Cereal Herbicides: Managing Tough-to-Control Weeds with New Cross-Spectrum Herbicide Varro® FX

For seasoned farmers, it’s a well-known truth: the earlier you tackle weed control, the better your chances for a successful crop. It’s not just about removing unwanted plants; it’s about ensuring your crops thrive by minimizing competition for vital resources like fertility, water, and sunlight.

Matthew Chastko, Regional Agronomic Solutions Advisor based at Richardson Pioneer’s Regina office, emphasizes the importance of early planning in weed management strategy. “Weeds can quickly hijack resources meant for a strong start for your crops, so early intervention is crucial. The critical period for weed management in certain cereal crops falls between the one and three-leaf stage. This is where producers should really be focusing their energy.”

Enter Varro FX, a new cross-spectrum herbicide from Bayer CropScience designed for spring and winter wheat. With a combination of Group 2 (thiencarbazone-methyl) and Group 4 (fluroxypyr) active ingredients, it targets a broad spectrum of weeds, including Group 1-resistant wild oats.

Why Varro FX?

Varro FX offers a wide application window and cross-spectrum targeting, making it a valuable tool for growers dealing with tough-to-control weeds. Says Chastko, “The application window is between the one and six-leaf stages, and whether applied via ground or aerial methods, the product is quite flexible – particularly when managing glyphosate-resistant populations.”

While crop staging is crucial, Chastko emphasizes it’s essential to ensure Varro FX is used before the presence of the first cereal node. “This is particularly crucial when considering the potential economic impacts. For example, just 10 wild oats per square meter can lead to a significant reduction in yield potential.”

Operational Efficiency & Flexibility

In addition to its agronomic benefits, Varro FX is the first Group 2 graminicide emulsifiable concentrate (EC) formulation available in Western Canada, eliminating the need for external surfactants. This adds to the convenience of mixing and handling while providing better coverage for consistent grass weed control.

The formulation proved beneficial in grower-led trials at key Richardson Pioneer locations over the 2023 season. “Varro FX showed a marked improvement over comparable products when mixing a sprayer load,” says Jordon Hilgers, Crop Inputs Manager at Balgonie Ag Business Centre. “There was far less foam, and it was a quick pour and rinse. General cleanup was much easier with the EC formulation – growers that trialed the product loved this feature.”

Varro FX can be tank-mixed with a wide range of cereal broadleaf herbicides. When determining the right tank mix partner, Chastko recommends mixing Varro FX with Infinity® or Buctril® M for robust action, especially against glyphosate-resistant kochia populations. Flexible re-cropping gives growers the added freedom to seed all major crops the following season, including in the brown soil zone.

Best Management Practices

While Varro FX offers significant benefits, it’s essential to adhere to best practices for optimal results. Chastko notes that due to its formulation, Varro FX is not suitable for durum wheat and should be applied to spring wheat instead. Growers seeking wild oat control in durum wheat should opt for the original Varro formulation.