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Horticulture 1000
HT1103 - Plant Management 3 - Integrated pest management (IPM)
Chemical Control
7

Integrated pest management (IPM)

Commercial growers prevent and control pests and diseases for optimum plant growth. They choose the most cost-effective management practice to match the type of crop they are growing and market they are supplying.

Integrated pest management or IPM is where a grower uses a combination of cultural, biological and chemical methods to prevent or control pests and diseases.

This approach came about because pests and diseases have developed resistance to chemicals, and consumers have become concerned about chemical use and residues on fruit and vegetables.

The method to use depends on the presence of natural enemies, the type of cultural control methods available and environmental factors.

Here is how a grower might protect a crop using integrated control.

Here is how a grower might protect a crop using integrated control

Monitoring

Crop monitoring is the key to IPM programmes. The grower regularly checks the pest and disease levels.

A pest limit or threshold is worked out for each crop species and this value is used to work out whether or not to spray. It is not cost-effective to spray if the pest numbers are below these levels. Growers only need to spray if the threshold is exceeded and then the sprays are used in rotation.

Sticky traps are used to catch pestsSticky traps are used to catch pests.

Sticky traps are used to monitor whitefly. The traps are checked regularly to detect the first whitefly.

 
IPM is used to protect these lettucesIPM is used to protect these lettuces.

IPM programmes have been developed for many crops.

Pests and diseases can be controlled in vegetable crops using IPM.

 

In the past the pests and diseases in these crops were controlled by calendar spraying which was costly and there was an increased chance of the build-up of resistance to the pesticide chemicals within populations of pests.

Integrated pest management has involved a combination of practices including introducing parasites, monitoring, selective use of chemicals and using resistant plants.

Kiwigreen is an IPM system used on kiwifruitKiwigreen is an IPM system used on kiwifruit.

The kiwifruit industry recognised the need to find ways to reduce chemical use in orchards.

The levels of scale and leaf roller are carefully monitored to see whether spraying is required.

Cultural methods used as part of this programme are pruning, training and opening up the canopy of kiwifruit plants to allow more air movement.

Growers who take part in the Kiwigreen programme have to complete written forms and keep a diary that records the practices used ensure produce meets quality standards.

 

Activity 7A This article appeared in a recent vegetable journal.
Use this to answer the questions that follow.

Attacking a Super Bug

Diamondback moth is a serious pest of the brassica crops, such as cabbage, cauliflower and broccoli.

Ten years ago diamondback moth had the vegetable industry in crisis worldwide as it had become resistant to every pesticide and there were concerns about spray residues.

A Crop & Food Research entomologist said there was only one possible solution to this – Integrated Pest Management or IPM. This involves using a ‘combination of controls’ on crop pests.

‘The IPM system is excellent – it’s the only way to go,’ said vegetable grower Tom Green of Gisborne.

‘It delivers on control, management of the pesticide, cost and quality of produce.’

‘There's less spraying which has resulted in a saving in pesticide use as well as less chemicals in the environment. The spray operators have fewer health problems from pesticides.’

‘The quality of the vegetables improved by applying pesticides only when there is a pest problem and there is less chance of the pests developing a resistance to a specific chemical.’

‘In the past a there was a maximum of five to seven sprays when growing a seventy day crop. With some of the crops we do now there's not a single spray. The absolute maximum we'd do now is three sprays – and that's on a very small area. Mostly it’s zero to two sprays.’

Test your understanding of what practices could control pests on brassicas by answering the questions below.


Complete the Assessment Activity in your workbook

Key points   Key points

  • Integrated pest management or IPM is the use of a combination of cultural, biological and chemical methods to prevent or control pests and diseases.
  • The IPM approach has come about because pests have developed resistance to pesticides and consumers have become concerned about chemical use and the residues on and in fruit and vegetables.
 

What's next?

Send your HT1103 workbook to your teacher.

Chemical Control