How Many Gallons To Spray An Acre

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2. Crop production
3. Weed management
4. Herbicides
5. How to calculate herbicide rates and calibrate herbicide applicators

Uniformly applying herbicides at proper rates is essential for effective weed management. A slight variation in the application charge per unit with some chemicals may issue in poor control of the pest or injury to the crop or environment, causing lost fourth dimension, effort and coin.

Herbicide rates may be given in terms of active ingredient or acrid equivalent per acre treated, or as pounds or volume of commercial product per acre.

Agile ingredient indicates the amount of non-acid herbicide in a formulation. Acid equivalent indicates the amount of an acid herbicide in a formulation.

Herbicides may be practical circulate (uniformly over the entire field surface) or in bands (narrow strips of herbicide centered over the row, with the area between rows left untreated).

The application rate in the treated area should be the same for both the band and the circulate application. You can reduce the amount of herbicide needed by as much as two-thirds by banding the awarding over the row and decision-making the weeds in the middle with mechanical tillage.

For example: A iii-pound-per-acre charge per unit requires iii pounds of herbicide for each ingather acre in a broadcast application, but only 1 pound is needed to apply the herbicide in 10-inch bands on thirty-inch rows. To calculate the corporeality needed for ring awarding, multiply the broadcast rate past the band width divided by the row width.

Commercial products incorporate different amounts of active ingredients or acid equivalent. The product label may give the amount of herbicide formulation to utilise per acre. If you have to calculate from the active ingredient amount, apply 1 of the following methods.

Powder

Split the pounds per acre of active ingredient past its concentration in the product. If 3 pounds of active ingredient are needed per acre, and the product is an lxxx percent powder, then divide 3 past 0.fourscore to get 3.75 pounds, the amount of powder needed per acre.

Liquid

For liquids, the concentration may exist given in acrid equivalent. Then carve up the pounds per acre of acid equivalent needed by the pounds per gallon contained in the product.

For example: If you need 3 pounds per acre of acrid equivalent and the product contains ii pounds per gallon, divide 3 by 2 to get 1.five gallons per acre. This is how much product y'all need.

After you've calibrated the sprayer to know your application rate in gallons per acre, divide that number into the gallons practical with each tankful to find how many acres each tankful covers.

So, multiply the acres per tank by the herbicide needed per acre to find the herbicide to put in each tankful.

For example: Assume you have a 30-foot sprayer that holds 500 gallons, and you want to utilise an herbicide at three pounds of active ingredient per acre. The production comes as an 80 percent wettable powder. You calibrate your sprayer on a 300-foot course and utilize 4 gallons of spray to the course.

Your calculations are:

Pounds of active ingredient per acre / concentration = three pounds per acre / 0.80 = 3.75 lbs. per acre

(4 gallons per test x 43,560) / (300 feet x 30 feet) = 19.four gallons per acre

(Gallons per tank) / (gallons per acre) = 500 gallons / 19.4 gallons per acre = 25.eight acres per tank

iii.75 pounds per acre  ten 25.8 acres per tank  = 96.8 pounds per tank

For a granular material that's 50 percent active ingredient

Pounds of active ingredient per acre / concentration = 3 pounds per acre / 0.50 = half-dozen.0 pounds per acre

The applicator must exist set to put on 6 pounds of the granules per acre.

Figure 1: Spray distribution design of dissimilar nozzle types.

The sprayer must be set to use the proper amount of full spray mixture. This is usually given in gallons per acre and is listed with the herbicide recommendations or on the product label. Typical amounts range from 10 to 30 gallons per acre.

To check the distribution blueprint across the smash, operate over a polish, bare surface area. Set the blast at the proper pinnacle higher up the ground and spray slowly and so the spray wets the ground. If y'all encounter streaks as it dries, raise or lower the boom.

When the application is even, that boom height is the proper distance to set the smash above your target plants, or ground. If you change nozzles or pressure, cheque the summit again.

To measure the corporeality applied by the sprayer, follow these steps:

1. Check the output of all the nozzles to brand sure they're flowing at the aforementioned rate. If a nozzle is flowing more than than ten per centum over its rated chapters, or more than than 5 percent higher up or below the average of all the nozzles on the boom, replace information technology.

2. With clean water in the tank, gear up the pressure level at the proper level for the nozzles you're using and arrange the nozzle height for uniform coverage.

3. Spray over a test course in the field at the speed you'll use while spraying. Annotation the throttle setting or speed indicator so you tin can use the aforementioned speed later. Note the fourth dimension it takes to spray the form, in seconds.

4. With the sprayer standing even so, operate it at the pressure you'll be using and collect the liquid from the nozzles over the same fourth dimension every bit information technology took to drive the course and measure the output in gallons.

5. Figure out the gallons per acre: Gallons per acre = Gallons per test 10 43,560 / treated area.

Note that area treated is the test course length multiplied by the width; or the course length multiplied by the band width, multiplied by the number of bands.

To measure the output of dry out cloth applicators:

1. Tie plastic bags over the ends of the delivery tubes.

2. Bulldoze the test class with the applicator running.

3. Counterbalance the collected material.

4. Calculate the rate: Pounds per acre = (Pounds per test x 43,560 / treated expanse)

Notation that treated surface area is the test course length multiplied by the width; or the grade length multiplied by the ring width, multiplied by the number of bands. Also, 43,560 is the number of square feet per acre.

If you use a flow meter to measure flow through the nozzle, the meter will show gallons per minute (GPM) for each nozzle. You calculate gallons per acre this way:

Gallons per acre = (GPM per nozzle 10 seconds per exam ten viii,712) / (course length x nozzle spacing in inches)

Banding

For banding:

Gallons per acre = (GPM per nozzle x seconds per exam x eight,712) / (course length x band width)

Converting to gallons

Converting to miles per hour

Converting to feet and acres

John A. Truthful, emeritus Extension engineer

Acknowledgements

Reviewed past Jonathan Chaplin, agricultural engineer, Higher of Science and Technology and the College of Nutrient, Agricultural and Natural Resources Sciences

Reviewed in 2021

Source: https://extension.umn.edu/herbicides/how-calculate-herbicide-rates-and-calibrate-herbicide-applicators

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