How to spray several acres to kill dogbane/johnson/pigweed grass?

[prof fate]

From what I've been able to find I can spray 2,4-D and kill the offending weeds.

HOW to spray is my question.

I have a spot sprayer...but no spray bar. I can build one (seen several videos from people that have done it).

The bottle says something like 2 quarts per acre....how on earth do you figure out how to do that?

I've only ever spot sprayed roundup, like on a fence line, driveway, etc - get the leaves wet and move on. I mix at 3oz per gallon and just go spray.

I assume you catch the flow and measure it over say, 1 or 2 minutes and add in 5 heads (or whatever on teh bar) and then the speed you're driving? Sounds like a word problem from HS...

Will 2-4-D work on the dogbane/pigweed/johnson grass? Add something else to it?

 

[nybirdman]

I would mix 24D and glyphosate(round-up) a spray bar.Mix to the size of your tank;not rocket science.I.E.I add a pint of each to 15 gal.tank.

 

[Roadworthy]

I believe 2-4-D is a broadleaf killer. It was also one of the two chemicals in agent orange so handle with care. Roundup (glyphosate) is a non selective herbicide but use with caution. It is also known to cause health issues in humans. Would a mix of 2-4-D and Roundup do you any good? Perhaps. Or perhaps your cure all would be Roundup.

 

[kthompson]

If you will be spraying more than once consider a sprayer with boom or a boom less one. If you are spraying roundup guess you are wanting to kill most of the vegetation. You might be fine with an electric pump but you need to do some math first. You need to read how many gallons per acre, probably between 10 and 20 gallons per acre which is the chemical mixed with water. You then will use nozzles that will work with the pressure your pump will provide (40 psi is a good common pressure) and the gallons per acre you want to apply at a speed you can work with. You have to consider the spacing of the sprayer nozzles also, I use 20 inch spacing but you may prefer another. This link looks good on the info they provide. How to Select the Right Nozzles for Your Sprayer

When you think you have it all figured out put a measure amount of water in it and get your speed and all where you think it should be and spray a measured area to see if all working together. One issue is watch to not skip nor over spray by much. Don't spray in much wind and believe it or not don't spray when no wind at all. 2-4-D can drift with believe the correct term "inversion". Some crops and flowers are easy killed by that.

 

[Complete Turf Care]

I would suggest you contact your local county agent and ask for the right product to kill your weeds in your situation. After you contact them, here are a few things to keep in mind.

1. 2,4-D is a restricted use pesticide. This means you must have a license to buy it and to apply it. However, you should be able to buy it in small quantities such as a quart at a time. As someone mentioned, it will drift easily. There have been documented cases of it drifting 20 miles across the Mississippi River. If there is a vegetable garden any where close, do not use 2,4-D.

2. If your weeds are more than about 12" tall, you would probably be better using a 'boomless' sprayer. Basically, that is one spray nozzle that will cover 14-18' wide in one pass.

3. You will need to calibrate your sprayer to see how many gallons per acre you are applying. You just can not add 2 or 3 ounces per gallon and go spray like you do with Roundup. Think of it like this.... If you the rate per acre is 32 oz. and you fill your tank with 15 gallons and add the 32 oz. to the 15 gallons, then spray your area but you only cover 1/2 acre with the 15 gallons. Then you have effectively put out 64 oz. per acre. Does that make sense? An easy way to calibrate would be to fill your tank with pure water and go spray and area. Measure the area you covered and then you can figure your approximate gallons per acre.

Now, if your rate of herbicide is 32 oz. per acre and your sprayer is putting out 15 gallons per acre, you know to add 32 oz per 15 gallons. This may sound complicated, but it really is not. And getting the rate per acre is important, especially when you get to using more expensive products, and to get the full effect of the herbicides.

Hope this helps.

 

[CADplans]

Spraying, is about the same as mowing grass,,
you can calculate how much area you will spray with a mowing calculator,,

It is simply the width, and the speed,,

Mowing Calcuator | How many acres can I mow in an hour

I did not look for a spraying calculator,, there probably is one somewhere,,,

You are in DEEP trouble if you have a hydrostatic tractor,, the speed will be ALL over the place,,

I use a gear drive JD 650 when I want to spray,, a nice solid speed, determined by the gear I select.

 

[old and tired]

...Will 2-4-D work on the dogbane/pigweed/johnson grass?

There are many herbicides that can control Dogbane when they are still seedlings, but few are as effective once the plant has been established. Fall application of 2.4-D is typically the most effective termination method.

2-4D will not be effective for eradicating Johnson grass. Can you spot spray Johnson grass with RoundUp?

How big are the weed plants you trying to kill? Are the weeds growing in anything you want to keep alive?

"...Sounds like a word problem from HS..." Also a question on most pesticide applicator license tests.

 

[Birdhunter1]

I apply 2-4D and Roundup at 1 oz of each per gallon of water in my 15 or 25 gallon sprayer and a squirt or two of dish soap.
The soap helps it to stick.

If it’s heavy brush or woody stuff (like fence lines) I’ll bump that 2-4D anywhere up to 3 oz per gallon.

 

[RalphVa]

Follow the label carefully on 2,4D. Stuff is very volatile. Can spray it, and the energy put into the spraying can volatilize it such that it can carry for several miles and then condense and totally kill someone's veggie garden a couple miles or so away.

Spray only on a calm wind and cooler day/morning.

Ralph

 

[prof fate]

I would mix 24D and glyphosate(round-up) a spray bar.Mix to the size of your tank;not rocket science.I.E.I add a pint of each to 15 gal.tank.

roundup/glyphosate will kill teh hay too....DO NOT want to do that.
Second, how much coverage (acrage) does that provide? How did you figure that?