Not sure if they make large quantities of chemical available to a consumer...but look into the Ortho Dial 'N Spray...I imagine there's other brands, but that's what I use when needed.

Ill second beehive. The ortho dial n spray is good cause you fill the resivore with your chemical and set the dial from 1 tsp to 8oz per gallon. It mixes with water and only mixes what is sprayed. If you have left over chemical, its not diluted, you can put it back in its container.

mroman59,

Here ya go. You can buy 2,4-D in quart, gallon, or even 2.5 gallon containers. Labeled for agricultural use, it is much cheaper. Just make sure you follow the directions, it is much more concentrated than the regular "stuff." I believe one of these at Tractor Supply, you only need one Tablespoon for two gallons of water.

You do not need a pesticide license to purchase 2,4-D. Quanity isn't really an issue as much as what the active ingredient is.

Forgot the link. Here ya go.

http://www.tractorsupply.com/lawn-garden/lawn-garden-chemicals/weed-killers/

You have enough garden hose and water pressure to use a hose end sprayer over 2 acres???

For 2 acres - You need boom sprayer, towed behind a tractor or ATV.

can you use a homade version and how much to use

Ancient threads stagger back to life every spring, it seems, like long-buried weed seeds dug up by people mistakenly tilling their lawns.

A homemade version of what? Weed killer? We don't tend to recommend them, or at least I don't, for reasons that they're downright dangerous.