DJanes1

The directions that come with the bulk round up left me confused with how much round up to water should be used. Does anyone know a generall formula? I buy the 2.5 gallon jug at TSC.

farm hunter

Here's what I do - \

The directions call for 20 oz per acre. It doesn't really matter if you mix that 20 oz with 20 gallons, 30 gallons, or 40gallons of waterand apply it one on 1 acre.

My sprayer puts out about 20 gallons of water per acre when I'm in 2nd gear. So I mix 20 oz with 20 gallons water - for one acre. If I'm spraying 3 acres - then 60 gallons water and 60 oz of 41% GLYPHOSATE.

In other words - the mixture isn't as important as knowing how much your sprayer puts out per acre.

FH

mrwake

OR two ounces to the gallon to kill grass 3-4 will kill most trees and well kudzo half and half

psandhu

FH nailed the answer.

i have a 15 gallon electric spray tank. it's attached to a 10.000 footboom with 6 nozzles that are calibrated for the output of the pump. it puts out 1.0 gallon per minute (it'll spray for 15.000 minutes). the spray swath is 11.000 feet.

i did the math. driving at 3.0000 mph for 15.000 minutes will cover 1.0000 acres. i know i'm exaggerating the figures with the zero's. but when i did my initial calculations, it worked out to exactly 43560 square feet covered by driving 3 mph with the 11 foot swath of the boom.

\

Criggster

The amount of concentrate you mix DOES matter! There is a huge % solution difference in 20 oz. glyphosateper 20, 30, or 40 gallons. Do the math! 20 oz divided by 20 gallons(2560 oz.)= .78% solution, 20 oz. divided by 30 gallons(3840 oz.)= .52 % solution and so on. The more water you use the less % of glyphosate you will have. According to the instructions most plants require a 1.5 % solution to effectively kill them.Or, about 60 oz. per 30 gallons= 1.56% solution. Do you guys get good kills using .78% solution 20 oz. per 20 gallons??? If so I need to cut way back!

psandhu

if you put too much water in your tank, but still apply the recommended amount of gly per acre, you'll have too much water and the solution will run off the leaves/blades.

Imagine spraying 500 gallons of water and 1 qt of gly on an acre. it would be so much that most of the gly would wind up on the soil.

Imagine spraying 1 quart of water and 1 qt of gly on an acre. the coverage and application would be so difficult that most of it would be wasted.

I think 15 gallons per acre is about the right amount.

farm hunter

You are right but so am I. If I put 40 gallons water in my tank, and only 20 oz of 41% gly - and spray in second gear - then I have 20 gallons solution left after I spray one acre. And I would need to spray it all a second time - to get all 20oz down on the acre.Thatwouldbe the same as applying 20oz per 20 gallons (but with better coverage in the end).

I think I read 20oz/acre - but used 22oz - just because. Mixedin 20 gallons works well for me - but most of my spraying is done on plants 6" or less when applying to Roundup Corn/Soybeans - I've had some larger plants not die back 100%.

FH

Wooddust

Go to Monsantos website and look at the label...there is no such thing as a general use rate and there is a different amount of carrier to use (water) per acre depending on the species you are going after.

It makes a HUGE difference on performance depending on the target. Dont believe this garbage that it makes no difference...and 20 ounces may be the rate for some uses but certainly not all uses.

Chemical companies spend a bloody fortune to build the data to support the lable...dont fall for the poster experts who over generalize.

Mr.G

When we get recommendations from our crop consultant to spray soybeans/corn with round-up - or any glyphosate - it is usually a 5 gallon/acre water rate using one quart of roundup and some surfactant.

Example fill for our sprayer - 1000 gal cap. is as such: 10 gallons Surfate (Surfactant sold by Agsco Inc.), 50 gallons glyphosate -

5 gallons per acre - 200 acres on one fill = 200 quarts/4quarts/gallon = 50 gallons

Sometimes we use 10 gallon nozzles but the rate stays the same - just fewer acres covered/fill.

I apologize if my math is incorrect in any way - the rates are correct tho.

farm hunter

I think you didn't like my post - you are entitled - I could be wrong but so far its worked for me.20 oz/acre was per the chart for <6" weedsin my corn plots - I did read the directions - and I should not have represented mymix as a "general formula", however-the mix I put down was fairly consistant with the average oz/arce listed for most applications. - It gives a good idea anyhow on where to start.

You are correct - we shouldn't over generalize - and it makes a big difference if you are trying to kill off 3 ft Ragweed or 4" foxtail.

Sorry if I offended - "general Question - general anwser" - Follow??

FH