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Soybean growth stage cutoffs for postemergence herbicide application

Sachin Dhanda, Weed science postdoctoral researcher, Sithin Mathew, Weed science graduate student, and Debalin Sarangi, Extension weed scientist

Soybean field treated with postemergence Cobra
 herbicide (within the label cutoff) showing
 temporary leaf injury. Photo: Sithin Mathew)
The erratic rainfall pattern this cropping season has led to disjointed soybean planting across Minnesota, with some farmers needing to replant their crops. As a result, soybean fields are currently at varying growth stages. Many acres are either receiving postemergence herbicides this week or have not yet been treated. It is essential to adhere to the growth stage cutoffs specified on herbicide labels for postemergence applications and to comply with the preharvest interval (PHI) which is legally required. The PHI represents the minimum time between the last herbicide application and the crop harvest. The restrictions are in place to prevent potential crop injury, herbicide carryover, environmental or food safety issues, and other concerns. If tank mixing two or more herbicides, the cutoff is determined by the most restrictive labels. Always consult herbicide labels prior to application to ensure compliance. Below is an updated table (as of July 3, 2024) summarizing soybean growth stage cutoffs and PHI for commonly used postemergence herbicides.

Table 1. Commonly used postemergence herbicides in soybean with their application restrictions.
Herbicide Active ingredient Soybean growth
 stage cutoff
 interval (PHI)
Anthem Maxx fluthiacet-methyl + 
Through the V6 stage 60 days
Arrow 2EC clethodim - 60 days
Assure II, Targa quizalofop-P-ethyl - 80 days
Basagran bentazon - 30 days for forage
or hay
Cadet fluthiacet-methyl through full flowering 60 days
Classic clorimuron ethyl - 60 days
Cobra lactofen R6 (full seed) 45 days
Dual II Magnum S-metolachlor - 75 days
Enlist Duo/ Enlist
One (for  Enlist
2,4-D + glyphosate /
Through R1 50 days
FirstRate cloransulam-methyl Prior to R2 (full flower) 25 days for forage or hay
70 days for grain
FlexStar fomesafen - 45 days
Fusilade DX fluazifol-P-butyl V5 (not more than 24 fl
oz/A; from R1 onwards, 
not more than 6 fl oz/A
60 days
Harmony SG thifensulfuron methyl Bloom stage 60 days
Liberty 280 SL
(only for LibertyLink
glufosinate R1 70 days
Outlook dimethenamid-P V5 -
Perpetuo/Resource flumiclorac pentyl +
pyroxasulfone /
flumiclorac pentyl
V6 60 days
Poast sethoxydim - 75 days
Pursuit imazethapyr Prior to bloom stage 85 days
Raptor imazamox Prior to bloom stage -
Resource flumiclorac pentyl - 60 days
Roundup PowerMax3
(for Roundup Ready
glyphosate Through R2 14 days
Scepter 70DG imazaquin - 90 days
Select MAX clethodim - 60 days
Ultra Blazer acifluorfen - 50 days
Varisto imazamox + bentazon Prior to bloom stage 30 days for forage or hay
Warrant acetochlor Prior to R2 -
Warrant Ultra acetochlor + fomesafen Prior to R2 45 days
XtendiMax (for
Roundup Ready 
dicamba R1; state and national
restrictions applied regarding
cutoff dates and temperature
7 days
Zidua SC pyroxasulfone V6 -

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