New Zealand feijoas are under a two pronged attack: from an established pest and a new strain of fungus.
Firstly, there’s the guava moth, that has caused problems since it arrived in Northland 20 years ago, gradually spreading south to Waikato and Coromandel. But now there are fears the anthracnose fungal disease, which has devastated crops in Kerikeri, could travel and infect fruit further south.
Guava moths have caused major problems for Peter Jack at his Kerikeri orchard but he was now more concerned about the anthracnose strain, called colletotrichum theobromicol.
"It starts off as a little bit of a purpley black spot and once you get a whole lot of wet weather the infection sets in. Mostly with these newer varieties [of feijoa] you get early fruit drop way back in the beginning of January where the fruit is only 25mm long and it falls off," he said.
The new strain behaved very differently from other versions of anthracnose because it was usually a post-harvest spot, but this version attacked the fruit before it was ready. No fruit from Mr Jack's orchard was sent to market this year because of the fungus, and he knew of three other orchards in a similar position.
Other orchardists further down the country should be worried about the fungus, he said. "If they're not, they certainly should be. With an insect, you can kill it. But with a fungus, it's way more difficult."
Feijoa Growers Association president Roger Matthews told scoop.co.nz it was ‘heart-breaking’ that the same growers who dealt with the guava moth are now faced with anthracnose: "There's certainly concern seeing some of the devastation caused in northern orchards. There is a hope that it's tied to the humidity rates that they find up north and that might limit its spread further south, although with climate change, anything could happen.
