Allotments 4 All

I have bought a container of glycophosphate which has a sprayer attatchment.  The area I need to cover with it is 12 feet by 20.  How do I spray this size of area easily.  The hand pump tires my hand after a few feet.   Can I dilute it and spray with a watering can?  Or will this stop the stuff  working properly?  Help please.

If it's a container with Just a spray on the top and is sprayed straight from container yes you could  pour it in to a watering can with a fine rose and use it that way ..It's a weaker mix for a watering can than a spray .But by how much you could dilute it down I wouldnt know  precisely, but  personally I wouldnt go more than 2 to 1..  See what others think ...

Thanks growmore.  I have just been round to the allotment and done it how you advised.