bydv risk how low is it

yellow belly · Nov 28, 2015

I have notilld wheat after rape that has had no slug pellets

the field was covered in spiders webs and when scratching in the rape stubble there was plenty of slug eggs as well as plenty of different insect life beetles ect

I have not found any small slugs grazing the wheat so I conclude that the beneficials have controlled the slugs by destroying the slug egges I saw at emergence

I am also not going to spray for aphids as the same benificials as well as the spiders will prey on any aphids that land on my crops

I believe I have a low risk because
1 we have not seen bydv for years
when it was bad in the 1980s it was on crops drilled in the early part to September which were emerged by the 15th and tillering by the 1st October
2 drilled first week of October emerged 10 to 12 days later in 2014 drilled on 24 September was up in the rows in 7 days no bydv seen in the crop
3 very few aphids seen in wheat crops in the summer
4 plenty of lady birds seen all year till first frost last week
5 no till but not drilled on the green sprayed off in early September so there was little green for aphids in September
I feal the risk is higher if drilling on the green the green cover needs to be indpected for aphids prior to drilling to reduce the risk

with such a low risk I do not want to add any insecticide to the system that will reduce all the benificials some may say the cost is low but a £1 and acre plus fuel and sprayer time it adds up to a couple of thousand

note on other farms the risk has to be analysed for local conditions
agronomists and farm managers have other pressures and making a wrong call is not allowed which an individual farmer who is responsible to no one else does not have

my saving over the last 20 years must be over £40 and acre on wheat

britt · Nov 28, 2015

I've not sprayed late September/early October drilled wheat for aphids in the autumn for the past 3 years, and not seen a problem. I have no intention of spraying it this time.

dontknowanything · Nov 28, 2015

yellow belly said:
agronomists and farm managers have other pressures and making a wrong call is not allowed which an individual farmer who is responsible to no one else does not have

This is a key point. However there should be nothing to stop one of them bringing up ideas like this if they feel it is worthwhile. Then the decision can be made jointly, when the risks of failure are known. If not possible, there's something wrong with the business.

doorknob · Dec 2, 2015

yellow belly said:
I have notilld wheat after rape that has had no slug pellets

the field was covered in spiders webs and when scratching in the rape stubble there was plenty of slug eggs as well as plenty of different insect life beetles ect

I have not found any small slugs grazing the wheat so I conclude that the beneficials have controlled the slugs by destroying the slug egges I saw at emergence

I am also not going to spray for aphids as the same benificials as well as the spiders will prey on any aphids that land on my crops

I believe I have a low risk because
1 we have not seen bydv for years
when it was bad in the 1980s it was on crops drilled in the early part to September which were emerged by the 15th and tillering by the 1st October
2 drilled first week of October emerged 10 to 12 days later in 2014 drilled on 24 September was up in the rows in 7 days no bydv seen in the crop
3 very few aphids seen in wheat crops in the summer
4 plenty of lady birds seen all year till first frost last week
5 no till but not drilled on the green sprayed off in early September so there was little green for aphids in September
I feal the risk is higher if drilling on the green the green cover needs to be indpected for aphids prior to drilling to reduce the risk

with such a low risk I do not want to add any insecticide to the system that will reduce all the benificials some may say the cost is low but a £1 and acre plus fuel and sprayer time it adds up to a couple of thousand

note on other farms the risk has to be analysed for local conditions
agronomists and farm managers have other pressures and making a wrong call is not allowed which an individual farmer who is responsible to no one else does not have

my saving over the last 20 years must be over £40 and acre on wheat

Do you have a university testing facility near by? Have you ever sent it a sample to be tested for bydv?

yellow belly · Dec 2, 2015

doorknob said:
Do you have a university testing facility near by? Have you ever sent it a sample to be tested for bydv?

the last test I read about mentioned that less than 10% were infected

Clive · Dec 2, 2015

yellow belly said:
I have notilld wheat after rape that has had no slug pellets

the field was covered in spiders webs and when scratching in the rape stubble there was plenty of slug eggs as well as plenty of different insect life beetles ect

I have not found any small slugs grazing the wheat so I conclude that the beneficials have controlled the slugs by destroying the slug egges I saw at emergence

I am also not going to spray for aphids as the same benificials as well as the spiders will prey on any aphids that land on my crops

I believe I have a low risk because
1 we have not seen bydv for years
when it was bad in the 1980s it was on crops drilled in the early part to September which were emerged by the 15th and tillering by the 1st October
2 drilled first week of October emerged 10 to 12 days later in 2014 drilled on 24 September was up in the rows in 7 days no bydv seen in the crop
3 very few aphids seen in wheat crops in the summer
4 plenty of lady birds seen all year till first frost last week
5 no till but not drilled on the green sprayed off in early September so there was little green for aphids in September
I feal the risk is higher if drilling on the green the green cover needs to be indpected for aphids prior to drilling to reduce the risk

with such a low risk I do not want to add any insecticide to the system that will reduce all the benificials some may say the cost is low but a £1 and acre plus fuel and sprayer time it adds up to a couple of thousand

note on other farms the risk has to be analysed for local conditions
agronomists and farm managers have other pressures and making a wrong call is not allowed which an individual farmer who is responsible to no one else does not have

my saving over the last 20 years must be over £40 and acre on wheat

agree totally, other than your point re green covers - it makes no odds IMO aphids presence doesn't mean BYDV they are only carriers so have to get the BYDV from somewhere, if you or your neighbours didn't have BYDV last year then where is it coming form ? also feel and have read that zero till crops confuse aphids that like to see green / brown lines to identify crops, they don't get that with zero till !

I have seen wheat drilling on the green after 5ft summer cover buzzing alive with aphids in late September, no insecticide or seed dressing and no BYDV and over 10t/ha yield

risk is overstated, the way people throw insecticides without thinking of the consequence is like farming for dummies or painting by numbers - no thought required and fear of loss marketing and advice prevails !

not sprayed or dressed seed for BYDV for some time now, I expect is saves a bit of money but more importantly I'm not harming beneficials which may in turn explain why I feel less need to use slug pellets and insecticides

insecticides create the need for insecticides - its a hamster wheel that you have to be brave and jump off at some point

yellow belly · Dec 2, 2015

I have seen where some farms have used 6 insecticides on osr
not used an insecticide on osr for a 10 years or more

if I have a few prediters per ms will aphids have a chance also will the slug eggs and juvenile slugs get eaten

Clive · Dec 2, 2015

yellow belly said:
I have seen where some farms have used 6 insecticides on osr
not used an insecticide on osr for a 10 years or more

if I have a few prediters per ms will aphids have a chance also will the slug eggs and juvenile slugs get eaten

no idea if its connected by I haven't seen few beetle issue in OSR when I know it has been a problem in my area in general since neonics were banned, is there a connection to beneficial population maybe ???

spiders are great slug hunters - my osr crops are covered with webs

ajd132 · Dec 12, 2015

Havnt and won't spray any hear. Was looking on the sprayer drivers uk Facebook here and it seems a lot of these really big farming units just hav a set spraying regime for certain crops that they just go with whatever the conditions. Someone was saying he will put his BYDV spray on in the next hard frost.....

The_Swede · Dec 12, 2015

BYDV spray on a hard frost is of course ridiculous but on the other hand is anyone actually surprised to hear such things.... even if these folks aren't bothered about beneficials on a large scale costs related to these 'cheap' sprays still add up... Remote, pre-conceived agronomy and farm management... fantastic.

doorknob · Dec 18, 2015

We see a lot of calendar based pesticide applications here as well. People just seem to get stuck in a habit and never look to change.

But "here" (western Oregon USA) yellow dwarf has become a real issue. Never really used to be so much, but too many years of no rotations and wall to wall grasses has not only removed the habitat for beneficial bio controls, but the pesticide usage has breed the perfect scenario for an outbreak of unseen size. This is what we are fighting now as well as seeing aphids adapt and increase in numbers.

So though I am in no position to give any advice, I will say that it might not be a bad idea for you to keep up on the yellow dwarf changes in your area. Once that virus adapts a strain to your perennials, look out. Then you will have lawns and grass ways harboring the virus for the aphids to stop in a pick it up.

Hindsight · Dec 18, 2015

doorknob said:
We see a lot of calendar based pesticide applications here as well. People just seem to get stuck in a habit and never look to change.

But "here" (western Oregon USA) yellow dwarf has become a real issue. Never really used to be so much, but too many years of no rotations and wall to wall grasses has not only removed the habitat for beneficial bio controls, but the pesticide usage has breed the perfect scenario for an outbreak of unseen size. This is what we are fighting now as well as seeing aphids adapt and increase in numbers.

So though I am in no position to give any advice, I will say that it might not be a bad idea for you to keep up on the yellow dwarf changes in your area. Once that virus adapts a strain to your perennials, look out. Then you will have lawns and grass ways harboring the virus for the aphids to stop in a pick it up.

You might find these report interesting. UK has a series of aphid suction traps located around the main arable area. Weekly assessed for aphid species flying and reported in these documents.

yellow belly · Dec 21, 2015

reading the reports the proportion of aphids at rothamsted that colonise wheat is 0 % so the risk to crops there is very low
but the report does say the risk that aphids in the crop will multiply in the current weather
aphid in the crop may be multiplying but if there were few aphids that entered the crop in oct nov the risk is low
any one got out on the sunny days and seen any aphids

I am very unwilling to use insecticides as there are many beneficials in my notill crops probably many more than there are aphids

look into the sun in the warm afternoon and look for specks on the leaf if you see a speck look closer to see if it is an aphid

in the 90s when I found them in December on 1 leaf wheat I sprayed one block less one field no bydv found in the spring since then I have not sprayed in the autumn it is possible to control bydv in march if many aphids are found or we get no aphid killing frost

in the 1980s when we had bydv very bad we burnt straw and drilled very early first week of September with crops 3 leaf and tillering by the end of September all high risk practices straw burning would not help the beneficials this year we nad no wheat up before the 10 October
the south and west will have potentially higher risk

from the trap data the north is also a risk

I will have look into catching or monitoring aphids locally in the future because insecticide resistance will prevent control being effective and farmers are technically capable of identifying aphid types and growth stage they are only another type of livestock

shakerator · Dec 22, 2015

yellow belly said:
reading the reports the proportion of aphids at rothamsted that colonise wheat is 0 % so the risk to crops there is very low
but the report does say the risk that aphids in the crop will multiply in the current weather
aphid in the crop may be multiplying but if there were few aphids that entered the crop in oct nov the risk is low
any one got out on the sunny days and seen any aphids

I am very unwilling to use insecticides as there are many beneficials in my notill crops probably many more than there are aphids

look into the sun in the warm afternoon and look for specks on the leaf if you see a speck look closer to see if it is an aphid

in the 90s when I found them in December on 1 leaf wheat I sprayed one block less one field no bydv found in the spring since then I have not sprayed in the autumn it is possible to control bydv in march if many aphids are found or we get no aphid killing frost

in the 1980s when we had bydv very bad we burnt straw and drilled very early first week of September with crops 3 leaf and tillering by the end of September all high risk practices straw burning would not help the beneficials this year we nad no wheat up before the 10 October
the south and west will have potentially higher risk

from the trap data the north is also a risk

I will have look into catching or monitoring aphids locally in the future because insecticide resistance will prevent control being effective and farmers are technically capable of identifying aphid types and growth stage they are only another type of livestock

I think your overestimating the power of pyrethroids and underestimating the protection of mulch cover. Just think of cyper as foliar knockdown /protection ....I have seen beetles and spiders in stubble looking full of vigour 4 days after application

I have seen bydv in no till 2nd cereals drilled end oct sprayed mid dec but never had prob on green into OSR or bean

After years of agonising over deter vs pyrethroids my conclusion is the latter is less damaging , but it's toss of the coin really

March drilling the way to avoid insecticides and sleep at night

shakerator · Jan 30, 2016

Bringing this old chestnut up again.....

Early oct drilled wheat

T sum 170 reached end Oct ..... Sprayed end Oct

Start fresh T count from 7th Nov.
Nov cet = 9 degrees, minus 3 = 138
Dec cet = 9 degrees, minus 3 = 180
Jan cet = 6, minus 3 = 90

It's been too wet to get on again, but these are incredible figures, with a total of well over 400 since last pyrethroid, the question is should 1 be added to the next pass ASAP???

Hopefully the colder spell earlier in the month will negate the above figure. This is a concern for me though, as in 2011/12 I was all "protect beneficials and keep scouting for aphids" and got burnt badly on a couple of fields

Volunteer stubbles and wild oats in long term no till plastered in aphids ....

britt · Feb 4, 2016

Were they second wheats where you had problems ?

Mr Charisma · Feb 4, 2016

Having seen the damage that BYDV can do ,,,,,,,,, cut 85 acres for next door neighbour and if memory serves me correctly sent about 55 ton back to the rainstorms , his neighbours was even worse I'm told it makes me very wary about dropping out an insecticide in the autumn

Made for quick combining tho , back home for tea ,,,,,, silver lining and such like

doorknob · Feb 6, 2016

Not all aphids carry the virus, and the off spring are not born with it, even if the parent were a carrier.

They have to stop off at a virus site and pick it up. But any stem piercing insect can carry and transmit the virus to the crop at any time. The virus does not freeze out as far as I have found, only the carrier numbers are reduced by a freeze. So if you have a site that is protected from sprays or a neighbor field that was not treated, the virus can be picked up at any time and spread.

Even though the BYDV "here", which now has a couple variations, one being "cereal yellow dwarf virus", has had a low occurrence history, with the over use of insecticides that goes with the lack of rotation, the carrier predators have all but vanished.

shakerator · Feb 6, 2016

britt said:
Were they second wheats where you had problems ?

First wheats also

bydv risk how low is it

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100% I’ve had enough of farming!

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