Implementing of an IPM programme for vegetable brassicas in New Zealand

  • Published source details Walker G.P., Cameron P.J. & Berry N.A. (2004) Implementing of an IPM programme for vegetable brassicas in New Zealand. Proceedings of the Fourth International Workshop, 26-29 November 2001, Melbourne, Australia, 365-370.


This study is summarised as evidence for the following.

Action Category

Use pesticides only when pests or crop damage reach threshold levels

Action Link
Natural Pest Control
  1. Use pesticides only when pests or crop damage reach threshold levels

    A replicated study in 1998-2001 in Gisborne and Hawke’s Bay, New Zealand (Walker et al. 2004) reported better control of pests by natural enemies when a threshold-based spraying regime was applied compared to conventional regimes. Insecticide use in vegetable Brassica spp. crops was reduced by 40-70% in the second year of the threshold-based spraying programme compared to conventional regimes. The threshold-based regime could potentially save NZ$125/ha when accounting for the cost of monitoring pests and assuming that spraying could be reduced by 3-4 applications/ha. Sprays (using a variety of insecticide types) were timed according to thresholds of diamondback moth Plutella xylostella and aphid (Aphidoidea) infestation, with selective insecticides used in rotation within each year. Details of experimental setup were not provided.

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust