How to Determine Herbicide Rates for My Sprayer



To decide if your sprayer is delivering the suggested amount of herbicide to kill weeds there are 3 speeds you want to understand. Output rate of this sprayer lets you understand how much water and herbicide is being delivered by the sprayer. Mixing rate is the ratio of herbicide to water to acquire complete kill of weeds. Application Rate is how much herbicide is in fact reaching the plants — the amount of herbicide the tag states should be applied to a specified area. Translating these speeds to cover the area you wish to treat can be perplexing if you have to convert to instruction for large quantities to your backpack or hand-carried sprayer.

Clean and Test Nozzle

You’ll should first ensure that your sprayer nozzle sprays in an even, uniform pattern. Removing any blockage allows your nozzle to present a consistent output speed for your own sprayer, eliminating the need for re-calibration each time you use it. Examine the nozzle by filling the sprayer’s tank with plain water and spraying an impermeable surface, like concrete, which permit you see your own pattern. If the pattern is not uniform, then clean the wax or replace it. For adjustable pattern nozzles, place the spray pattern to the desired width and mark the setting with a permanent marker so you can repeat the same output each usage.

Calibrate Sprayer Output Rate

Find your sprayer’s output speed by marking out an area of 10 feet by 10 feet. Fill your sprayer with plain water. In one corner start spraying the marked area. Walk at an even pace, completely coating the Lawn Care service Bakersfield with a sweeping movement and spraying at a constant rate. Walk up and down the square until you’ve sprayed the whole area with little to no overlap. Use a stopwatch to measure the number of seconds it takes to spray the test area. Repeat the procedure using the same walking speed and sprayer pressure. Average the two times collectively. Refill the sprayer with water. Spray water into a large bucket with the same pressure and for the average number of seconds it took to cover the test region. Measure the number of ounces of water are in the bucket. Divide by 128 ounces to convert to gallons. That really is your sprayer’s output speed in gallons per 100 square foot. Output rate tells you just how much fluid is being delivered from the sprayer onto the plants being handled.

Determine Sprayer Coverage

When blending herbicide with water, first determine the number of gallons of water are necessary to cover the area you wish to deal with. Water is the medium which carries the herbicide to the plants being treated. Understanding how much water is necessary to cover an area determines how much herbicide to increase the water so it’s used at the recommended application rate on the tag. If the area to be treated is 200 square feet, along with your test area of 100 square feet required 2 liters of water to cover it, then split 200 square feet by 100 square feet, which equals two. Multiply that by 2 liters — the amount of water to cover 100 square feet — for a total amount of 4 liters of water to put in the sprayer.

Add Herbicide

Herbicide labels say the blending speed, usually in ounces of herbicide to gallons of water. As a result, the amount of herbicide added to this sprayer is decided by the amount of gallons of water are in the sprayer. If the tag recommends an application rate of 4 ounces of herbicide per gallon of water, then for each gallon of water in the sprayer, add 4 ounces of herbicide. As an example, if 4 liters of water are required to treat 200 square foot, then you’d add 16 ounces of herbicide to the water. This gives a herbicide application rate of 16 ounces per 200 square feet, or 8 ounces per 100 square foot.