Early Preplant (EPP) Herbicide Applications…How Early Can They be Sprayed

How early can herbicides be sprayed before corn or soybeans are planted? The below article provides some information about early preplant applications.

Historically, we have not recommended early preplant herbicide (EPP) application in our region with a couple of exceptions, such as for marestail control. In general, residual herbicides applied more than two weeks ahead of planting almost always require additional weed control often in the form of a post application. With the adoption of Roundup Ready soybean and corn and now with Xtend, Enlist E3, and LLGT27 soybean varieties, there may be more opportunity to apply a residual burndown program two or more weeks ahead of planting with the idea of coming back with a well-timed post treatment. A number of herbicide labels specify in days what is allowed EPP. Herbicide rates may increase for EPP, so consult a current herbicide label for specific use directions. The table below provides some spring EPP application intervals for some common corn and soybean products.

Table 1. EPP application intervals for selected herbicides.

A. Crop: Corn

Herbicide	Spring preplant application (maximum number of days ahead of planting)*
Acuron, Acuron Flexi	28
Anthem Maxx	45
Atrazine	30
Degree, Harness, etc.	30
Balance Flexx, Corvus	21 – 30
Hornet	30
Instigate	14
Lumax EZ, Lexar EZ	14
Dual	30
Princep	14
Resicore	28
Surestart II	30
Verdict, Sharpen	30
Valor, Fierce	30
Zidua	45

B. Crop: Soybean

Herbicide	Spring preplant application (maximum number of days ahead of planting)*
Anthem Maxx	45
Authority products	45-60
Canopy	45
Envive, Trivence	anytime
FirstRate	28
Dual	30
Optill, Sharpen (2 oz/A), Verdict	30
Prowl	45
Prefix	15
Python	30
Sharpen (2 oz/A), Verdict	anytime
Sonic	anytime
Surveil	14?
Valor	14
Valor XLT	anytime

* Maximum interval may specify that a sequential application is necessary.

 

 

Regarding some of the popular PPO/Group 14 soybean herbicides (e.g., Valor products, Envive, Fierce, Trivence, Authority products, Sonic, Surveil, others), if using these in combination with Sharpen/Verdict/OpTill/Zidua Pro for control of marestail, there is a 14-day restriction before planting. So, if you tank mix Sharpen-containing products with another PPO/Group 14 residual herbicide (with the exception of Prefix) you must wait 14 days to plant soybeans. Or if Sharpen is applied EPP in a burndown mix without the PPO residual product, then you must wait 2 weeks before applying the Group 14 residual herbicide at planting.