Disease Management

Directions for research in the certified organic management of Phytophthora cinnamomi in avocados (PDF file) January 2012, Report number 2012-1.  Report written for New Zealand Organic Avocado Growers (NZOAG)

Initial trials of Kelp (Macrocystis pyrifera) as a fungicide and health promotor on grapes (PDF file) May 2012. Report number 4-2012


Pest Management

Initial Results for Tomato Potato Psyllid (TPP) Management with Mesh Crop Covers July 2012. Report number 3-2012

Download the full report (2.2 MB pdf file)


  • Initial trials of mesh crop covers indicate that they are an effective control measure for TPP. However, the statistical significance of the field trial was mixed, so the results must be treated with caution.
  • Contrary to expectations potato blight was much lower under the covers. This may have been a fluke result and it is possible the opposite may be found in later trials.
  • This is the result of only one field trial, which needs to be repeated to confirm the results. On this basis it would be unwise for farmers and growers to ‘bet the farm’ and purchase large amounts of mesh solely for TPP management.
  • However, it is suggested that producers who can afford to take some financial risk, do consider purchasing mesh to cover a small proportion of their crop, to test it under their production systems. Ideally that would be done as part of a properly randomised replicated trial to ensure the rigour of the results. This can be done in conjunction with the BHU Future Farming Centre who can provide assistance and statistical analysis for free.

 Media coverage

Farmers Weekly "Organic solution to TPP"

Central South Island Farmer - "Mesh covers could beat TPP"

Rural News "Crop cover to combat psyllid?"

Soil Management including tillage / cultivation

 Understanding biological / organic fertilisers using kelp (Macrocystis pyrifera) as an example (PDF file). May 2012. Report number 2-2012.

Weed Management

Expanding the Potential of Intrarow Soil Thermal Weeding

The full colour booklet (hard copy) from the Non-Chemical Weed Management Workshop held on the 19 June 2012 is available for purchase at a cost of NZ$30.00 + GST inc. P&P.The booklet includes all the slides from the presentations in PowerPoint 'handout' format of six slides per page.  The booklet is 48 pages long and contains 248 slides of information, including references.To purchase a copy please email This email address is being protected from spambots. You need JavaScript enabled to view it.


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