Spray tips get renewed attention as bigger weed, insect, disease challenges emerge

Date:03-11-2013

After years of primarily using one-size-fits-all spray tips that are ideal for spraying Roundup Ready crops, growers may now need to own an arsenal of nozzles specific to a range of chemistries.
 
“For the last 15 to 20 years, it has been glyphosate, glyphosate, glyphosate, so you were aiming for drift control and big droplet size,” says Tim Stuenkel, global marketing communications manager for TeeJet Technologies. “Today we are entering a time where we are dealing again with a broader range of chemistries for weeds, insects and diseases. It is a new, more complicated world where proper tip selection is becoming more important.”
 
As a result, some spray tips introduced in the early 2000s that have seen less use in recent times are likely to find their way back onto nozzle turrets, says Gene Schellhorn, spray technology product manager at Hypro. “With weed resistance to glyphosate building up and the reemergence of dicamba and 2,4-D, some of the tips that have been on the market for a few years may have a rebirth. Choosing the right spray tip for your chemical is going to become more critical than ever. The age of forgiving spraying is coming to a close.”

While what is old is becoming new again, both for chemistries and spray tips, manufacturers continue to develop new nozzles, nozzle bodies and related equipment. Here’s a look at the some of the latest innovations designed to maximize product performance, monitor particle size and streamline sprayer operation.
 

The TurboDrop Asymmetric DualFan nozzle, introduced by Greenleaf Technologies in 2011, balances the dual goals of providing excellent coverage and canopy penetration while minimizing drift. The nozzle has an asymmetric spray pattern and dual tip sizes that create a mix of particle sizes that help achieve both goals, says Will Smart, Greenleaf president.

“With the upcoming formulations of glyphosate with dicamba and 2,4-D, there is a lot of talk about droplet size and shifting more to coarser size,” he says. “Coverage also will be critical. With this design, we can create whatever droplet size that you want. You can get enough drift control and coverage at the same time.”

The DualFan nozzle achieves these goals in several ways. It uses two spray tips, with a forward-facing tip oriented at 10 degrees and a rear-facing tip canted at 50 degrees. The forward tip, which is half the size of the rear tip, puts out smaller droplets for improved coverage. The rear-facing tip puts out larger droplets, which surround the smaller droplets as the sprayer moves across the field. This improves penetration, while also reducing drift, Smart says.

Based on field experience, Greenleaf now recommends that every other nozzle should be mounted backwards on the boom, with the rear-facing tip facing forward. This results in four distinct spray patterns delivered to the target, further improving overall performance, Smart says.

In most DualFan sizes, the droplet spectrum is medium-coarse below 80 psi and medium-fine above 80 psi. At 30 to 60 psi, the nozzle provides a droplet size excellent for glyphosate. Smart recommends running the nozzle at 60 psi and above for contact herbicides, fungicides and insecticides.