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Plantback Restrictions for Herbicides Used in South Florida Sugarcane1
C. Rainbolt2Although 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 illegal 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 into one table. 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 can 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 illegal 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.
Herbicides
Rotational Crops
Common
name
Trade
names*
Celery
Cilantro
Chines Cabbage
Corn, Field
Corn, Sweet
Lettuce1
Melon
Parsley
Pepper
Radish
Rice
Snap beans
Spinach
CityplaceSt. Augustine
Months after Application before planting
2,4-D acid form.
Unison
1
1
1
02
02
1
1
1
1
1
02
1
02
02
2,4-D amine
many
none
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
Asulam (many), Asulox, Asulox XP
none
Atrazine
Aatrex, Atrazine (many generics)
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, others
43
43
43
43
43
43
43
43
43
43
43
43
43
43
Diuron
Direx, Karmex, others
24
24
24
24
24
24
24
24
24
24
24
24
24
24
Diuron/ Hexazinone
DuPont Velpar K-4 Max
24
24
24
24
24
24
24
24
24
24
24
24
24
24
Flumioxazin
Valor SX
184
184
184
9
184
184
184
184
184
184
9
184
184
184
Halosulfuron
Sandea
36
36
36
1
3
35 or 18
2
36
4
35 or 12
2
2
24
36
Halosulfuron/ Dicamba
Yukon
36
36
36
1
3
18
4
36
10
12
3
9
24
36
Metribuzin
Metri DF, Sencor, others
12
12
12
4
12
12
12
12
12
18
8
12
12
12
Paraquat
Gramoxone Max, Gramoxone Inteon
none
Pendimethalin
Prowl H20, others
12
12
12
12
12
12
12
12
12
12
12
12
12
12
Trifluralin
Treflan, others
5
5
5
5
5
5
5
5
5
5
5
5
12-146
5
Trifloxysulfuron
Envoke
184
184
184
7
7
184
184
124
12-187
124
7
184
184
184
* 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.
1Lettuce includes iceberg, leaf types, endive, and escarole.
2Labeled crops may be planted within 29 days of application; however, under dry, cool conditions the possibility of crop injury exists (particularly in the first 14 days).
3The Banvel label does not list a minimum months before planting if normal harvest of the treated crop occurs.
4A bioassay should be performed prior to planting any of these crops.
5Can be planted 3 months after application of Sandea on muck soils only.
6Should not be planted for 12 months after a spring application or 14 months after a fall application
712 months for transplanted bell peppers if a successful bioassay is conducted. 18 months for all other peppers.
Footnotes
1. This document is SS AGR 273, one of a series of the Agronomy Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date July 2007. Visit the EDIS Web Site at http://edis.ifas.ufl.edu.2. C. Rainbolt, assistant professor, Agronomy Department, Everglades Research and Education Center--Belle Glade, FL; Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, 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.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.
U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
Copyright Information
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