From 1 May to the end of August is the time to use 24-D ester for thistles and flat weeds in established pastures. 24- D is a volatile chemical that can leave a residual smell for up to 2 days. It is important to make sure that all neighbours are notified prior to spraying and that the wind is blowing away from any potential sensitive areas. Conditions of use can be found on the Northland Regional Council web site under the Air Quality Plan.
There are other non volatile types of 24- D such as Baton and Ammo Max. They are very low odour and can be applied in built up areas safely.
One big problem facing farmers at the moment are weeds that appear to have become resistant to sub-lethal chemical rates. This has been caused by prolonged application of low rates of 24-D. This has caused weeds like Buttercup and Penny royal, Carrot weed or Parsley Drop Wort to become resistant to 24-D.
Label recommendations state in most cases that 2-3 litres per ha to be applied. History has shown that often only 1 litre per ha has been applied which has taken out scotch thistles but has slowly built up resistance in other weeds.
It is important to have good weed identification and recommendation before application starts. Weed Identification can be sourced by phoning Richard at NVC or looking up the web sites Northalnd Regional Council weed and pest control or Pest Web NZ.
Richard is happy to come out and go over a weed plan that suits your pasture and farming policy.
NVC are offering special deals on application for any areas over 40 ha so phone today for a price. We are fully computerised with GPS guidance so you can have peace of mind that the chemical has been applied at the correct rates.
Winter is also a good time apply Gibberellin products such as in Pro Gibb or Pasture Gibb.
All products work the same; it is a grass stimulant not a fertiliser. We have mixed Gibberellins with urea in a mixing tank and have had excellent results that double the growth rates of urea by its self. Best results are gained when Gibb acid is applied within 5 days of grazing and 24 days before re- grazing. The label recommendations state that you don’t exceed 6 applications per year. Our best results have been to use Gibb every other time in conjunction with urea (it has cut a lot of urea bills in half).
We have large mixing tanks now to dissolve urea into a liquid form which is giving better results with a more even spread. This avoids the striping you see with granulated application. Results have shown responses from the nitrogen to be 20-30% more efficient.