Rainfast Time for Postemergence Herbicides Commonly Used in the Everglades Agricultural Area: Quick Reference Sheet1

D.C. Odero 2

If rainfall occurs soon after herbicide application, it can affect the effectiveness of postemergence herbicides. Certain postemergence herbicides differ in their time requirements for rain-free periods (rainfast) following application. The exact time required to protect herbicide activity and efficacy will vary with weed species, environmental conditions, and other factors, including the type of adjuvant added to the spray mix. It is important to always READ THE LABEL instructions on rainfastness before applying postemergence herbicides during periods when rainfall is frequent. For more information on rainfastness and pesticide use, see the EDIS publication PI238 – Rainfastness of Pesticides (https://edis.ifas.ufl.edu/pi238).

The table below (Table 1) shows the required time interval between herbicide application and rain-free period for postemergence herbicides commonly used in sugarcane and vegetable production in the Everglades Agricultural Area and the surrounding region.

Tables

Table 1. 

Rainfast time for postemergence herbicides commonly used in the Everglades Agricultural Area.

Herbicide

Common name

Hours until rainfast

Aim

Carfentrazone

1

Armezon

Topramezone

1

Assure II

Quizalofop

1

Asulam (various)

Asulam

48

Asulox

Asulam

48

Atrazine (various)

Atrazine

4

Banvel

Dicamba

4

Basagran

Bentazon

4

Cadet

Fluthiacet

4

Callisto

Mesotrione

1

Clethodim (various)

Clethodim

1

Clincher SF

Cyhalofop

2

Dicamba (various)

Dicamba

4

Envoke

Trifloxysulfuron

3

Evik

Ametryn

4

Fusalide DX

Fluazifop

1

Glyphosate (several)

Glyphosate

1–4

Goal/Goal Tender

Oxyfluorfen

1

Gramoxone Inteon

Paraquat

0.25–0.5

Grasp SC

Penoxsulam

1

Grasp Xtra

Penoxsulam + triclopyr

1

Londax

Bensulfuron

4

Metribuzin (various)

Metribuzin

6

Poast

Sethoxydim

1

Propanil (various)

Propanil

4

Pursuit

Imazethapyr

1

Reflex

Fomesafen

1

Regiment

Bispyribac-sodium

8

Roundup Original Max

Glyphosate

1–2

Roundup PowerMax

Glyphosate

0.5

Roundup WeatherMax

Glyphosate

0.5

Sandea

Halosulfuron

4

Select/Select Max

Clethodim

1

Sharpen

Saflufenacil

1

Touchdown CT2

Glyphosate

0.5–1

Touchdown HiTech

Glyphosate

0.5–1

Touchdown Total

Glyphosate

0.5–1

Ultra Blazer

Acifluorfen

4

Yukon

Halosulfuron + Dicamba

4

2,4-D amine (various)

2,4-D amine

6–8

2,4-D ester (various)

2,4-D ester

1–3

Footnotes

1. This document is SS-AGR-351, one of a series of the Agronomy Department, UF/IFAS Extension. Original publication date August 2011. Revised September 2018. Visit the EDIS website at https://edis.ifas.ufl.edu for the currently supported version of this publication.
2. D.C. Odero, associate professor, Agronomy Department,UF/IFAS Everglades Research and Education Center, Belle Glade, FL.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication do not signify our approval to the exclusion of other products of suitable composition. Use pesticides safely. Read and follow directions on the manufacturer's label.