Timing is Critical with Pre-Emergence Flumioxazin-Based Herbicides in Soybeans

Timing is Critical with Pre-Emergence Flumioxazin-Based Herbicides in Soybeans April 26, 2017

Soybean planting has started in Nebraska and it’s time to apply pre-emergence herbicides.

Six weeds have evolved resistance to glyphosate in Nebraska. The best way to effectively control resistant and other hard-to-control weeds is by applying residual, pre-emergence herbicides with multiple effective modes of action.

Several new herbicides recently registered in soybean are in this category and could be considered.

Flumioxazin-based herbicides are commonly used for weed control in soybean. They can be applied pre-plant or pre-emergence, but NOT after soybean emergence. This is applicable for herbicide products with only flumioxazin (such as Rowel, Valor) as well as when flumioxazin is a part of the pre-mix (such as Afforia, Envive, Enlite, Fierce, Rowel FX, Valor XLT, Fierce XLT, Trivence) or when flumioxazin is tank-mixed with other herbicides.

Flumioxazin-based herbicide premixes have shown excellent broad-spectrum weed control in soybean when applied pre-plant or pre-emergence. If growers are not able to apply them before soybean emergence, they must NOT apply post-emergence because severe crop injury may occur. Therefore, it is advisable to apply them within three to four days of planting soybean.

Application after soybeans have begun to crack, or are emerged, will result in severe crop injury. When flumioxazin-based herbicides are applied, it is also recommended NOT to irrigate when soybeans are cracking.

Soybean seedling
Figure 1. Soybean emerging in a field in south central Nebraska. Do NOT apply flumioxazin-based herbicides such as Afforia, Envive, Enlite, Fierce, Rowel, Rowel FX, Valor, Valor XLT, Fierce XLT, and Trivence after soybean have begun to crack or are emerged. (File photo by Amit Jhala)