TDOC

8-1206
B873
no.1206      

 

Waite rgraSS and \7o k1 ntee r

Sorghum Control in Com

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The Texas Agricultural Experiment Station, Neville P. Clarke, Director, The Texas A&M University System, College Station, Texas

l“ “ w:

Cover photos.
Left: Untreated corn. Right: Corn treated
with AAtrex at 3.75 pounds per acre.

CONTENTS

SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .i

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 

METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 "5

RESULTS AND DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..1

Watergrass Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Preplant Herbicide Incorporation with a Tandem Disk . . .1 m
Preplant Herbicide Incorporation with a Rolling 

Cultivator ., . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Preemergence Herbicides . . . . . . .  . . . . . . . . . . . . . . . . . . . . .2
Postemergence-Directed Herbicides . . . . . . . . . . . . . . . . . . . 

Combination Trials with Preplant, Preemergence,
and Postemergence-Directed Herbicides and

Cultivation . . . . . . . . . . . . . . . . .y . . . . . . . . . . . . . . . . . . . . . .3

Volunteer Sorghum Control ._ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Preplant Herbicides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Preemergence Herbicides . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

SUMMARY

The demand for corn has increased in the Panhandle, where
new hybrids better adapted to irrigated conditions can be grown
successfully. In 1977 about 1.2 million acres of corn were grown in the
Panhandle. Studies have been needed, however, to find methods for
controlling watergrass and volunteer sorghum. Four years of weed
control research at Dumas, Etter, and Pantex, Texas, have shown
that watergrass and volunteer» sorghum can be controlled in corn.

Planting corn before May 1, applying a preplant incorporated
application of AAtrex at 3.75 to 5 pounds per acre, and cultivating
twice resulted in top yields and excellent watergrass control‘. Good

‘W

control was obtained when Sutan+ and Eradicane were incorporated _

with a disk immediately prior to bedding and when corn was
"watered up" after planting on dry beds. Preemergence applica-
tions of Lasso and Bladex followed by postemergence-directed
sprays of Evik or Lorox gave adequate control and near maximum
yields. Wheat can be planted the same year after use of short residual
herbicides. g
Volunteer sorghum was controlled in corn with Sutan+ and
Eradicane when applied preplant and incorporated with a tandem
disk before bedding. Corn was planted dry and "watered up."



7

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Wate rgrass and V010 nice r

Sorghum Control in Corn

A. F. Wiese, E. W. Chenault,
D. E. Lavake, and Dale Hollingsworth*

Corn production in Texas has been declining
since 1940. In 1950, 1960, 1970, and 1977, Texas corn
acreage was 3.0, 1.3, 0.6, and 1.6 million acres, re-
spectively. Before 1960, corn production was primar-
ily in the eastern part of the State. Corn would not
grow under dryland conditions in the Panhandle and
available varieties took large quantities of irrigation
water. Since 1965 the situation has changed. Hybrid
sorghum has replaced corn in the eastern part of the
State, and the demand for corn has increased in the
Panhandle where new hybrids better adapted to irri-
gated conditions can be grown successfully. In 1977
about 1.2 million acres of corn were grown in the
Panhandle.

Common weeds in Panhandle corn fields are
pigweed (amaranthus species), watergrass (Echino-
chloa crusgalli (L.) Beauv. barnyardgrass), crab-
grass (Digitaria species), volunteer sorghum (Sor-
ghum bicolor (L.) Moench), and johnsongrass (Sor-
ghum halepense (L.) Pers.). Studies before 1969 indi-
cated that most herbicides used in corn controlled
pigweed. 1 As a result, studies were conducted to find
methods for controlling watergrass and volunteer
sorghum.

METHODS

Studies were conducted in furrow-irrigated
fields from 1969 to 1974 at the North Plains Research
Field, Etter, the Harvey Garrison Farm near Dumas,
and the Texas Tech Center at Amarillo (Pantex). Soil
was Sherm silty clay loam at Etter and Dumas and
Pullman clay loam at Pantex. Both soils contain about
one-third each of sand, silt, and clay and 1.5 percent
organic matter.

In an effort to control watergrass, herbicides
were applied preplant, preemergence, and post-

‘Professor and research associates, respectively, The Texas Ag-
ricultural Experiment Station, Amarillo.

Wiese, A. F., E. W. Chenault, and D. E. Lavake. 1970. Chemical
Weed Control in Corn. Texas Agric. Exp. Stn. PR-2728. In Con-
solidated PR 2723-2730. pp. 59-66.

KEYWQHDS: Corn / watergrass / volunteer sorghum / Texas /
Panhandle/weed control/watergrass control/volunteer sorghum
control

emergence directed (spraysdirected at the base of
emerged plants). Applications were made with a
tractor plot sprayer in 20 to 30 gallons per acre of
carrier to plots from l to 6 rows wide and 30 to 100 feet
long. Herbicides applied preplant were incorporated
with either a tandem disk before bedding or a rolling
cultivator after bedding-

Tables l-l0 show the herbicides applied and
rates of active ingredients (ai). All herbicide rates in
this paper are given as pounds of active ingredient of
both dry and liquid formulations. Table 11 contains
detailed descriptions of herbicides in order of ap-
pearance in previous tables.

After preliminary studies, the most effective pre-
plant, preemergence, and postemergence her-
bicides were combined with cultivation in an attempt
to find the most effective control practice for
watergrass in corn. In other studies, herbicides were
applied preplant or preemergence to control volun-
teer sorghum.

Weed control estimates were obtained by plant
counts or visual estimates about 4 to 6 weeks after
planting or treatment. Corn and weed yields were
obtained by harvesting portions of treated plots.

RESULTS AND DISCUSSION

watergrass Control

Preplcrnt Herbicide Incorporation
With a Tandem Disk t

Herbicide incorporation was evaluated for 2
years, Table 1. In 1970, herbicides were applied to flat
ground and incorporated with a tandem disk, ap-
proximately 1 month before corn planting. Later, soil
was bedded, the field preplant irrigated, and corn
planted in moisture. Under these conditions, weed
control with AAtrex and mixtures of Sutan and
AAtrex was about 80 percent. In 1974, incorporation
time was changed. Herbicides were applied to flat-
land and incorporated with a disk 3 days before
planting. Corn was planted in dry beds and watered
up for emergence. Weed control was exceptional
with 4 pounds per acre of Sutan”, Eradicane, and 3
pounds of Sutan* mixed with 1.5 pounds per acre
of Bladex.

Preplant Herbicide Incorporation
With a Rolling Cultivator

Incorporation of preplant herbicides with a roll-
ing cultivator for watergrass control in corn was
evaluated for 5 years, Table 2. However, the same
herbicides were not evaluated in all years. In 1970,
the first year of the trial, Lasso at 3 pounds per acre
and Sutan at 5 pounds per acre gave the best weed
control. In 1971, about 75 percent weed control was
obtained with 3 pounds per acre of AAtrex alone,
Lasso mixed with AAtrex at 3 and 2 pounds per acre,
and Lasso at 3 pounds per acre. In 1972, weed control
with all herbicides was much improved compared to
the previous 2 years. AAtrex applied alone, AAtrex

- mixed with Lasso, and Outfox gave better than 9O

percent control. In 1973, AAtrex, Lasso mixed with
AAtrex, and Prefox gave excellent weed control at
moderate rates of application. In 1974, most her-
bicides and herbicide combinations gave excellent
weed control. AAtrex and Bladex, each at 3 pounds
per acre, gave 87 and 93 percent control, respec-
tively. Outstanding control was obtained also with
Bladex mixed with Sutan+, AAtrex mixed with
Sutanfi Prefox, Eradicane, and Avadex mixed with
Lasso. There was no corn injury.

Preemergence Herbicides

Five years of studies with preemergence her-
bicides are summarized in Table 3. As with other
methods and times of application, none of the her-
bicides gave consistent watergrass control for all 5
years. Herbicides that gave satisfactory results were
AAtrex, Lasso, Bladex, Lasso mixed with AAtrex,
Outfox, Prowl, Lexone, and CGA 18762.

Postemergence-Directed Herbicides

Weed control by postemergence-directed her-
bicides was evaluated for 3 years; results are sum-

TABLE 1. WATERGRASS CONTROL IN CORN AFTER INCORPO-
RATION OF PREPLANT HERBICIDES WITH A TANDEM DISK

Watergrass control, %

Lb/A
Herbicide (ai) 1970a 1974b
AAtrex 2 56
3 84
Lasso 3 43
Princep 2 63
3 73
Sutan or Sutan* 4 1OO
5 73
Sutan + AAtI-ex 3 + 1 79
Eradicane 4 99 I
Sutan+ + Bladex 3 + 1.5 96
4 + 1.6 97

aHerbicides applied March 23, tandem disked twice, irrigated,
bedded, and corn planted May 2.

bHerbicides applied April 19, tandem disked twice; corn planted
April 22 and watered up.

2

marized in Table 4. None of the herbicides eliminated
watergrass. During the first 2 years, the only her-

bicides that gave greater than 7O percent control

were Outfox, AAtrex applied in an oil-water emul-
sioncarrier, AAtrex mixed with Dowpon, and a high
rate of Bladex. During the first 2 years, soil conditions
were rather dry and weeds may have been difficult to
kill. In 1973, weeds were 2 inches tall and growing in
wet soil; consequently, some of the herbicide treat-
ments gave greater than 9O percent watergrass con-
trol. The best herbicides were Evik, Lorox, Paraquat
mixed with AAtrex, Mowdown, and Bladex.

TABLE 2. WATERGRASS CONTROL IN CORN AFTER INCORPO-
RATION OF PREPLANT HERBICIDES WITH A ROLLING CUL-

TIVATOR §
Watergrass control, %
Lb/A
Herbicide (ai) 1970a 1971b 1972c 19739 19749
AAtrex 2 5O 85
3 65 77 9O 93 87
4 83
6 92
Bladex 2 32 47 63
3 93
4 6O 77 83
Bladex + Sutan 1 + 3 43 65
1.6 + 4 97
Lasso 2 52 78 33
3 86 7O 88
4 77 6O
Princep 3 64 57 88
Sutan or Sutant 4 60
5 83
6 97
Sutan + AAtrex 3 + 1 74 68 77 93
4 + 1.5 100
6 + 2 ~ 9O
Lasso + AAtrex 1.5 + 1 5O 88 78
2 + 1 52 78 77
3 + 1 75 88 87
3 + 2 93
Outfox 4 95
6 93
Prefox 4.8 85 9O
6   85 87
Eradicane 4 73 9O
6 73 1OO
Avadex + Lasso 1.5 + 1.5 83
2 + 2 9O

aHerbicides applied to prewatered beds April 30, rolling cultivated
once, and corn planted May 2.

“Herbicides applied to prewatered beds April 30, rolling cultivated‘

once, and corn planted May 1. I

°Herbicides applied to dry beds May 3, rolling cultivated twice, and
corn planted June 5.

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°Herbicides applied to dry beds May 10, rolling cultivated twice, and pfi

corn planted June 22.

eHerbicides applied to prewatered beds April 18, rolling cultivated
twice, and corn planted April 22.

 ,, )

Combination Trials With Preplant.
Preemergence. and Postemergence-Directed

Herbicides and Cultivation

Studies were conducted in 1971, 1972, and 1973.
None of the herbicide combination treatments com-
pletely eliminated Watergrass in 1971, Table 5. Con-
trol on Iune Z3, 1971 varied from 67 to 84 percent when
preplant herbicides were applied after pre-

TABLE 3. WATERGRASS CONTROL IN CORN WITH PRE-
EMERGENCE HERBICIDES

Watergrass control, %

Lb/A
Herbicide (ai) 1970a 1971b 1972C 197s“ 1974B
AAtrex 2 61 67 87 8O 85
3 66 91 86
4 93 95
Lasso 2 51 28 43 58 88
3 27 77 58 95
4 8O
Bladex 2 68 57 62 72 ~
4 63 61 93
6 83 75 99
Lasso + AAtrex 1.5 + 1 58
2 + 1 62 83 83
3 + 1 6O 83 75
Outfox 2 87
4 88 91
6 92 96
Fiowtate 2 47 37 33 79
s 55 25‘ 70
4 so 52‘
6 68
Lorox + AAtrex 1 + 1 78
1.5 + 1.5 88
Bladex + Lasso 1.5 + 1 67
1.5 + 2 57
Mowdown 1.5 27
2 32 57
3 72
4 8O
Banvel + Lasso 0.25 + 0.5 52
0.25 + 1.5 53 86
0.5 + 2.5 94
Prowl 0.75 83
1 97
1.5 98
Lexone 0.5 97
1 97
CGA 18762 1.6 70
2.4 68
3.2 91
aPlanted and treated May 2. Data taken June 23.

“Planted May 1, treated May 4, and data taken on June 23.

°Planted May 5, treated May 6, and data taken on August 16.
“Planted and treated June 22, and data taken August 6.
ePlanted and treated April 23, and data taken June 20.

‘Severe corn injury on these treatments.

irrigation, and from 48 to 76 percent when preplant
herbicides Were applied prior to preplant irrigation.
Short residual herbicides, such as Lasso, Were more
effective when applied closer to planting. Applying
additional herbicide preemergence after a preplant
application did not increase control over applying
the total amount of herbicide preplant. Post-
emergence herbicides applied When corn was 1 foot
tall and Watergrass Was 4 to 6 inches tall did not have
an appreciable effect on Weed control. Although
Watergrass thrived on check plots, corn yields in 1971
were the same as those Where herbicides reduced
Watergrass stand and vigor, since corn planted in
early May has a competitive edge on Watergrass that
does not emerge until late May.

In 1972, corn was planted Iune 5, and Watergrass
emerged with the corn. Iust prior to application of

TABLE 4. WATERGRASS CONTROL IN CORN WITH POST-
EMERGENCE-DIRECTED HERBICIDES

Watergrass control, %

Lb/A
Herbicide (ai) 1970a 1972b 1973C
Outfox 0.5 73 47
1 77 42
2 78 62
AAtrex + oild 0.5 62
1 67
2 77
Evik + Se 1 48 47 88
2 62 53 87
'3 47 9O
Lorox + S 1 40 23 72
2 52 70 85
3 l 87 92
AAtrex + Dowpon 0.5 + 1 47
1.5 + 1 67
2 + 1 75
Paraquat + 0.25 + 1 33 63
AAtrex + S - 0.25 + 2 77
0.5 + 1 » 50
0.5 + 2 90
1 + 2 67 I
Bladex + S 1 20 48
2 40 63
3 85
4 8O
Lasso + 1 + 0.5 10
AAtrex + S 1 + 1 23 75
1.5 + 1 28
1 + 2 68
2 + 2 8O
Mowdown + S 1 76
2 85

aCorn and weeds 14 and 2 inches. No crop injury.
“Corn and weeds 18 and 5 inches. No crop injury.
°Corn and weeds 36 and 2 inches. No crop injury.
dNon-phytotoxic emulsitiable oil at 1 gallon per acre.
eSurfactant in water carrier at 0.5%

directed postemergence sprays on Iuly 10, grass con-
trol was better in the furrows than on the beds where
only preplant herbicides had been applied, Table 6.
For example, grass control was 66 percent on top of
the bed and 91 percent in the furrow where 3 pounds
per acre active ingredient of AAtrex were applied
prior to planting. This occurred because dry soil con-
taining herbicide had to be removed from the bed
during planting in order to place seed in moist soil.
When a preemergence application followed plant-
ing, weed control was markedly improved on the
bed. In early August, the most effective weed control
was obtained when 2 pounds per acre of AAtrex
were applied preplant and another 2 pounds per
acre were applied at planting, cover photos. As in
1971, postemergence treatments did not enhance
weed control unless a short residual herbicide had
been used for a preplant treatment.

At corn harvest in 1972, the check plots produced
4,991 pounds per acre of mature, dry watergrass,
Table 7. Most herbicide treatments that resulted in
good corn yield held watergrass growth to less than
1,000 pounds per acre. Corn yields varied from 90
bushels per acre on untreated areas to 150 bushels
per acre when AAtrex was applied at 2 pounds per
acre preplant and again at l pound per acre
preemergence. Uncontrolled watergrass decreased
yields by reducing the number of ears and causing

plants to run short of water during maturity. The latter
effect was shown by ear moisture content at harvest,

which was lowest on the check plots and highest Q‘

where yields were considerably greater.

In 1973, watergrass emerged only after receiving
2 inches of rain l month after planting. At that time
corn was 18 inches tall and able to compete. AAtrex
at 3 pounds per acre applied either preplant,
preemergence, or as a split application at both pre-
plant and preemergence resulted in the best
watergrass control for the entire season, Table 8. If
less was applied, grass control was reduced.
Watergrass control was increased by postemergence
herbicides, especially if control had been poor with
preplant or preemergence treatments. Post-

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emergence sprays of Lorox or Evik increased weed f

control by Lasso from 35 to 75 percent. Wheat could
be planted the same year after the two treatments
with short residual herbicides. Weed yields were
over 3, 000 pounds per acre on the check plot and less
than 800 pounds per acre on treated plots. Plots
treated with AAtrex at 2 pounds per acre preplant
and 2 pounds per acre of Evik postemergence di-
rected were weed-free at harvest. Untreated areas
yielded 34 bushels per" acre, and all treatments
yielded between 49 and 61 bushels per acre. Yields
were low because only one post-plant irrigation was
applied.

TABLE 5. CORN YIELDS AND WATERGRASS CONTROL RESULTING FROM PREPLANT, PREEMERGENCE, AND POSTEMERGENCE

HERBICIDES AND CULTIVATION, 1971

Preplant herbicides applieda

Following Prior to
pre-water pre-water
Pre_ Posh % control“ % control“

Preplant Lb/A emergence Lb/A emergence Lb/A   Corn   Corn
herbicide (ai) herbicide (ai) herbicide (ai) June 8 June 23 (bu/A) June a June 23 (bu/A)
AAtrex 3 84 ab 78 ab 112 a 85 a 74 a 116 a
Princep 3 76 bc 75 ab 111 a 60 d 73 ab 124 a
AAtrex 2 AAtrex 1 80 bc 79 ab 1 O7 a 68 cd 69 ab 123 a

3 1 88a 80ab 108a 74bc 76a 117a

2 AAtrex + 1 82 bc 68 b 114 a 62 cd 59 bc 127 a

1 gpa oil°
3 Evik + 2 86 a 67 b 116 a 62 cd 64 ab 122 a
0.5% s“
AAtrex + 1 + 3 1 84 ab 71 ab 118 a 65 cd 69 ab 126 a
Sutan
Lasso 2 Lasso 2 73 b 81 ab 110 a 85 a 48 c 113 a
Lasso+ 3+1 83ab 84a 118a 88a 59bc 113a
AAtrex 
AAtrex 2 AAtrex 1 Evik + 2 84 ab 79 ab 115 a 71 cd 77 a 110 a
0.5% S

Check 0d Oc 116a 0e 0d 128a
aMeans followed by the same letter are not different at the 5% level of significance.

“June 8 was prior to postemergence sprays and July 23 was after postemergence sprays.

°Sun 11E oil at 1 gallon per acre in a water carrier.
dDupont WK surfactant at 0.5% of carrier volume.

4

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3

Volunteer Sorghum Control

Preplant Herbicides .

The tandem disk and rolling cultivator Were

g evaluated for incorporating preplant herbicides
applied to control volunteer sorghum in corn, Table
9. In 1969, herbicides were incorporated with a tan-
dem disk about l month before planting. After incor-
poration, beds were formed, preplant irrigation
applied, and corn planted in Wet soil. In 1974, her-
bicides were applied and incorporated 3 days prior to
planting corn on drybeds and Watering up. Sutan
was the best herbicide in 1969, when herbicides were
applied 1 month before planting. In 1974, outstanding
results Were obtained with both Sutan” and

Eradicane when corn Was watered up. The rolling
cultivator was not as effective for incorporating her-
bicides for volunteer sorghum control as the tandem
disk. In 3 years of study, only Sutan at 6 pounds per
acre and a mixture of Avadex and Lasso gave satis-
factory control of the volunteer sorghum Without in-
juring corn.

Preemergence Herbicides

Studies were conducted in 1969 and 1974, Table
l0. In 1969, preemergence herbicides had very little
effect on growth of volunteer sorghum. In I974, Lasso
at 2 and 3 pounds per acre and Lexone at l pound per
acre gave outstanding control of volunteer sorghum.

TABLE 6. WATERGRASS CONTROL FROM PREPLANT, PREEMERGENCE, AND POSTEMERGENCE HERBICIDES AND CULTIVATION,

b 1972a

\

‘bPrior to application of postemergence sprays.
°Sun 11E oil at 1 gallon per acre in a water carrier.
dDupont WK surfactant at 0.5% of carrier volume.

P July 5b August 9
Preplant r Lb/A zrrrTergence Lb/A ercffjrgence Lb/A Grass °°n"°' % Grass °°m'°' %
herbicide (ai) herbicide (ai) herbicide (ai) Bed Furrow Bed
AAtrex 3 66 cd 91 ab 6O b-e
4 83 a-c 96 a 8O ab
Princep 3 49 d 91 ab 36 d-f
AAtrex 2 AAtrex 1 88 ab 95 a 81 ab
2 2 91 a 97 a 91 a
2 AAtrex + 2 49 d 86 a-c 65 a-c
Oil°
2 1 53 d 87 a-c 67 a-c
2 AAtrex I 2 48 d 79 b-d 69 a-c
(no oil)
AAtrex + 1 + 3 51 d 95 a 33 ef
Sutan
1 + 3 AAtrex + 2 59d 91 ab 71 a-c
Oil
 Lasso 3 O g 50 e O g
Lasso + 3 + 1 20 ef 75 cd 13fg
AAtrex
Lasso + 3 + 1 2 21 e 74 d 45 c-e
AAtrex I Q
fiAtrex 3 Evik + Sd 2 48 d 94 a 64 a-d
Check M 0 g 0 f O g
aMeans followed by the same letter are not different at the 5% level of significance.

TABLE 7. WATERGRASS AND CORN YIELDS FROM PREPLANT, PREEMERGENCE, AND POSTEMERGENCE HERBICIDES AND
CULTIVATION, 1972a

Pre- Post-

W t C C b
Preplant Lb/A emergence Lb/A emergence Lb/A   —2r—n— 229-5’-
herbicide (ai) herbicide (ai) herbicide (ai) (Lb/A) (Bu/A) (No/A)
AAtrex 3 442 c-e 141 a 12,672 a
4 820 c-e 148 a 11,904 a-c
Princep 3 1,561 b-d 137 a 12,192 ab
AAtrex 2 AAtrex 1 150 e 150 a 12,288 ab
2 2 3 e 125 a-c 11,328 a-c
2 AAtrex + 350 de 137 a 11,616 a-c
oilb
2 245 de 137 a 11,328 a-c
2 AAtrex 310 de 133 a-c 12,480 ab‘
(no oil)
AAtrex + 1 + 3 1,647 bc 135 ab 11,712 a-c
Sutan
1 + 3 AAtrex + 332 de 146 a 12,288 ab
oil
Lasso 3 3,889 a 106 cd 9,600 bc
Lasso + 3 + 1 2,262 b 123 a-c 12,192 ab
AAtrex
3 + 1 913 c-e 127 a-c 11,520 a-c
AAtrex 3 Evik + S° 202 e 123 a-c 1 1,136 a-c
Check 4,991 a 90d 9,216c

aMeans followed by the same letter are not different at the 5% level of significance.
“Sun 11E oil at 1 gallon per acre in a water carrier.
°Dupont WK surfactant at 0.5% of carrier volume.

TABLE 8. WATERGRASS CONTROL AND CORN YIELDS FOLLOWING PREPLANT, PREEMERGENCE, AND POSTEMERGENCE HER-I
BICIDES AND CULTIVATION, 1973a

Post- | o W a G -
Preplant Lb/A Preemergence Lb/A emergence Lb/A Grass Comm’ A atergrass ram
herbicide (ai) herbicides (ai) herbicides (ai) 8-9-73“ 9-19-73° (Lb/A) (Bu/A)
AAtrex 3 95 a 95 ab 152 61 a
2 AAtrex 1 94 a 95 ab 152 49 ab
1.5 1.5 94a 95a 152 56 ab
1.5 AAtrex + 1.5 83 a-c 95 ab 152 56 ab
oile
1 Evik + s‘ 2 7s a-d 9s ab s1 s7 ab
2 2 90 a 100 a 0 61 a
1.5 Lorox + S 1.5 76 a-d 93 a-c 213 52 ab
AAtrex + 1 + 3 AAtrex + 1.5 70 a-e 91 a-d 274 57 ab
Sutan oil
AAtrex 3 89 ab 94 ab 183 58 a
AAtrex + 1.5+3 1.5 64 c-f 93 a-c 213 55 ab
Ramrod
1.5+3 58 d-g 74e 793 58a
AAtrex + 1.5+2 1.5 46 f-h 83 b-e g 518 51 ab
Lasso
Lasso 2.5 Lorox + S 1.5 33 h 75 e 762 54 ab
2.5 Evik + S 2 39 gh 76 e 732 57 ab
Check 0 i ' or 3,049 s4 b
aMeans followed by the same letter are not different at the 5% level of significance. . I
“Prior to application of postemergence sprays.
°At harvest.
“Calculated from weedy checks and data on September 19. Statistical analyses were not made. ‘

eOne gallon per acre Sun 11E oil with carrier.
‘0.5% Dupont WK surfactant by volume of carrier.

6

TABLE 9. PERCENT VOLUNTEER SORGHUM CONTROL IN
CORN WITH PREPLANT INCORPORATED HERBICIDES

Lb/A Tandem disk Rolling cultivator
Herbicide (ai) 1969a 1974b 1969C 19709 19748
Lasso 1.5 4O
2 6O 72 23
3 62 ~ 29
4 5O
AAtrex + 1 + 1 6O 57 17‘
Lasso 1 + 2 49-
AAtrex 1 27
2 47 O O 32
3 25
4 72 0
Sutan or 4 7O 96 33 59 32
Sutan+ 5 87 6O
6 91 72 9O 63
Sutan + 3 + 1 57 53 19
AAtrex 3 + 2 45
Eradicane 4 96 65
6 66
Sutan+ + 3 + 1.5 75 33
Bladex 4 + 1.6 93 32
3 + 1 55 38
3 + 2 71
Avadex + 1.5 + 1.5 ~ 94
Lasso 2 + 2 94
CGA 18762 1.6 33
2.4 6O
3.2 I 64

aHerbicides applied April 17, tandem disked twice, bedded, pre-
watered, and corn planted on May 20.

“Herbicides applied April 19, tandem disked twice, bedded, corn
planted on April 22 and “watered up.”

°Herbicides applied May 14 to beds, rolling cultivated twice, corn
planted May 2O and “watered up.”

“Herbicide applied May 23, rolling cultivated twice; corn planted
May 28, and data taken June 1.

eHerbicides applied April 18, rolling cultivated twice; corn planted
April 22, and data taken June 19.

TABLE 10. VOLUNTEER SORGHUM CONTROL WITH PRE-
EMERGENCE HERBICIDES

Volunteer sorghum control, %

Lb/A

Herbicide (ai) 1969a 1974b
AAtrex 1 O

2 2O 6O
Lasso 1 O

1.5 23

2 98

3 1OO
Bladex 1 3

2 13

4 O
Maloran 1 15

2 22

4 l 37
Princep 1 13

2 23
Lexone O.5 33

1 1OO

aHerbicides applied and corn planted on May 20.
“Herbicides applied and Excell E-56 corn planted on April 23.

AL

 

TABLE 11. HERBICIDES AND FOUR ADJUVANTS usEo iNonoER o|= APPEARANCE IN TABLES 1 THROUGH 1o

Designation
to Chemicals or
trade name WSSA common name Formulation Manufacturer
AAtrex Atrazine 80% WPa ClBA-Geigy
Lasso Alachlor 4 lb/gal Monsanto
Princep Simazine 80% WP ClBA-Geigy
Sutan Butylate 6 lb/galb Stauffer.
Chemical Co.
Sutan * Butylate with 6 lb/gal Stauffer
antidote Chemical Co.
Eradicane EPTC with antidote 6.7 lb/gal Stauffer
Chemical Co.
Bladex Cyanazine 80% WP Shell Chemical Co.
Dutfox Cyprazine 1 lb/gal Gulf
Prefox Ethiolate 4 lb/gal Gulf
Avadex Diallate 4 lb/gal Monsanto
Rowtate Cisanilide 65% WP Diamond-Shamrock
Lorox Linuron 50% WP DuPont de Nemours
& Co., lnc.
Mowdown Bifenox 2 lb/gal Mobil
Prowl Penoxalin 3 lb/gal American Cyanamid
Lexone
(Sincor) Metribuzin 50% WP Dupont de Nemours
& Co., lnc. and
Chemagro
CGA 18762 Procyazine 80% WP CIBA-Geigy
Dowpon Dalapon 74% WP Dow Chemical Co. A
Paraquat-Cl Paraquat 2 lb/gal Chevron Chemical Co.
Oil Non-phytotoxic oil
with 2% emulsifier 100% liquid Sun Oil Corp.
Evik Ametryne 80% WP CIBA-Geigy
S Dodecyl Ether of
Polyethylene Glycol 100% liquid Dupont de Nemours
& Co., lnc.
Maloran Chlorobromuron 50% WP CIBA-Geigy

aSignifies a wettable powder or dry formulation.
“Indicates active ingredient per gallon of liquid.

 

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ACKNOWLEDGMENTS

This report is the result of cooperative research of
Science and Education Administration-Agricultural
Research (SEA-AR), U. S. Department of Agriculture,
Amarillo; Texas Tech University Center, Pantex; and

‘The Texas Agricultural Experiment Station, Amarillo.

Appreciation is expressed to Harvey Garrison,
Who furnished the experimental site 1O miles east of
Dumas, Texas, in 1971 and 1972, as Well as doing all
farming operations on the field Where these studies
Were conducted.

!/

u’ ‘Xl

Mention of altrademark or a proprietary product does not constitute a guarantee or a warranty of the
product by The Texas Agricultural Experiment Station and does not imply its approval to the exclusion of

other products that also may be suitable. _ _
All programs and information of The Texas Agricultural Experiment Station are available to everyone

without regard to race, color, religion, sex, age, or national origin.

The Texas Agricultural Experiment Station, Neville P. Clarke, Director, College Station, Texas

2.25 M — 5-79 . -