfly activity can help manage this risk, allowing beneficial insects to keep pest levels in check with a lower level of pest pressure.

Here is how these practices work in an on-farm setting:

Cultural practices: Crop rotations can disrupt pest lifecycles. For instance, green bridges increase the risk of aphid infestations in subsequent cereal crops. Rather than using forage oats as a break crop or part of a multi-species mix between cereal crops, opt for annual grasses instead to help prevent aphids from overwintering.

Mechanical control: Cultivation is one method of mechanical control. By cultivating a paddock, you remove trash and dead matter from where insects can harbour until the next crop is planted. While this does not eliminate all risk, it improves your odds.

Companion planting: Identify plants that beneficial insects can use as food sources and integrate them into your farming system. However, be sure to consider potential negative impacts. 

Biological control: Protecting naturally occurring beneficial insects in our environment is currently our most effective biological control. However, as more biological control options enter the New Zealand market, this area will expand. Targeted chemical inputs are crucial for protecting and promoting these beneficial populations.

Targeted chemical control: Only use strategic and targeted chemical applications. Once pests cause economic damage beyond the control of beneficial insects, it is essential to assess the pest and beneficial insect populations and the crop growth stage. In early growth stages with multiple pests, broader-spectrum insecticides may be appropriate as the beneficial population may not have established yet. However, established crops with a good population of beneficial insects, targeted approaches are preferable because repopulation of the pest is less likely. 

Not all IPM strategies are applicable in every situation. Trade-offs may exist. However, a greater understanding of these strategies will reduce chemical inputs. This will protect their efficacy, the environment, and ultimately, our food production systems.

To learn more about incorporating an IPM on your farm, contact your local PGG Wrightson Technical Field Representative.