Understanding Label Rates
Herbicide labels express dose as product per area, per tank volume, or as a percent solution. This calculator lets you enter whichever format your label uses, then converts it into a clear amount of product and water. When you switch units, the underlying target stays the same, so the final mixture remains consistent across liters, gallons, hectares, acres, and square meters.
Calibrate Sprayer Output
Accurate mixing depends on sprayer calibration. First, measure how much water your sprayer applies over a known area using your normal walking speed, pressure, and nozzle. Record the spray volume per area. If your output is higher than expected, you will overapply even with a correct mix, so adjust speed, pressure, or nozzle selection before treating valuable beds. Recheck calibration whenever you change nozzle, boom height, or pressure settings.
Dilution and Concentration Math
For tank mixes, the calculator multiplies tank capacity by the chosen rate. For area-based rates, it multiplies treated area by rate, then divides by the number of tanks to show per-tank amounts. Percent solutions are handled by volume fraction, so a 1% solution equals 10 mL product per liter of final mix. Always confirm whether the label rate refers to formulated product or active ingredient.
Mixing Order and Compatibility
Mixing technique affects performance and equipment life. Fill the tank halfway with clean water, start agitation, then add measured product and optional surfactant. Top up to final volume and keep agitating. Hard water, muddy water, or incompatible adjuvants can reduce control or cause clumping. Perform a jar test when combining products, and avoid mixing unless the label allows it.
Safety, Drift, and Records
Use protective clothing, gloves, and eye protection, and mix in a well ventilated area away from children and pets. Prevent drift by spraying during low wind and using coarse droplets near ornamentals. Rinse measuring tools, triple rinse the container if required, and record date, site, target weed, weather, and quantities. Good records support repeatable results and safer troubleshooting.
FAQs
1) Can I mix different herbicides together?
Only if every label permits tank mixing and the combination is compatible. Do a jar test, keep agitation, and never exceed any maximum rate. When unsure, apply products separately and follow local regulations.
2) Why does my area rate change the per-tank amount?
Area rates depend on your spray volume per area and how many tanks you plan to use. If walking speed, nozzle, or pressure changes, your output changes too. Recalibrate, then reenter the updated spray volume.
3) Which units should I choose for the rate field?
Use the same units shown on the label. If the label lists mL per liter, choose mL/L. If it lists fluid ounces per gallon, choose oz/gal. The calculator converts results so you can measure accurately.
4) How should I add surfactant or adjuvants?
Enable the surfactant option, enter its dose, and add it after the herbicide unless the label states otherwise. Measure carefully, maintain agitation, and avoid household detergents. Use only adjuvants approved for your crop and target weeds.
5) Does the calculator use active ingredient percentages?
No. It calculates using the formulated product rate you enter. If your label specifies active ingredient, convert it to a product rate using the product concentration on the label, then enter the converted value here.
6) Should I subtract product volume from water volume?
For most backpack or boom tanks, product volume is small compared with water. The calculator estimates water to add for better accuracy, especially with small tanks or high rates. Always mix to the final marked fill line.