EFFECTS OF. may, 2, 4-9, AND
ENDOTHAL ore cams AND ween specses

Thesis for #19 Degree of M. S.
MICHiGAN STATE COLLEGE
Charies Coffingham

‘E953

THESI‘ .

 

This is to certify that the '

thesis entitled

-. . Effe as of MOP, 2-h-D, and Endothel

   

 

on Oats and head Species.
presented bl]

     
 

Charles Gettingham

 
 
 

has been accepted towards fulfillment
of the requirements for

Me 8. degree in Fem Qrgps

      
     
  
    
 

. Major professor

   

Date-g”, 1/17/fo

  

£13?st OF 110?, 2,h-D, AND EWJOTHLL
ON OATS Aim ween SPECIES

By

Charles Cottingham
“"‘\

AN ABSTRACT

Submitted to the School of Graduate Studies of Michigan
State College of Lgriculture and Applied Science
in partial fulfillment of the requirements
for the degree of

hASTdR OF SClfith
Department of Farm CrOps

Year 1953

 

W/
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Vf/Lf‘

Charles Cottingham

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The effects of the amine form of hCP and 2,h-D, and Endothal on
Clinton Oats and weed species at various stageSemfl.rates were studied
in a field experiment at Hichigan State College in 1953.

The treatments studied were the effects of: (l) Pre-emergence
Spraying, (2) Spraying when the oats were eight inches high and (3)
Spraying when the cats were fully headed.

The rates of Spraying were (1) one quarter, one—half, and three
Quarters of a pound per acre of hCP, and 2,h-D, and (2) one, two, and
four pounds per acre of endothal. .

The results of this experiment indicated that (l) the best yield
of oats came from plots having he best control of Lady's thumb smartweed,
(the predominating species). however, all plots produced low yields due
to climatic conditions. (2) Test weights were inconsistent among
treated plots, and differences were not great enough to be considered
important due to an adverse growing season. (3) None of the chemicals
adversely affected the number of heads per unit of row. (h) Plots were
very weedy, with an average of lh95 weeds per SQuare yard. (5) Lndothal
gave excellent control of lady's thumb for all rates amistagescfiTSpray-
ing. The post eme gence stages and rates burned the leaves of the oats,
(é) Endothal was efficient in killing wild buckwheat where it was
present. (7) Best control of tickle grass was ootained from 2,h-D applied

as a pre-emergence spray. however, all chemicals at all rates and stages

of application gave some control. (8) L“mhsquarter was controlled best

-1-

Charles Cott

‘4

ngnam

by applications of use at the fully headed stage. (9) In seneral, 2

by

,h-D
gave best control of ragweed. ill chemicals gave some control for all
rates andstages of application. (10) Because of low yield, test weight,

and a thin stand of cats, along with a lack of uniformity of weed Species,

and adverse weather cond'tions, this experiment should be duplicated.

EFFECTS or 1-;CP, 2,144), no dh’DOl‘ij
0»: eggs AM was) SPSCInS

Charles Cottingham

A TdESIS

Submitted to the School of Graduate Studies of Michigan
State College of agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of

h} STEft 0F SCIEL‘VCE

Department of Farm CrOps

1953

THESIS

LC KNUNLJLD Limi‘fl' S

The writer wishes to express his sincere
thanks to Professor Boyd h. Churchill for his
valuable advice and encouragement in making
this thesis possible. appreciation is also
expressed to my wife Laura for her continued
assistance and encouragement through the en-
tire program.

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MC; hih‘IiLS LND I-IETEEODS . . . . . . . . . . . . . . .

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

hffect on field of Oats.......
Effect on Test deiqht of Oats.

CONTSnTS

Effect on Lumber of Heads per Unit of how.
Total n her of Needs by Species.........
Effect on Lady's ‘humb Smartweed.........

Effect on Tickle Grass........
Effect on Lambsquarter........
Effect on hagweed.............
‘ifect on Foxtails............
Effect on Wild Suckwheat......
hffect on Barnyard Grass......

SUi.;';JLhYQOOOOOO00.000.000.0000000000

BIBLIOGhiPHY.......................

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Chemicals were used for weed control as early as 1900, but little
emphasis was placed upon their use until around 1935. Sulfuric acid
was one of the earlier chemicals used, but with the discovery of 2,h-D
in l9hh, it has all but disappeared for this purpose. wartime investi-
gations showed the usefulness of 2,h-D as a possibility of destroying
enemy crOps as a selective Spray on mall grains. Damage to crOps may
be caused by 2,h-D if applied at too high a rate, or at the wrong time.
Dinitro compounds have also been used for selective Sprays on small
grains, but they too have some objectionable features.

The eXperiment reported here was set up to study the effects of
various chemicals on yield, test weight, and number of heads of cats,

and on the weed Species present.

thIbw OE LITthTUhE

Burrows and Olsen (1) reported that injury to oats occurred when
Sprayed with 2,h—D ester at Six ounces acid equivalent per acre when
the oats were 5-6 and 20 inches high.

Coupland (3) reported that weed control in cats was better when
treated with 2,h-D than when hCP was used. hCP caused less damage to
oats than 2,h-D. Yields were higher from hCP treated plots than from
plots sprayed with 2,h-D.

Shafer and Finnerty (7) found that one—quarter and one-half pounds
of 2,h-D ester applied at the jointing stage resulted in serious yield

eductions in two of four years. amine salt at one-half and one pound
resulted in similar reductions in one year.

Finnerty (5) found that hCP amine, while Slightly less effective
in weed suppression, was definitely less injurious to oats than were
either 2,h-D amine or ester.

Taylor (b) reported that treatments with 2,h—D ester, and hCP amine
applied at eight ounces per acre, two weeks after emergence to wheat and
barley were relatively ineffective against such weeds as wild buckwheat,
Lady's thumb, and barnyard millet. A reduction in yield was experienced
from the 2,h-D ester on barley, and the hCP amine on wheat.

Zalik (9) found that applying Six and twelve ounces of 2,h-D ester

to oats when they were six inches high reduced the yield significantly.

Davidson (h) repor ed that there is a period when cats are
vulnerable to 2,h-D treatments, commencing about two weeks after
emergence and lasting for a period of about two weeks.

Janzen (6) reported that 2,h-D ester reduced the yield of oats by
about ten percent with the three ounce rate, and by fifty percent with
six ounces in cold weather, but no reduction in yield occurred from
eight ounces applied in warmer weather.

Burrows and Olson (2) reported that oats treated with 2,h-D ester
and amine, showed no Significant difference in the mean yields for
chemicals, rates of seeding, and dates of treatment, and damage to the

main culms by early treatment was compensated for in all cases by

tillering.

MLTERIALS AND thHODS

Clinton oats were planted at the rate of one and one-half bushels
per acre in rows one foot apart on hay S, 1953. Plots were 6 x 2h.2
feet, randomized, and in quadruplicate.

The chemicals used were the amine form of hCP and 2,h—D, and
endothal. The rates used were one-quarter, one-half and three-quarters
pound acid equivalent per acre for MOP and 2,h-D. The rates for endothal
were one, two, and four pounds per acre. Chemicals were applied,

a) as a pre-emergence Spray,
b) when the oats were eight inches high,
0) when the oats were fully headed.

When the chemicals were applied when the cats were fully headed,
the Spray nozzle was held below the oat heads, and above the weeds. L11
treatments were compared with the check plots which were not Sprayed.

Weed counts by Species were made in plots representing the pre-
emergence and eight inch stages on June 29, 30 and July 1. Similar
counts were made for treatments made after the oats were fully headed,
on July 15, 16 and 17. The number of heads per twelve feet of row was
determined for each plot. The four center rows of each plot were
harvested on July 25 to determine yields per acre. Test weight per

bushel of oats from each plot was also determined.

hbSbLTS 5ND DISCUSSION

Effect on Yield of Cats

ill yields of oats were very low due to adverse weather condi-
tions.

Table I Shows the effect of hCP, 2,h-D and endothal applied at
three different rates and dates upon the yield of cats in bushels per
acre.

WhenthP was applied as a pre-emcrgence spray, yields varied less
than one bushel per acre for all Spraying rates. The same is true for
the eight inohstage of application. With one exception, this was also
true for the fully headedstage of application. Changing the rate of
application or applying MOP at the eight inch or fully headed stages
had little detrimental or beneficial effect on yield. however, applying
hCP as a pre-emergence treatment increased yields 3.8 bushels or more
per acre, regardless of the rate used.

When 2,h-D was applied as a pre-emergence Spray, yields varied
only nine-tenths of a bushel per acre between the one—quarter and one-
half pound rates, in contrast to 3.1 bushels for the three-quarter
pound rate. With one exception, the yield of oats varied less than one
bushel per acre where 2,h-D was applied when the cats were eight inches
high. Applications made when the cats were fully headed resulted in

only seven-tenths of a bushel difference between the three rates of Spray-

ing. .Lll yields were only slightly greater than the check plot.

TAQLE I

YIELD ca OATS IN BUsHmLS Fax Asha'waaw SPRLYAD WITH
h.C.P., 2,h-D, LND fiNDOThiL AT DIFthhNT hires -

 

 

 

 

 

 

 

Chemical Hate Time of lpplication
Pre-emergence Eight Inches Fully headed

M.C.P. .25 27.2 23.11 23.7
2,h-D .25 2u.b 25.6 25.1
Endothal 1.0 29.2 27.9 26.1
14.0.13. .5 27.0 23.8 2?.
2,14-D .5 25.? 21.3 25.7
Endothal 2.0 30.0 29.6 23.2
14.0 .P. .75 27.9 214.3 23.2
2,h-D .75 27.9 25.7 25.3
Endothal u.0 23.7 25.7 21.5
Check 2h.l 2h 1 2h.1

 

 

Post emergence treatments with endothal showed some burning of the
oats leaves especially when spraying was made after the oats were fully
headed, and at the higher rates.

When endothal was applied as a pre-emergence Spray the yields were
highest when the rate was two pounds per acre. The one pound rate,
however, was only 1.6 bushels per acre lower. The four pound rate was
7.1 bushels less than the two pound rate. The highest yield may be
explained by the excellent control of Lady's thumb smartweed, the most
frequent appearing Species, as shown in Table II. Yields varied 3.9
bushels per acre at the eight inch:atmgeof application for all Spraying
rates, with the lowest occurring from the four pound rate of application.
AS the rate increased, the yield decreased for all rates of applications
when the oats were fully headed. Yields varied h.3 bushels per acre
between treatments, with the lowest again at the four pound rate of
application. All yields from endothal applied at one pound per acre
were greater than the check plots, however, the two pound rate applied
when the oats were fully headed, and the four pound rate applied as a
pre-emergence Spray and when the oats were fully headed gave Slightly
less yields than the checks.

Effect on Test height of Cats

Table II Shows the effect of MCP, 25h-D and endothal applied at
three different rates and dates upon the test weight of cats per bushel.

‘fest weights were very low for all plots including the checks due

to adverse growing conditions. Check plots averaged only 27.0 pounds

—'-

Tthn II

'l‘iL‘Sl' WzfilG'rIT OF OATS PER )1) Shri- Sfd:.Yr-..D WITH i~1.C .P. , 2 ,LL-D,
LNJ fiHDOTHLL LT DIFFdRENT hthS AND DhTfiS

 

 

 

 

 

 

Chemical hate Time of Lpplication
Pre-emergence Eight Inches Fully headed

1-L.C.P. .25 29.0 25.0 27.6
2,h-D .25 25.3 27.0 25.9
Endothal 1.0 27.5 27.5 27.3
M.C.P. .SO 27.b 20.3 23.6
2,h-D .50 2u.9 27.3 27.0
Endothal 2.0 27.1 27.1 2b.?
M.C.P. .73 28.0 27.1 2;.6
2,h-D .75 2é.h 27.9 25.0
Endothal h.0 2b.h 27.7 2>.3

 

Check 27.0 27.0 27.0

 

per bushel. Test weights of treated plots were inconsistent and

differences were not great enough to be considered important.

Effect on humber of Heads per Unit of Row

Table III shows the effect of KCP, 2,h-D and endothal applied at
three different rates, and two different dates upon the head count of
oats per twelve feet of one row in each plot.

When.hCP was applied as a pre-emergence Spray, head counts varied
less than Six heads per twelve feet of row for all Spraying rates. All
rates of Spraying were greater than the check plot which received no
treatment. As the rate increased, the number of heads increased slightly
for all Spraying rates when the oats were eight inches high. As in the
pre-emergence date of application, all Spraying rates were greater than
the check plot.

When 2,h-D was applied as a.pre-emergence spray, head counts varied
less than eight heads per twelve feet of row for all spraying rates.

All spraying rates were greater than the check plot. head counts varied
9.3 heads between the one-quarter and three-quarter pound rates, in
contrast to 20.3 heads for the one-half pound rate when the cats were
eight inches high. hgain, all spraying rates were greater than the
check‘plot.

AS the rate of endothal was increased as a pre-emergence Spray,
head counts also increased, with the largest number for all rates and

dates of Spraying occurring at the four pound rate. When endothal was

TADLE III

I‘J'M'LBEE CF HANDS 05 0!.TS Plight Tflle F 1.1.33 OF ROW hrizil‘i SthYLiD lt'ITH
hCP, 2,h-D LNJ ENDOTHLL AT Thane DIFFhfihflT nhTfiS AND TWO DATES

 

 

 

 

 

 

Chemical hate Time of {pplication
Pre-emergence Eight Inches

in.C.P. .25 177.5 166.0
2,h-D .25 183.3 193.8
Endothal 1.0 173.5 19s.}
h.C.P. .50 172.3 171.5
2,h-D .50 15h.3 173.5
Endothal 2.0 , lb9.0 181.3
M.C.P. .75 172.5 189.6
2,h-D .75 177.0 18h.5
Endothal h.0 209.0 197.3

 

Check 16h.0 l6h.0

 

11

applied when the cats were eight inches high, head counts were approxi-
mately the same for the one and four pound rates, however, the two
pound rate was lower. hndothal showed higher head count than the check,
as was true for EC? and 2,h-D.

“a

lne fully headedstagecd‘application was not PGCOPUéd because it

was the same as the check plot.

Total humber of Needs by Species

Table IV Shows the total number of weeds by Species per square
yard. The field was very weedy, with lady's thumb smartweed being the
predominating Species. Since the check plots contained a small number
of wild buckwheat, barnyard grass, foxtails, and other weeds, ani they
were not evenly distributed over the field, they are not shown in

tabular form. The four predominating species were more uniformly dis-

tributed and are shown in tabular form. The term foxtails, includes

CD
0.3

both the gr en nd yellow species. Other weeds includes Canada thistle,

black nightshade, perennial sawthistla, quackgrass, perennial Smartweed,

rough pigweed, field sorrel, knotweed, major plantain, hull thistle,

and yellow trefoil.

Effect on Lady's Thumb Smartweed

Table V Shows the effect of LC}, 2,h-D and endothal applied at three
different rates and dates upon the average number of Lady's thumb Smart-

weed alants per square yard.

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iecies weeds Pe

 

Lady's Thumb lChl

Tickle Grass 1E0
Lambsguarter 136
'.-. a. gwe e d 9 0
Foxtails 27
Wild Buckwheat g
Barnyard Grass 3
Other Needs 6

 

Total 11.9};

 

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Chemical hate Time of {pplication
Ira-emergence night Inches fully needed
n.C.P. .25 027.5 “39.7 LC3.b
2,h-D .25 L19.o “07.0 292.5
endothal 1.0 50.; 0.0 h0.t

 

706.5
325.0
11.3

1'; CC 0P 0 0:") LICB .3
2.u—u .50 L55.3

’ 1.5

dndothal

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1131.0
17u.3
1.5

n.C.P. .75 556.5 ll
2,u-U .75 h73.3 l
endothal h.0 6.5

N
O'\1\]
C (cw

 

Check 10h1.0 10h1.0 10hl.0

 

lb

MO? was the least effective of the three chemicals for controlling
Lady's thumb. It was most effective if applied when the cats were about
eight inches high giving approximately seventy—five percent control.
When applied as a pre-smergence spray

, the control was only slightly

‘9

bove fifty percent. Spraying with.hCP when the oats were fully headed

m

gave very little control as far as actual kill was concerned but the weeds
did Show some effects of the treatment. The effectiveness of the chemi-
cals was not influenced to any great extent by rates that were used.

The amine form of 2,h—D was somewhat more effective in controlling
Lady's thumb than hCP. The pattern of control was very Similar for the
two chemicals as far as rates and times of applications were concerned.
Pre-emergence was least effective of all dates used, and applications
made when the oats were eight inches high were most effective. Results
from the three rates used were very Similar as shown in figure 1. The
effect of 2,h—D on lady's thumb that was short of killing was very
Similar to that of hCP. Plants twisted, Showed malformations and were
stunted to varying degrees.

endothal gave excellent control of lady‘s thumb as Shown in Table V.
Best control was effected at the heaviest rate, however, excellent
control resulted when only one pound of endothal was used per acre.

The most effective time of application was when oats were eight inches
high, but applications at other times were also very efficient.
A comparison of the three chemicals at the three rates can be noted

readily by referring to figure 1. A Similar comparison of these chemicals

can be made for the three times of application by referring to figure 2.

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Number of Weeds

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210-

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Check.

Figure l.

 

I

1/u 1/2 3/h . 1/b 1/2 3/h 1
MOP - 2,h-D . Endothal

Comparison of MCP, 2,h-D and Endothal applied at three
different rates on Lady‘s thumb.

15

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Check
Pre-emergence
Eight inch stage

Fully headed

Endothal

Figure 2. Comparison of MCP, 2,h-D and Endothal applied at three

different dates on Lady's thumb.

17

Effect on Tickle Grass

Table VI shows the effect of ACP, 2,h-D and endothal applied at
three different rates and dates upon the average number of tickle grass
plants per square yard.

As an average for all times of applications, hCP gave better con-
trol as rates increased as shown in figure 3. Applying RCP at the pre-
emergence and eight inch stages gave better control than the fully headed
stage as shown in figure h. All rates and dates of application of MOP
gave a minimum of seventy-five percent control of tickle grass.

MCP was less effective than 2,h-D as a pre-emergence Spray for
controlling tickle grass. Almost complete control was obtained with
three quarters of a pound of 2,h—D on this weed.

bndothal was more effective at the pre-emergence and eight inch
stages than at the fully headed stage of application. Endothal was the
least effective of the three chemicals for controlling tickle grass.

The effects of rates for the three chemicals is shown in figure 3.

A comparison of the three times of application is shown in figure h.

Effect on Lambsquarter

Table VII shows the effect of MCP, 2,h-D and endothal applied at
three different rates and dates upon the average number of Lambsquarter
plants per square yard.

MCP was the most effective of the three chemicals for controlling

lambsquarter. It was most effective if applied when the oats were fully

ThdLE VI

lb

xvragca LULsEa or TICKLE cease PLANTS Pea ngnaa than
wutw SFnlIuD WITH hCP, 2,h-D, 1ND axhoralt

 

 

 

 

 

 

 

Chemical hate Time of Ipplication
Pre-emergence night Inches Fully headed

MOP .23 53.3 50.3 71.3
2,u-D .25 37.3 32.3 53.3
Endothal 1.0 25.0 lu.3 56.0
hCP .50 21.0 27.8 76.5
2,u-D .50 6.3 L8.o h6.0
Endothal 2.0 3.0 35.5 137.3
hCP .75 31.3 17.8 50.8
2,h-D .75 .6 Sh.0 h9.5
bndothal h.o 38.3 1h.3 32.3
Check 160.0 180.0 180.0

 

 

 

    

 

 

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Check

Figure 14.

m Check
- Pre-ecmergence

31 Eight inch stage”

  
 

:33". Fully headed

'Mfi-Dy.

-u=uasurnk

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. moi
Qomdlnvfl‘lh .. pg“. . ,..

 

' MCP

Comparison of MOP, 2,Lt-D and Endothel applied at three”
different dates on tickle grass.

Endothal.

 

-——-—- ~—

 

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TLBLE VII

avenues WEBER or Lid-LB sewage PLANTS FEE. emu-.2; $21.0
waaw seaayab wire nor, 2,h-D AND auaoraxL

 

 

 

 

 

 

 

Chemical Hate Time of ipplicrtion
Pre-emeggence night Inches Fully headed

hCP .25 63.3 39.0 51.8
2,h-D .25 72.3 53.3 22.5
Endothal 1.0 113.5 03.0 85.3
map .50 28.5 7b.3 23.3
2,u-D .50 u1.0 33.0 52.5
Endothal 2.0 08.3 75.5 125.8
he? .75 17.5 17.0 15.0
2,h-D .75 31.5 63.0 L26
Endothal b.0 57.: 53.3 97.5
Check 136.5 136.5 136.5

 

headed giving approximately eighty percent control, however, the pre—
emergence and the eightzbmflistageof application gave more than sixty
percent control as shown in figure 6. The effectiveness of the chemical
was influenced as the rates increased as shown in figure 5.

The amine form of 2,h-D gave somewhat less control of lambsquarter
than.HCP. The pattern of control was similar for the two chemicals as
far as dates were concerned, but different for the rates. Applications
made when the oats were fully headed gave slightly better control than
applications made at the other two dates. Results from the three rates
were very similar, with the one-half and three-quarters of a pound rates
‘giving slightly better control than the one—quarter of a pound rate as
shown in figure 5.

Endothal was the least effective of the three chemicals for con-
trolling lambsquarter.p It was most effective if applied when the cats .
were eight inches high giving approximately fifty percent control. When
applied as a.pre—emergence Spray, the control was about forty percent.
Spraying with Endothal when the oats were fully headed gave very little
kill, but the weeds were stunted and showed some effects of the chemical.
The effectiveness of the chemical was influenced slightly by the four

pound rate of application, as shown in figure 5.

Effect on Ragweed

Table VIII shows the effect of hCP, 2,h-D and endothal applied at
three different rates and dates upon the average number of ragweed

Plants per square yard.

_ -———r.-.

_ --..Number of Needs per.'Square lard..-

.’~ _ us ........

910

770.3-

7.0 o;

680~

5a:

1‘90,

390

883-

 

 

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Figure 5 .

 

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3101D _ 2 ,b-D Endothal

Comparison of NSF, 2,h-D and Endothal applied at three
different rates on Lambsquarter-.

Number of weeds per Square Yard

1050

980

910

810

770 .

700

630

350 _
280

210

 

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- Pre-emergence

{‘3 Eight inch stage

 

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Chec k MCP

Figure 6. Comparison of MCP, 2,14-D and Endothal applied at three
different dates on Lambsquarter.

TABLE VIII

AVrlm’. GE 3‘11“er 0F RJLG'MEID PL} N‘l'S PEh‘ Sim-.3115 12-320
WHnN SthY D WITH ESP, 2,h-D AND EhUOTihL

2S

 

 

Chemical

hate

Time of fpplication

Pre-emergence

hight Inches

Fully needed

 

 

 

1"ch .25 73.0 26.3 21.3
2,h-D . .25 3h.3 2t.a 9.&
Lndothal 1.0 38.0 10.5 22.5
MCP .50 9.5 28.3 31.0
2,)4-D 050 503 3805 805
Endothal 2.0 15.0 2.5 ‘ 22.5
hCP .75 11.3 36.0 5.3
2,h-D .75 6.8 50.3 6.8
Endothal h.0 5.5 9.5 8.3
Check 96.0 96.0 96.0

 

Data on ragweed control is less reliable than for lady's thumb
because of less uniform distribution of the weed.

he an average for all times of applications, MCP gave better con-
trol of ragweed as rates increased. (Shown in figure 7.) spplying hCP
when the oats were fully headed gave approximately eighty percent con-
trol. The pre-emergence, and eight inch stages gave slightly less than
seventy percent control as shown in figure 8.

‘With the exception of the eight inch stage of application, 2,h-D
was more effective than.hCP. The effectiveness of the chemical was not
influenced to any great extent by the different rates that were used.

Endothal was most effective at the eight inch stage of application.
At the pre-emergence and fully headed stages of application, Endothal
was less effective than 2,h-D. The effectiveness of the chemical was
greatly influenced by the rate of application. The heaviest rate gave
the best control.

A comparison of the three chemicals as to rates is shown in figure 7.
The effectiveness of the different dates of application is shown in

figure 6 .

Effect on Foxtails

The effect of MCP and 2,h-D on foxtails was erratic, and in over
fifty percent of cases, no control was indicated at any rate or time
of application. Endothal was ineffective as a pre-emergence spray

regardless of rate, but gave complete control on two occasions at the

1050
: 9&)
I 910

IEhO

U3 1:“ :7 \n 0‘. N w—
E3 E3 ?8 8; ES 23 23

. Number of Weeds per Square Yard

m
E?

3210
1A0

70

 

Check

Figure 7.

2.7 . ,,

 

 

 

 

 

 

 

1/u 1/2 3/u 1/u 1/2 3/u' ' 1 2
MOP 2,h-D Endothal

Comparison of MOP, 2,h-D and Endothal applied at three
different rates on Ragweed.

 

h

28

 

 

 

Endothal

 

. Fully headed

 

5;;3 Eight inch stage

m Pre-amergence

$51.33 Check

 

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Check

, 2,h-D and Endothal applied at three

different dates on Ragweed.

A

Comparison of MOB

Figure 8.

eight inch and fully haaxaistagescfi'application. hates of endothal.

did not make much difference.

affect on Wild Buckwheat

Stands of wild buckwheat were not uniform, and treated plots often
contained more of this Species than was found in the check plots.
hCP did not show any control of this weed except when applied at the
highest rate at the fully headed stage. 2,h-D was not effective at any
rate or time of application. Endothal at the four pound rate when ap-
plied as a pre-emergence Spray, reduced wild buckwheat to five-tenths
of a weed per SQuare yard. At the eight inch and fullv headed stages,

all rates of endothal gave one-hundred percent control.

affect on Barnyard Grass

The distribution of barnyard grass was very irregular, and the
checks contained an average of only three plants per square yard. The

majority of treated plots contained more barnyard grass than the checks.

3o

Sbivl-lifl

l. The effects of the amine form of EC? and 2,h-D and hndothal on
Clinton oats and weed species at various times and rates were studied.

2. Yields of all plots were low due to climatic conditions. best
yields came from plots with the best lady's thumb control.

3. Test weights were inconsistent among treated plots, and differ-

ences were not great enough to be considered 'iportant due to an adverse

05%

owing season.
h. none of the chemicals ad ersely affected the number of heads per
unit of row.
5. Plots were very weedy, with an average of 1&9; weeds per square
yard.
6. bndOthal gave excellent control of lady's thumb for all rates

1

and dates. The post emergence rates nd dates of Spray burned the leaves

03

of the cats. Endothal was efficient in killing wild buckwheat where it
was present.

7. Best control of tickle grass was obtained from 2,h-D applied as
a pre-emergence Spray. however, all chemicals at all rates and dates
of application gave some control.

8. Lambsquarter was controlled best by applications of hCP at the
fully headed date. The effectiveness of 2,b-D was almost as pronounced

E S l'iCP .

kn)
H

2,h-D gave best control of ragweed. All chemicals
gave some control for all rates and dates of application.
10. Because of low yield, test weight, and thin stand of cats,

alon~ with a lack of uniformit* of weed s ecies and adverse weather
a 3 2

conditions, his experiment should be duplicated.

BlBLIOGRAPHY

Burrows, V. D., and Clson, P. J. heaction of Oats to 2,h-D butyl
ester when applied at twenty different stages of growth.

H

to. Cent. Weed Cont. Conf. 9:7h, 19/2.

Burrows, V. D., and Olson, P. J. The effect on yield of Exter
oats (sown at two rates) by treating with two rates of 2,h-D
ester (butyl) and amine (mixed) at four dates. no. Cent.
Weed Cont. Conf. 9:7h-75, 1952.

Coupland, h. T., Relative effect of MOP and 2,h-D on yield of oats.
no. Cent. Weed Cont. Conf. 9:75-76, 1952.

Davidson, J. G., Reaction of bxeten cats to 2,b-D applied at
different growth stages. ho. Cent. Heed Cont. Conf. 9:6h,
1952.

Finnerty, D. 1., lield ofNemaha oats and seed production of wild
buckwheat as affected by 2,h-D and KCP applied at tillering
and jointing stages of cats. ho. Cent. deed Cont. Conf.
9:62-83, 1952.

Janzen, P. J., Control of weeds in Small Grains. No. Cent. weed
Cont. Conf. 9:6h, 1952.

Shafer, h. E. and Finnerty, D. W., Response ofNemahaloats to 2,h-D.
mo. Cent. weed Cont. Conf. 9:82, 1952.

Taylor, D. K., Effect of one in comparison to 2,h-D and hCP on
wheat and barley; No. Cent. Weed Cont. Conf. 9:63, 1952.

Zalik, Saul, Effect of two 2,h-D esters on the yield of Victory
oats and Argentina rape. 50. Cent. Weed Cont. Conf. 9:8h,
1932.

IGAN STATE UNIVERSITY LIBRARIES

aluminium IIIH l

1293 3046 8460

 

MICH