May 22 2025

May News

Tour Report

 

Following the last 2 publications that shared insights from the TNZ and VNZI European Tour of Learning, I am please to say that there is a report covering all aspects of the topics that we learnt about on the TNZ website here: https://www.tomatoesnz.co.nz/hot-topics/european-tour-of-learning/ 

If you have any questions about the trip in general or about a particular aspect of it, please don’t hesitate to ask. 

 

 

Spray workshops

In March, TNZ hosted 2 practical spray workshops to address some issues that might be hindering growers when they spray their crops. Dr David Manktelow is a spray application specialist and had many tips and tricks to share. We are currently editing a video which we hope to be able to share with you soon after this magazine is published, but in the meantime here are some things you can already think about: 

Know where the pest you’re targeting sits in your crop and the coverage requirements of the agrichemicals you use. For example, whitefly adults are likely to be in the top section of the plants, on the underside of leavesEfficacy for most soft whitefly control chemicals requires direct contact with the pest. 

The 110o flat fan nozzles that are fitted to many tomato vertical spray booms, project about half their output downwards, which means spray coverage to leaf undersides is compromisedIn the workshops, David demonstrated how a pair of 40o hollow cone nozzles more efficiently projected spray upwards into the canopy and significantly improved under-leaf coverage.     

The workshops emphasised the need to visualise spray coverage and then compare coverage achieved from changes to spraying practices by using folded water sensitive papersTwo ways to use the papers are 1) pinning them through your crop target area, and 2) clipping horizontal and vertical papers up a vertical spray pole. These are shown in the coming video. 

Before spraying always check your filters and nozzles, clean them if required 

Always check the product labels for application rates and other use instructionsOnce you have an appropriate spray tank mix, the size of the spraying target should dictate how much spray volume you need to apply.  

You will need to make adjustments according to the age of the plant – a plant with more or less foliage and the density of plants will require different volumes of spray. 

There is no point in spraying past the point of run off as this will mean you are essentially spraying the floor and wasting your money! 

If your spray equipment allows it, spraying opposite row sides from the opposite travel direction will almost always provide better spray coverage than spraying both sides from the same travel direction.    

Because greenhouse growing means there’s no rain to disperse the spray mix, it needs to land in the right place. Using an appropriate adjuvant can help improve spray coverageThat is a large subject that deserves its own article and video! 

Make notes and take photos! Each time you make a change to your sprayer set up, use water sensitive papers to determine if the change was positive or not. Your photos and notes will allow you to repeat what worked well. 

Finally for now, if you have the ability to add air assistance to your sprayer, this can significantly help to improve spray coverage and it opens up an opportunity to use lower volume concentrate spraysAgain this is a large subject that deserves its own coverage. 

There’s a guide to sprayer set ups available here and when ready the video will be posted here too: www.tomatoesnz.co.nz  

Thank you to NZ Gourmet for allowing us to host this workshop in one of their capsicum GHs. 

 

 

Spray papers before adjustment

Spray papers before adjustment

 

Spray papers after adjustment

Spray papers after adjustment

 Greenhouse maintenance

 

 

 

Some growers will be pulling out tomato plants and preparing to plant other crops over the winter months. James at Apex advises the following next time you’re doing maintenance: Check your gutters and clear out any blockages; clean the glass outside and inside to maximise light coming in; replace any seals that are worn; repair any glass breakages that you see as these will be a way for cold air and pests to enter; check your vents are working including the gearbox drivers and grease the drive systems. For any help no matter the make of your greenhouse, you can contact Apex on telephone 0800 100 618. 

 

Pest and disease gaps analysis

 

As part of TNZ’s commitment to A Lighter Touch, we collect data (anonymously) to help determine what pests and diseases have been an issue for you over the last 12 months. It’s important for us to understand what you have problems with in the greenhouse. If you can take a few minutes to complete this short survey, this will directly influence the pest management work that TNZ continues to invest in:https://forms.office.com/r/NMVddjhLh8 

Spray diaries 

 

These help to determine the habits of tomato growers in general – what substances are being used, how often and what areas should TomatoesNZ be focusing their research and spending e.g on MRLs onAll spray diaries are held as anonymous records. I would really appreciate it if you could email me yours now on Dinah.cohen@tomatoesnz.co.nz  

An updated MRL booklet and poster for greenhouse tomatoes is available here:https://www.tomatoesnz.co.nz/about/useful-docs/  

 

Levies  

Finally, levies. Our new Commodity Levies (Fresh Tomatoes)Order (2024) has come into effect as of 1st April. There are no changes to note but I will be sending out levy forms to growers in the next few weeks. If you only sell your fresh tomatoes through a wholesaler, there’s nothing for you to do. However, if you sell any of your crop directly to restaurants or consumers (at farmers markets, farm gate etc), levies for the period 1st April 2024 to 31st March 2025 will be due for payment by 30th June 2025. 

Save the dates!

 

12th June|10am-2pm there will be a workshop on liberibacter in conjunction with Potatoes NZ and with funding from VICE. Expert on TPP, Jessica Vereijssen from Plant and Food Research will lead this session. 

25th June| 2pm-6.30pm (including a 30 minute break) First aid course specifically for growers. Thanks to funding from HortNZ, we are pleased to offer this in person course for growers. Places will be strictly limited to 20 people.https://forms.office.com/r/URv2EvdydG  

26th-27th |August, Wellington the HortNZ conference. TomatoesNZ has 20 free tickets worth $639 (2 days of conference plus the Gala Dinner on 27th August) for grower members up for grabs. Please email me ASAP to claim one of these. There will be sessions on energy, our greenhouse tomato integrated pest management guide and much more. Dinah.cohen@tomatoesnz.co.nz  

For more info on both of these events, please see the HortNZ weekly emails. Not already receiving these? You can sign up here: https://www.hortnz.co.nz/membership/signup/