Right-arm fast
Member
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.
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.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.
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.
Some of mine was. Some not. They could both now have similar levels of Aphids?OP crops is NOT treated with deter. Hence his concern.
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 ...
Hi, yes your correct to draw attention to these factorsNot 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.
Have you found the classical dead hearts associated with wbf???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.
Hi
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
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.
The latter. Prior experience given the number of days in nov where day temps >12.
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.