Summary of Research with Herbicides VA. 14
and Suggested Methods for Control of Vfeeds in Some Vegetable "\
Crops Growing on Organic Soils.
Twelve herbicide experiments were carried out with sweet corn on the
organic soils of the Florida Everglades from 1952 to 1954. Amounts are ex-
presded in the terms of active ingredient on a per.acre basis except for CMU
whieh was commercial grade,
CiU at 2 pounds and DNOSBP at 12 pounds have given the beat results without
reducing yields. Good moisture of the surface soil is necessary for best weed
1, Studies of time and method of 2 .-D application on different varieties.
Golden Securet y and rld- RushE vari es were most sueptible to 1njuery
Ors7 bp6undsoof 2,4-D amine. Ioana and Calumet were most tolerant. Yields
were severely reduced by over-all applications of 2,4-D at the 4 to 5 and 6
to 7 inch stages in both experiments. In one experiment, significant reduc-
tion in yields also occurred when the plants were treated over-all at the 2
to 3 inch stage. Directional applications caused a significant reduction in
yields only at the 6 to 7 inch stage. On the basis of these two tests, it
appears that over-all applications of 2,I-D can be made safely on the sweet
corn hybrids commonly grown in the Everglades area on plants up to 2 inches
high. Although no reductions in yield or grade resulted from over-all appli-
cations to plants from 15 inches high to silking, some 2.,-D symptoms were noted
on these plants, therefore, it is suggested that later treatments should be
restricted to directional applications after the corn reaches 12 to 15 inches
2* Comparison of NIX and 2 h-D applied directionally Good post-emergence
weed control wa-obtain- 7it oth materials Some burning of the lower
leaves occurred with NIX at 10 pounds but no significant reduction in yield
3. Results with CMU. Diiectional and over-all applications of 2 pounds of CM
on p~iaits 15inche tall gave good weed control without reducing yields,
4. Eary post-emergence with DNOSBP, Application of DNOSBP at 3 pounds per
acre as early post-emergence treatment when the corn plants were in the two
leaf stage gave very good weed control without affecting yields. Treatments
at the four leaf stage significantly reduced yields and delayed maturity of the
ears by approximately two days.
$5 Combining pre- and post-emergence applications. Combinations of pre- and
post-emergence applications of herbicides id not affect yields except in the
case of CIPC and in the case of 2,U-D when applied at the one pound rate under
conditions of heavy rainfall and high temperatures. Pre-emergence applications
of DNOSBP at 12 pounds and CMU at 2 pounds with post-emergence applications of
0.75 pounds of 2,4-D or NIX at 10 pounds gave good to excellent weed control,
- 2 -
Lettuce and Endive
Good to excellent control of weeds was accomplished with pre-emer-
gence application of CIPC on lettuce and endive growing in muck soil. The
duration of weed control appeared to depend on the rated of CIPC, method of
handling the soil in relation to herbicidal treatment, and the moisture in the
upper layer of soil. CIPC rates of 10 pounds or more, applied after rolling
the ground when the upper layer of soil was relatively high in moisture content
at medium temperature of 680 F, gave a commercial control of weeds until har-
vest. With endive, some injury occurred with rates. of 12 pounds or more of
CIPC, A rate of 8 to 10 pounds of CIPC seems safe for endive. Lettuce toler-
ated higher rates than endive, but 10 pounds of CIPC per acre seems sufficient,
Ten pounds of pelletized CIPC and 6 pounds of the liquid formulation, applied
before thinning, appears promising for post-emergence weeding of lettuce and
endive. The liquid form produced more damage to endive than to lettuce.
From 1952 to 1954 inclusive, 14 experiments were carried out on
chemical control of weeds in cabbage growing in muck soils. Rates of herbicides
used in these experiments are expressed in pounds per acre.
Pre-emergence. Twenty pounds of TCA or 10 pounds of Oktone were
the best herbicides for pre-emergence weeding of cabbage ard they did not affect
yields. TCA gave good control of grasses. Oktone controlled broadleaf weeds
and gave fair control of grasses. An application of 8 poiuds of TCA followed
by 8 pounds of Oktone was promising for the control of both broad-leaf and grass
weeds* Seeding of cabbage in a weedy field followed by delayed pre-emergence
treatment with 5 to 10 pounds of Oktone gave better control of weeds than simi-
lar rates of Oktone in a field freshly prepared, planted and treated.
Post-emergence. Application of 10 pounds of NIX resulted in good
control of all types of small weeds, although yields were decreased due to
reduction in size of the cabbage heads.
Pre- and post-emergence combined.- Ten pounds of Oktone and 15 pounds
of TCA applied as pre-emergence treatments, each in combination with 7.5 and
10 pounds of NIX applied as post-emergence, gave good control of weeds. All
combinations reduced yields of cabbage significantly.
Pre-transplanting.- Excellent control was obtained on plots where
weeds were allowed to germinate and were treated with 8 pounds of Oktone prior
to transplanting. Cabbage transplanted 9 and 34 hours after treatment were
Outlines of Experiments and Results Fllow.
Suggested iMthods of WVeed Control
Summary of the best herbicides and Rates of Application in Some Vegetable Crops growing on Peat and Muck Soils at the
Everglades Experiment Station, from March 1952 to May 1955. Amounts are of actual active ingredient on a broadcast
basis for one acre in 30 gallonsof solution except where otherwise stated.
Crop : Predominate :
: type of weed : Herbicides and Rates
: PRE-EIERENCE SPOST-EIERGENCE
Beans : Broad leaf :DNOSBP*-9 to 12 lbs. after seeding.
: :DNOSBP 3 lbs. applied jus-t when the
: :beans are breaking through, but not yet :
: :above the ground.
Cabbage : Broad leaf :Oktone 8 to 10 Ibso in diesel oil. :NIX** 10 lbs. per acre in 90 gallons water direc-
Cauliflower: :Oktone 5 lbs. in diesel oil as delayed :tionally. Some temporary burning to the leaves. It
Collards : :pre-E. in a weedy field. :appears also to reduce yields.
Broccoli : Grass :TCA-15 lbs. ;Spot treatment with 5 lbs. dalapon in 60 gal, of water
2DNOSBP--9 12 Ibs.
:CMU 2 Ibs.
:2,4-D 2 Ibs,
,Early post-E. with 3 Ibs. of DNOSBP applied before the
:third leaf appears. 2-4D Amine @ 0.75 lbs. overall up
:to 2" high and directional when plant 12" tall up to
silkingg. Nix-1O Ibs. applied directionally without
: : :touching the corn. C;v --2 lbs.-directionally applied
Lettuce : Broad leaf :Chloro IPC 10 Ibs. :Chloro IPC 6 lbs. Temporary burning of the leaves
and grasses :: and some reduction in yields occurred. 50 lbs./A
S. .of 20% pelletized CIPC.
Endive Broad leaf :Chloro IPC, 8 to 10 Ibs. :Same as for lettuce.
: and grasses
Pepper : Broad leaf :Oktone-10 Ibs. in diesel oil :Directional only to the base of the pepper plants
; :Oktone--5 Ibs. in diesel oil as delayed :when weeds are very small.
: :Pre-E in a weedy field :Nix** 7 Ibs. in 90 gal. water; Lion oil 16-about
: Grass :TCA-10 lbs. :10 gal. per acre, 10" Band; No-Ho oil--about 10 gal.
S:per acre, 10" Band; Endothal 3003-6 lbs. per acre,
S: -i__n 30 gal, water.
Eggplant Broad leaf Oktone 10 lbs. in diesel oil Same as for pepper.
Onions : Broad leaf : Chloro IPC 10-12 Ibs.; 2-4D Amine 2 lb. : 2.5% Sulfuric acid. Potassium cyanate 12 lbs.,
S: : 10,0 Ibs. Nix in 90 gals. of water.a;d 0 lbs./A
: : of 20% pelletized CIPCO.
Carrots : Broad leaf 10-12 Ibs./A CIPC : Stoddard Solvent 50-70 gal./A; CIPC 4 Ibs./A in 30
Sand grasses :: gallons of Stoddard Solvent. CIPC 6 Ibs./A in 30
: : : gallons of water 50 lbs./A of 20% CIPC pellets.
Parsley : Broad leaf : Same as for carrots
: and grasses :
Celery : Broad leaf : M-2 at the rate of 1 lb. per 100 square: Stoddard Solvent 40-70 gallons per acre. Post-trans-
Sand grasses : feet (decreases stand but the celery : planting. 8 Ibs./A of CIPC in 30 gallons of water.
: : plants appeared healthy and the control : 0gal./A of Hydrin in 30 gal. of water 50 lbs./A
: of weedstas good. : of 20% Chloro IPC pellets. 4 Ibs./A of CIPC in
a : : Stoddard's solvent. The post transplanting treat-
: .: ments should be applied directionally.
* DNOSBP-Dinitro-o- secondary butyl phenol--Trade Names--Sinox PE, Preemerge--contain 3 Ibs. per gal. ** Trade Name
CO1ENTS-Pre-emergence means the Vpplication of chemical anytime after seeding but before emergence. In these experiments
the chemical s were applied one to three days after seeding and rolling. Delayed Pre E. in a weedy field means to seed the
crop in a field in which the weeds are about 1 inch tall and then apply. the herbicide. rollingg means to pack or smooth
out the soil by the use of a roller). Post-emergence is the application of herbicides when the crop is already up. Best
post-E. weed control is obtained when herbicides are applied to very small weeds.
V. L. Guzman & E, A. Wolf
Weed Control Experiments in Vegetable Crops
Amounts indicated are on a per acre basis
N~t.o No Subject Treatment Design Remarks
o, 8 Pre and Post Emergence 1-Check-Tillivated and hand weeded Split Plot No.2 -Weeds in middle of
Weed Control in Cabbage 2-P.E. Oktone 5.0# in diesel. Post Major Treatments: row controlled with
and Cauliflower in E. NIX 7.0#(directionally applied) A Weedy Field 4.0# Oktone in diesel
clean and weedy fields 3-Same as 2 plus tillivation in the B Clean Field as Post E.
6 89 Chloro IPC in Carrots 1-Check-Tillivated and to be hand Randomized Sure Rained
2-Tillivation, 1 hand weeding, and
10# CIPC (pellets)
3-CIPC 10# P.E.+ 20# of CIPC pellets
4-CIPC 10# P.E.+ 10# CIPC (pellets)
5 as Post E.
5-CIPC W# P.E. in Stoddards Solvent
t same Post E.
6 90 Chloro IPC in lettuce, Same as 89 except that in Treatment 5 Randomized Sure Rained
and Endive water was used instead of Stoddards Blocks
Solvent and the post emergence treat-
6 96 Post transplanting weed 1-Check-hand weeded Randomized All treatments tillivated
control in celery 2-8# CIPC Blocks in the middles.
3-4# CIPC-Stoddards Solvent All herbicides applied
4-10# CIPC (in pellets) directionally.
5-10 gal. hydrin
6-Stoddards Solvent-70 gals.
6 97 Screening of Herbicides Herbicides in pounds per acre in parenthesis
for P.E. in some vegeta- from W to E. 1-CIPC(10);2-CIPC(U4). Stoddard S.;
ble crops from N to S. 3-N5518(8);4-N-5519(8);5-N5520(6) $a-Check;
Tomatoes, peppers, egg- 6-N5521(6);7-CDAA(8) 8-CDEA(8);9-CDEC(8);lO-Dala-
plant, lettuce, endive, pon(10);1I-TCA(10);12-Dalaponi2, -D(10+2);13-HC-
carrots, cabbage, broc- 1281-S(3);14-2, -D(3);16-Hc-1281A(3);17-c-1281AD(3);
coli, cauliflower, col- 18-Oktone(10) 19-Gaigy l44(10);20-Check;21-CIPC low
lards, radish, mustard, volatility in Stoddard S. (4);22-CIPC low volatility
rutabaga, turnips, onions in water (4); 3-CMU(2); 24-BP-1 (10);25-Pb-2 (10);26-PB-
squash(2 rows), okra, but-s(10) 26-PB-t(1(O);27-PB-4B(10) 28-PB-5(10);29-CIPC
terbeans, English peas, (10);30-Check.
blackeye peas, snap beans
(Ii rows), sweet corn(trows)