How much glyphosphate mix do I need.

We're going up to spray the deer plots this morning. The weeds have completely taken over and crowded out my plot seed mix last year.
I have a 25 gal tank with electric pump and a wand. I bought a 2 gallon jug of glyphosphate - 41%.
Want to kill off everything on about 1 1/2 acres. How many gallons should I mix and at what ratio?
The jug came with a booklet but it's about 40 pages long. Sheesh!
I plowed and disced both plots this spring but didn't plant anything, just let the weeds/quack grass grow. I mowed both plots last weekend. Hoping to spray today then disc and plant winter rye in about 2 weeks.
Anyone have a rule of thumb for how much to mix?
I would appreciate any advice.

For a field burndown I use glyphosate at the rate of one quart per acre in a mix using 20 gallons of water per acre. You can make it hotter using 1.5 quarts/acre.

The instruction book IS confusing. It gives directions based on how fast you are driving, how much water you will use, and what kind of stuff you want to kill.

None of that stuff applies when using a 2 1/2 gallon pump up garden sprayer. What DOES work for me is to pour in enough glyphosate to cover the bottom of the sprayer, and then fill with water.

A 25 gallon tank WILL be different.

Broadcast spraying 1 to 2 qt per acre. Spot spraying in a pump sprayer 3-4 oz per gallon.
AaronSEIA

1 gallon per 50 gallons water or 2.66 oz per gallon of water is what I use and have very good luck. Don't forget the stuff to make it stick to all plant, some use dish washing soap some use the store bought stuff.

I would mix in some 24D

I have a 25 gal sprayer with a wand .I use 4 oz per gallon works good for me
RICK

don't forget the exciter for the roundup. my rule of thumb is 1 qt per 10 gallon of water. probably don't need that much in a spot sprayer because everyone has a tendency to drown things. the exciter is really important. most times i don't up the RU rate, i up the excitor rate.

FWIW I use three ounces per gallon of water and have at it. It works for me. A week or so later I go back and get the spots I missed.

You left out a lot of details... how big are the weeds? Those 40 pages you didn't want to read spell out specificly how much product is needed to kill each kind of weed, and it what size. You mentioned quack grass... if you do have quack grass and you want it dead (not just give it a headache) you will need 2 quarts to the acre of the STANDARD roundup product. There are also formulations with a stronger formulation- which do you have???

Last you need to know the application rate of your sprayer, as in 10 or 20 gallons per acre. Any ideas? Once you know that, you can do the math- example: something like 10 gallons of solution per acre, the solution containing 2 qt to the acre of 41% glyphosate.

To do it right the first time, you need to do your homework, and that involves reading the directions. Yes, you can skip the parts about applying with an airplane, but read the Rate of application part.

One can kill lots of weeds with a rate of 1 ounce of Roundup per gallon of water. I have used that rate for the last twenty years or so. Higher rates will give faster visual verification of the herbicide's effectiveness but it also empties the billfold faster.

The instructions say 2 oz. per gallon of water with a spot sprayer, and I get a complete kill with that rate. As someone else said, you tend to spray more product with a hand wand. 3 or 4 oz. is overkill, IMHO, and I think you get a better kill if you don't overdo it.

I'd put a pint (16 oz.) in 8 gallons of water for the first go-around, see how far it goes, and go from there.

I use 1 qt. per acer. My sprayer does 25 gallons per acer. I also add a pint per acer of water conditioner to the mix. I'm not sure of the contents of the conditioner as it has a different label on it every time I buy it from my chemical supplier. Left over spray is used in my hand sprayer with good results. I would add some 24D to the mix if you got it. Remember that it will be a few days before you see the results of spraying roundup.

As coonie said....read the parts of the book that pertain to your area, you will save money and get a more effective kill. It may also recommend a tank mix for hard to kill weeds. Ben

You are more spot spraying than field spraying. So I would mix a 2-3% solution. That would be 3-4 ounces per gallon of mix. Now I would also add the same amount of 2-4D. There are many broad leaf weeds that RR really does not kill very well. Then you really should use a surfactant too. This can be simple Dish soap. It helps break the surface tension of the water so it spreads out more evenly. An ounce per gallon is plenty if you use dish soap.

Fill you tank half way and add your chemicals. Then fill the tank up. Then add the dish soap. Take you wand and stick it under the surface of the water/chemical mix. Use the pressure of the wand to agitate the mix.

Now Two weeks is a short time to get a total kill with the RR. I would wait 3 weeks myself. Our plenty early for Rye anyway. Actually mowing the weeds down will make them harder to kill as you do not have much leaf area to take the chemical in to the root system.

You should spray when the weeds are growing & before you mowed it.

Question that was not answered was using that hand wand on the spot sprayer is how many gallons do you think it would take to cover that 1 1/2 acre. If it would take 1/2 a tank the mixture would be way different than if it would take 2 tanks to cover the area. I myself have no idea about how much water that type of sprayer would use to cover that area. Never tried to just ground cover with mine, just trees. So would one tank be enough to do that 1.5 acres or would he have to haul a second tank up to cover the area. Once that is figured out then time to start figuring rate of mix. So if it would take 10 gallons of water to cover that 1.5 acre the mix of roundup to water would be way different than if it took 50 gallons to cover the same area. I have done a lot of spraying with a boom sprayer so I can calculate that without problems, just do not know about how much a hand held sprayer would put on per acre. Would depend on how fast you can walk or with his 25 gallon unit would he be having to do a circle around sprayer and move it or pulling on a trailer behind a moving garden tractor. Getting the gallons of water figured out is first then the rate and those directions do nothing to figure out gallons the area will take to cover. So about what he needs to do is take the sprayer with just water and spray the area first and figure out how many gallons of water he used to cover the area and that is how many gallons of total mix he needs to make up using the correct rate for what he is wanting to kill. You all are good on amount of concreant to use, just isn't telling him total amount of mix he needs. If somebody has a better sujestion as to figure out total gallons of water needed I would like to hear it. At 1 pint to acre you might need 5 gallons of water mix or you migke need a 1 pint to 30 gallon mix depending on how wet you get the weeds and ground.

I've used an ounce per gallon since the 70's and it still works. Now they sell 43% so do you mix less per gallon. A lot of weeds and grasses are becoming immune so I guess we'll up the dose. A little Cross Bow (8 oz in 15 gallon) mixed with it helps. According to Monsanto 2% is what you need.

https://www.roundup.com/smg/goprod/...2;jsessionid=48ED5705BA8A7C56FA850CA37D58A317

The big thing is what type of roundup. Most generics are 4# active per gallon vs 6# for say powermax or weathermax. Both of which have stuff in their so you do not need to add other surfactants. If spot spraying with a wand 2 qts per 25 gal is how i mix, you can add 2 qts 2-4D if you have large broadleaf weeds also. The rate is not terribly important if you give weeds a good soaking. If you were broadcast spraying 64 oz. Per acre in 10 to 20 gal. Per acre would be sufficient.

good luck
Joe

Should have sprayed before you mowed.

This is getting overly complicated. Spraying with a wand and spraying with a boom are TOTALLY different.

You don't need to know gallons per acre or applications per acre, or ground speed or any of the of the boom sprayer facts.

What you need is to mix a solution that will kill the weeds then start the job of spraying back and forth, back and forth until you have wet everything down "once", with a spot spray solution. Generally 1.5 to 2 oz. of roundup per gallon will kill weeds. adding 2,4,D or Crossbow will help the kill rate. Dish washing soap will help the kill rate.

So 2oz. per gallon x 25 gal = 50 oz. per tank full. read the label. There are 128 oz per gallon. 2 gallon equals 256 oz, so you have enough to mix 5 tanks (at the rate of 2 oz per gallon.

I have a 25 gal wand sprayer, your arm is going to get very tired.

Wow.
Lot of replies!
We left at 7 this morning. There were 4 replies then.
Am back home again. It's done.
I filled the 25 gal tank half full, put 3 quarts of the weed killer in it and about 12 oz of Dawn dishwashing liquid, mixed it up with a stick then filled the tank full.
I used the rear dirt scoop on the 3 point to carry the tank and stood on it with the wand. My friend drove slowly. I just guestimated on the flow rate and adjusted the tip on the wand. We did the 1 1/2? acre of plots and had about 1 gal left at the end. Pretty good for guesswork. The last bit of it I sprayed around the sides of the garage where I can't get in to mow.
Arm wasnt tired but I broke the glass screen on my phone sitting on the scoop. Grrr.
What's done is done.
We'll see how effective it was when I go back up there in two weeks.
Many thanks to all of you. This is a great board.

I use a backpack type of sprayer and until I read the book I put a quart of RU in it and put the water to it it makes a 3 gallons tank. I was a dummy. It takes about a quarter of that amount. I have added diesel and dish soap to the mix and had the best results with the soap. Spray time is early in the day or at least 4 hours of daylight left. I make sure it's a good sunny day and if it's not ya gotta do it earlier in the day. Read the booklet it explains how the stuff does it's job. Once you understand what and how and when the stuff works it will be alot cheaper and easier. My totally unscientific results are day or two after applying no change in plant color days 3-5 sickly green to yellow and days 5-7 yellow to dried up and dead.

If that don't kill it ...try fire!

3 oz per gal for hard to kill weeds-guaranteed

I don't know the herbicide history of that plot, but you might have glyphosate resistant broad leaves in there. That's where the 2-4d comes into play. Generally in a situation like yours you should use glyphosate for the grass and 2-4d for the broad leaves so you can be darned shure everything will be dead.

I should add, if you make a weed sick but not dead you might have to wait awhile to spray again because the sick weeds won't take in the second spray as well. It's better to hit it with both barrels the first time. Adding an adjuvant will help kill the waxy surfaced fine leaved broad leaves that 2-4d has trouble with.

Before I read this I was going to suggest that 2 qt would give a solid kill on the estimated area... Good guesswork on the application rate of the sprayer! You over applied a bit but not too much on the product. I doubt much will remain after a week.

Rod