Nozzle Science Still Advancing
In recent years there has been a move to find a balance between drift control and coverage/efficacy, says Will Smart, president of Greenleaf Technologies. “The adoption of air induction nozzles without proper attention to droplet size has led to some unsatisfactory results in the past – drift control might have been great, but the chemical efficacy was compromised.�
In fact, Mark Bartel, Wilger Inc., says chemical companies are now working with tip manufacturers during their product development to find or develop tips and application techniques to maximize the performance of the chemicals with “a big eye on environmental concerns.�
Carolyn Baecker, president of CP Products Inc., points to the unrelenting pressure of lawsuits from “interests which oppose production agriculture.� Sadly, she believes these opponents have done a pretty thorough job of convincing the public that organic products are superior and that all spraying is harmful. “We’ve failed, as an industry, to respond to the criticisms effectively,� Baecker says.
Spray Pressure
With growing interest in superior drift control in new herbicide-tolerant cropping systems, Stuenkel expects his company’s Turbo TeeJet Induction (TTI) nozzle to become increasing popular. Specifically, this tip is ideal for minimizing off-target movement of a wide range of chemicals including glyphosate, 2,4-D and dicamba, Stuenkel says. The TTI’s air induction flat spray tip offers a wide operating pressure range of 15 to 100 psi, while producing Ultra Coarse (UC) and Extremely Coarse (XC) droplets.
Wilger’s Bartel is also seeing many tank mixes with chemicals that work best with different droplet sizes. He says the company’s patented COMBO-RATE body systems provide the ability to spray with tips of different droplet sizes to match multiple chemical requirements. Wilger just introduced the COMBO-RATE II design to give users more mounting options.
Smart has found Greenleaf’s most popular nozzle is the Medium Pressure TurboDrop XL, which has been around for 15 years. It works well between 30 and 120 psi, with the best drift control at below 60 psi.
The TurboDrop uses a modular system that can easily be modified to change droplet size without altering the flow rate. Greenleaf has now designed a “D� version (think dicamba, 2,4-D, Drift Control) that will make a slightly larger droplet spectrum than our standard versions, says Smart.
Greenleaf’s low pressure AirMix nozzle, introduced in 2001, sparked a trend to replace conventional flat fan nozzles with the same size air injection, or Venturi nozzles, says Smart. Since they operate well between 20 and 90 psi, the user can simply exchange the red extended range flat fan or turbo flat fan with a red low pressure AirMix or another low pressure venturi nozzle, put it in the same cap, and get a 50% to 80% reduction in drift.
The company’s Medium and Low Pressure Venturi nozzles, the TDXL and AM, do an effective job of delivering Medium to Coarse droplets that are useful for more types of applications, according to the company.
Spray Patterns
Another way to balance drift control and chemical efficacy is to either increase carrier rates – which is definitely a trend Smart is seeing from chemical companies – or to increase the number of spray patterns directed at the target. Hence, Smart says he’s also seeing more twin and double fan injection nozzles over the past couple of years. Most of them spray forward and backward, with a 60 degree separation between patterns.
Smart believes these multiple spray trajectories will become even more prevalent with the introduction of previously noted new chemical formulations with 2,4-D and dicamba. These chemicals have a history of causing off-target damage to susceptible crops.
Chemical companies are being proactive, not only with new formulations that are designed to minimize drift, but also with educational programs to bring the marketplace up to speed on these new products. Smart believes they will recommend higher carrier rates (15 gallons per acre minimum), minimum wind speeds and Coarse, Very Coarse and Extremely Coarse droplet sizes. “I believe multiple spray trajectories will become even more prevalent,� he adds.
Greenleaf’s TurboDrop TwinFan, introduced in 2005 for Asian Soybean Rust, sprayed 30 degrees forward and 30 degrees backward, with air-energized droplets primarily in the Coarse-Medium range. The company’s new TurboDrop Asymmetric DualFan sprays 10 degree forward and 50 degree backward, to compensate for faster sprayer speeds. With these types of nozzles, operators are effectively spraying the target twice in one pass, says Smart.
In fact, applicators can maximize the dual spray approach even more. With Greenleaf’s Asymmetric DualFan, operators can also alternate the nozzles on the boom to give a total of four different spray trajectories, 50 degree forward, 10 degree forward, 10 degree backward and 50 degree backward. This configuration has proven to be very effective for contact herbicides, fungicides and insecticides.
Other Innovations
Al Harmon, agricultural division manager of Germany-based Lechler, notes that there few “brand new� developments in nozzle technology these days – and there really won’t be until some product delivery systems change or until chemical companies change the style and rates of tank mixes. “You can’t shove more liquid through today’s nozzles,� he notes.
Lechler is now highly focused on training and assisting retail farm supply stores to educate all levels of applicators on proper drift-reducing techniques. In particular, the company has developed a tips/instruction sheet that can be fine-tuned for assorted crop targets, including corn, soybeans, wheat, cotton and specialty items. It can be laminated and hung inside the store – or printed for handing out to ag chem buyers to take with them.
Harmon points out that retailers such as Tractor Supply Co. can have very specialized regional application practices, and their salesman need to be well-versed on the proper use of lots of nozzle part numbers. Here too, Lechler can help.
Last year the company named Green Leaf, Inc. of Fontanet, IN, as its exclusive sales and distribution agent for North America. Lechler’s spray nozzle and parts inventory relocated to Fontanet.
Manufacturers have begun to offer a host of other helpful tools that will aid in drift reduction. New for the 2013 season, TeeJet has developed the Sentry 6120 Droplet Size Monitor (DSM) that utilizes a simple in-cab display and boom-mounted pressure transducer to provide real-time spray droplet size information to the operator. The information is valuable as spraying can vary with ground speed and system pressure. The system also alerts the operator when high- and low-pressure limits have been exceeded based on user-adjustable presets.
The Sentry 6140 Tip Flow Monitor (TFM) uses individual turbine-style flow meters mounted on the nozzle body to measure and compare flow rates of each tip on the boom. Flow variances caused by plugged, partially plugged, mismatched or damaged spray tips can be quickly and precisely detected, explains Stuenkel. “The operator is alerted to a flow abnormality on the in-cab console as well as a blinking LED mounted on the boom near the spray tip,� he says.
“The TeeJet SpraySelect tip selection mobile app has proven to be a popular and useful tool for a range of end users,� says Stuenkel. Operators enter the target application rate, tip spacing, ground speed and droplet size requirements – then the app recommends tips series, size and operating pressure. (It is available for free download on both OS and Android devices.)
At Greenleaf Technologies’ Website, operators can take advantage of the company’s online Nozzle Calculator to help with tip selection. Here, users enter nozzle spacing, speed and gallons per acre rate and the calculator lists appropriate nozzle choices. It also tells what the droplet size will be at the pressure required for a specific application.
For quick clean-out, the RapidStop nozzle body adapter from TeeJet evacuates the air trapped in spray booms. Getting rid of trapped compressible air in the sprayer plumbing system reduces the accumulator effect common in most sprayers, which can result in noticeably faster tip shutoff. RapidStop can be added onto a variety of TeeJet wet boom nozzle bodies on both new and used sprayers.