By Dr. Jason Deveau
OMAFRA application technology specialist

The first modern air blast sprayer was developed in the mid 1900s, competing with existing equipment before it was adopted by the majority. We’ve come a long way. As application technology continues to evolve and grow, so do the choices facing growers.

Whether considering optional features, or selecting a new sprayer (boom or airblast), start by prioritizing your goals. Perhaps work-rate is a priority, so look to sprayer capacity to reduce the number of refills and consider wider booms or over-the-row technology to reduce the number of passes. Perhaps the crop is adjacent to sensitive areas or homes and drift control is a priority; consider deflectors, shrouds and ensure the sprayer can produce the pressure required to operate drift-reducing nozzles.

When compiling a prioritized list, reflect on the positives and the negatives of your current sprayer and talk to other growers about their experiences. It may come down to personal preference, but consider the following points:

• Necessity – Is a new sprayer really needed? Manufacturers have a number of retrofit kits available to upgrade and improve sprayers. If poor pesticide performance has led to the decision to purchase a new sprayer, be sure it’s related to the technology and not to an operating error.
• Crop type and acreage – Consider the size of the planting and the size, shape and density of the crop(s). Can the sprayer adapt to provide adequate coverage throughout the growing season and in the long-term? How flexible is the sprayer when spraying different products onto different targets?
• Sprayer capacity and filling – Fewer refills means a higher work rate, but increased capacity also means more weight, so consider the effects on navigation, turning radius and soil compaction. Is the tank easy to fill? Is a chemical injection system or induction bowl required or preferred?
• Cleaning, calibrating and maintenance – Cleaning water reservoirs, tank-rinsing nozzles and overall accessibility should be considered. Review the steps required to winterize and to calibrate the sprayer. Is it easy to access parts? Is operator exposure minimized?
• Horsepower – This is an important consideration for airblast sprayers, because fans move a lot of air and liquid. Tank agitators also require power. Consider selecting from the higher range of manufacturer-recommended horsepower to improve longevity. Remember, that fans typically don’t have to operate at the maximum-rated rpm, particularly early in the season.  
• Nozzle technology and operating pressure – Consider the range of nozzle-types intended for use and ensure the sprayer can provide sufficient pressure. While more expensive, diaphragm and piston pumps have fewer moving parts in contact with the spray solution, reducing cleaning time and operator exposure.  
• Spraying conditions – A sprayer must be reliable, even in adverse conditions, so consider the operating environment.  Night spraying, uneven terrain, high winds, dry conditions – many environmental factors can impact sprayer performance and may warrant special consideration. Investigate deflectors, shrouds and the structural framework and durability of the sprayer.  

These are all just considerations. The best advice I can give you is to ask lots of questions. If you have any questions, or would like to know more, please feel free contact me at jason.deveau@ontario.ca.