Second attempt to fight pest vine

Thursday March 31, 2016 Written by Published in Environment
New Zealand entomologist Quentin Paynter and plant pathologist Chantal Probst with a wheelbarrow full of mile-aminute plants infected with a rust fungus that spreads and kills the pest plant. The photo was taken during the first attempt to establish the fungus last year. 16033105 New Zealand entomologist Quentin Paynter and plant pathologist Chantal Probst with a wheelbarrow full of mile-aminute plants infected with a rust fungus that spreads and kills the pest plant. The photo was taken during the first attempt to establish the fungus last year. 16033105

Cook Islands Ministry of Agriculture is doing another round of tests on Rarotonga to control the mile-a-minute vine that is choking bush and plantations around the island.

 

Agriculture’s Dr Maja Poeschko says plants with the rust fungus Puccinia spegazzinii were brought in earlier this month with the aim to control the invasive weeds and mile-a-minute plants around the islands.

However she said they would have to wait and see what the results would be.

“A pathologist brought in the infected plants and we had them under light conditions until yesterday, but we still don’t know whether this will be a success or not”.

Poeschko said it would take another three weeks for the Ministry to determine whether these set of plants will last and finally bring results.

“This time we had a bit less humidity and didn’t put the plants outside straight away. Now we are waiting to see the symptoms on the leaves.”

Poeschko said Ministry of Agriculture staff would be looking for spores of the fungus spreading on the tested plants.

“If weather conditions are just right, within two days the spores appear and if they land on a moist leaf they may survive and will be able to grow.”

Poeschko says it’s a matter of propagating fungus-infected plants so that they will spread and grow in abundance. If the infected plants do grow successfully they will be planted at various spots around the island and could make a difference to the amount of mile a minute vine on the island within just two years.

However, it’s not an easy process.

“When the plants depart New Zealand they have to go through Biosecurity which has to approve that they are free of pests and diseases other than stated in the import permit.

Unfortunately during the last test, Biosecurity didn’t approve the plants because they found mites on the plants and they needed to treat them with a chemical. This is partly why they didn’t survive.”

In April, New Zealand scientists are expected to be in Rarotonga again and they will continue to inspect the current test.

The Ministry of Agriculture hoped to have the rapidly-growing vine under control within the next few years. The effort is part of a $1 million project to control a number of invasive weeds in the Cook Islands, funded by New Zealand’s Ministry of Foreign Affairs and Trade.

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