Oct 19 2023

October News

Whitefly IPM Workshop


Growers gathered online and in person at this popular workshop on managing whitefly in greenhouse tomatoes using an integrated pest management (IPM) approach. Ahead of the prime season for whitefly infestation, Seth Laarakkers described the fundamentals of an IPM approach, and finished by sharing the progress of the TomatoesNZ and A Lighter Touch trials on new native predators which, in theory, should help keep whitefly under control while they hunt for Psyllid.


The key points were:


  • Scout well, preferably with a hand lens
  • Introduce predators early and regularly
  • Pay attention and help the predators if you need to.


If scouting occurs regularly and with sufficient resolution, and this is coupled with an understanding of what you are seeing, the effects of regularly introduced Encarsia controlling a whitefly population are obvious. At this stage we can apply physical mode of action sprays to help the encarsia keep up if required. Understanding the different temperatures that Encarsia survive at (the greenhouse should be at a minimum 24-hour average of 16 degrees) is important in determining your strategy. The average naked eye won’t be able to see whitefly eggs, however mature larvae, pupae and adults are easily recognised. That is why a scout with a hand lens is so important. We explored a decision making tree (available on the TomatoesNZ website) which described the course of action to take for 3 levels of infestation. This was followed by a discussion around the 3 levels of spray (physical, soft, and hard) and why repeat applications are critical to success. There is no point in applying chemicals that impede your predators, short term control often leads to long term problems. For a better understanding of the hour long presentation, please see the resources from the workshop, the slideshow, an educational video and a decision tree matrix that will help you to get a better understanding. (add website link) Please note that these have been developed specifically for tomato growers but might transfer to other greenhouse crops. For any questions on beneficial insects, please contact Bioforce https://www.bioforce.co.nz/ or contact Dinah info@tomatoesnz.co.nz


Keep an eye out for future workshops on other pests as more data is generated from the trials.


Image of a Whitefly

IMG 0963 4


Korean language workshop on Energy


We were delighted to host a workshop on reducing energy demand for Korean language growers last month. Ellery Peters, an Energy Engineer Project Manager, organised a presentation which went through some of the items on the check list available for all growers to access on the EECA website: https://www.eeca.govt.nz/co-funding/sector-decarbonisation/covered-cropping-decarbonisation-pathway/tools-and-resources/

Jiny Kim, who recently joined the TNZ board, did a wonderful job of simultaneously translating the material into Korean and the feedback was excellent. Lots of opportunities to ask questions and share knowledge.

If you know of a community of tomato growers whose first language isn’t English, please get in touch with Dinah to enable more workshops and networking opportunities for growers in other languages to be hosted.


 Energy Audit

It would be really helpful for future projects around energy to have an idea of the current set up of your growing site – the age and materials used in the construction of your greenhouse(s), the energy you use and how much of the year you heat, other equipment that you already have etc.

Please take 5 minutes to complete this survey: https://forms.office.com/r/gn2W2s9Wcq


Clean Energy Tech Fund


One of the funds that was talked about at the energy workshop was for hot water heat pumps. EECA are currently helping to fund the supply and installation costs of electric hot water heat pumps in greenhouses. These can be a cost effective and efficient means of heating without using fossilised fuel but also without the need for a costly boiler or adding storage space for the supply of fuel such as biomass, recycled oil etc.


Projects can be funded up to 50% with a maximum project cost of $150k. Please see https://www.eeca.govt.nz/co-funding/industry-decarbonisation/gidi-clean-tech/hot-water-heat-pumps-programme/ for further information about applying for this funding.