Hot, dry summers and mild winters are putting extra pressure on the country’s tamarillo growers as Tomato Potato Psyllid (TPP) populations thrive. Robyn Wickenden and Aaron Davies bought a one-hectare tamarillo orchard just out of Maungatapere, Northland in late 2016. From there operating Mya Enterprises Ltd has been a steep learning curve in growing, picking, grading and selling tamarillos. Just two years later Robyn became secretary for the NZ Tamarillo Growers Association (NZTGA), and in March 2020 was made its chairperson.
And if battling a pandemic wasn’t hard enough, the Tomato Potato Psyllid (TPP) has been prolific leading to widespread Liberibacter infections on tamarillo orchards, particularly in Northland.
“Last year and the year before, we had two really dry, hot summers and mild winters. The psyllid absolutely blitzed everybody. This is one of the reasons we’ve gone down to such small grower numbers, people have decided to give up growing.”
Aaron and Robyn were one of just two tamarillo growers who exported the fruit last year. “This year we won’t be exporting, we just won’t have the fruit.”
TPP was first detected around Pukekohe in tomatoes and potatoes in 2008, and the insect spread very rapidly to all growing areas during 2009 and 2010. TPP lives and reproduces on all plants from the Solanaceae family, including tomatoes, potatoes, capsicums, eggplant and such weeds as nightshade and tobacco weed.
“When the psyllid liberibacter infection came into New Zealand around 2008, it devastated our industry and we’re not big enough to keep fighting and doing the research and all the rest of it that needs to be done.”
Tomato crops have mostly shifted indoors as their way of combating it, while potato growers have found that putting their crops under netting made a big difference, Robyn says.
Robyn and Aaron attempt to cover their tamarillo orchard with psyllid netting. On 29 January the couple made their first attempt to hoist the net in place over the orchard.
“At 10 o’clock a 60kmh gust of wind came through and we then spent the next four hours battling holding the net in place. It was just like having the wind under a sail … by 2 o’clock we gave up and pulled it all back down again.”
Since then, Robyn and her husband have been holding out for two calm days in order to get the netting in place over the orchard. Finding a way to control TPP is crucial for the survival of Robyn and Aaron’s orchard.