Weed Management in Sugarcane - 2007
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Weed Management in Sugarcane - 2007

   

Weed Management in Sugarcane - 20071

C. Rainbolt and J. A. Dusky2

Successful weed control is essential for economical sugarcane production in Florida. Weeds can reduce cane yields by competing for moisture, nutrients, and light during the growing season. Weed control is most critical early in the season prior to sugarcane canopy closure over the row middles. Heavy weed infestations can also interfere with sugarcane harvest by adding unnecessary harvesting expenses. A weed that is allowed to mature and produce seed will multiply weed control problems for future years. See Table 1 for available herbicidal options.

Crop Rotation

Crop rotation patterns will affect the weed management of a sugarcane crop. Weed management must be intensified in successive planting operations. Traditionally, the fallow period between final ratoon harvest and planting has effectively been used to manage troublesome weed populations. This is accomplished primarily by mechanical cultivation. Flooding fallow fields also aids in weed control through the development of an anaerobic environment in which weed seed germination and seedling growth is impaired. Under successive planting management, weed populations are not severely reduced between crops and weed pressure will increase if adequate control measures are not implemented.

Crop Competition

Crop competition for sunlight is one of the most important concepts to be utilized in effective weed control. A good stand of surgarcane that emerges rapidly and uniformly and forms a complete canopy that shades the row middles early in the season is very helpful in reducing weed competition. The loss of cane stools in ratoon crops due to rodent, insect, or harvest damage will create open spaces in the sugarcane canopy in which weeds can proliferate. A concentrated effort to maintain maximum cane populations throughout all phases of production will benefit weed control efforts.

Cultivation

Cultivation can be an economical means of suppressing weed growth. To assure that the sugarcane plants get the early advantage in the competition for sunlight, a height differential must be established between cane plants and weeds. Preemergence herbicides are most effective in establishing this height differential. Only when the cane plants are growing taller than competing weeds can mechanical cultivation be effective. However, cultivation when weeds are not present due to application of a herbicide or previous cultivations are not recommended. Cultivation when weeds are not present can encourage germination of additional weed seeds, and can remove the layer of herbicide present when soil-applied herbicides are used. In ratoon crops, mechanical cultivators must be able to cut through surface debris and throroughly mix the soil.

Herbicides

Herbicides can be useful and economical tools in sugarcane production. They must be incorporated into an overall management plan to obtain their maximum benefit. It is important that sugarcane plants have the initial competitive advantage against weeds. Preemergence herbicide applications, in conjunction with mechanical cultivation, help to ensure the early season advantage. Directed or semi-directed postemergence herbicide applications can generally only be effective if the sugarcane is taller than the competing weeds. Accurate herbicide placement is crucial for banded or directed applications. High application speeds and rough fields can result in poor application uniformity, particularly with banded applications. Speed must be limited if movement of the boom or drop nozzles results in excessive amounts of herbicide actually depositing in the untreated strip. Broadcast applications are generally less affected by these factors, since nozzle overlap helps insure uniformity of herbicide placement. Proper timing of herbicide application with respect to the growth stage of the weeds is extremely critical. Normally, weeds should be treated when they are 4 to 8" in height. Read the label for the proper time of application.

The herbicides suggested are those that have performed well in IFAS research. Herbicide users must read the label and follow all instructions and precautions carefully. Accurate calibration of application equipment is extremely important. The effectiveness and economic usefulness of herbicides must be evaluated by each grower for his particular situation. Initial use of these chemicals should be restricted to a limited acreage for familiarization. You are responsible for the performance of the chemicals you use. Herbicides, like any pesticide, should be handled with care. Store herbicides behind locked doors in the original containers with the label intact and separated from seed, fertilizers, and other pesticides.

Tables

Table 1. Weed management in sugarcane.

Trade Name & Broadcast Rate/Acre of Commercial Product

Common Name and

Broadcast Rate/Acre

of Active Ingredient

Remarks

FALLOW LAND MANAGEMENT

MUCK AND SANDY SOILS
glyphosate

(several)

(3.25 - 4 qt)


 glyphosate

(4 - 5 lb)


 For control of emerged annual and perennial weeds growing in or around sugarcane or in fields to be planted to sugarcane. This product will control undesirable sugarcane. When repeat applications are necessary, do not exceed a total of 8.125 lb of ai/A per growing season. Apply in 10 to 40 gal of water per acre. For specific rates of application and instructions for control of various weeds, consult the label. For information concerning low rate technology applications, consult the label.

PREEMERGENCE-PLANT CANE

MUCK SOILS
AAtrex Nine-0 (2.2-4.4 lb) AAtrex 4L (4-8 pt)

Atrazine 90DF (2.2-4.4 lb)

Atrazine 4L (4-8 pt)

Atrazine 90WDG (2.2-4.4 lb)


 atrazine 1

(2 - 4 lb)


 Broadcast or band by ground equipment. Apply at time of planting or ratooning but before cane emerges. (Maximum annual rate is 10 lb of ai/A. No mixing/loading within 50 ft of canals.) Now a Restricted Use Pesticide.
K-4

(4 lb)


 hexazinone + diuron

(0.53 + 1.87 lb)


 For control of annual grass and broadleaf weeds, applications should be made immediately following planting and row packing and prior to crop and weed emergence. For best weed control, applications should be made to a firm, well-prepared seedbed that is free from clods or excess plant residue. When applying K-4 alone or in combination with other diuron-containing products, do not exceed a total annual application of 6 lbs of diuron per acre. Do not apply more than 7.5 lbs of K-4 per acre per year and do not apply K-4 within 234 days of harvest.
Prowl 3.3 EC

(2.4 - 4.85 qts/A)

or

pendimethalin 3.3

(several)

(2.4 - 3.6 qts/A)

+

Sencor

or

metribuzin

(several)

(1 - 2.33 lb/A)


 pendimethalin

(2 - 4 lb)

or

pendimethalin

(2 - 3 lb)

+

metribuzin

(0.8 - 1.86 lb)


 Controls most annual grasses and broadleaf weeds. Broadcast or band by ground equipment. Apply at the time of planting or ratooning, but prior to weed emergence. Rainfall within 7 days of application is needed to incorporate the herbicide into the soil, or activity will be significantly decreased. Do not exceed 5.95 lb ai/A of pendimethalin, or 2.33 lb ai/A metribuzin in one growing season.
atrazine (several)

(2.2-4.4 lb) or (4-8 pt)

+

Sencor

or

metribuzin (several)

(1 - 2.33 lb/A)


atrazine

(2 - 4 lb)

+

metribuzin

(0.8 -1.86 lb)


 Controls most annual grasses and broadleaf weeds. Broadcast or band by ground equipment. Apply at the time of planting or ratooning, but prior to weed emergence. Rainfall within 7 days of application is needed to incorporate the herbicide into the soil, or activity will be significantly decreased. Do not exceed 10 lb ai/A of atrazine or 2.33 lb ai/A metribuzin in one growing season.

PREEMERGENCE-PLANT CANE

SANDY SOILS
AAtrex Nine-0 (2.2-4.4 lb)

AAtrex 4L (4-8 pt)

Atrazine 90DF

Atrazine 4L

Atrazine 90WDG


 atrazine 1

(2.0 - 4.0 lb)


 Good soil moisture or light rainfall is essential. Broadleaf weed control may be superior to annual grass weed control. May be used in split application: 2.0 lb/A preemergence and 2.0 lb/A as required. Application schedule may be delayed until small weeds and cane have emerged. (Maximum annual rate is 8.6 lb of ai/A. No mixing/loading within 50 ft of canals.) Now a Restricted Use Pesticide.
Drexel Diuron 80W

Drexel Diuron 4L

Karmex DF (2-4 lb)


 diuron

(1.6 - 3.2 lb)


 Controls broadleaf weeds better than grasses especially under low soil moisture. An additional directed postemergence spray of 1.6 lb/A may be applied to prolong weed control.

MUCK AND SANDY SOILS
glyphosate

(several)

(3.25 - 4 qt)


 glyphosate

(4- 5 lb)


 For control of emerged annual and perennial weeds prior to cane emergence. Higher rates are to be used for difficult to control weeds. For specific rates of application and instructions for control of various weeds, consult the label. For information concerning low rate technology applications, consult the label.
Prowl 3.3 EC

(2.4 - 4.85 qt)

or

pendimethalin 3.3 (several)

(2.4 - 3.6 qt)


pendimethalin

(2 - 4 lb)

pendimethalin

(2 - 3 lb)


Controls most annual grasses and certain broadleaf weeds. Broadcast or band by ground equipment. Apply at time of planting or ratooning but before weeds emerge. May be applied by air. May be applied twice per season. May be applied at layby with ground equipment in a spray directed under the sugarcane canopy. Must be incorporated thoroughly and uniformly by either mechanical incorporation or rainfall within 7 days after application. Do not exceed 5.95 lb of ai/A in one growing season.


Prowl H2O

(2.1 - 4.2 qt)


pendimethalin

(2 - 4 lb)


A microencapsulated formulation which reduces odor and staining. Weed control is equal to that of other Prowl formulations. Do not exceed 5.95 lb of ai/A in one growing season. For additional recommendations, see above.


Valor SX

(6 - 8 oz)


 flumioxazin

(0.19 - 0.25 lb)


 Apply before the crop emerges. Can be applied pre- or postemergence to control both grass and broadleaf weeds. If applied postemergence, control will be improved with the addition of 1 qt per acre methylated seed oil, 1qt per acre crop oil concentrate, or 0.25% v/v nonionic surfactant. Residual activity is reduced when applied to soils with more than 10% organic matter. Refer to the supplemental label for sugarcane for more specific information. Do not apply more than 12 oz per acre within a single growing season. Do not apply within 90 days of harvest.

PREEMERGENCE-RATOON CANE

MUCK AND SANDY SOIL
After fertilization, cultivate row middles and then apply selected herbicide listed above for plant cane crops. Apply before or soon after stubble regrowth. Cultivate and apply herbicide to trash rows when trash has decomposed, if practical. Tillage machinery should not throw weedy soil onto chemically treated areas.

PREEMERGENCE-RATOON CANE - MUCK SOIL
K-4

(4 lb)


 hexazinone + diuron

(0.53 + 1.87 lb)


 For control of annual grass and broadleaf weeds, applications should be made immediately following harvest and prior to subsequent weed germination. Excess plant residue on the soil surface may decrease the effectiveness of K-4 and should be removed or minimized.

K-4 may also be applied postemergence to ratoon sugarcane until the crop reaches a height of 18 inches or within 234 days of harvest, whichever is more restrictive. Postemergence applications of K-4 to actively growing sugarcane may result in crop injury when daily temperatures exceed 80° F. When daily temperatures exceed 80° F, post-directed applications are recommended. If weeds are present at application, a tank-mix partner is recommended for improved postemergence control. If

K-4 is used in a tank mixture with other herbicides, read

and follow all use instructions, warnings and precautions on companion herbicide labels. If weeds are present at the time of application a non-ionic surfactant at the use rate of 0.25% v/v or crop oil concentrate at the use rate of 1% v/v is recommended. If a tank-mix partner is being used, follow the most restrictive adjuvant recommendation.

POSTEMERGENCE

MUCK SOILS
Sencor DF

(1.33 - 2.66 lb)


 metribuzin 1

(1.0 - 2.0 lb)


 For control of pigweed, butterweed, goosegrass, and broadleaf panicum. Should be used as a directed spray. Avoid contact with cane foliage. Apply before weeds are 6" tall. Do not use on sugarcane grown on sandy soil.

MUCK AND SANDY SOILS
2,4-D Amine2

(many trade names)


 2,4-D

(0.5 - 2.0 lb)


 Controls broadleaf weeds, including spiny amaranth, ragweed, morningglory, and many others. Use high rates for large or difficult-to-control weeds, such as alligatorweed. Take care to prevent spray drift to sensitive crops, and consult the Florida Organo-Auxin herbicide rule prior to application.
2,4-D Amine +

Dicamba2

(several trade names)

(2-6 pts)


 2,4-D + Dicamba

(0.97 - 2.9 lb)


Controls many annual, biennial, and perennial broadleaf weeds. Use 2 pts for control of annual weeds, and for difficult perennials up to 6 pts may be used in a single application (at 4-6 pts per application injury to sugarcane is likely to occur). Re-treat as needed, but do not exceed 16 pts total per growing season. Take care to prevent spray drift to sensitive crops, and consult the Florida Organo-Auxin herbicide rule prior to application.
AAtrex Nine-0 (2.2-4.4 lb)

AAtrex 4L (4-8 pt)

Atrazine 4L (4-8 pt)

Atrazine 90DF (2.2-4.4 lb)


 atrazine 1

(2.0 - 4.0 lb)


 Apply onto seedling weeds 2-3" tall and with not more than 3 expanded leaves. Semi-directed spray preferred. With good soil moisture or light rainfall, this treatment will provide some residual control of annual grass and broadleaf weeds, especially on sandy soils. (Maximum annual rate is 8.6 lb of ai/A. No mixing/loading within 50 ft of canals.) Now a Restricted Use Pesticide.
Asulox

or

asulam (several)

(6-8 pt)


 asulam

(2.5 - 3.34 lb)


 Apply to foliage of immature seedling grasses. Application may be broadcast overall, directed, or semi-directed in cane at least 14" tall. Apply only once per season. Do not tank mix. Do not apply less than 90 days before harvest. A non-ionic surfactant may be added to the spray at 0.25% v/v. Will control alexander grass, broadleaf panicum, and other annual grasses but response is slow.
Dicamba2 (several trade names)

(1-1.5 pt)


Dicamba

(0.25 - 0.75 lb)


 Controls many annual, biennial, and perennial broadleaf weeds. Use high rates for large or difficult-to-control weeds, and for difficult perennials 2-4 pts may be used in a single application (at 2-4 pts per application injury to sugarcane is likely to occur). Re-treat as needed, but do not exceed 4 pts total per growing season. Take care to prevent spray drift to sensitive crops, and consult the Florida Organo-Auxin herbicide rule prior to application.


Envoke - Plant Cane

(0.3 - 0.6 oz)


trifloxysulfuron-sodium

(0.23 - 0.45 oz)


 Apply to seedling weeds less than 4-6 inches in height. Provides good control of yellow and purple nutsedge, spiny pigweed, alligatorweed, broadleaf panicum, itchgrass, and several other grass and broadleaf species. Applications to plant cane can only be made post-directed to cane that is >18" tall through layby. Tank-mixtures with Evik or atrazine may reduce grass control. Preliminary results suggest that 2,4-D tank-mixtures may also reduce grass control, particularly when higher rates of 2,4-D are used. Apply with non-ionic surfactant at a rate of 0.25 % v/v. Crop oil concentrate may be used (0.5 to 1% v/v) ONLY when applying post-directed.
Envoke - Ratoon Cane

(0.3 - 0.6 oz)


trifloxysulfuron-sodium

(0.23 - 0.45 oz)


 May be applied post over-the-top at 0.3 oz until cane reaches 24" in height. The 0.6 oz rate may be applied post-direct to cane that is >18" tall through layby. For additional information, see above.
Envoke - Plant Cane

(0.6 oz)

+

Asulox

(4 pt)


 trifloxysulfuron-sodium

(0.23 oz)

+

asulam

(1.65 lb)


 Apply post-directed to sugarcane that is 18" tall through layby. Best for seedling weeds less than 4-6" in height. This tank-mixture controls a broader spectrum of grass and broadleaf species than Envoke or Asulam applied alone, and provides better control of larger grasses. Provides good control of yellow and purple nutsedge, spiny pigweed, alligatorweed, broadleaf panicum, fall panicum, goosegrass, itchgrass, and several other grass and broadleaf species. Preliminary results suggest that 2,4-D tank-mixtures may also reduce grass control, particularly when higher rates of 2,4-D are used. Apply with non-ionic surfactant at a rate of 0.25% v/v.
Envoke - Ratoon Cane

(0.3 - 0.6 oz)

+

Asulox

(4 pt)


 trifloxysulfuron-sodium

(0.23 oz)

+

asulam

(1.65 lb)


 Apply 0.3 oz Envoke and 4 pt Asulox over-the-top of sugarcane that is up to 24" tall. Apply 0.6 oz Envoke and 4 pt Asulox post-directed in sugarcane that is up to 18" tall through layby. Apply with non-ionic surfactant at a rate of 0.25 % v/v.
Evik

(0.5 - 1.5 lb)


 ametryn

(0.38 - 1.14 lb)


 Apply only as directional or semi-directional spray to annual grass and broadleaf weed seedlings up to 3" tall. Especially effective against alexandergrass. For mixed weed infestations, activity is increased by adding 0.5% v/v surfactant to the spray. Apply up to 2 repeat applications at 30 day intervals. Avoid wetting cane foliage.
glyphosate

(several)

(4 - 5 qt)


 glyphosate

(4 - 5 lb)


 This product may be used through hooded sprayers for weed control between the rows of sugarcane. A hooded sprayer is a type of shielded applicator. Sugarcane must be at least 3 ft tall. Contact with the cane foliage by either the spray mixture or treated weed foliage will cause cane injury. For specific rates of application and instructions for control of various weeds, consult the label. For information concerning low rate technology applications, consult the label.
Sandea

(0.75-1.33 oz)


 halosulfuron-methyl

(0.032 - 0.063)


 For control of purple and yellow nutsedge. Also controls some broadleaf species. See label for details. Apply to emerged nutsedge after sedge has reached 3-8 leaf stage. May apply to any stage of sugarcane growth. No more than 3 applications (including preplant) may be made with the total use rate not to exceed 2 2/3 oz of product by weight (0.125 lb ai) per acre per year. Should be applied with ground rig with 10 or more gallons of water per acre. Add crop oil concentrate at 1% v/v or a non-ionic surfactant that contains at least 80% active ingredient at 0.25-0.50% v/v. Applications should be made to actively growing weeds.
Yukon

(4-8 oz)


 halosulfuron-methyl

(12.5 %)

+

dicamba

(50.0 %)


 For control of purple and yellow nutsedgeand broadleaf species. See label for details. Apply to emerged nutsedge after sedge has reached 3-8 leaf stage. Add crop oil concentrate at 1% v/v or a non-ionic surfactant that contains at least 80% active ingredient at 0.25-0.50% v/v. Applications should be made to actively growing weeds. Do not make more than 2 applications per season. Take care to prevent spray drift to sensitive crops, and consult the Florida Organo-Auxin herbicide rule prior to application.
1 WARNING: The following information has been added to the atrazine and metribuzin labels. This statement should be heeded by all prospective users and steps should be taken to comply with this label change:

"Atrazine and metribuzin are chemicals which can travel (seep or leach) through soil and can contaminate groundwater as a result of agricultural use. Atrazine and metribuzin have been found in groundwater as a result of agricultural use. Users are advised not to apply atrazine or metribuzin where the water table (groundwater) is close to the surface and where the soils are very permeable, i.e., well-drained soils such as sands and loamy sands. Your local agricultural agencies can provide further information on the type of soil in your area and location of groundwater. In addition, some product label statements include as a further qualification of risky soils, soils containing sinkholes over limestone bedrock, severely fractured surfaces, and substrates which would allow direct introduction into an aquifer."

2 See fact sheet SS-AGR-12 Florida's Organo-Auxin Herbicide Rule for state rules pertaining to application of organo-auxin herbicides in Florida.

Footnotes

1. This document is SS-AGR-09, one of a series of the Agronomy Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Revised December 2006. This publication is also a part of the Sugarcane Handbook, an electronic publication of the Agronomy Department. For more information you may contact the editor of the Sugarcane Handbook, R.A. Gilbert (ragilber@mail.ifas.ufl.edu). Please visit the EDIS Website at http://edis.ifas.ufl.edu.

2. C. Rainbolt, assistant professor, Agronomy Department, Everglades Research and Education Center--Belle Glade, FL; and J. A. Dusky, Professor and Assistant Dean for Extension; 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.

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 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

This document is copyrighted by the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) for the people of the State of Florida. UF/IFAS retains all rights under all conventions, but permits free reproduction by all agents and offices of the Cooperative Extension Service and the people of the State of Florida. Permission is granted to others to use these materials in part or in full for educational purposes, provided that full credit is given to the UF/IFAS, citing the publication, its source, and date of publication.