Integrated Pest Management

A pest is an organism that threatens a valued resource. In agricultural environments, monocultures can help pest populations to expand if there is no food or refuge for natural predators, or if natural predators are killed by pesticides. Pest species tend to bounce back quicker after treatments, and there is a risk that they will develop resistance to pesticides or that other pests will replace them.

Long-term use of broad-spectrum pesticides for invertebrate pest control is not sustainable.

Integrated Pest Management (IPM) is the management of pest populations using all relevant control practices in a complimentary manner. The aim is to maintain populations below the economic injury level and reduce impacts to the environment.

An effective broadacre IPM strategy works by:

·         providing refuge for beneficial species that act as natural pest biocontrols (e.g. native vegetation, grass interrows, stubble retention);

·         adopting cultural controls that reduce pest populations and boost beneficial insect populations;

·         using selective pesticides/ biopesticides that target specific pests; and

·         applying economic thresholds to avoid unnecessary spraying and to take advantage of a crop’s ability to compensate for pest damage at certain crop stages.

Cultural control options that minimise pest pressure and encourage predators or beneficial species include:

·         Pruning

·         Dust control

·         Windbreaks

·         Crop health

·         Weed control

·         Hygiene

·         Time of harvest

·         Crop rotations; and

·         Strategic grazing

Biopesticides are selective insect diseases (fungal, bacterial and viral) that have been mass reared for use against insect pests. Bio-pesticides:

·         have little or no effect on beneficial organisms;

·         are harmless to humans and wildlife; and

·         leave no toxic residues.

Deciding whether treatment is necessary requires regular monitoring of pest populations. Accurate identification of beneficial and pest species is fundamental to IPM.

IPM does not exclude the use of chemical pesticides but uses it as a ‘last resort’ support tool rather than the main weapon. It encourages the use of selective pesticides that specifically target pests and do not affect beneficial species, thereby enhancing the potential for biological control.

Source and acknowledgements: Grains Research and DevelopmentCorporation; NT Dept. Primary Industries and Fisheries