Controlling poppies and grassweeds across the arable rotation

Poppy time to sprayIndependent agronomist Peter Riley looks beyond this year’s arable crops and plans a longer term assault on difficult and obvious weeds such as black-grass and poppies. He also saw a lot of sow-thistles and thistles on his travels last season, but not in East Anglia where he applied his longer term policy based on using propyzamide-based herbicides in oilseed rape.

Pestwatch

Frit Fly Report – 4th November 2014

Cereal tillers attacked by Frit fly typically show dead-heart symptoms as the larvae bore out the centre shoot, causing a loss of tillers. Frit fly larvae can move from tiller to tiller, and attacks on young plants can lead to plant loss. Plants attacked but not killed are stunted and grow poorly.

There are lots of reports of Frit fly damage in cereals this autumn, particularly in crops following oats or grass. Frit fly can be a particular problem of spring oats (and maize) in May/June even affecting the oat ear, and the subsequent generation will attack the following cereal. Many reports now are of dead-hearts in the newly establishing cereal.

Wheat plants showing dead-heart symptoms from Frit fly damage

Wheat plants showing dead-heart symptoms from Frit fly damage

For further information on the Frit fly life cycle and risk assessments see here.

FAQs 

If I am seeing dead-hearts, is it still worthwhile treating for Frit fly?

Where crops are showing dead-heart symptoms, Equity®/Dursban® WG will not have good activity. However it may have activity on larvae that are migrating from plant to plant.

What is the Integrated Pest Management (IPM) rate for Frit fly?

Typically crops should now be past the high risk category so the IPM rate could be appropriate. The IPM use rate of Dursban WG is 0.5 kg/ha or Equity is 0.75 L/ha.

Action

If treatment is justified use Equity at 1.5 L/ha (or IPM rate as above if appropriate) applied in 200 to 1000 litres of water/ha.

If using DursbanWG the recommended rate is 1.0 Kg/ha (or IPM rate as above if appropriate) applied in 200 to 1000 litres of water/ha.

An interval of 14 days must be observed between applications of Equity or Dursban WG and UNITE® or Broadway® Star, regardless of weather conditions. For Atlantis WG and similar approved formulations leave a longer interval of 4 weeks for crop safety. For other compatibilies please refer to Equity or Dursban WG tank-mix advice.

Use low drift nozzles and extend buffer zones to preserve Dursban WG and Equity use.

For conventional boom sprayer:

  • Use LERAP – low drift – three star  nozzles
  • AND adopt a 20 metre no-spray buffer zone (1 metre for dry water bodies)

Say No to Drift

 

 


Aphid Report – Updated Autumn Update


We apologise for an error in aphid report of 27th October 2014. Updated report below.

The aphid monitoring programme conducted by Rothamsted Research has confirmed the presence of grain aphids (Sitobion avenae) and bird-cherry aphid (Rhopalosiphum padi) that carry the kdr mutation making them resistant to pyrethroid insecticides. Bird-cherry aphid and Grain aphid and bird-cherry aphid (Rhopalosiphum padi) are the main vectors for the important as they transmission of barley yellow dwarf virus (BYDV) in winter wheat and barley.

Pyrethroid insecticides, such as cypermethrin, have been invaluable in the control of aphid species as they have been cost-effective. However the over-reliance of pyrethroid insecticides has resulted in resistance.

Independent trials conducted in autumn 2012 and reported at Crop Protection Northern Britain 2014 (*Dewar et al., 2014) demonstrated that Dursban WG was the most consistent insecticide treatment when applied against resistant or susceptible grain aphid. Dursban WG achieved faster aphid control than cypermethrin, vital when combating virus transmission.
blackgrass control

Action

Monitor crops and where aphid species are present and pyrethroid resistance is implicated, consider an application of Dursban WG or Equity. Trial results have shown that applications of Dursban WG applied via LERAP 3* nozzles did not reduce aphid control.

If treatment is justified use Equity® at 1.0 L/ha applied in 200 to 1000 litres of water/ha.

If using Dursban® WG the recommended rate is 0.6 Kg/ha applied in 200 to 1000 litres of water/ha.

An interval of 14 days must be observed between applications of Dursban WG and UNITE® or Broadway® Star, regardless of weather conditions. For approved formulations of iodosulfuron-methyl-sodium and mesosulfuron-methyl leave a longer interval of 4 weeks for crop safety.

Use low drift nozzles and extend buffer zones to preserve Dursban WG and Equity use.

For conventional boom sprayer:

  • Use LERAP – low drift – three star  nozzles
  • AND adopt a 20 metre no-spray buffer zone (1 metre for dry water bodies)

    Say No to Drift

 

 

*A M Dewar, A J G Dewar, L A Haydock, S P Foster and M S Williamson. Alternative insecticides to control cereal aphids, Sitobion avenae, that are resistant to pyrethroids. Crop Protection in Northern Britain 2014, pp 136-136

 

Check out application conditions for your postcode

KWD banner imageThe popular and helpful on-line decision support “traffic light” system to aid the timing of both ASTROKerb® and Kerb® Flo 500 is now up and running. Uniquely data can be obtained by growers and agronomists at postcode level. This traffic light system works by reporting soil temperatures and soil moisture deficits in every individual postcode area across the UK.

Important label update for users of ASTROKerb

Dow AgroSciences is pleased to inform growers and advisors that CRD has granted an approval for ASTROKerb® to allow the straw from oilseed rape crops treated with ASTROKerb to be burnt for heat or electricity production. The following updated statement will now appear on the label : “DO NOT remove oilseed rape straw from the field unless it is to be used for burning for heat or electricity production.”

Agronomy Update – 21 October 2014

In this Edition

Getting the best ryegrass control in winter wheat
I have no blackgrass so why should I bother with a “residual”?
What can I use to control vol. beans in wheat?

This Edition’s FAQs:
Does Kerb Flo 500 control ryegrass?
Is there still “no –known” blackgrass resistance to Kerb Flo 500?
Can I use Galera this autumn?

Dates for the diary