Killing off thristles in new ley

countyhouse

I re seeded with Clover a field on 6 June. It was sprayed off but had a thick infestation of creeping thristle. It wasn’t ploughed for about eighty years and is damp/dark soil. I had to have it rotovated as it couldn’t be ploughed due to shallow stone drains which have been repaired over the last two years.

I was advised not to use thistlex in a new ley as it is only suitable for reseeds over a year old. It will also kill the Clover.

one suggestion from a local Agri store is to spray with a mix of Tribe 75 WG 100 (7 GRMS/HA) and mcpa 1litre to HA, however in the case of mcpa it is not recommended for new keys under a year old!! This combination may not kill the Clover.

I would appreciate some guidance here

nilhg

https://www.pcs.agriculture.gov.ie/media/pesticides/content/products/labels/05696%20-%20Tribe%2075%20WG%20-%202022%20to%20date.pdf

Tribe doesn't have label clearance for reseeds or even established grassland so technically it would be illegal for you to use.

I don't think you have many good options bar top for this year than try and get rid of the thistles next year with something like pastor trio

countyhouse

Thanks very much for that, I won’t be getting that then.

what is the difference between paster trio and thistlex. Would both kill the new reseed if used now or just set the growth back?

nilhg

Thistlex

https://www.corteva.ie/products-and-solutions/crop-protection/thistlex.html

Pastor Trio

https://www.corteva.ie/products-and-solutions/crop-protection/pastortrio.html

Pastor trio actually has a reduced rate label recommendation for newly sown leys so that's an option this year, possibly follow up with Thistleex next year for a more permanent effect.

Almost all of the grassland herbicides apart from the older hormone herbicides are mixes of a small enough number of active ingredients, Cloparayid would be best on thistles so the rate of that is higher in Thistlex.

Sometimes products don't have label clearance for uses because the cost of getting it (doing the field work in experimental plots) wouldn't be justified by the sales, it dosen't necessarily mean it will kill or harm your reseeds but you'd have no comeback and if inspected would be in trouble with the PCS section of the Dept.

countyhouse

Nilhig,

Thank you very much for the advice in this case together with your knowledge about the various herbicides.

I bought the Paster trio this afternoon and I will use it when I get a dry day.

Bass Reeves

What was recommended to me a number if years ago was to graze the field hard and spray with MCPA after cattle were taken out and before the clover developed new leaves

It worked at the time the clover took a slight hit but recovered