Aphids in non deter cereals

Discussion in 'Cropping' started by Right-arm fast, Jan 14, 2019.

  1. Just wondering if anybody has found any. We have about 100acres of wheat with no seed dressing at all which seems to be pretty clean but I am a bit paranoid about it.
     
  2. ih1455xl

    ih1455xl Member

    Location:
    northampton
    Buy some sheep so you have something else to worry about
     
  3. farmerm

    farmerm Member

    Location:
    Shropshire
    I will soon be corrected but won’t the Deter seed dressing have losts its effect by now, for one thing it is diluted through much more biomass now? Regards finding Aphids, I avoid looking at crops unless the ground is dry enough to take a sprayer without making deep water collecting channels. I worry less about what I don’t know.
     
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  4. Hindsight

    Hindsight Member

    Location:
    Lincolnshire
    OP crops is NOT treated with deter. Hence his concern.
     
  5. farmerm

    farmerm Member

    Location:
    Shropshire
    Some of mine was. Some not. They could both now have similar levels of Aphids?
     
  6. Brisel

    Brisel Member

    Location:
    Dorset
    If your crop is clean, stop worrying. We've had enough frosts to stop the aphids flying for fresh infection. When was it sown and has it had any follow up treatments in the autumn? If you start to see yellow spots in the crop from wingless bugs hopping around, treat with an insecticide.
     
  7. Its also dry, so i am thinking its a good moment especially with a bit of cold weather coming to help. I walked it again and have found the odd aphid...……...
     
  8. shakerator

    shakerator Member

    Location:
    LINCS
    Not easy to find aphids. Doesn’t take much to infect.

    It has been exceptionally mild. I know winter is forecast, but unless we get some -8 or lower temps I think they will have carried on reproducing. No deter here- 1 hallmark- and judging by the T sums it may not be enough coming out of winter ...
     
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  9. Hindsight

    Hindsight Member

    Location:
    Lincolnshire
    Not sure you are quite correct. Bird Cherry aphid are more susceptible to frost, but grain aphids more tolerant.

    So for grain aphids then temperatures down to possibly -6 to -8 but less than that for Bird Cherry, say -2.

    Then of course is the periodicity of the frost and any mitigating factors such as crop canopy or the aphids have moved slightly below the soil surface. And those mitigating circumstances in conjunction with the Grain aphid issue is why you have chosen the most extreme temperature of -8C.
     
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  10. shakerator

    shakerator Member

    Location:
    LINCS
    Hi, yes your correct to draw attention to these factors

    Goes without saying I expect to find both species in the field .

    Have just looked up the CET figures for the T sum and it appears to be nearly 300 since I applied the pyrethroid late October. (Late September drilled so around 300 at application time too) So the frosts are needed pretty pronto IMV

    Later sown on BG land will be fine I’d imagine with 1 treatment or deter
     
    Last edited: Jan 14, 2019
  11. Flat 10

    Flat 10 Member

    Location:
    Fen Edge
    Anyone found any WBF activity yet? I think I did today in late Nov sown WW after beet. Couldn't find a maggot but it's thinned out in stretches and better where rolling tractor ran. Never saw the rooks pulling it out.
     
  12. I did not find any bydv carrying aphids in the autumn then frosts in October reduced the likely movement
    The aphids we found were peach potatoe in rape volunteers

    If aphids have come in since October there is plenty of time for winter frosts to kill them or spray in March
    The trials in the 1980s showed that later infesting aphids could be controlled in March if weather did not do them

    Not sprayed in the last 30 years and seen very little bydv
    My beneficial levels also higher due to notill and no sinscecticide use

    September emerged wheat is the most yield affected from September infestation the yield losses are several times lower every weeks emergence after October 1
     
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  13. robbie

    robbie Member

    Location:
    the brecks norfolk
    Have you found the classical dead hearts associated with wbf???

    In early autumn I found a few patches of dead heart in a field of continuous wheat, it was far to early to normally see damage. The patches also correlated with wet patches in the spring were the wheat thinner.
     
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  14. Hindsight

    Hindsight Member

    Location:
    Lincolnshire

    Assuming the end of October pyrethroid killed any aphids that were present is it likely more aphids would have flown in since? Your statement assumes that either the pyrethroid did not kill the aphids or that there has been subsequent invasion in early November.
     
  15. Hindsight

    Hindsight Member

    Location:
    Lincolnshire
    Just to promulgate in a relatively malicious way aphids today was a lovely day for walking fields. No wind and about 8C with dry soil - not often one can walk fields in January in low shoes with no soil picking up at all. I had a look at a field of failed Oilseed Rape which was today being sprayed with glyphosate ready for replacement Spring Barley or Linseed. Barley volunteers about 30 cm tall having been there since end August. Now in that 'cover crop' I could find easily Bird Cherry and Grain Aphid. Mainly singletons with just off female with nymphs.
     
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  16. shakerator

    shakerator Member

    Location:
    LINCS
    The latter. Prior experience given the number of days in nov where day temps >12.
     
  17. Are we expecting frosts by the weekend? Hopefully that will help.
     
  18. Hindsight

    Hindsight Member

    Location:
    Lincolnshire

    Yes, I share your concerns. But given the superb weather of past 14 days with fields that will travel with a sprayer why then have you not treated all your winter wheat with a pyrethroid insecticide. From your posts in this thread I would have expected you to have been out with the sprayer taking full advantage of these unbelievable conditions. Regards.
     
  19. Brisel

    Brisel Member

    Location:
    Dorset
    2 spray days in the last 3 weeks here. Been trying to get on with spraying off field margins & cover crops.
     
  20. shakerator

    shakerator Member

    Location:
    LINCS
    About to do so ! I have never treated twice before . Suppose I’m making a big thing of it as some don’t intend to treat at all !
     
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