Weeding out the Bay’s worst plant pest

Noogoora bur is one of the worst agricultural weeds in the world.

Bay of Plenty Regional Council is is trying to raise awareness of the threat of noogoora bur at this crucial time of year when maize and other crops are about to be harvested.

They ask anyone who sees it to get in touch with council. Given there is a lot of machinery moving around the Te Puna, O¯ mokoroa and Katikati areas, the spread of noogoora bur between properties in these areas is a real concern.

Why Noogoora bur matters to you

Noogoora burr is one of the most serious and widespread weeds in the world. It contaminates crops and spreads rapidly if not controlled. It will reduce production in maize crops and pasture by competing for moisture, nutrients and light.

Thought to have arrived in New

Zealand in contaminated maize seed, Noogoora bur is usually found on arable land — often in maize paddocks — but will just as easily colonise pastoral land.

What you can do to help stop the spread

Stopping the spread of Noogoora bur relies on firstly keeping it off a property and then secondly identifying any infestations that require control.

Practice good biosecurity to keep Noogoora bur and other weeds off your property.

Ensure contractors entering your property have clean equipment to avoid the introduction of new weeds.

Prompt action is necessary to eradicate new and/or isolated patches of Noogoora bur and to prevent the weed becoming established.

Report suspected Noogoora bur, or other weeds as soon as possible.

In the Bay of Plenty the regional council will help you to control Noogoora bur.

How to ID Noogoora bur

Noogoora bur is particularly obvious at this time of the year when crops are just about to be harvested.

It is a fast-growing summer annual. It grows as a single stemmed plant (eg among maize) or bushy plant (in the open) up to 2m tall.

Its leaves look like grape leaves but are dark green above and paler below, hairy, with prominent purplish veins.

Stems are rough to the touch and streaked with purple.

Seeds are egg shaped burs, 10-25mm long covered in hooked spines. They occur in clusters on the stems and tips of branches.

Each plant can produce 10,000 seeds per year and seeds can remain dormant in the soil for many years.

— Bay of Plenty Regional Council