Oil-Based Adjuvants in Weed Control
In the world of herbicide application, adjuvants are essential tools that help maximize product performance, reduce costs, and improve environmental safety. Among these, oil-based adjuvants—especially Methylated Seed Oils (MSOs)—have become a cornerstone of effective weed control strategies.
This guide offers a concise overview of oil-based adjuvants, their evolution, and how distributors and applicators can leverage them for better results in the field.
From Petroleum to Plant-Based Oils: A Brief History
Oil-based adjuvants have been used since the 1950s to enhance herbicide performance. Early formulations relied on petroleum-based oils, which helped herbicides stick to and penetrate plant surfaces. However, these products had notable limitations:
- Phytotoxicity: Risk of crop damage
- Volatility: Reduced herbicide persistence
- Environmental concerns: Non-renewable and less biodegradable
In the 1970s, the industry shifted toward Methylated Seed Oils (MSOs)—a safer, more effective alternative derived from modified vegetable oils. MSOs quickly gained popularity for their superior performance and sustainability profile.
MSO in Modern Tank Mixes
- MSO + surfactants for improved spreading and penetration
- MSO + drift reduction agents (DRAs) to meet spray drift regulations
- MSO + water conditioners to counter hard water effects
Why MSO-Based Adjuvants Matter
For distributors and applicators, MSO-based adjuvants offer several key advantages that translate into better weed control, lower input costs, and greater customer satisfaction.
Performance Benefits:
- Enhanced penetration into waxy or thick-cuticle weeds
- Improved spray coverage through reduced surface tension
- Increased herbicide uptake, especially in broadleaf species
- Lower application rates, saving product and money
Operational Advantages:
- Fewer spray passes required—saving time and labor
- Lower flammability—safer to store and handle
- Biodegradable and renewable—ideal for sustainability-conscious customers
These benefits make MSO-based adjuvants a value-added solution for distributors and a performance booster for applicators.
Target Weeds: Where MSO Excels
MSO-based adjuvants are particularly effective against:
- Broadleaf weeds: Known for their waxy leaves and complex root systems
- Certain grass weeds: Such as giant foxtail, especially under stress conditions that thicken leaf cuticles
For applicators dealing with hard-to-wet foliage or herbicide-resistant populations, MSO can significantly improve control outcomes.
Recommended Application Rates
While herbicide labels should always be followed, here are general guidelines to help distributors and applicators make informed recommendations:
Per Acre:
- 1–2 pints per acre for surface treatment and known weed infestations
Per Volume:
- 0.5–1.0% v/v (2–4 quarts per 100 gallons) to optimize spray solution properties
Note: Misapplication can reduce efficacy and may void product guarantees. Always consult the herbicide label for specific instructions.
Brewer Products: Trusted MSO Solutions
Brewer International has been a leader in adjuvant innovation for over 40 years, offering a wide range of MSO-based products trusted by applicators and distributors across the U.S.
MSO Products:
These products are designed to maximize herbicide absorption and translocation, making them ideal for high-performance applications.
These formulations are excellent for situations where leaf burn or non-target sensitivity is a concern, while still offering strong wetting and spreading capabilities.
Why Choose Brewer
- Proven formulations backed by decades of field success
- Broad product range for agriculture, aquatics, forestry, and land management
- Trusted by agronomists and applicators nationwide
- Support for regulatory compliance and product stewardship
Brewer products help you deliver performance, safety, and value—the trifecta that keeps customers loyal and operations efficient.
For distributors, MSO-based adjuvants offer a compelling product line that meets the demands of modern Integrated Pest Management. For applicators, they provide reliable, effective solutions that improve herbicide performance and reduce operational costs.
- Ensures product availability when demand spikes in early spring
- Helps avoid supply chain delays during peak season
- Allows for better pricing and bulk purchasing opportunities
- Supports pre-season tank mix planning with reliable adjuvant options