The Argument for Fall Spraying + Tips for Success

Most growers are gearing up for fall spraying, but there are a few hold outs who don’t see the point, we’ve got some news for you — fall applications are extremely beneficial. Allow us to tell you why (plus, we’ve got a few tips for you).

Control Weeds, Insects and Corn Residue

While fall treatments help prevent winter annuals and weeds to keep fields clean through spring planting, this application period can include more than just weed treatments. By applying nitrogen to corn stubble, growers can boost decomposition to knock down corn residue and weeds at the same time.

“Fall spraying tends to be more enjoyable than in the spring — you’re not in a huge rush and you can take more time to do a better job,” said Chris Weaver, Apache Sprayers Application Parts Specialist.

Additionally, when heavy weed cover blankets spring fields, soils remain cool longer, delaying tillage operations and planting. Some winter weeds also provide a haven for insects that attack emerging crops.

Enjoy the Flexibility

More often than not, spring tends to cause undue stress when Mother Nature doesn’t cooperate. Cold and wet conditions can push planting dates, resulting in a shorter timeframe for pre-plant herbicide applications, leading to more growers adding a fall herbicide application into their weed control programs. If you plan for a fall herbicide application and the weather doesn’t allow it, growers still have their spring application to set things right.

“Fall herbicide applications provide a head start on weed control,” Weaver said. “If you’re only counting on spring pre-plant applications and weather keeps you at bay, you have no back up plan.”

Check Your Flow Control System

Before starting, Weaver suggests growers check their sprayer’s flow control system to make sure it is working properly. Application rates are critical for spraying the right amount of nitrogen and herbicides so growers get the most from those applications without wasting product.

“The flow control system regulates the applied gallons per acre and prevents the sprayer from over- or under-applying,” Weaver explained.

To check the flow control system, start spraying while the machine is sitting still. Open the manual control screen on the rate controller and increase or decrease the rate, looking to see if the spray pressure responds as it should. That will ensure the control valve is working. As this is happening (usually on the same screen), look at the value for gallons per minute and make sure the reading is not zero. If so, the flowmeter is working properly.

Be Mindful of the Weather

“Typically, I like to get my fall applications done right after harvest,” Weaver said. “In my experience, the warmer the daytime temperature is, the better the results. I like a temperature of 55 or higher for fall applications — otherwise it seems like the chemicals don’t work as well.”

Weaver also said to stay on top of frost forecasts in the weather reports to make sure you avoid freezing your sprayer lines.

Check out the Apache Blog for more articles and up-to-date industry news.

Whether you are top dressing wheat or doing pre-plant herbicide applications, there are a few things to remember when servicing sprayer nozzles and tips. To help our customers solve some of the most prevalent problems in the field, the Apache Sprayer team got together with additional experts within the industry to gather the best tips for nozzle care throughout the year.

Quick Tips for Sprayer Nozzle Maintenance

Start the season by running clean water through the sprayer and at the end of each spraying day, to thoroughly clean the spray tips. Chemicals will eventually gum up the tip and cause uneven spray patterns or, worse, plug the tip completely. Always use water or compressed air to clean a spray tip. Using sharp objects such as a pocket knife or a piece of wire will cause damage to the tip. With proper care, you can extend the life of spray tips significantly.

“Most problems with spray tips are a result of a lack of maintenance and calibration,” said TeeJet Technologies Manufacturer Representative, Bryan Fowler. “Taking a close look at the spray pattern for consistency and distribution across the boom will alert you to the problem sooner and help you avoid poor application results. Many times, it can be difficult to look at a tip and actually see a problem.”

Sprayer Nozzle Tests and Checks

Fowler suggests performing a catch test on a few of the tips to better analyze the issue. A catch test uses a catch cup over the nozzle to measure output and flow rates.

“It is a good practice to perform a catch test on a few of the tips; if a few are out of specification by more than 10 percent, then it is time to replace them,” Fowler said. “This means that a tip that is rated to spray 0.4 GPM (ex. XR8004) at 40 psi is actually spraying 0.45 GPM, it should be replaced. If more than a few tips on the boom are performing this way, all of the tips on the boom are probably worn and will need to be replaced.”

It’s very hard to detect nozzle wear by sight alone as there can be very little evidence of wear. Greenleaf Technologies Regional Sales Manager William Smart agrees that nozzle checks are an essential part of upkeep, but also stresses the use of strains and boom height adjustments to prevent malfunctions.

The Importance of Nozzle Cleaning

“Nozzles need to be protected from plugging through the use of strainers upstream of the nozzle,” Smart said. “But even with proper straining, nozzles can sometimes plug. Nozzles that come apart easily (without the need for tools) and that have visible metering orifices will speed up the cleaning process. Air, water and the occasional broom straw or toothbrush is all that should be used for cleaning.”

Boom Height + Sprayer Nozzle Correlations

Smart says boom height is also important to create a uniform distribution of the spray with your selected nozzle.

“A good rule of thumb for 110-degree nozzles is matching the nozzle spacing to the boom height,” Smart said. “So, for 20-inch spacing, a minimum 20-inch boom height will ensure uniformity along the length of the boom. Keeping the boom as close as possible to this target will also maximize coverage, penetration and drift control.”

Do you have another common nozzle issue? Tell us about it in the comments below! Need help nozzle selection?

Check out our handy white paper.

Selecting the proper nozzle type is essential for proper pesticide application. The nozzle is a major factor in:

• Determining the amount of spray applied
• Uniform application
• Coverage reaching its target surface

Nozzles break the liquid into droplets, form the spray pattern, and propel the droplets in the proper direction. They also determine the amount of spray volume at a given operating pressure, travel speed and spacing. Drift can be minimized by selecting nozzles that produce the largest droplet size while providing adequate coverage at the intended application rate and pressure.

We want to help you find the perfect nozzle for your application, so we’ve researched each type to give you a better idea about the pros, cons and overall differences.

Download our Nozzle Selection 101 Cheat Sheet

Even Flat-Fan Sprayer Nozzle

“Even flat-fan nozzles are utilized in banding applications (as opposed to broadcast spraying),” said TeeJet Technologies Manufacturer Representative, Bryan Fowler. “These tips will deliver an equal amount of spray across the entire width of the spray pattern to ensure even distribution.”

These nozzles do not produce a tapered edge and do not require overlap. The nozzle height and the spray angle both control the spray pattern width. Extended range flat-fan nozzles are designed to work under a much larger range of pressure compared to a regular flat-fan nozzle. This nozzle is recommended for the grower who is looking for uniform distribution and wants more drift control at lower pressures.

“We’ve recommended growers use the TurboDrop Venturi in combination with even flat-fan nozzles for over 20 years to provide a low-drift version of the even flat-fan,” said Greenleaf Technologies Regional Sales Manager, William Smart. “When combining the two, the even flat-fan should be double the size of the TurboDrop Venturi. The Venturi will control the flow rate, and the larger pattern tip will allow the air injection to work properly.”

Twin-Orifice Flat-Fan Sprayer Nozzle

Twin-orifice flat-fan nozzles produce two spray patterns with one orifice angled 30 degrees forward and the other orifice angled 30 degrees backward. This nozzle is noted for spraying smaller droplets in both spray patterns providing more penetration and coverage.

“Twin pattern tips are designed to deliver two inline patterns, roughly 60 degrees apart,” Fowler said. “This enables the spray to approach the surface area of the target from two angles and improve the chances of thorough coverage.”

Off-Center Flat-Fan Sprayer Nozzle

Another new fan design is the off-center fan, which is used for boom-end nozzles so the swath is uniform from end-to-end and not tapered at the edges.

“The off-center (OC) nozzle will distribute the spray laterally, away from the end of the boom,” Fowler said. “This will help it to reach an area beyond the length of the boom. This could be used as a boom-end nozzle, delivering herbicide to spray fence rows or ditches.”

“Off-center nozzles are also often used in orchards and vineyards to spray along the tree trunk line or strip spray under a grape vine,” Smart said. “This is another situation where using Greenleaf Tech Venturis to convert conventional off-center nozzles to air-injected OC nozzles would help prevent drift from affecting trees and vines or prevent overspray along a fence row.”

Air-Induction Flat-Fan Sprayer Nozzle

The air-induction nozzle is noted for producing large drops through the use of a venturi air aspirator. The venturi draws the air into the nozzle, and then the air is mixed with the solution to create larger spray droplets, which reduces drift potential.

“Air-induction (AI) spray tips are ideal for situations that involve spraying solutions that have little tolerance for drift,” Fowler said. “Typically, this will involve herbicides that could possibly harm non-target plants. Although air induction spray tips vary in style and pattern, the primary characteristic is that they have a greatly reduced quantity of drift prone droplets compared to the non-AI versions of the same tip. Many are available in both single and twin patterns.”

Flood Sprayer Nozzle

Flood nozzles are similar to full-cone nozzles in that they produce large droplets and their ideal overlap is 100 percent. The flood nozzle produces a spray pattern that is similar to the even flat-fan nozzle but emits larger droplets.

“Flood style tips have large open passages and will not easily plug,” Fowler said. “Many times, this tip is utilized as a pre-emerge application tip. The large droplets are very good for soil applied products in broadcast applications.”

Hollow-Cone Sprayer Nozzle

Hollow cone nozzles provide more complete coverage of plants due to the smaller droplets it emits. Looking at the spray pattern, the hollow cone is formed by a circular orifice that creates a cone shape pattern with an open center.

“This style of tip is typically utilized in fruit and vegetable spraying,” Fowler said. “In these applications, insecticide and fungicide application are very common and the requirement for thorough coverage dictates the need for smaller droplets. These applications are either directed over the top and sides of the target (vegetables) or sprayed into a wind current to carry the spray into the canopy; this would be typical of an air blast sprayer in fruit trees.”

“Hollow cones are often misused in broadcast applications,” Smart said. “They were designed for spraying over the row in combinations of two to three nozzles. They can also be used for banding applications like an even flat-fan.”

Full-Cone Sprayer Nozzle

The full-cone nozzle utilizes the same circular-shaped orifice as the hollow cone except this nozzle produces output through the entire cone spray pattern, as opposed to the hollow cone. The full-cone nozzle produces

larger droplets making this nozzle more drift resistant.

“Full-cone nozzles are frequently used in tobacco spraying,” Fowler said. “This is typically for applying chemicals in a directed pattern for sucker control. The full-cone nozzle creates a coarse spray over the top of the plant so that it will run down the plant to the buds.”

Check out our white paper for more information about nozzle selection or contact your local Apache Sprayer Dealer.

A pressure drop in your Apache sprayer can really put a kink in proper spray coverage. When this happens, it’s likely due to a chemical sediment build up clogging the strainers in the nozzle tips. Apache sprayers are equipped with the solution. To help keep nozzle tips from becoming blocked, each boom section includes a 1-inch strainer with a 50-mesh screen and a 2-inch full-port Banjo® main product strainer with a 50-mesh screen.

“If the 2-inch strainers become clogged the boom pressure could drop, if the 1-inch section strainers become clogged the boom pressure could increase,” said Gary Grant, Ohio Valley Ag Equipment Specialist. “Both could result in poor spray pattern and inaccurate application rate problems. Anytime you recognize a pressure change in your normal operating range, strainer clogs or other blockage factors need to be addressed immediately.”

If chemical build up still occurs, it’s time to remove the strainers and clean them. This is done by soaking the strainers in a large bucket filled with water and a small amount of dishwashing liquid for around 20 minutes. Most of the sediment will dissolve. What doesn’t dissolve can be scrubbed away with a cleaning brush. To prevent this problem from happening in the future, run the rinse tank on the sprayer to clean out the booms if you think the sprayer will be sitting idle for two (or more) days. If your sprayer is parked for a longer period of time, run the agitation in the tank to keep the tank mix stirred.

Quick Tips for Nozzle Care

• Run the rinse tank to clean booms if there has been significant downtime between sprays.
• Run the tank agitation function if the sprayer has been idle for several days.
• Remove and clean strainers with dishwashing liquid and water if clogs persist.

For questions and concerns about your Apache sprayer pressure, please do not hesitate to contact your Apache dealer for assistance. Want to learn more about nozzle selection for your Apache? Read more.

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