pesticides over their fields — an operation that demands precision and strict attention to detail. Since compressed air powers many of the most popular crop sprayers, we at Mattei know a thing or two about good application.
The following tips can help you minimize spray drift, raise a healthy crop, and get the greatest returns from your nozzles and air compressors.
Pesticide droplets may take some time to reach their desired destination. In fact, a droplet with a 100-micron diameter — the approximate breadth of a human hair — takes about 11 seconds to fall just 10 feet. Because of the air resistance working against them, even smaller droplets can take four to five times longer to fall.
Since wind can guide these slow-falling droplets in the wrong direction, farmers should always take spray drift into account before they begin spraying. While some are inclined to hike up pressure in hopes of speeding the fall of these droplets, increased pressure only decreases droplet size, thus increasing the risk of spray drift. Pay close attention to where the wind may take your chemicals and adjust your droplet size accordingly.
As mentioned above, greater pressure results in smaller droplets. It follows, then, that decreased pressure forms larger droplets. Pesticide applicators should be careful about changing pressure while moving over a field, since pressure changes during application will result in in uneven distribution.
Since nozzle pressure is automatically reduced upon slowing, it’s also wise to slow your pace when applying near a neighbor’s fields. Since larger droplets are less likely to drift, you’ll reduce the chances of spraying your neighbor’s crops.
Some newer nozzles such as Venturi-style models offer the ability to create larger droplets at any pressure. Venturi-style models also feature a hole that creates air bubbles in the spray by drawing air into the liquid flow, decreasing the likelihood of spray drift in the process. To achieve your desired results, always carefully survey the market for available options before purchasing new nozzles.
A given nozzle will produce droplets of various sizes — with or without manual adjustment. In fact, when spraying a medium droplet of 225 to 325 microns in diameter, between 5% and 10% of the droplets will likely be 150 microns or less in diameter, while another 5% to 10% will likely have a diameter larger than 450 microns. Don’t hesitate to replace your nozzles if their usual range of droplet sizes is too broad for your needs.
Regardless of wind pressure, spray drift increases at warmer temperatures. Spraying one to two feet above the crop canopy rarely creates significant drift, but even a single foot higher greatly increases the possibility of it, and its effects of are only heightened in hotter weather.
While increasing droplet size can minimize spray drift, scaling back pressure too much to create larger droplets can result in insufficient crop coverage. Droplets of 300-micron diameter can cover more than twice the area that a 400-micron diameter can. You should always strive for the right balance, maintaining a droplet size that reduces drift while maximizing coverage and pesticide efficacy.
Rate controllers can help you establish consistency in output and coverage. If you need to double your spraying speed, for instance, you’ll need four times the nozzle pressure to maintain the same volumetric output, since you’ll cover twice as much ground in the same time. A rate controller can regulate droplet size and pressure in response to fluctuating demands.
At Mattei, we know that compressors power many pieces of essential agricultural equipment, including your automated crop sprayers. After decades of experience, we also know that your air compressor system can make or break your business.
That’s why farmers should consider Mattei rotary vane compressors, which promise peak consistency and reliability across applications. Designed for quality and durability, our unique rotary vane technology extends your compressor’s service life while providing up to 35% higher energy savings than traditional rotary screw compressors.
For over fifty years, Mattei has helped farmers around the world maximize yields and minimize energy consumption without sacrificing the quality of their crops. With another farming season on the horizon, we’re proud to remain a backbone of global agriculture.