Spraying Smartweed in Kikuyu/Paspalum Pastures

5 posts

Member for

6 years 5 months
Last seen: 03/08/2018 - 21:05
Joined: 10/14/2017 - 20:38

Spraying Smartweed in Kikuyu/Paspalum Pastures

Hi All,

 

Our place is floodplain country, with heaps of rushes, smartweed and fireweed.

 

I'm getting amazing results on the bullrushes using 540 glyphosate applied with a "Rotowiper", nearly 90% first application with the grass untouched.

 

Now I'm looking for a selective spray for the smartweed, which heavily infests the place in the wetter parts.

 

I'm using a Silvan 600L tractor spray unit with a boomless spray nozzle setup.

 

I was going to use Metsulphuron at 6gm/100L water, with a bit of soap/wetting agent, but am getting warned it will knock over my kikuyu/paspalum pastures as well.

 

I really want to get this smartweed out, as the neighbor will cut round bales for me for free and keep half of them as payment.

 

Can anyone recommend a selective spray that will suit the task without damaging my pasture, and without too long a witholding period?

 

Cheers for any help.

Last seen: 03/28/2024 - 10:29
Joined: 02/28/2011 - 14:19

Hi Cowbloke,

Welcome to the forum and thanks for the question.

I would use Kamba M at 2.5 to 4 litres per ha if boom spraying or 300 mls per 100 litres if spot spraying. All label rates and registered. I would add 5 grams of metsun 600 for good measure and increased residual activity. No grazing withholding period. This will not hurt paspalum or kikuyu.

Please ensure you consult the chemicals MSDS (Material safety data sheet) and label prior to use.

Regards,

Stuart 

(Farmstyle consultant)

Last seen: 03/08/2018 - 21:05
Joined: 10/14/2017 - 20:38

Thanks very much Stuart,

 

Was just speaking to Specialist Sales in Toowoomba, and he was recommending MCPA 750. I think the reason was it was less likely to kill my clover than the Kamba M. What's your thoughts on that?

 

http://www.specialistsales.com.au/products-53/crop-protection-chemicals/herbicides/mcpa-750-selective-herbicide-20-litre.html?___SID=U

 

As he reckoned it was softer on broadleaf pastures and a good thistle/fireweed (which I also have but wasn't thinking about so much) killer. I'd just sent him back a question regarding adding a bit of Metsulfuron as well, just for good measure.

 

My 600L sprayer has a boomless nozzle, and I have gone through the exercise on another property (with no kikuyu) of working out litres/ha, but ended up just running metsulfuron at 10g/100L, with 200ml/100L of wetter. I then just aimed for wetting of the tops without runoff and got an amazing kill on bracken and various other weeds with no pasture damage.

 

If I treated my boomless sprayer as a "spot sprayer" and ran 300ml MCPA 750 + 5gms metsulfuron + 200ml wetter per 100L, and went for the same amount of wetting do you think that would be OK, or do you think the Kamba M is the better solution?

 

If you really think I should calibrate the sprayer I will, but it's a bit of a pain to do and would prefer to use a more forgiving mix.

 

Cheers,

 

Neil.

Last seen: 03/28/2024 - 10:29
Joined: 02/28/2011 - 14:19

Hi Cowbloke,

It is very difficult to control broadleaved weeds, especially woody weeds in a pasture situation and retain the clover. The clover will have already set seed and germinate next year. The MCPA 750 will not harm the clover as much but will not control the smart weed. You have the option of an expensive Herbicide used in Lucerne which would not harm your clover but with your current equipment it would be almost impossible to apply it correctly for the best results.

I hope this has been of assistance.

Regards,

Stuart

Last seen: 03/08/2018 - 21:05
Joined: 10/14/2017 - 20:38

It's funny, I had one supplier recomend MCPA 750 in preference to the MCPA/Dicamba blend (specifically for smartweed), and various other recommendations.

 

It's been all manner of recommendations regarding smartweed. Not saying this one is wrong by the way.

 

I'm tempted to just go with 6gms of metsulfuron/100L with a bit of wetter.

 

I have that handy and there's no withholding on it.

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