Get your sprayer in shape
What you're spraying to control pests in your crops may not be as important as how you're putting it down. That makes good sprayer calibration more important than it's ever been, especially considering both pesticide and herbicide costs and ultimately, the price you can fetch when marketing your crop.
"Calibration, perhaps more than anything else, will have a direct impact on achieving effective pest control and the cost of crop production," according to Ohio State University ag engineer Erdal Ozkan. "Higher pesticide costs and new chemicals designed to be used in lower doses make accurate application more important than ever. There is no better time than early spring to take a closer look at your sprayer."
And, Ozkan recommends calibrating frequently. Research has shown farmers who calibrate "before every spray operation" typically have applicatoin errors less than 5% of the time. "Only 5% of the applicators who calibrated their equipment less than once a year (once every 2, 3 or 4 years) achieved the same degree of application accuracy," Ozkan says, citing University of Nebraska research on sprayer calibration.
The goal of any one of many ways to calibrate your sprayer is the same: Find out exactly how much product is coming out and where it's going. There are multiple ways to do it, Ozkan says, but it can be done fairly quickly.
"It usually doesn’t take more than 30 minutes to calibrate a sprayer, and only three things are needed: a watch showing seconds, a measuring tape, and a jar graduated in ounces. A pocket calculator also will be handy," he says. "Usually the ultimate goal when calibrating a sprayer is to find out the actual application rate in gallons per acre. There are many methods to choose from to determine this."
Variables like speed across the field, droplet size and nozzle adjustment all have major implications to the effectiveness of your spraying. Make sure you take these all into account when you're making adjustments before you start to spray.
"Always keep in mind that changes in spray pressure will help you bring the application rate to what you want, but you may not be getting the size of droplets recommended for a given application. Higher spray pressures cause reduction in droplet size which may increase the risk of spray drift," Ozkan says. "Getting the right amount of chemicals on the ground is not enough to achieve effective pest control. How the chemical is deposited on the spray target is as important as the amount deposited. Make sure that all nozzle tips are properly aligned. Some nozzles require overlapping adjacent spray patterns."