2.3 Integrated Pest Management 

Key Knowledge: principles of integrated pest management

What is IPM? Integrated Pest Management is a science-based decision-making process that focuses on long-term prevention of pests and their damage. It isn’t about "killing everything"; it’s about managing the ecosystem so that pests stay below a level where they cause economic harm.
It identifies and reduces risks from pests and diseases through a combination of biological, cultural, physical, and chemical tools in a way that minimizes economic, health, and environmental risks

In Victoria, IPM is the Gold Standard for resilience. It moves away from a calendar-based spraying schedule to an as-needed approach based on monitoring.

The Different Aspects of IPM

PRACTICE  Use the information below to add to your notes or table on pests and diseases.

Cultural Management

We can manipulate the environment to disrupt the pest's life cycle with strategies such as:.

• • Crop Rotation: Planting different species each year so pests like thrips, aphids or soil-borne fungi don't have a permanent host.

  • Eliminating the Green Bridge: Eliminating weeds (like Wild Radish) during the fallow season. This removes the bridge that allows diseases and pests like fungal rusts, aphids and thrips to survive between main crops.

  • Maintaining Hygiene: Cleaning headers, tractors, and boots to prevent the spread of fungal rust spores or footrot bacteria between properties.

Biological Management

Growers encourage or introduce beneficials to manage pest populations, or use the plant's own DNA to fight the threat. Strategies include:

• • Conservation of existing beneficials: Leaving native vegetation strips to provide a home for ladybirds, lacewings and small birds that will eat damaging insects.

  • Introducing beneficials: Purchasing and releasing predatory mites or parasitoid wasps into a production system.

  • Resistant Varieties: Plant breeders develop cultivars with high resistance to diseases like Cereal Rusts. This reduces the need for foliar fungicides.

Chemical Management 

Targeted intervention is required when the pest or disease load threshold is reached. they may do this by:

• Targeted Chemical use: Using narrow-spectrum (selective) pesticides that kill the target pest but do not harm beneficial insects, or by using equipment that ONLY targets one specific pest (this is still very new technology and is not yet used widely.)

• Resistance Management: Rotating between different chemical groups to prevent pests from developing biological resistance.

Monitoring and Thresholds

An IPM plan is only as good as the data collected. Farmers use specific tools to decide when to act:

1. Detection: Identifying the presence of a pest (e.g., finding the first orange pustule of rust).

2. Monitoring: Quantifying the population.

   • Sticky Traps: Blue traps are specifically used for monitoring western flower thrips (WFT) because they are highly attracted to the blue wavelength. Yellow sticky traps are used to identify the presence of other insect pests like aphids.

   • WEC (Worm Egg Counts): Measuring the parasite burden in livestock manure.

3. Thresholds: The action point. If the likelihood of an animal becoming sick or unfit for sale is reached, or if the cost of the pest damage is predicted to be higher than the cost of the treatment, the farmer triggers a control measure.

PRACTICE

Key Skills Practice: Risks and Resilience Use the marking scheme to evaluate your work 

Q1: Monitoring and Thresholds (3 Marks)

A Victorian grain farmer is scouting her wheat crop and finds a small number of fungal rust pustules. However, she decides not to spray a fungicide immediately. Explain the economic threshold and why a farmer might wait to use a chemical control.

Q2: Biological Resistance (4 Marks)

A vegetable grower has used the same chemical pesticide to control aphids for five years. Recently, he noticed the aphids are no longer dying after being sprayed. Analyse how biological resistance has occurred in this population and suggest a strategy to fix this problem.

Q3: Integrated Management of Livestock (3 Marks)

Intestinal worms can be a major threat to sheep. Discuss how a cultural control method, such as paddock rotation, works alongside a worm egg count to reduce the use of chemical drenches.

SAC/Exam Tip: 

If you are asked to discuss or evaluate IPM, remember these three value points:

• Environmental: Reduces chemical runoff into Victorian waterways and protects biodiversity (like bees).

• Economic: Saves money by only applying chemicals when necessary and reduces the risk of biological resistance making chemicals useless in the future.

• Social: Meets consumer demand for food with lower chemical residues (clean and green produce).