Flea beetle and previous crop.

[Niteforce]

Talking to my agronomist last week about flea beetle in this years crop and he was saying that leaving the volunteers growing in last years neighbouring Osr stubble would keep them in it so not migrating into new crop.Does anyone else do this if so have you noticed less numbers in new crop ?? I usually spray off volunteers and cultivate a seed bed by now but are willing to leave abit longer while new crop gets established if it will ease the pressure.

 

[Manny]

I was going to do the same but volunteers were covered in slugs last night and not a csfb in sight. So I have just got in from running a carrier through the rape stubble hoping to get a good kill on the slugs mechanically. Will get rolled late tomorrow night in hope of killing a few more. I'm hoping some more rape will come and attract any csfb that are about as I'm not planting my rape till next week.

 

[MrNoo]

I think it's just a very low pressure year on FB so far. All my ex rape stubble ground has been worked but very little sign of any FB damage, OSR drilled 8th Aug and beyond showing very little sign of FB damage, it's the slugs that have been the issue here.

 

[Brisel]

Flea beetle prefer eating the leaves of a succulent newly emerged brassica, less so in a tough old volunteer but they will be in the volunteers and may stay there so there may be some truth in it. Of course the more plants you have, the greater the reservoir of food for flea beetle...

AHDB note on CSFB here https://cereals.ahdb.org.uk/media/1079572/lr-cabbage-stem-is55-summer-2016.pdf

 

[Flat 10]

Flea beetle prefer eating the leaves of a succulent newly emerged brassica, less so in a tough old volunteer but they will be in the volunteers and may stay there so there may be some truth in it. Of course the more plants you have, the greater the reservoir of food for flea beetle...

AHDB note on CSFB here https://cereals.ahdb.org.uk/media/1079572/lr-cabbage-stem-is55-summer-2016.pdf

I've just been reading this for information with respect to thresholds for treatment, having been and inspected my crop and found relatively high numbers feeding last night and it discusses monitoring larval infestation and possibly treating later on? I didn't think anything could control the larvae in the stem?

 

[Gong Farmer]

Correct, don't even bother trying.

 

[Flat 10]

Correct, don't even bother trying.

You are referring to the larvae, aren’t you? Would you bother treating the adults now? Given that we might only get 50% control? I can’t decide if one treatment is better or worse than none as I will take out the beneficials

 

[Paul Gosling]

Evidence from year 1 of a 2 year trial ADAS are doing for AHDB gavce mixed results. In theory leaving volunteers should work to reduce CSFB in the new crop and it did at one site, but not the other.

 

[Gong Farmer]

You are referring to the larvae, aren’t you? Would you bother treating the adults now? Given that we might only get 50% control? I can’t decide if one treatment is better or worse than none as I will take out the beneficials

Yes, larvae. You might still get some control of adults now (according to your own previous experience) but I would only try once.

 

[Niteforce]

Going to check for population in old crop tonight .Then might try a experiment in 2 different neighbouring fields . spray and cultivate 1 and leave the other.

 

[Wombat]

Just been discing up this years rape stubble and loads of plants have FB damage.

 

[Case290]

Looked in day time saw bit of damage. Thought I go and look
Later
Wow just been and looked way more than last year. Osr just coming through on the better soil.

 

[Flat 10]

Just come in from doing mine, could see loads when I went in the field. Needed to spray gramincide anyway so decided to have one go at them. Many of the plants are trying to put out true leaves so this might get them past vulnerable stage. Pretty much decided not to spray them again

 

[Mr Charisma]

Can't see first field that was planted surviving the CSFB
Just of to have a look at 2nd field

 

[Case290]

How many flea beetle is to many think I’ve got one ever 3inch sq seams hell of a lot . Think previous crop doesn’t have a lot to do with it as some were fallow & some after wheat. previous rape crop 4 yrs ago no rape stubble any where near (1/2 mile approx ) . Last years rape volunteers seam to be flea beetle free. No logic or pattern I can see.

 

[Wombat]

Stubble turnips drilled 10days ago covered in flee beetle damage here

 

[Case290]

Best nozzle out of .. Forward back blue defy 3D or guardian air blue or Flat fan blue .

 

[Brisel]

Finer spray quality is best for a small bug like flea beetle. Flat fans then 3D then GA last

 

[Wombat]

Just been out to look at some stubble turnips and the little things are hoping around everywhere. Could find them easily where ever I stopped for a look.

 

[Case290]

Sprayed my osr last night went and looked after I had finished and found lots of dead ones. Thought that was wondfull . Just been and looked and they have replenished and there are just as many again.