|
Crop Crack 14.11.09
By Wendy Fearon
The weather is still offering a very mixed bag and time is of the essence with regard to autumn herbicide application. Some of you may not know but products containing IPU are no longer available for use in the UK.There is still a good choice of autumn herbicide products available but most of these must go on early. The drop in temperature this week will certainly help the persistence of chemical applied.
Chlorotoluron (CTU) is of the same family of chemistry as IPU, and has identical mode of action and very similar spectrum of weeds controlled, including AMG, chickweed, mayweed & groundsel. Its’ principal limitation is its potential to scorch; certain varieties of winter barley & winter wheat are not tolerant to CTU, so can only be used on named varieties (check approved variety list). In addition, only use when the seed is well covered and the crop is not under any stress.
Flufenacet offers the widest window for good AMG control – it is very residual so will remain active for an extended period after application, controlling from pre-emergent through to beginning of tillering. Ideal timing is very early post-emergent – a new definition for this timing is now being used, peri-emergence, meaning around the time of emergence as distinct from some time after emergence.
Iodosulfuron & mesosulfuron (both sulphonyl-ureas, SUs) will control AMG well into mid-tillering, but have contact activity only, therefore requiring all the AMG to be emerged for control to be satisfactory, so really can only be used from early spring onwards. (In addition these actives can only be used on winter wheat, not winter barley or winter oats.)
Pendimethalin (PDM) is also very active on AMG, but pre-emergent only. It is much less soluble than IPU, so persists for longer in the soil. PDM also has a much wider BLW spectrum than IPU.
Diflufenican (DFF) is another widely used active in the autumn; it is residual and has a wide spectrum of BLWs controlled, taking out larger emerged BLWs than many other residuals, but has no AMG activity whatsoever.
Flufenacet will be the mainstay of AMG control in the 2009-10 crops. This active also gives good activity on brome
and perennial rye-grass when used at its’ maximum rate. CRYSTAL contains flufenacet and pendimethalin and can be used on all varieties of winter barley & wheat.
BUCKLER contains CTU & DFF. Where the variety list allows this product should be tank-mixed with the CRYSTAL. Its inclusion will extend the spray-window of CRYSTAL, allowing larger weeds to be controlled than if the CRYSTAL were used alone. The CTU will also bring groundsel activity to the mix, whilst the DFF will broaden the spectrum of emerged BLW controlled, including chickweed & mayweed. Only use when the seed is well covered, and not subject to stress as a result of waterlogging or frost
Grain Store Hygiene
We have had a number of enquiries over the last couple of weeks with regard to grain store pests.Reldan can be used in barley,wheat,oats,rye and triticale in store. With moisture content as good as it was this autumn it seems many crops were not dried and stores not properly cleaned and the pests are now appearing. Grain will lose weight, reduce in nutritional value and be of a lower quality if left untreated. Pest activity can also lead to heating and development of moulds.
To apply RELDAN for grain conveyor rates below 5 tonnes per hour, apply 20ml Reldan in 1.5litres of water per tonne of grain. At rates above 5 tonnes per hour apply 20ml Reldan on 0.75 litres of water per tonne of grain.
ACTELLIC may also be used on stored grain as an admixture. It is important to note whichever insecticide you choose that moisture content of the grain is kept at or below 15%.
I
|
