Buckeye Yard and Garden onLine

Erik Draper reported that a recent day spent testing PRESSURE GAUGES FOR PESTICIDE SPRAYERS revealed some interesting, and troubling results. Of the 25 gauges tested for accuracy, only 3 were within 1-2 lbs. of the actual pounds per square inch (psi) as measured by the gauge tester. Most gauges were 5-10 lbs. off or read lower than the actual psi generated. The gauges most often off by 20-50 lbs. were the higher pressures gauges, such as those used on air blast sprayers. One person brought their old gauge and the new one they just purchased to replace that old one. Just for fun, the new gauge was tested and found to be off or low by 10 lbs.! After testing a few new gauges, it turns out that it is not that unusual for new gauges to be less than perfectly accurate.

What this means is that most of the pesticide applications were misapplied by 10-20%. This under application of chemicals can result in frustration and less than satisfactory control of pests and/or diseases. Calibrating sprayers begins with testing the pressure gauge and ends with testing each of the nozzles. Doing a simple calibration to begin the season is better than doing nothing at all. Especially when the cost of replacing a spray gauge or nozzles is truly insignificant compared with the cost of the chemicals being applied and the cost of achieving no control of pests and diseases. Take some pressure off of yourself and calibrate that sprayer.

For more information, see:

• Boom Sprayer Calibration Fact Sheet
  
• Calibrating Turfgrass Chemical Application Equipment