Understanding Herbicide Application Methods

Learn about the five basic herbicide application methods and determine which is best for your vegetation management needs.

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When you’re fighting weeds on a budget, understanding herbicide application methods is critical to implementing a successful industrial vegetation management program. Planning ahead by educating yourself on the best approach for your situation is key to maximizing results — and your budget.

IPT – Great for Controlling Specific Species in Utility ROW and Non-Crop Areas

Individual plant treatment (IPT) can be an effective and affordable brush control method for targeting specific woody plant species. It’s typically used in areas where it’s critical to maintain safe, reliable access around roads, utility sites and railroads. IPTs are usually applied using a backpack sprayer.

Key benefits of IPTs:

Can save time and money compared to broadcast treatments
Reduce risk of off-target herbicide movement
Protect important wildlife habitats and encourage growth of native species
Can be applied using standard equipment

Here are the basics of the four IPT application methods.

Tactics vary by each species targeted. See our full brochure for details.

Foliar sprays

Apply to the mature, healthy foliage of target plants
Spray in spring and summer growing seasons for most woody species
Can use either a backpack sprayer or ATV-mounted sprayer
Adjustable ConeJet 5500-X3 to X5 nozzle is recommended

Basal bark

Apply to the basal stems of target plants
Most effective on smooth-barked plants and plants with one or a few basal stems
NOTE: Missing one basal stem may result in a live plant
Summer is the best time to apply stem sprays with Method^® 240SL herbicide
Apply with a backpack sprayer for best results
ConeJet 5500-X1 or X2 nozzle is recommended

Hack-and-squirt/injection

Apply to spaced cuts around the trunk of the target tree
Cuts must penetrate through bark into living tissue and produce a cupping effect to hold the herbicide
Can be used any time of year except during a heavy sap flow or drought
Apply to cuts with a spray bottle or herbicide gun attached to a backpack sprayer

Cut stump treatment

Apply to the cut surface of the target plant
Application must occur immediately after cutting
Can be used any time of year
When hand-cutting, a backpack sprayer will be most effective

Backpack – Best for areas accessible by foot

This method involves an individual spraying while walking with a backpack tank of herbicide. Backpacks can be manual or motorized, and various spray nozzles are used to apply premixed herbicide depending on the target species. This method is ideal for areas where using a boom isn’t necessary, like municipal sites.

Correctly spraying a percent solution is crucial to getting the right application rate and the best results. Below are a few key factors. More details are available here.

A consistent walking speed is key to maintaining uniform application
Spraying pressure should be kept constant as lower pressure will increase application rate and droplet size
Keep the distance between the spray nozzle and plants consistent

Boom spraying – Use for larger areas with smooth terrain

A boom sprayer is a rig that’s pulled behind a four-wheeler or tractor. Herbicide is sprayed from a nozzle attached to the end of a long arm called a boom. This method is useful for larger areas, such as bareground sites or roadsides.

Here are a few tips for effective boom spraying:

Follow product label recommendations and requirements for nozzle type, spray rates, agitation, adjuvant and so on
Make sure all components of your sprayer are suitable to the application type you need
- Inspect the tank, nozzles, hoses and pressure gauges
- Verify nozzle spacing, flow rate and number of active nozzles
Check spray pressure range, speed range and boom height range
Calibrate the sprayer, taking into account flow rate, pressure, travel speed and spray uniformity
Do a final check before spraying, and perform periodic checks while spraying
Ask your Envu representative if any adjuvants are necessary when you use more than one herbicide

Tank/truck spraying – For larger, easily accessible areas

Large trucks with tanks attached to the back are perfect for applying herbicide on large areas like rights-of-way and backslopes of highways and the areas around cable barriers and guardrails.

Aerial spraying – Perfect for large, remote areas

This method is exactly what it sounds like: using an airplane or helicopter to apply a large amount of herbicide over a remote area. If your treatment area is very large and/or not accessible by a wheeled vehicle, aerial application is the ideal choice.

Work with your Envu rep to assess your needs and develop a specific treatment plan. Always refer to the manufacturer's instructions and product label for maintaining necessary PPE, use sites and specific application instructions.