The tables on page 4 of the Syngenta Demand CS label give rates for structural surface area (other instructions for turf, ornamentals, etc.). For demonstration, lets stay with the middle rate/concentration of 0.03% solution = 0.4 ounce/gallon listed in earlier table. .
First Table:
The first table on page 4 says you can apply that 0.4 ounce of active ingredient on 800 -1600 sq. ft., diluted in 1 to 5 gallons water. The second table chooses 1000 sq. ft. (even number near the middle). There is wiggle room here per the legal instructions.
Second table expands the concept:
You might be able to apply 1 gallon/1000 sq. ft. water carrier on hard smooth surfaces but need up to 5 gallons of carrier on more porous surfaces (mulch, etc.). In either case, they want the same amount of product/active ingredient applied to that 1,000 sq. ft.. (0.4 ounce product).
Here's a simple analogy for demonstration. 20' x 50' driveway = 1,000 sq. ft. Let's say you want to apply the middle concentration (0.4 oz) on your driveway. On hard, sealed concrete you might be able to mix 0.4 ounce/1 gallon and cover it all. On a porous pea stone driveway it might take 5 gallons of solution to wet everything. You mix 0.4 ounces in 5 gallons, still = 0.4 ounces product applied to the entire 1,000 sq. ft. driveway.
Professional applicators will develop a feel for the calibration amount/1000 sq. ft. with experience. The correct way starting out is to measure/estimate the sq. ft. of area you are covering. i.e., 4' band x 250 lineal ft. = 1,000 sq. ft.. You then practice with plain water in sprayer to determine how many gallons per 1000 sq. ft. you need. You then mix the proper amount of product in the correct amount of water and apply it, give or take a bit. Again, the label gives some wiggle room.
Calibration is a very important step learned by certified applicators to meet the legal requirements of the label (the law). The goal is to apply the correct amount of product/active ingredient per sq. ft.
