Black grass 2021

[Dog]

Up until now we have not had a problem with black grass. But one field seems to have got away on us. It’s first wheat after osr and would expect it yield about 10t/ha. There is not enough grass to effect the yield but too much to pull by hand. The area is about 12ac which would be about 4% of our total wheat area. The field has not been ploughed for 3 years.
what would people do who have had previous experience of this. My options are
a) harvest the crop, clean down machinery, plough ASAP and drill wheat as late as possible or spring barley
b) glyphosate, get as many chits as possible and drill wheat as late as possible or spring barley
c) might be an option to whole crop it but black grass has headed and would need cutting in a week or two so there won’t be much of a whole crop yield.

 

[benny6910]

Personally I would spray it if it isn’t possible to pull it by hand. I have a friend who gets gangs of people in to pull blackgrass. I think it worked out about £40 acre for what he had done. With wheat around £180 it would be a shame to destroy 50 ton of crop in my opinion if it was possible to pull it even if you had to pay a sizeable labour bill.

 

[Two Tone]

Harvest the crop, clean down machinery, plough properly in early October and immediately combi plant Hybrid Winter Barley. Give it a good pre-em stack of something like Crystal 4l/ha plus DFF 0.2l/ha, then followed by Avadex.

Ploughing it with a properly set up plough will bury the seed and the hybrid Barley will help out-compete the Blackgrass that survives the pre-em.

Don’t delay drilling too long or the worsening conditions will reduce the Barley’s ability to out-compete the Blackgrass.
If you have ploughed it well enough and buried the seed properly, you should get a good relatively BG free crop.

 

[Shutesy]

In my experience the theoretical usage of gangs of people coming in to rogue blackgrass sounds pretty good but trying to actually organise them to come in is another thing entirely. There is only so many rogueing gangs out there and a hell of a lot of blackgrass and other weeds that farmers want rogued, I'd guess a lot of people will have had rogueing gangs booked up a while ago.
If the OP has the option to wholecrop then I would be tempted to do that this year, it'll be a financial hit comapred to taking the 12ac of wheat to grain harvest but probably far better in the long run. Blackgrass will only just be heading and will take another couple of weeks to flower before producing viable seed and a bit longer then for the seed to start falling out when cut so give it a few weeks then wholecrop IMO.

 

[Bigjon44]

Harvest the crop, clean down machinery, plough properly in early October and immediately combi plant Hybrid Winter Barley. Give it a good pre-em stack of something like Crystal 4l/ha plus DFF 0.2l/ha, then followed by Avadex.

Ploughing it with a properly set up plough will bury the seed and the hybrid Barley will help out-compete the Blackgrass that survives the pre-em.

Don’t delay drilling too long or the worsening conditions will reduce the Barley’s ability to out-compete the Blackgrass.
If you have ploughed it well enough and buried the seed properly, you should get a good relatively BG free crop.

Plough this autumn, Bury all blackgrass seeds then don't Plough again for 7 years min

 

[Two Tone]

Plough this autumn, Bury all blackgrass seeds then don't Plough again for 7 years min

That is certainly one possibility.
However I fecked this farm up with BG by Min-tilling it, then returned to ploughing it properly for 6 years always using Hybrid Barley as the 2nd white straw crop.
Got BG control back under control enough to now start moving towards Zero-tilling.
So far, so good here. But I’ll repeat that is here and won’t in any way guarantee it will work everywhere.

If you can bury BG seed deep enough so that it is at least 2” below anywhere it can find daylight, 70% of it will die in the first year, then 70% of the 30% that is left the following year, and again the year after etc until after 7 years its has virtually all gone.

However, if you can plough it at different depths each year and in the same directions for 2 years on the trot, this also helps because a plough never fully inverts the soil, only turning it over by about 120 degrees. So it is vital that you get the skimmers set to at least 1” wider than the landslides and forward speed just right to throw the surface soil into the bottom of the furrow. I have found the ideal furrow width is a minimum of 16” here.

What you will end up with is relatively BG free fields, except for the headland bit a few metres into the field at each end where you can’t help but double plough, where the ins and outs are.

 

[teslacoils]

12ac? Rogue it unless it's a carpet. If carpet, then roundup it. You may think it's thick, but you'll be surprised. Do a bit each day. Start at the edges. Keep at it. Good fortnight and you'll get it done.

 

[Two Tone]

I’d think very carefully before Roundup-ing off pushing £10k’s worth of crop off out of 300 acres.

 

[Flatlander]

Keep in mind the combine will need some serious cleaning if the bg is still there at harvest time. Most will have dropped by then but there is always some. I’d lightly disc the field and make it grow. Doing this a few times will get most of it in a sprayable stage then hit it with round up. Plenty of time to do it during autumn and winter and be clean for spring barley,

 

[Case290]

O tolerance. Your be stuck with it if you don’t. If you haven’t had it before can’t imagine its the hole field. Knapsack it pull it out burn the worst parts with the sprayer.

 

[Brisel]

I’d think very carefully before Roundup-ing off pushing £10k’s worth of crop off out of 300 acres.

There's the longer term picture to consider - allowing a big seed return means a serious amount of change in the rotation to get it back under control later on. 12acres at 3 t/ac at £175/t is £6.3k assuming the whole field is written off. It won't do 4 t/ac with that kind of infestation. Start looking at a few spring crops at a much lower margin and less reliability.

Sometimes the first loss is the best one.

 

[teslacoils]

I shall be roguing for 200hrs at least this year. Usually start the week before lincs show. You've got ages before the seed is viable so get stuck in and the roundup the worst bits. Mark the area well, and remember if next year. One the data are long and the weather is warm it can be quite fun. Get the Mrs trained up too. Cold pint of cider after.

 

[fudge]

Up until now we have not had a problem with black grass. But one field seems to have got away on us. It’s first wheat after osr and would expect it yield about 10t/ha. There is not enough grass to effect the yield but too much to pull by hand. The area is about 12ac which would be about 4% of our total wheat area. The field has not been ploughed for 3 years.
what would people do who have had previous experience of this. My options are
a) harvest the crop, clean down machinery, plough ASAP and drill wheat as late as possible or spring barley
b) glyphosate, get as many chits as possible and drill wheat as late as possible or spring barley
c) might be an option to whole crop it but black grass has headed and would need cutting in a week or two so there won’t be much of a whole crop yield.

If it's not going to effect the yield "too much" in your words I would definitely harvest it. Then amend rotation to minimise your problem. on our marsh land, where bg is endemic, I would avoid winter barley since control measures in that crop are nothing like as effective as in spring barley.

 

[Lincsman]

Clean down after combining and fallow it next year, IE do nothing until July 2022, then spray and plough down, then drill as late as you dare and the chances are there will be so little blackgrass it wont be worth spraying... all from experience.

 

[Two Tone]

There's the longer term picture to consider - allowing a big seed return means a serious amount of change in the rotation to get it back under control later on. 12acres at 3 t/ac at £175/t is £6.3k assuming the whole field is written off. It won't do 4 t/ac with that kind of infestation. Start looking at a few spring crops at a much lower margin and less reliability.

Sometimes the first loss is the best one.

OP says he thinks the infestation isn’t large enough to knock yield that much. 1st wheat after OSR, he thinks will still do 4 tons/acre. @£200 = £9.6K

 

[Brisel]

OP says he thinks the infestation isn’t large enough to knock yield that much. 1st wheat after OSR, he thinks will still do 4 tons/acre. @£200 = £9.6K

Fair comment. It is a big hit to take at once.

What do you think about the longer term cost if there is a lot of seed return?

 

[Lincsman]

Fair comment. It is a big hit to take at once.

What do you think about the longer term cost if there is a lot of seed return?

Depends how you farm it, not much if you do it right.

 

[GeorgeK]

The big plus is hopefully you haven't got much seed mixed throughout the soil profile yet, worst thing would be to min till it and have it popping up for years every time the soil is disturbed. Perhaps combine then zero till a forage crop specifically to be cut before the BG seeds? This way most seeds are left on the surface to either germinate or become non viable, you still get a crop of sorts and zero seed return next year.

 

[Brisel]

Depends how you farm it, not much if you do it right.

And how do you do it right?

• Wide crop rotation
• Delayed drilling
• Stale seedbeds
• Rotational "proper" ploughing
• Spring crops
• Prevent seed return by rogueing/spraying out
• Use a range of modes of action in your chemistry
• Higher seed rates
• Competitive crops
• Check & improve soil structure, organic matter, pH, drainage & nutrient status
• Machine hygiene

 

[Lincsman]

And how do you do it right?

• Wide crop rotation
• Delayed drilling
• Stale seedbeds
• Rotational "proper" ploughing
• Spring crops
• Prevent seed return by rogueing/spraying out
• Use a range of modes of action in your chemistry
• Higher seed rates
• Competitive crops
• Check & improve soil structure, organic matter, pH, drainage & nutrient status
• Machine hygiene

Yes..


But delayed drilling, with a good Pre em along with ploughing is 90% of it.