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Publication #HS1410

Quick Reference Guide to Postemergence Herbicides for Citrus Weed Control 1

Ramdas Kanissery, Camille E. McAvoy, Jamie D. Burrow, Stephen H. Futch, Brent A. Sellers, and S. Shea Teems2

Products recommended in the Florida Citrus Production Guide and their effects on weed management. This publication is best viewed as a PDF.

Tables

Table 1. 
 

Herbicidea

MOAb

REIc

Hours

PHId

Day(s)

Weeds Controlled

Comments

Suggested Rate per Acre

 

Grasses

Broadleaf

Nonselective Systemic Herbicides

Glyphosate—Undertree

G

(9)

Variese

1

X

X

Avoid contact with citrus fruit, foliage, and green bark.

Rainfall within 1–6 hours after application may reduce effectiveness.

Annual weeds: 0.75–1.5 lb A.E.f

Perennial weeds: 1.5–3.75 lb A.E.

See product label for annual maximum rate.

Glyphosate—Chemical mowing

G

(9)

Varies

1

X

X

Do NOT mow within 1 week before or after treatment.

Bahiagrass: 0.125 lb A.E. followed by 2nd application 45 days later

Bermudagrass: 0.125–0.37 lb A.E.

Glyphosate—Wiping

G

(9)

Varies

1

X

X

Use wipers to remove tall growing and difficult weeds.

5%–10% solution—carpet wiper 50%–100% solution—panel wiper

Glyphosate—Spot treatment

G

(9)

Varies

1

X

X

Avoid contact with citrus fruit, foliage, and green bark.

1%–2% solution

Glyphosate plus

2,4-D—Landmaster II

G, O

(9, 4)

48

7

X

X

Apply with shielded and hooded sprayers in citrus middles or under the trees. User must have supplemental labeling at time of application. See label for min. distance from susceptible crops, record-keeping requirements, and additional restrictions.

Rainfall or irrigation within 4 hours may reduce effectiveness. Heavy rainfall or irrigation within 2 hours will wash product off foliage, requiring repeat treatment.

Use recommended rate in 10–40 GPA

Annual weeds: 1–8 qt

Perennial weeds: 4–8 qt

Maximum of 8 qt/year

 

Rate per application

Maximum rate/year

Max. # appl./yr

Min. time btwn. appl.

Nonselective Contact Herbicides

Carefentrazone-

ethyl

AimEC

E

(14)

12

3

X

X

Adjuvant is required such as nonionic surfactant or crop oil concentrate.

Avoid contact with green tissue or fruit.

Finished spray volume of at least 20 GPA required.

Max 2.0 fl oz

7.9 fl oz

 

14 days

Glufosinate-ammonium

Rely 280

H

(10)

12

14

X

X

Warm temperatures, high humidity, and bright sunlight improve performance. Avoid contact or spray drift with green bark, stems, or foliage. Spot treatment: 1.7 fl oz per gallon of water. Apply to undesirable vegetation foliage until wet but prior to runoff.

48–82 fl oz

246 fl oz (4.5 lb a.i.)

 

14 days

Paraquat

Gramoxone SL 2.0

D

(22)

24

-

X

X

Addition of surfactant or crop oil concentrate is essential for maximum contact activity. Avoid contact with citrus fruit, foliage, and green bark.

Per new labeling requirement, applicators must complete mandatory training program and be certified applicators of restricted-use pesticides.

2.5–4.0 pt

20 pt

   

Selective Systemic Herbicides

Fluazifop

Fusilade DX 2 E

A

(1)

12

14

X

 

Do not apply to grasses under stressed conditions. For spot treatment use 1% v/v solution with 1% crop oil concentrate or 0.25% nonionic surfactant in 30–40 GPA.

24 fl oz

72 fl oz

 

21 days

Mesotrione

Broadworks 4 L

F2

(27)

12

1

 

X

Allow at least 12 weeks between applications at 6 fl oz/A and at least 6 weeks between applications of 6 fl oz/A and subsequent applications of 3 fl oz/A.

Use of a crop oil at 1% v/v or nonionic surfactant at 0.25% is recommended.

Addition of ammonium sulfate is suggested.

Max 6 fl oz at 1st appl.

12 fl oz

 

6 weeks

Sethoxydim Poast

Plus 1.0 EC

A

(1)

12

15

X

 

Repeated applications at 3–4 week intervals may be required to control some species.

Carrier volume should not exceed 20 GPA.

Spot treatment use 1.5%–2.25% v/v solution of Poast Plus w/1% crop oil concentrate.

2.25–3.75 pt

15 pt

   

Saflufenacil

Treevix

E

(14)

12

-

 

X

4Use methylated seed oil and ammonium sulfate to optimize burndown activity.

Avoid contact with citrus fruit, foliage, flowers, buds, and green bark.

Increased efficacy at water volumes of 20 to 40 GPA.

*Additional Dormant Period Application: May be applied sequentially up to 4 times per year only if 1 or 2 applications occur from postharvest to the beginning of bloom.

Max 1.0 oz

3.0 oz

(4.0 oz*)

3

(4*)

21 days

Always read individual product labels for complete directions for use, restrictions and limitations, and tank-mix and additive recommendations.

a All listed pesticides are registered and trademarked products.

b Mode of action class (MOA) for citrus pesticides from the Herbicide Resistance Action Committee (HRAC). Weed Science Society of America (WSSA) classification is provided in the parentheses.

c Restricted Entry Interval

d Preharvest Interval

e REIs vary from 4–12 hours depending upon glyphosate formulation chosen. Check the individual product label to confirm REI.

f Acid Equivalence—conversion factors on reverse

Table 2. 
  • Glyphosate rates are often stated in pounds acid equivalent (A.E.) per acre instead of active ingredient (a.i.) per acre because only the “glyphosate acid” portion of product formulation is herbicidally active.

  • The glyphosate concentration in acid equivalent (A.E.) is specified normally on the product label's front panel in the “ingredient statement” as pounds per gallon (lb/gal) of the glyphosate acid in the product.

  • Use calculate the amount of the product needed to achieve the recommended rate of A.E. per acre.

Acid Equivalence Conversions for Glyphosate

Acid Equivalence (A.E.) (lb/gal)

Rate per Treated Acre in A.E.

0.094 lb

0.188 lb

0.282 lb

0.37 lb

0.75 lb

1.5 lb

2.25 lb

Amount of product to equal the above pounds of A.E.

3.0

4 oz

8 oz

12 oz

16 oz

32 oz (1 qt)

64 oz (2 qt)

96 oz (3 qt)

3.7

3.25 oz

6.5 oz

9.75 oz

13 oz

26 oz

52 oz

78 oz

4.0

3 oz

6 oz

9 oz

12 oz

24 oz

48 oz

72 oz

4.5

2.7 oz

5.4 oz

8 oz

10.5 oz

21.3 oz

43 oz

64 oz

5.0

2.4 oz

4.8 oz

7.5 oz

9.5 oz

19.2 oz

38.4 oz

57.6 oz

Various formulations of glyphosate are currently registered for use in Florida citrus. It is important to adjust the application rate used according to the product concentration. A product concentration is stated in pounds per gallon of acid equivalent (A.E.) on the label.

Footnotes

1.

This document is HS1410, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date March 2021. Visit the EDIS website at https://edis.ifas.ufl.edu for the currently supported version of this publication.

2.

Ramdas Kanissery, assistant professor, Horticultural Sciences Department, UF/IFAS Southwest Florida Research and Education Center; Camille E. McAvoy, laboratory technician, UF/IFAS SWFREC; Jamie D. Burrow, Extension program manager, UF/IFAS Citrus Research and Education Center; Stephen H. Futch, Extension agent (retired), UF/IFAS CREC; Brent A. Sellers, professor, Agronomy Department, and center director, UF/IFAS Range Cattle Research and Education Center; and S. Shea Teems, lab manager, UF/IFAS SWFREC; 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 do not signify our approval to the exclusion of other products of suitable composition. Use herbicides safely. Read and follow 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 UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.