Pesticides are used by people and intentionally applied to the environment for the purpose of improving the quality of life for humans, domesticated animals, and plants. Because we are highly dependent on pesticides for our existence, one challenge we continuously must deal with is spray drift.
What is spray drift?
When herbicides are applied, spray droplets or particles can move through the air, at the time of herbicide application or soon thereafter, from the intended target to non-targets primarily due to wind conditions. Spray drift can be in the form of droplets, dry particles, or vapor, all of which can have devastating impact on non-targets.
Why should we be concerned about spray drift?
- Pesticides are expensive and should not be wasted by allowing them to drift off target.
- Pesticides are undesirable in the environment for several reasons, including smell, danger to wildlife and other non-targets, groundwater contamination, and can be hazardous to human health.
- Pesticides that drift can damage sensitive crops in surrounding areas leading to lawsuits. Therefore, a greater awareness of pesticides in the environment has caused spray drift management to become every applicator’s business.
What are Some of the Major Factors that Affect Spray Drift and Potential Solutions?
- Spray characteristics such as volatility and viscosity of the pesticide formulation.
- Large-sized spray droplets are less likely to drift off-target compared with small-sized spray droplets.
- Certain types of adjuvants can modify the properties of the spray solution to increase the viscosity of the spray and reduce drift from the target.
- Equipment and application techniques.
- Drift-reducing nozzles, e.g., air induction nozzles that are designed to produce large, air-filled, coarse droplets and which substantially reduce the risk of spray drift.
- Techniques specifically designed for managing submersed weeds in aquatic systems, e.g.,
- Subsurface injection just below the water surface.
- Deep-water injection or bottom placement to allow herbicide to be placed near the bottom the aquatic system or in the mat of submersed aquatic weed.
- Invert applications where specialized equipment is used to create an invert. An invert is a mayonnaise-like droplet that is highly viscous that can reach the intended plants you want to control without drifting off-target.
- Invert droplets are liquid emulsions that are made up of water surrounded by oil, as opposed to standard emulsions of oil surrounded by water as is typical when a standard crop oil concentrate is used as the adjuvant with a herbicide.
- Weather conditions at the time of application
- Air movement, temperature, and humidity are factors that need to be accounted for when applying herbicides to control terrestrial weeds and aquatic plants that are not submersed.
- Wind, waves, inflow, outflow, and currents can dilute herbicides and impact the control of aquatic weeds.
- Operator care, attitude, and skill – custom and private applicators need to be knowledgeable of:
- The latest technologies and techniques that help reduce spray drift.
- Current state and federal government laws governing pesticide spray application as they relate to spray drift.
Now that we’ve covered the basics of spray drift in terrestrial and aquatic systems, let’s discuss how Brewer’s I’vod nonionic surfactant is used in application. I’vod is commonly used cross the United States in aquatics, fishery, agriculture, utility rights-of-way, forestry, and industrial spraying, and is one of Brewer International’s most widely used adjuvants.
What is I’vod?
- I’vod is formulated with limonene, nonionic surfactants, and selected emulsifiers.
- The selected emulsifiers allow the pesticide to be mixed with a large volume of oil.
- Limonenes are natural oils that are sourced from pine and from the peel of citrus fruits, like orange and lemon.
- By using the naturally occurring limonene oil that is safe for the environment, the previously preferred diesel petroleum oil has been replaced.
- I’vod is widely used as an invert oil for herbicide sprays.
- The properties of an invert oil make it possible for a water-soluble pesticide to be dispersed in an oil carrier.
- Aids in reducing drift by increasing the viscosity of the spray droplets. Because oil evaporates more slowly than water, invert emulsion droplets shrink less; therefore, more pesticide reaches the target.
- The oil helps to reduce runoff and improves rain resistance. It also serves as a sticker-spreader by improving surface coverage and absorption.
- Nonionic surfactant
- I’vod can be mixed with a variety of chemicals including other pesticides and fertilizers.
- I’vod reduces the surface tension of spray droplets which improves the wetting of plant foliage and increases herbicide uptake.
- I’vod helps breakdown the waxy cuticle of leaf surfaces which enables more effective herbicide uptake and improved control.
- Used widely in aquatic systems.
- Most herbicides used for aquatic weed control are nonselective. In addition, wind, waves, inflow, and outflow currents can dilute herbicides. Therefore, they need to be applied with precision to ensure they reach their target and are effective.
- Herbicides applied with I’vod have been used successfully to control floating and emersed aquatic plants, as well as noxious weeds and brush in the upper Midwest US states. Due to the production of mayonnaise-like droplets when I’vod is used, the spray mixture can be applied with accuracy from a good distance at relatively high pressure.
- I’vod enables delivery of herbicide spray with precision in aquatic systems using subsurface injection or deep-water injection techniques.
Specific mixing instructions for using I’vod in preparing herbicide spray:
- Read all label directions before beginning.
- Inject I’vod from a separate tank compartment (or its own container).
- Use an orifice size and valve setting for desired rate and volume.
- I’vod’s oil:water phase can be varied over a range of 1:10 to 1:30 depending on type of equipment or herbicide used.
- Make sure you follow all label directions regarding herbicides-added-to-water phase.
- Do not exceed label instructions for the herbicide rate per acre.
- If invert breaks, check equipment for air leaks, then adjust water and invert orifices. Water quality can affect the invert.
Figure illustrates equipment layout for the application of I’vod with herbicide. The pump pulls I’vod through the system separately from the water and herbicide mixture with rates determined by orifices. A ‘flash’ invert takes place in the blender before being sprayed onto target weeds and brush.
By using I’vod, you get:
- A combination of drift control agent, penetrant, and sticker with rain resistance properties in one product.
- An invert oil-herbicide spray mixture that results in thick mayonnaise-like droplets that do not drift off-target when applied.
- A product with improved odor qualities, compared to older invert formulations.
- A product that is environmentally safe and does not require the use of diesel to create the invert as was typically done.
- A product that you will apply at lower rates compared with older invert formulations.
Read the Label!
- Make sure you read the pesticide label and follow all recommended instructions.
- Brewer International warrants that the product conforms to the chemical description on the I’vod label when used according to directions under normal use conditions.
In use for several decades, I’vod is used by several applicators across the country and in a variety of ways. Brewer International customers trust our dedication to quality ingredients, tried and true formulas, and positive outcomes.