July 10, 2003

 

Clean Residue Out of Spray Tank

Trace amounts of herbicide left in the sprayer can injure a crop when the sprayer is used again, according to Rich Zollinger, North Dakota State University Extension weed specialist. "A gallon or two left on the bottom of the tank doesn’t seem like much but it can seriously damage a crop depending on the herbicide used."

The herbicides that can cause the most damage are those applied at low concentrations. Those include all ALS herbicide mode of action products such as Sus, Imi and TPS and hormone-type herbicides such as 2,4-D, MCPA, dicamba and Tordon. "Even 1 percent of the recommended rate of these herbicides will definitely cause damage to many broadleaf crops," Zollinger says. "The damage to legumes caused by trace amounts of ALS herbicides in the spray is greater in the presence of grass-selective herbicides."

Immediately after using either ALS or hormone herbicides, the sprayer should be thoroughly cleaned using the appropriate method. Sprayer cleanout procedures are given on many herbicide labels and the procedure on the label should be followed for specific herbicides.

The following sprayer cleanup procedure is effective for most herbicides:

Step 1. Drain the tank and thoroughly rinse the interior surface with clean water. Spray rinse water through the spray boom for at least five minutes.

Step 2. Fill the sprayer tank with clean water and add a cleaning solution (many labels provide recommended cleaning solutions). Fill the boom, hoses, and nozzles and allow the agitator to operate for 15 minutes.

Step 3. Allow the sprayer to sit for eight hours while full of cleaning solution so the herbicide can be fully desorbed from the residues inside the sprayer.

Step 4. Spray the cleaning solution through the booms.

Step 5. Clean nozzles, screens, and filters. Rinse the sprayer to remove cleaning solution and spray rinsate through the booms.

Common types of cleaning solutions are chlorine bleach, ammonia, and commercially formulated tank cleaners. Chlorine lowers the pH of the solution which speeds the degradation of some herbicides. Ammonia increases the pH of the solution which increases the solubility of SUs and weak acid herbicides. Commercially formulated tank cleaners generally raise pH and act as detergents to remove herbicides.

Never mix chlorine bleach and ammonia as a dangerous and irritating gas will be released.

"Sprayers should be cleaned as soon as possible after use to prevent the deposit of dried spray residues, Zollinger says. "A sprayer should not remain empty overnight without cleaning."

Sprayer cleaning solutions for herbicides:

• Ammonia plus water: 2,4-D, Accent, Accent Gold, Ally/XP, Amber, Amplify, Assure II, Basis, Basis Gold, Cimarron/Max, Classic, dicamba, Escort, Exceed, Expert, Finesse, FirstRate, Harmony GT, Glean, Option, Peak, Permit, Python, Resolve, Steadfast, Stinger.
• Ammonia plus Simple Green at 1:1 ratio plus water: Callisto, Lumax.
• Kerosene or diesel fuel followed by ammonia plus water: 2,4-D ester
• Ammonia or commercial tank cleaner plus water: Action, Basagran, Beacon, Buctril plus Atra, bromoxynil, Callisto, Classic, Cobra, Dual/II/Magnum, Extreme, Fusilade DX, Fusion, Gauntlet, Gramoxone, Harness, Harmony Extra/XP, Hornet WDG, Lasso, Lightning, Moxy, Moxynil, Northstar, Prowl, Pursuit, Pursuit Plus, Raptor, Reflex, Resource, Select, Surpass, Treflan, trifluralin, and Ultra Blazer.
• Water: Command, Extreme, glyphosate, Lightning, Raptor.
• Detergent plus water: Aim, Atrazine, and Sencor.
• Commercial tank cleaner plus water: Flexstar, Liberty, Liberty ATZ, Shotgun, and Touchdown
• Detergent or commercial tank cleaner plus water: Celebrity Plus, Clarity, Distinct, Marksman, Poast Plus, Turbo, Ultra Blazer, and Yukon.
• Ammonia, commercial tank cleaner, or detergent plus water: Poast.
• Baking soda (1 to 2 pound per100 gallons of water): Engame

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Source: Rich Zollinger, (701) 231-8157, richard.zollinger@ndsu.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu