Useful formulae for working out nozzle selection, forward speed, application rate
Note: The symbol ‘/’ used in the formulae means divide, eg 6/2 = 3 means 6 divided by 2 = 3. Also, always work out the multiplication sections first and leave the division part of the formula to last.
? Nozzle output (litres/min) = Application rate (litres/ha) x forward speed (kph) x nozzle spacing (metres)/600.
? Forward speed (kph) = nozzle output (litres/min) x 600/application rate (l/ha) x nozzle spacing (metres).
? Application rate (l/ha) = nozzle output (l/min) x 600/ forward speed (kph) x nozzle spacing (metres).
(To convert from gallons per acre, multiply by 11.2 to give litres per hectare (l/ha)).