Everglades Station Mimeo Report EES 64-8 October, 1963
CHEMICAL WEED CONTROL FOR SUGARCANE IN.THE FLORIDA EVERGLADES /
SJ. R. Orsenigo .
Recommendations and suggestions given here are /
based on research conducted by the Everglades/ "
Experiment Station and supplemented by data
developed elsewhere. Growers are urged to
observe the manufacturer's label and precautions ,
for commercial use of herbicides in sugarcane. ,
The economics and potential of weed control chemicals in farm management must
be evaluated by each grower in his particular situation. Initial use of these
chemicals should be restricted to a limited acreage for familiarization.
Herbicides are effective, economical tools in sugarcane production they
are not substitutes for good agronomic practice. The best chemical performance
will be obtained by adhering to certain guides: USE the RIGHT CHEMICAL for the
particular weed problem at the RIGHT TIME, in the RIGHT AMOUNT, WAY and PLACE.
Most preemergence herbicides are effective only against germinating weed seed
and small annual weed seedlings. These chemicals generally do not control emerged
weeds and should be applied promptly after planting or to freshly weeded soil.
Preemergence chemicals perform best when applied to a moist soil surface or when
application is followed by moderate rainfall.
Broadcast-overall herbicide application is indicated in plant sugarcane since
the conventional ridge-and-furrow planting system does not permit ready tillage of
row middles if chemicals are applied to the drill. Less pronounced ridge-and-
furrow to almost flat planting are desirable if'premergence herbicides are to be
used., This will prevent soil shifting, exposure of untreated soil and subsequent
All herbicide rates are given on a PER TREATED ACRE basis in terms of the usual
commercial formulation. Good, uniform ground coverage is necessary. Sprayable
(soluble salts,I emulsifiable concentrates and wettable powders) and granular formu-
lations (df some chemicals) are available. The customary active ingredient content
of herbicides mentioned in this report is given in the Glossary along with herbicide
nomenclature and terminology.
RECOMMENDED herbicidal treatments (chemical, rate, manner of use) are those
generally reliable for commercial production when used as specified. Growers
without prior herbicide-use experience should confine initial applications to a
'' SUGGESTED herbicidal treatments represent promising materials not fully
evaluated locally and materials approved for sugarcane under conditions not
generally applicable to the Everglades. Growers may wish to use these on a very
1.. A revision of part of EES Mimeo Report 62-5.
2. Associate Horticulturist, University of Florida, Everglades Experiment Station,
Belle Glade, Florida.
CHEMICAL WEED CONTROL FOR SUGARCANE
PREEMERGENCE TO ANNUAL WEEDS IN PLANT 'CANE
A. Early-fall planting (mid-August to mid-October): Use a modified ridge-and-
furrow and apply herbicides immediately after covering when mature seed
of good quality is planted at the proper rate. Use procedure "B" below
if seed quality is poor or planting rate is low.
B. Late-fall planting (after mid-October): Keep 'cane fields clean-cultivated
until need for replanting "skips" can be determined. After replanting
"skips" in stand or after a decision not to replant: clean-cultivate
to a modified ridge-and-furrow and apply herbicides immediately with a
directed or semi-directed spray to minimize wetting the 'cane foliage.
Granular formulations may be applied over the plants.
FOR ORGANIC SOILS
It will be necessary to supplement this treat-
ment with a postemergence 2,4-D spray for broad
leaf weed control at 1 to 2 months after appli-
8 to 10 qts/A This combination will provide good grass and
broadleaf weed control for extended periods
2 gts/A under average soil moisture and rainfall condi-
This is a commercial formulation of "Randox"
and 2,4-D acid.
"Randox" and "Limit" will not control perennial or established weeds.
Weed control with this chemical is improved with good soil moisture
or light rainfall and is decreased by heavy, persistent rainfall.
This chemical usually provides good annual grass
weed control which has continued into the ratoon
crop following application. Broadleaf weed
control is usually inferior.
FOR SANDY SOILS
Good soil moisture or rainfall is essential.
Broadleaf weed control frequently is better
than annual grass control. May be used in a
split application: 2j lb/A after small weeds
have emerged and 'cane beginning to come up,
with 2 lb/A later as required by weed growth.
Controls broadleaf weeds better than grasses,
especially under low soil moisture. An addi-
tional directed postemergence spray of 2 lb/A
may be used if needed.
PREEMERGENCE TO ANNUAL WEEDS IN RATOON CANE : ALL SOILS
c. Before or after emergence of stubble growth in trash-free rows only:
.Tillivate row middles, then apply chemicals listed for plant
crops above. Apply soon after ratooning in early fall and late spring
harvest; do not delay more than 2 weeks during rest of harvest season.
Tillivate and apply herbicides to trash rows when trash decomposes.
POSTEMERGENCE TO SUGARCANE AND ANNUAL WEEDS: ALL SOILS
D. For emerged annual grasses only:
Alexandergrass, crabgrass, goosegrass, etc.
lb/A Apply with directed or semi-directed
sprays to avoid wetting 'cane foliage.
Apply 2 or 3 times at 7 to 10 day
intervals. Bermudagrass and other
perennial grasses controlled readily.
Serious yield reduction can occur if
much sugarcane foliage is wet repeatedly
Apply only to seedling grass (and broad-
leaf) weeds 2 to 3 inches tall and with
not more than 3 expanded leaves. Use
semi-directed equipment. With good
soil moisture or light rainfall this
treatment will provide some residual
control of annual grass and broadleaf
weeds, especially on sandy soil.
E. Spot treatments to control emerged annual and perennial grasses:
7 to 10
lb Apply as light foliage wetting spray
only to clumps or individual plants of
annual or perennial grasses, especially
Napiergrass, paragrass, barnyardgrass,
Bermudagrass, wild sorghum, and others.
F. For emerged broadleaf weeds:
For 2,4-D susceptible
2 qts/A Amine salt preferred
For 2,4-D resistant weeds (nightshade, dog fennel, ground cherry and
2,4,5-T 1l qts/A Amine salt preferred
For mixed broadleaf weeds;
2,4-D + 2,4,5-T at 3/4 lb/A each in tank mixture.
For Pellitoryweed (Artilleryweed);
a. "Atrazine", "Karmex" or "Telvar" at 1/2 to 3/4 lb/A
b. 2,4-D amine at 1/2 lb/A
c. Triton X-100, 1% by volume (Other surfactants of equal
activity may be used)
The 2,4-D component may be omitted for fields near sensitive
crops or where other broadleaf weeds are not a problem.
These combinations should be applied with directional spray
G. For mixed annual grass and broadleaf weeds:
For small seedling weeds;
"Atrazine" 4 lb/A As for "D" above.
For larger established weeds;
t...... l"Dowpon" plus 2,4-D As for "D" and "F" above.
GLOSSARY AND STATUS OF HERBICIDES CLEARED FOR SUGARCANE
Chemicals recommended or suggested for Florida
Atrazine 2-chloro-4-ethylamino-6-iopropylamino-s-triazine. Geigy "Atrazine 80W",
an 80% wettable powder. Maximum rate: 5 lb/A per application; 12
lb/A per crop.
Dowpon Sodium salt of 2,2-dichloropropionic acid. Dow "Dowpon", 74% acid
equivalent. Maximum cleared rate 11.1 Ib/A acid equivalent. Effective
against established grasses. Should be used in split applications.
2,4-D Amine salt formulations of 2,4-Dichlorophenoxyacetic acid containing
4 lb/A acid equivalent. Many suppliers. Maximum cleared rate 2 Ib/A
acid equivalent applied prior to 'cane emergence or postemergence until
lay-by. Use caution to prevent damage to nearby sensitive crops.
Fenac Sodium salt of 2,3,6-trichlorophenylacetic acid. Amchem "Fenac" con-
taining 1.5 lb/gal acid equivalent.
Karmex diuron, 3-(3,4-dichlorophenyl)-1,l-dimethylurea. duPont "Karmex", an
80% wettable powder. Maximum cleared rate for Florida is 4 lb/A pre-
emergence to weeds after planting with added postemergence sprays to
a maximum of 6 lb/A.
Telvar monuron, 3-(p-chlorophenyl)-l,l-dimethylurea. duPont "Telvar", and
80% wettable powder. Cleared rate same as for Karmex.
Randox CDAA, 2-chloro-N,N-diallylacetamide. Monsanto "Randox" containing 4 lb/
gal active. Maximum cleared rate is 10 lb/A; do not apply more than
once per crop nor within 10 months of harvest. Monsanto "Limit" contains
Randox and 2,4-D acid.
2,4,5-T Amine salt formulations of 2,4,5-trichlorophenoxyacetic acid containing
4 Ib/gal acid equivalent. Many suppliers. Rate of 1 lb/A acid equiv-
alent cleared for use postemergence to weeds growing in established
cane. Use caution to avoid damage to near-by susceptible crops.
Other cleared chemicals not suggested for Florida.
PCP or P entchlorophenol. Available from several suppliers. Cleared at 4.5
Penta lb/A when used preemergence to 'cane at 1 to 2 days after planting.
Cleared at same rate for directed postemergence sprays before weeds are
2 inches tall.
NaPCP or Sodium salt of pentachlorophenol. Available from several suppliers.
SPCP Cleared at 44 lb/A preemergence immediately after planting and before
weed seedlings emerge. A rate of 10- lb/A is cleared for use immed-
iately after weed seedlings emerge.
Silvex propylenegylcolbutylether esters of 2-(2,4,5-trichlorophenoxy)propionic
acid. Formulations containing 4 lb/gal acid equivalent are available
from Amchem, Chipman and Dow. Cleared for use in Louisiana only at
1 lb/A acid equivalent preemergence to 'cane and weeds or after off-
barring and not when 'cane exceeds 3 to 3- feet tall. Cleared for use
in Hawaii only at 5 lb/A acid equivalent preemergence after planting
or ratooning and before 'cane emergence. Use limited to 2 applications
per crop. Precautions similar to 2,4-D and 2,4,5-T necessary.
Simazine 2-chloro-4,6-bis(ethylamino)-s-triazine. Geigy "Simazine 80W", an 80%
wettable power. Application rates and conditions similar to Atrazine.
NaTCA or Sodium salt of trichloroacetic acid. Available from many suppliers in
STCA formulations containing about 80%o TCA equivalent. Cleared at 31.7 lb/A
for pre- and early postemergence and at 45 lb/A acid equivalent as late
postemergence directed sprays at base of 'cane plants.
2,4,5-T As given above. Cleared at 4.5 lb/A acid equivalent for preemergence
use in Hawaii only.
SHORT GLOSSARY OF HERBICIDE TERMINOLOGY
Band application Using the herbicide in a narrow, continuous strip in, over
or along the crop row rather than over the entire field.
Broadcast application Using the herbicide over an entire field or area.
Contact herbicide An herbicide that kills primarily by direct contact with
plant tissue rather than by translocation within the plant.
Directed application Using an herbicide in a restricted location such as the
crop row or bed at the base of plants to avoid wetting plant foliage.
Overall application Applying an herbicide from directly above plants.
Postemergence treatment Application after crop plants emerge. Treatments may
also be specified as postemergence to weeds or both crop and weeds.
Preemergence treatment Application after a crop is planted but before it emerges.
Treatments may be specified preemergence to weeds-or both crops and
weeds. Treatments may be specified preemergence to weeds but post-
emergence to the crop. Usually, preemergence treatments are made before
both crop and weeds emerge. Contact preemergence treatments kill emerged
weeds by contact action and are applied before the crop comes up.
Residual preemergence treatments kill weeds as their seed germinate or
as the seedlings emerge, either before or after crop come-up.
Preplanting treatment Application of an herbicide before planting a crop.
USE CAUTION WHEN APPLYING 2,4-D and 2,4,5-T
Chlorophenoxy herbicides are capable of causing severe injury to sensitive
vegetable, fruit and ornamental crops several miles from the actual spraying site.
The degree of hazard in the use of these chemicals is related directly to the
manner of application and weather conditions. Aerial application is most hazardous.
Ground"equipment should be operated with low spray volume and at low spraying
pressure. Not-more than 10p of a farm unit should be treated per day. Chlorophenox
herbicides should not be applied within one-half mile of susceptible crops except
under the most carefully controlled and supervised conditions. These chemicals
should not be applied when wind velocity exceeds 8 mph in isolated areas nor when
wind exceeds 4 mph when sensitive crops are grown less than 2 miles downwind. The
safest formulations are the salts, particularly amine salts. The above,rules-of-
thumb are guides to the prevention of damage, not guarantees.
READ THE LABEL
Labels on herbicide containers should be read and understood prior to use of
the chemical contained therein. This is the final and most appropriate guide to
economical and successful chemical usage.
EQUIPMENT FOR SUGARCANE HERBICIDE APPLICATION
A separate mimeographed report, EES 64-9, contains information on basic
spraying equipment, calibration, shielded sprayer design and methods of appli-