Brendon Hoyle – Ashbern Farms
Intonsa thrips wreak havoc at Sunshine Coast strawberry grower
A new and highly destructive thrip has torn through East Coast strawberry crops this season, including Ashbern Farms’ Sunshine Coast operation, and Brendon Hoyle says the priority now is getting ahead of it before it returns next year.
The pest, intonsa thrip, arrived in force in August, at the worst possible point in the season.
“It just does such a magnificent job of destroying the fruit,” Hoyle says. “We get typically a very bronze-looking green fruit, which becomes very hard and no good. Some of the lesser-infected crops just end up looking dull very quickly.”
The insect is a rasp-feeder, scraping the surface of the fruit, and the damage leaves the skin compromised and vulnerable to further loss.
“The fruit will start to repair that damage by creating scar tissue, and the scar tissue is what ultimately makes it look dull,” he says. “And then it breaks in rain. Even a very light shower, four mil, will do a significant amount of damage, because the skin is already compromised.”
The losses at the peak of the season were severe.
“August was just a shocker. We had fields that we were throwing 70% of the fruit in the bin, and that was in the field,” Hoyle says. “That 30% that went to the shed, I don’t even think we managed to pack up 50% of that. So of that whole crop that we picked over two weeks, we probably threw 85% of it in the bin.”
He says the timing hurt most, because it struck when the crop was at its heaviest.
“It’s just a pity that it hit us during our peak, where it was at its heaviest load and we lost all of that,” he says.
The strawberries have since staged a partial recovery, which has softened the blow to the wider season. “We’ve kind of got a secondary flush that’s come through, and it’s not too bad,” Hoyle says. “So it’s not detrimental for the crop for the season, just the one picking. Now we’re on the shoulders, it seems to have calmed down a bit.”
Because Ashbern grows organic as well as conventional on its Sunshine Coast farm, two approaches to controlling the thrip were trialled: biological controls in the organics and more conventional pesticides in the conventional.
“Once you start going down the hard chemical route, you tend to clean the entire crop up of everything, good bugs and bad bugs, except for the Intonsa,” he says. “There’s no competition for flowers, there’s no competition on fruit, and we just see the numbers bloom.”
His answer is a stronger integrated pest management program, leaning on predators such as cucumeris and orius that feed on the thrips at different life stages.
The plan for next season is to have that ecosystem in place before the thrip arrives, not after.
“You cannot catch up; that’s what we have learned this year,” Hoyle says. “You’ve got to stay ahead right from the beginning. If you can get something in early to control the juveniles before they get into that adult stage, I think you’ve got half a chance.”
For more information:
Brendon Hoyle
Ashbern Farms
Tel: +61 417 193 050
brendon@ashbernfarms.com.au
