by : Tyler Sandlin, Extension Crops Specialist; David Russell, Extension Weed Specialist;
Eros Francisco, Extension Grain Crops Specialist
What is saflufenacil?
Saflufenacil is a group 14 PPO herbicide. Saflufenacil is the active ingredient in Sharpen
herbicide and one of the active ingredients in Verdict herbicide. This chemistry provides
excellent burndown control of marestail/horseweed and other broadleaf weeds in soybeans
when used properly. Good coverage (minimum of 15 GPA water volume) and a methylated
seed oil (MSO) are required for optimal performance. Soybeans can be planted immediately
following an application of 1.0 oz/Acre of Sharpen or 5.0 oz/Acre of Verdict respectively, on
non-coarse soils (see herbicide labels for other restrictions on rate and soil type). Silt loam or
silty clay loam soils commonly found in the TN Valley Region of Alabama fall into this category
and can be planted with no pre-plant interval at the above rates.
When is Soybean Varietal Sensitivity Seen Following an Application of Saflufenacil?
It has been documented that soybean varieties differ with respect to level of tolerance or
sensitivity to saflufencacil. A varietal response is typically seen when an application of Sharpen
or Verdict is made and a sensitive variety of soybean is planted immediately following the
application, and rainfall is incurred while the germinating seeds are imbibing water or cracking
the soil surface. During these events, the herbicide is imbibed into the seed or comes in contact
with the hypocotyl when it is emerging. Poor closure of the seed furrow, especially on
conventionally tilled soils and a heavy rain event following application and planting can also
contribute to injury.