Roundup mix quantity

[Albanach]

I've got around 2000 square metres to spray (some hard paths and some 'soft' areas) and I'm finding the label very confusing? Has anyone got a mix quantity they use?
I think I should be aiming for an application rate of 1.5 - 6 l/ha which according to the knapsack spray info is 50ml per 2litres of water.
The product is Roundup Biactive. The soft area is what I hope to have as a lawn. We bought an unfinished house site and there's never been any work done in the garden.

[Aberdeenplotter]

What weeds are you looking to kill. If you are intending putting the area down to grass, I'm assuming you will at least be turning the soil over and at that stage you will be able to remove most of the weeds including nasty perennials.

Having said that, as a rule of thumb, I use 100cc per gallon which is slightly weaker than the concentration on the labeling but is sufficiently strong for most weeds.

[Albanach]

Yep my plan is to spray and leave for 3-4 weeks, then turn over soil and spray again if necessary leave for another 3 weeks then work the soil to a fine consistency then sow seed.

[Kristen]

I'm finding the label very confusing?

With all due respect you are using an agricultural product which is sold on the assumption that the person has been trained in how to use it. As well as the maths you need to understand the type of vegetation you are needing to treat, and the delivery rate of the sprayer that you are planning to use (which is probably the biggest unknown, including what speed you walk out, and how wide an arc you then cover with the nozzle, as well as what rate the nozzle delivers). DIY products are sold with greater tolerance - although I expect also less effective, and more expensive.

I think I should be aiming for an application rate of 1.5 - 6 l/ha which according to the knapsack spray info is 50ml per 2litres of water.

I've never seen 6L/ha quoted, although perhaps that is for Knotweed or somesuch. Either way that wide range of application rates doesn't translate into a single dilution strength - unless you alter your walking speed and spraying arc accordingly

The most common rate is 3.2L/ha (I doubt that 1.5L is enough for any persistent weeds, but would be fine for annual weed seedlings) and I agree with AB:

Having said that, as a rule of thumb, I use 100cc per gallon which is slightly weaker than the concentration on the labeling but is sufficiently strong for most weeds.

Me too - I have a "measure" which I have marked with 80ml and 100ml and I pour to somewhere between the two (which saves me having to try to get it just right - its a big can, with a large spout!) and then I fill up my sprayer to the 5L mark - I reckon that's about the same as 100cc per gallon

I've got around 2000 square metres to spray

Another way to look at it is that that is 0.2ha, so assuming 3.2L/ha application rate you need to put on 640ml - so if you actually use somewhere between 0.5L and 0.75L of Roundup, once you have sprayed it on the area, then that should be "enough" Don't spray it on to the point where it runs off. If you haven't put enough on, when you have finished, my advice would be to go over it again - particularly on any "nasty" weeds.

Yep my plan is to spray and leave for 3-4 weeks, then turn over soil and spray again if necessary leave for another 3 weeks then work the soil to a fine consistency then sow seed.

I would suggest re-spray in 2 weeks for anything that has not gone yellow, then cultivate two weeks after that. Once you turn over the soil it will be a while before you have anything showing worth spraying ... but any roots that were still alive will come back with hefty weed plants quite a while later, so your aim needs to be to kill everything before you cultivate, rather than after - for example rotavating will chop up all the roots and any [belonging to pernicious weeds] that are not dead will each regrow into a plant

[Alison]

With all due respect you are using an agricultural product which is sold on the assumption that the person has been trained in how to use it. As well as the maths you need to understand the type of vegetation you are needing to treat, and the delivery rate of the sprayer that you are planning to use (which is probably the biggest unknown, including what speed you walk out, and how wide an arc you then cover with the nozzle, as well as what rate the nozzle delivers). DIY products are sold with greater tolerance - although I expect also less effective, and more expensive.(

You see this probably sums up exactly what scares me about these products, people who don't know what they're doing can relatively easily get hold of them and use them at far greater strengths than necessary. If used irresponsibly the spray can drift all over. In this case the OP is quite sensibly asking for advice but this will not be true of all users and without the training to which you refer these things can be very dangerous.


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[Kristen]

You see this probably sums up exactly what scares me about these products, ...

^^^ this ^^^

Although in the case of Roundup I reckon its going to kill whatever it touches, pretty much regardless of concentration, so I think the drift / pollution risk is "acceptable" and Roundup is amongst the "safer to use" chemicals that are out there. But that's only my opinion - and having said that there much less margin of error with a 5L container of agricultural-grade Roundup than the 0.5L pot of safer-for-Joe-public that you get in the Garden Centre ...

Personally I would use eye and face protection when mixing, because the commercial containers of Roundup have a huge opening and are likely to "splosh" when poured (although I expect that many DIY users wouldn't bother with that, as they have probably never perceived such a need when using other chemicals available for DIY being as how they are designed for poor-handling by end-users etc) but other than that I don't have many qualms about it (as Roundup is only mildly toxic), and thus the O/P is likely to be safe ... but that is full of words like "assume" and "probably" and "maybe" ...

Its when I see people talking of using much more dangerous chemicals, for example where a professional would use a full body suit and breathing apparatus, that I worry - but then my answer would of the "don't do it" type

[Kristen]

P.S. Might be worth a Google for Safety Tips when using Agricultural Chemicals to at least be aware of what would be regarded as prudent.

[bearded bloke]

Dilutions should be :

Annual Grasses & Annual Broad Leaved Weeds 1:67 with water

Perennial Weeds 1:40 with water

Remember spraying should not be done until weeds have emerged and are actively growing

As well as all the sage advice above,it would be very prudent to check the wind direction & strength prior to spraying,as the overspray/drift is going to kill whatever it lands on.

[The poly tunnel poet]

Please be careful, we only ever seem to discover the pitfalls of products years after their effect has caused undeniable damage....

[Kristen]

I am certainly not going to disagree with you, but Roundup has been on sale since 1973 and close to 100,000,000 Litres of Glyphosate is used in the world each year ... If there is a significant and dramatic effect its taking its time to become detectable.

[Nicos]

...bit like the effects of nitrates on the water table??

Our water source is apparently within 'normal limits' whatever that is...but there are a lot of neighbours who use pumped well water who are really concerned about the build up of chemicals contaminating their drinking water.

All the nature conservation peeps we have spoken too out here also look really horrified when we mention glyphosates.

As has already been mentioned...these things do take time to present themselves.
But as I am not an expert in this field I'm going to say nowt else

[Kristen]

We live in arable East Anglia and filter our (mains) drinking water for Nitrates. One of the many things we are "Not sure" about ...

[The poly tunnel poet]

Yes the figures seem to show us nothing to worry about, but many products are being pulled from shelves all the while and banned.

Although, those figures also suggest, someone grows wealthy, and large piles of money have the effect of preventing information detrimental to product sales becoming public knowledge.

I would only ask you research, and make your own mind up with a greater understanding of the many points of view appearing on the net.

I always remember a point in the book, "Silent spring".....

It was along the lines of,

a chemist would not enter a lab and mix the chemicals, that a world of gardeners throw on unwanted crops and insects. It was at that point I thought, if a chemist would not mix all those chemicals that run off into waters and small ponds, what on earth are we doing?

The products we are free to use come with many guidelines for wearing this and that kit, goggles, suits and breathing apparatus. Why? If there is no risk to human health?

Perhaps I am over cautious but an additional thought. If no one is looking for a thing, it is going to be found eventually, but not as quickly as it ought to be!

Tptp

PS, just read part of this thread lower down the weed main page. may be worth a read

http://www.growfruitandveg.co.uk/gra...ate_75793.html

[bearded bloke]

Well as the original point of the thread has been full-filled & is going into the perennial to use or not to use,I would say that I like the forum in general am largely as organically minded as possible,that said I do use glyphosate products on flagstone & block paved areas of my garden
This lead me to be a little curious about attitudes to this subject on other forums,whilst mooching about I stumbled on a thread that did worry me more than the chemical itself,seems some people changed the chemical formula ...




Wonder if these people are actually qualified chemists or enthusiastic amateurs

[Aberdeenplotter]

Please be careful, we only ever seem to discover the pitfalls of products years after their effect has caused undeniable damage....

yes, like potatoes are bad for you this week and come next week the advice has changed again.