Note the time it takes to spray the course, in seconds. Note the throttle setting or speed indicator so you can use the same speed later. Spray over a test course in the field at the speed you’ll use while spraying.

With clean water in the tank, set the pressure at the proper level for the nozzles you’re using and adjust the nozzle height for uniform coverage. If a nozzle is flowing more than 10 percent over its rated capacity, or more than 5 percent above or below the average of all the nozzles on the boom, replace it. To measure the amount applied by the sprayer, follow these steps:Ĭheck the output of all the nozzles to make sure they’re flowing at the same rate. If you change nozzles or pressure, check the height again. When the application is even, that boom height is the proper distance to set the boom above your target plants, or ground. If you see streaks as it dries, raise or lower the boom. Set the boom at the proper height above the ground and spray slowly so the spray wets the ground. To check the distribution pattern across the boom, operate over a smooth, bare area.

Typical amounts range from 10 to 30 gallons per acre. This is usually given in gallons per acre and is listed with the herbicide recommendations or on the product label. The sprayer must be set to apply the proper amount of total spray mixture. The applicator must be set to put on 6 pounds of the granules per acre.įigure 1: Spray distribution pattern of different nozzle types. Pounds of active ingredient per acre / concentration = 3 pounds per acre / 0.50 = 6.0 pounds per acre (Gallons per tank) / (gallons per acre) = 500 gallons / 19.4 gallons per acre = 25.8 acres per tankģ.75 pounds per acre x 25.8 acres per tank = 96.8 pounds per tank For a granular material that’s 50 percent active ingredient (4 gallons per test x 43,560) / (300 feet x 30 feet) = 19.4 gallons per acre Pounds of active ingredient per acre / concentration = 3 pounds per acre / 0.80 = 3.75 lbs. You calibrate your sprayer on a 300-foot course and apply 4 gallons of spray to the course.

The product comes as an 80 percent wettable powder. Then, multiply the acres per tank by the herbicide needed per acre to find the herbicide to put in each tankful.įor example: Assume you have a 30-foot sprayer that holds 500 gallons, and you want to apply an herbicide at 3 pounds of active ingredient per acre. To calculate the amount needed for band application, multiply the broadcast rate by the band width divided by the row width.Īfter you’ve calibrated the sprayer to know your application rate in gallons per acre, divide that number into the gallons applied with each tankful to find how many acres each tankful covers. You can reduce the amount of herbicide needed by as much as two-thirds by banding the application over the row and controlling the weeds in the middle with mechanical cultivation.įor example: A 3-pound-per-acre rate requires 3 pounds of herbicide for each crop acre in a broadcast application, but only 1 pound is needed to apply the herbicide in 10-inch bands on 30-inch rows. The application rate in the treated area should be the same for both the band and the broadcast application. Herbicides may be applied broadcast (uniformly over the entire field surface) or in bands (narrow strips of herbicide centered over the row, with the area between rows left untreated). Acid equivalent indicates the amount of an acid herbicide in a formulation. Herbicide rates may be given in terms of active ingredient or acid equivalent per acre treated, or as pounds or volume of commercial product per acre.Īctive ingredient indicates the amount of non-acid herbicide in a formulation.

Crossbow herbicide application rates