Three-point sprayers are mounted to the back of tractors in order to efficiently spray crops or shrubbery. Some models are equipped with spray wands that can be used with a boom system.
Three-point sprayers come in various sizes. They range in capacity from 40 to 150 gallons. They are activated by either 12-volt or PTO-driven pumps.
Sprayer boom systems are arms with a 4- to 6-foot center rail and outside, foldable rails attached with hinges. When fully extended, a boom can span 30 feet. However, three-point sprayers operate just as effectively on tractors without boom systems, especially in heavily wooded areas where plant life can be damaged by the girth of the boom. Many boom units can be removed and reapplied for use in diverse habitats.
The calibration of a three-point sprayer is necessary for equal dispersion of herbicides. If using the wand application, mix an amount of herbicide according to the herbicide's preparation instructions. Do so in a quantity large enough to meet the rate per acre recommendation. When using either a boom or boomless sprayer, calculate the gallons of water the sprayer disperses using the flow rate, band-width coverage and ground speed. These numbers are available in the owner's manual that accompanies the three-point sprayer.