Tomato grower and TomatoesNZ board member, Anthony Tringham, along with his wife Angela from Curious Croppers in Clevedon, recently hosted Professor Steve Wratten and PhD student Morgan Shields from Lincoln University at their greenhouses.
Together with Chris Thompson from Bioforce, they conducted a bug scouting expedition at their site. Anthony has a tunnel house with an old crop in it that has not had insecticide applied for many months. Differing to standard practice, he lets weeds grow plentifully around the houses to increase ecological complexity.
The group did some sweep netting around the greenhouses, however as the weather was cool they did not find too many bugs. A few TPP were identified which were quite small in size. Anthony hopes this indicates that they are being eaten before they mature. Whitefly was being parasitised by Encarsia Formosa, and European red mite was found.
They also picked leaves and checked them under a binocular microscope. Few beneficial insects were found outside the glasshouses given the weather, but they did find some predatory brown lacewings.
Morgan gave a protocol to Anthony and Angela about how to set up ‘banker plants’ comprising TPP and Tamarixia in enclosed cages in the older houses so that they can ‘trickle’ Tamarixia into the main houses at the desired quantities and intervals by breaking off leaflets as needed. Morgan advised this is cheaper than buying them every week and gives the growers more control over and understanding of the system.
Professor Wratten advises this protocol can be made available to all NZ tomato growers if they are prepared to not spray everywhere.
As the weather warms Anthony and Angela wait to see how their ecosystem develops.
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