With spraying season upon us, this is the time of the year for applicators to complete their nozzle shopping. Because each part of the application equipment plays a critical role in achieving maximum performance from the sprayer, each component must be selected carefully to successfully complete the tasks associated with it.
Although nozzles are some of the least expensive components of a sprayer, they hold a high value in their ability to influence sprayer performance. They determine the gallon per acre intended application rate, and fix droplet size, which plays a significant role in achieving improved penetration into the crop canopy and better coverage on the target pest.
Making the wrong choice in nozzle selection can hurt applications in various ways. The applicator may end up leaving streaks of untreated areas and causing non-uniform pest control. Seriously uneven applications may even mean complete failure of pest control and require repeat applications. Perhaps most seriously, the wrong nozzle choice may lead to off-target application and pesticide drift which can damage adjacent crops and increase application costs.
Selecting the best nozzle requires careful consideration of several important factors including: sprayer operation parameters (such as application rate, spray pressure, travel speed); type of chemical sprayed (herbicides, insecticides, fungicides); mode of action of chemicals (systemic, contact); application type (broadcast, band, directed, air assisted); target crop (field crops, vegetables, vineyard, shrubs and trees, etc.); and spray drift risk.
Nozzle selection is a two-step process. First, determine the type of nozzle best for a given situation. Next, determine the appropriate size of that nozzle that will be capable of providing the desired gallons per acre application rate under various operating conditions such as travel speed and spray pressure.
Each nozzle type is designed for a specific type of target and application. For example, a nozzle designed for broadcast spraying is not good for spraying pesticides over a narrow band. While one nozzle may be best for a given situation, it may be the worst choice for another.
Once the type of a nozzle is determined, applicators also must buy the right size of that nozzle to achieve the desired application rate (gallons per acre) needed for spraying at different travel speeds. Nozzle catalogs are filled with tables and charts showing application rates, given a nozzle’s flow rate (gallons per minute) delivered at various pressures and travel speeds. However, the charts are only for a limited number of travel speed and nozzle spacing situations.
Most nozzle manufacturers have now developed applications for smartphones that provide the exact nozzle flow rate required for any given set of application parameters, and identify a specific set of nozzle recommendations for those parameters. To find these Apps, simply visit the App Store on your smartphone or tablet and do a search under “Spray Nozzle Calculator.”
Spray nozzles are typically the least costly items on a sprayer, but they play a big role in achieving maximum efficacy from the pesticide applied, while keeping the off-target drift movement of pesticides to a minimum. Chemicals work best if the rates on labels are maintained throughout application, and this is best achieved by installing the right nozzle type and size on the sprayer, so choose carefully!
Choose correct nozzles for your equipment
