Risky or not

[Barmyfarmer]

Sprayed some stubble off with glyphosate on Saturday, hoping to drill on Wednesday, weathers changed and could do with getting grass undersown with barley in today, agronomist says I shouldn't do it because it needs 5 days before drilling anything into it... Do I risk it?

 

[Sam Partridge]

Sprayed some stubble off with glyphosate on Saturday, hoping to drill on Wednesday, weathers changed and could do with getting grass undersown with barley in today, agronomist says I shouldn't do it because it needs 5 days before drilling anything into it... Do I risk it?

Are you in a dry area, as in would you expect to experience drought like conditions May into June?

 

[Barmyfarmer]

Are you in a dry area, as in would you expect to experience drought like conditions May into June?

Nope, on heavy clay aswell

 

[deleted user 837354]

What needs 5 days before drilling? I'm confused. Neither grass nor barley will see the light of day for at least a week.

 

[Sam Partridge]

Nope, on heavy clay aswell

no experience of clay, could it bake off in a dry spell and cause problems? I'd probably just go for it. Assuming your agronomist means the glypho needs 5 days to work? most labels say 24-48 hours needed until drilling

 

[Woody j]

Sprayed some stubble off with glyphosate on Saturday, hoping to drill on Wednesday, weathers changed and could do with getting grass undersown with barley in today, agronomist says I shouldn't do it because it needs 5 days before drilling anything into it... Do I risk it?

There’s no risk

 

[deleted user 837354]

Basically, glyphosate is into the target weeds very quickly. For small weeds in stubbles grown only from roots, you are ok to have left it only 24 hours although I have known farmers cultivate or plough or drill the stuff within hours of it being sprayed (not saying this is a good idea mind) and I can't honestly tell you I've seen any big fudge ups result from this.

Where you need to leave roundup alone to work is in with spraying off massively weedy stubbles (spear thistles, rosebay willow herb, scrub etc etc etc or fully grown cover crops, OR grassland that has either been there a while (i.e. years) OR where it likely contains couch or creeping bent or rushes.

In the above circumstance I used to think leaving it for 3 days before applying manure/slurry and then plough after at least week has elapsed.

I have had people apply pre-emergence chemistry with glyphosate on board before with no issues.