Plantback Restrictions for Herbicides Used in South Florida Sugarcane1

D. C. Odero, R. Negrisoli, M. VanWeelden, and S. Swanson 2

Although sugarcane is a relatively competitive crop, weed pressure can have a negative impact on yields. Consequently, most fields are treated with herbicides one or more times during the growing season. Regardless of whether an herbicide is primarily a pre- or postemergence product, some have the potential to persist in the soil for long periods of time. Ideally, herbicide applications would provide long-term weed control during the growing season but would dissipate to a safe level before the next crop is planted. In some situations, herbicides that persist in the soil for long periods of time can injure subsequently planted crops, or these crops can accumulate injurious herbicide residues. The potential for rotational crop injury depends on complex interactions among herbicide characteristics, soil type, soil moisture and temperature, and the sensitivity of the rotational crops. Herbicides that persist in the soil usually have a section on the product label detailing specific rotational crop (plantback) restrictions. These restrictions indicate how much time must pass between herbicide application and the planting of a sensitive crop. The rotational crop restrictions on herbicide labels take into account basic chemical properties of the herbicide, the persistence of the herbicide, typical environmental characteristics of the state or region, and the sensitivity of rotational crops.

This publication condenses rotational crop restrictions for herbicides registered for use in Florida sugarcane (Table 1). When considering the application of herbicides, it is very important to understand the effects that a persistent herbicide may have on subsequent crops. Information on herbicide labels should be used to make better decisions about the crop sequence in a rotation, about which herbicides to use or avoid in a system, and about the rate and timing of herbicide applications. When planning weed control programs, the labels for all herbicides that will potentially be used in crop rotation should be studied along with this bulletin to prevent label violations, reduce economic losses due to herbicide carryover, and avoid injurious herbicide residues.

Tables

Table 1. 

Minimum number of months following application of herbicides registered for use in sugarcane before it is safe to plant selected rotational crops.

Herbicide

Rotational Crops

Common Name

Trade Names*

Celery

Cilantro

Chinese Cabbage

Corn, Field

Corn, Sweet

Lettuce1

Melon

Parsley

Pepper

Radish

Rice

Snap beans

Spinach

St. Augustine Sod

 

Months After Application Before Planting

2,4-D acid

Unison

1

1

1

02

02

1

1

1

1

1

02

1

02

02

2,4-D amine

Several

NCS3

NCS3

NCS3

7/14D4

7/14D4

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

2,4-D/

Dicamba

Brash, Weedmaster

4

4

4

4

4

4

4

4

4

4

4

4

4

4

Ametryn

Evik

9

9

9

4

4

9

11

9

11

9

4

9

9

11

Asulam

Asulox, Asulox XP, Asulam (several)

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

NCS3

Atrazine

Aatrex 4L, Aatrex Nine-O, Atrazine (several)

12

12

12

12

12

12

12

12

12

12

9

12

12

12

Clomazone

Command 3ME

12

12

12

9

9

12

12

12

9

12

9

9

12

12

Dicamba

Banvel, Clarity, several

45

45

45

46

45

45

45

45

45

45

45

45

45

45

Diuron

Direx 4L, Karmex DF, Karmex XP, several

24

24

24

24

24

24

24

24

24

24

24

24

24

24

Hexazinone

Velpar L, Velpar DF

24

24

24

24

24

24

24

24

24

24

24

24

24

24

Flumioxazin

Valor SX

186

186

186

9

186

186

186

186

186

186

9

186

186

186

Halosulfuron

Sandea

36

36

36

1

3

37 or 18

2

36

4

37 or

12

2

2

24

36

Halosulfuron/

Dicamba

Yukon

36

36

36

1

3

37 or 18

9

36

10

37 or

12

2

9

24

36

Mesotrione

Callisto

18

18

18

0

0

18

18

18

18

18

10

18

18

18

Smetolachlor/

Atrazine/

Mesotrione

Lumax EZ

18

18

18

0

0

18

18

18

18

18

18

18

18

18

Metribuzin

Metribuzin 75DF, Sencor, Tricor DF, Tricor 4F

12

12

12

4

12

12

12

12

12

18

8

12

12

12

Paraquat

Gramoxone Max, Gramoxone Inteon

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Pendimethalin

Prowl H20, Prowl 3.3, Pendimax 3.3, Satellite 3.3, Satellite Flex, Satellite HydroCap

12

12

12

12

0

12

12

12

12

12

12

12

12

12

Terbacil

Sinbar

24

24

24

24

24

24

24

24

24

24

24

24

24

24

Topramezone

Armezon

18

18

18

0

0

18

18

18

18

18

3

9–1810

18

18

Trifluralin

Treflan, several

5

5

5

5

5

5

5

5

5

5

5

5

12–148

5

Trifloxysulfuron

Envoke9

9–126

9–126

9–126

7–12

7–12

1126

186

9–126

186

9–126

7–9

7–96

9–126

9–126

*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 does not signify our approval to the exclusion of other products of suitable composition.

1 Lettuce includes iceberg, leaf types, endive, and escarole.

2 Labeled crops may be planted within 29 days following application; however, under cold soil temperatures and/or excessively wet or dry conditions the possibility of crop injury exists (particularly in the first 14 days).

3 Plantback restriction not specified in the label. NCS = next cropping season plantback.

4 Planting must be delayed for a minimum of 7 to 14 days at use rate of 1 or less to greater than 1 pint per acre, respectively.

5 Banvel label: no crop rotation restrictions exist if normal harvest of the treated crop has occurred.

6 Successful soil/field bioassay must be performed prior to planting any of these crops.

7 Can be planted 3 months after application on muck soils only.

8 Should not be planted for 12 months after a spring application or 14 months after a fall application.

9 Rotational interval dependent on the rate of Envoke applied per season. See the label for rate and corresponding interval required for each crop.

10 Rate of 0.75 fluid ounce per acre is 9 months, rates of 1 to 2 fluid ounces per acre are 18 months.

Footnotes

1. This document is SS AGR 273, one of a series of the Agronomy Department, UF/IFAS Extension. Original publication date July 2007. Revised November 2010 and September 2018. For current recommendations, please visit the EDIS website at https://edis.ifas.ufl.edu.
2. D. C. Odero, associate professor, Agronomy Department, UF/IFAS Everglades Research and Education Center; R. Negrisoli, graduate assistant, Agronomy Department, EREC; M. VanWeelden, Extension agent, UF/IFAS Extension Palm Beach County; and S. Swanson, Extension agent III, UF/IFAS Extension Hendry County; UF/IFAS Extension, Gainesville, FL 32611.

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 does not signify our approval to the exclusion of other products of suitable composition. All chemicals should be used in accordance with directions on the manufacturer's label.