AgPest » AgPest » Tag » Weed

Time to apply herbicides to yellow bristle grass:

AgPest — Sat, 16 Dec 2017 19:45:06 +0000

Apply herbicides to yellow bristle grass before seed heads ripen. Avoid moving stock from infested to clean paddocks – seeds can survive in dung.

Don’t make hay from paddocks heavily infested with yellow bristle grass or other summer growing grass weeds – the seeds survive in hay. In contrast, yellow bristle grass seeds do not survive in well-made silage and wrapped baleage.

Chilean needle grass becomes evident this month.

AgPest — Tue, 12 Dec 2017 20:30:54 +0000

Chilean needle grass will become evident in pastures in November-December. Keep an eye out for the reddish purple colour of the seed heads when they first emerge. Each seed has a 7 cm long awn (bristle-like tail). This grass is most likely to be found in pastures on north/west-facing drought-prone slopes but may be present in contaminated stock feed / hay. If you suspect that you have it, please contact your local council biosecurity people for identification and management advice immediately.

Be alert for Chilean needle grass

AgPest — Tue, 14 Nov 2017 19:00:29 +0000

Chilean needle grass will become evident in pastures during November and December as its distinctive purple-coloured spikelets, with their developing long-awned needle-sharp seeds, emerge from elongating flower stems. Details of this invasive grass can be found here on AgPest. This grass is most likely to be found in pastures on north/west-facing drought-prone slopes. If you suspect that you have it, please contact your local council biosecurity people for identification and management advice.

Chilean needle grass becoming evident

AgPest — Sun, 05 Nov 2017 19:30:51 +0000

Prevent establishment of Field Horsetail

AgPest — Sat, 30 Sep 2017 19:30:29 +0000

Field horsetail (Equisetum arvense) is a very difficult to control perennial weed that regrows each spring/summer from an extensive underground root system. Preventing establishment is the best form of control. Make sure your contractors machines are clean and ask where the machines have been.

This root system comprises actively growing rhizomes that can penetrate to more than 1 m in depth, from which green fern-like fronds grow each year. Attached to the deeper rhizomes are small tubers which remain dormant while the rhizome stays alive. Upon the death/decay of the rhizome, or when it becomes detached due to cultivation or other means, the tubers are able to produce new plants.

Summer active grass weeds

AgPest — Sat, 30 Sep 2017 19:30:17 +0000

If your run-out pasture was infested with summer-active grass weeds last summer, consider growing a forage crop for one or two summers prior to sowing the perennial pasture. This provides the opportunity to selectively spray the summer-active grasses and prevent weed seeds from replenishing the seed bank and infesting newly sown pastures. Forage crops will also disrupt clover root weevil populations allowing better subsequent establishment of young clover.

Summer-active grass weeds

AgPest — Fri, 01 Sep 2017 00:45:43 +0000

If your run-out pasture was infested with summer-active grass weeds (such as yellow bristle grass) last summer, consider growing a forage crop for one or two summers prior to sowing the perennial pasture. This provides the opportunity to selectively spray the summer-active grasses and prevent weed seeds from replenishing the seed bank and infesting newly sown pastures.

Velvetleaf focus firmly on fodder beet seed

AgPest — Thu, 10 Mar 2016 03:21:47 +0000

The Ministry for Primary Industries (MPI) is encouraging farmers and growers who have planted certain varieties of imported fodder beet seed to check their crops for the presence of an aggressive agricultural weed, velvetleaf.

MPI has been investigating the appearance of this pest weed on a small number of South Island properties and has been steadily building a picture of where the weed is present and if there are any common factors between affected properties.

Plants and Environment Surveillance Manager Mark Bullians says MPI has now positively identified velvetleaf on 10 properties across the South Island and has seven further suspected cases yet to be verified.

“The common denominator is fodder beet crops and, in particular, crops grown from two varieties of imported fodder beet seed.

“Velvetleaf plants are appearing in rows where this fodder beet seed has been drilled and farms concerned have planted either Kyros and/or Bangor seed.

“While we are not certain this is the full picture, we now know that some lines of these two seed varieties are very likely to have been contaminated with velvetleaf seed. For this reason we urge anyone who has planted Kyros and Bangor fodder beet seed to check their fields immediately for the presence of velvetleaf. The seed has been distributed mostly in the South Island but some has been sold in the North Island.

“If you believe you have found this distinctive weed, call MPI immediately on 0800 80 99 66.”

Velvetleaf is a tall-growing weed reaching heights of up to 2m. It has buttery yellow flowers and large velvety heart shaped leaves.

Mr Bullians says farmers are advised to photograph any plants, contact MPI and mark the location of plants so they can be found again easily. He cautions against pulling up plants, or allowing cattle to graze infested crops, and says an MPI or local council representative will visit and carefully remove any plants to make sure velvetleaf seed, if present, is not spread.

Velvet leaf is a serious weed pest overseas, damaging crops by competing with them for nutrients and water. It is an Unwanted Organism under the Biosecurity Act, and as such, entry to New Zealand is prohibited.

MPI is investigating how the weed seeds could have entered New Zealand. The affected consignments met New Zealand’s importing requirements and were certified as weed-free by the exporting country. The Ministry is currently reviewing the import requirements for seed.

Mr Bullians says the Ministry is working closely with primary industry bodies from both the animal and grain/seed sectors as well as regional councils on managing this situation. As a precautionary measure, MPI has directed seed and grain retailers not to sell or distribute any remaining stock of the affected seed lines and these retailers have also been directed to instruct buyers to return any unsown seed.

For full information visit: mpi.govt.nz/alerts or contact MPI Mediaphone 029 8940328 or media@mpi.govt.nz