CHEMICAL WEED CONTROL METHODS SUGGESTED FOR GOFERM TRIAL
IN VEGETABLE CROPS ON ORGANIC SOIIS -
J, R. Orsenigo
This report is a revision of EES Mimeo Report 56-13, The
suggestions in this report are based on experiments con-
ducted by V. L, Guzman and others with vegetable crops on
organic soils during the years 1952 to 1956, inclusive,
and are intended only for trial use on a small scale for
grower familiarization. Certain of the herbicides
included in this report do not have Pure Food and Drug
Act approval for commercial use in vegetable crops as of
EVERGLADES STATION NIMEO REPORT 57-6
Belle Glade, Florida
May 9, 1957
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CHEMICAL VIEED CONTROL METHODS SUGGESTED FOR GROVER TRIAL
I VERGTABLE CROPS ON ORGANIC SOILS
(A visionn of EES Iimeo Report 56-13)
J. R. Orsenigo /
Weed killing chemicals or herbicides offer the grower another tool in
growing vegetable crops* More effective, more selective, longer lasting, and
safer herbicides, and ways to use them, are being developed each year. By
themselves, these chemicals are no "quick-cure", but they do hold much promise
in reducing production "headaches" and costs attributable to weed infestations
in vegetable crops. The usage of these materials is being both extended and
intensified each year and in the future probably will become as integrated a
part of vegetable production as insecticides and fungicides are at present.
The chemicals and application methods which follow are suggested for
grower use on a small or pilot scale in certain vegetable crops on organic
soils to help growers become acquainted with herbicides and methods of
chemical weed control and to help evaluate the adaptability and economy of
these materials to each grower's situation under his ovn conditions. Amounts
of herbicides are expressed on a per acre basis in terms of commercial product
for Dowpon, Karmex and TCA and in terms of active ingredient for the other
herbicides mentioned. In experimental applications, the herbicides were
applied in water solution at the rate of 30 gallons per acre.
1. Rando:,: mid Vegec.ex have given excellent control of broadleaf weeds
and annual grasses at rates of 4 to 8 lbs./A.
2. Dinitro, 12 Ibs,/A,; 2,4-D amine, 2 Ibs./A.; and Karmex IT, 2 lbs./A,
have each given good results without yield reductions.
Weed control is best when there is good moisture at the soil surface.
3, 2,h-D amine at 3/4 Ib./A. applied overall to sweet corn at the one-
inch stage gave good weed control and did not reduce yield. This herbicide
at the same rate could be applied directionally to corn 12 inches tall.
46 Dinitro gave good broadleaf weed and grass control at 3 and 4 Ibs./A.
as an early post emergence spray when corn plants were in the incipient two-
leaf stage. Yields were not affected.
1/ Assistant Horticulturist, Everglades Experiment Station, Belle GLade,
* Active ingredients and sources of the herbicides and a glossary of
herbicide terminology are listed on pages 3 and h4
5* Karmex W applied directionally at 2 lbs,/A. on corn plants 15 inches
tall has given good control of broadleaf weeds and grasses without reducing
yields. This herbicide is ineffective under conditions of low soil surface
6. Combination treatments of pre-emergence applications of Dinitro or
Karmex W (see #2 on Page 1) followed by post emergence sprays of 2,-Df (see
#3 on Page 1) have given excellent weed control.
LETTUCE and ENDIVE
1, CIPC at 10 Ibs./A. gave commercial control of weeds in lettuce until
harvest w en applied after rolling to soil relatively high in moisture content
at moderate temperatures (680 F.). Rates of CIPC over 10 lbs./A. caused some
injury to endive.
2. Vegedex has shown considerable promise at 4 Ibs./A. for weeding of
lettuce and endive. Both endive and chicory suffer slight stand reductions
and a temporary retardation of growth from this rate of application,
CABBAGE, direct seeded
1. Vegedex at 4 to 8 lbs./A. has given excellent control of all weeds
for longer than six weeks.
2. TCA gave good control of grasses and did not reduce yields when applied
at 15 lbs.TA.
3. Vegedex applied at 4 lbs,/A. one day after emergence did not injure
cabbage and provided good weed control.
Pre-seeding in Seedbeds:
1. MC-2 fumigation with this material (98% methyl bromide and 2% chloro-
picrin) at the rate of 1 to 2 Ibs. per 100 square feet of bed surface gave
excellent control of weeds Seeding o.f celery should be delayed at least four
days after fumigation covers are removed from the beds.
2. Randox and Vegedex gave effective weed control when applied at
8 ibs./A.-just prior to setting.
3, Randox and Vegedex applied at 8 lbs./A. immediately after setting and
followed by overhead irrigation have given excellent weed control.
4. CIPC has given good weed control when applied during cool weather at
10 lbs./A .
5. Stoddard Solvent applied directionally at 40 gallons per acre has given
g(od weed control,
66 Combination treatments of Vegedex or CIPC (at 4 Ibs./A.) in Stoddard
Solvent have given good ieed control and shown residual persistence in the soil.
CIPC isopropyl N-(3-chlorophenyl) carbamate (Diamond, Fasco, General, Ortho
and other chemical suppliers)
Dinitro alkanolamine salts of Cinotro-O-sec-butyl phenol, Sinox PE or Premerge
(Dow, Standard Agricultural and other chemical suppliers)
Karmex Vi 3-(p-chlorophenyl)-l, 1-dimethylurea, CMU (duPont)
Randox a-chloro-N, N-diallyl acetamide, CDAA (Monsanto)
TCA sodium salt of trichloroacetic acid, STCA (Dow, duPont, General and other
2,4-D amine amine salts of 2,L-dichlorophenoxyacetic acid (many formulators
Vegedex 2-chloroallyl diethyldithiocarbamate CDEC (Monsanto)
Band application applying the herbicide in a narrow continuous strip in, over,
or along the crop row rather than over the entire field area.
Broadcast application applying the herbicide over an entire area rather than
in a band only,
Contact herbicide an herbicide that kills principally by direct contact with
plant tissue rather than by translocation within the plant.
Directional application applyingan herbicide to a restricted location such as
the base of the crop row or bed at the base of plants.
Post emergence treatment application made after the crop plants emerge.
Treatments may be specified post emergent to weed growth also.
Pre-emergence treatment applications made after the crop is planted but before
its emergence. Contact pre-emergence is a treatment made after weed
emergence but prior to crop emergence. Residual pre-emergence is a
treatment which kills weeds as their seeds germinate or as they emerge,
either before or after the crop has emerged.
Pre-planting treatment any application made before the crop is planted.
Pre-transplanting treatment an application made before setting the transplanted
Post transplanting treatment an application made after the transplant crop
has been set in the field.
Selective herbicide a chemical which is more toxic to one plant than to
Soil sterilant a herbicide that prevents the growth of plants when applied
to the soil; the effects may be either temporary or permanent.
Systemic herbicide a chemical toxic to the plant which is trans-located
within the plant.
Table 1. A summary of the best herbicides and application rates in certain vegetable crops on organic
soils ascertained from experiments conducted at the Everglades Experiment Station. Rates are
stated in terms of active ingredient per acre for all materials except Dowpon, Karmex W and
TCA which are given as quantities of commercial material. All treatments are broadcast at the
rate of 30 gallons of water solution per acre.
Predominant Herbicides and Rates of Application
Crop weeds Pre-emergence Post Emergence
Beans Broadleaf Dinitro, 9 to 12 Ibs./A.
May also be applied at 3 Ibs./A.
when beans are breaking through
but not yet above ground
Cabbage Broadleaf Vegedex, 4 to 8 Ibs./A. Vegedez, 4 Ibs./A.
Collards Grass Randox, 4 to 8 Ibs./A., very As above, and
Vegedex,h to 8 Ibs./A. Dowpon spot treatments, 5 Ibs,
in 60 gallons of water.
_TCA, 1 Ibs./A. _____..
Sweet Broadleaf Randox or Vegedex, I to 8 Ibs./A* Dinitro, 3 to 4 Ibs./A. at incip-
Corn ient two-leaf stage
Dinitro, 9 to 12 lbs./A. 2, U-D amine, 3/4 Ib./A. overall
up to one inch stage and directionally
Karmex W, 2 lbs./A. on plants 12 inches and taller
Karmex W, 2 Ibs./A. applied directionally
2, Ra D amine, 2 lbs./A., as ab
Grass Randox or Vegedex, 8 Ibs./A. Dinitro, as above
Lettuce Broadleaf CIPC, 8 to 10 lbs./A., over- CIPC, 6 lbs./A., may cause temporary
and and ea irrigation after leaf burn and some yield reduction
Endive *Grass application helps control
Vegedex, h lbs./A., very promising CIPC, 50 Ibs./A. of 20% pelletized
Pepper Broadleaf Randox and Vegedex, h Ibs./A., very
Grass As above Dowpon spot treatment at rate of
Onions Broadleaf CIPC, 10 to 12 Ibs./A. 2.%. sulfuric acid
and 2, -D anine, 2 lbs./A. Potassium cyanate, 12 lbs./A.
Grass Vege ix, h to 8 lbs./A. CIPC, 50 lbs./A. of 20% pelletized
Randox, h lbs./A., very promising
Carrots Broadleaf CIPC, 10 to 12 lbs./A. Stoddard solvent, 50-70 gpa
and and Vegedex, h to 8 Ibs./A., promising CIPC, C lbs./A,. in 30 gpa of
Parsley Grass Sotddard solvent
CIPC, 6 lbs/A. in water before
CIPC, 50 lbs./A. of 20 % pelletized
and See text See text