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thesis entitled
SPRAY AUUIlIVLS AND CHEMICAL HARVEST
AIDS FUR NAVY BEAN (gags-gang 11139.05)
AND POTATO (Solanum Egygrgsgm)

mm‘mm

presented by

DALE ROBERT MUTCH

has been accepted towards fulfillment
of the requirements for

flagtg[§_ degree in Crop & Soil Science

 

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SPRAY ADDITIVES AND
CHEMICAL HARVEST AIDS FOR
NAVY BEAN (Phaseolus vulgaris)
AND POTATO (Solanum tuberosum)

 

 

‘BY

DALE ROBERT MUTCH

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements

for the degree of

MASTER OF SCIENCE

Department of Crop and Soil Sciences

T980

ABSTRACT

SPRAY ADDITIVES AND CHEMICAL HARVEST AIDS FOR
NAVY BEAN (Phaseoulus vulgaris)

 

AND
POTATO (Solanum tuberosum)

 

BY

DALE ROBERT MUTCH

Chemical harvest aids are an important management practice for

potato (Solanum tuberosum L.) vine desiccation. At present, no

 

chemical harvest aids are registered for use on navy bean (Phaseoulus

 

vulgaris L.) in Michigan, although prevailing weather conditions would

frequently favor their use.

Greenhouse and field experiments were conducted to evaluate ametryn
(Z-ethylamino)-4-(isopropylamino)-6-(methylthio)-§:triazine), endothall
(7-oxabicyclo (2,2,l,) heptane-2,3-dicarboxylic acid), dinoseb (2'§££?
butyl-4,6-dinitrophenol), and paraquat (l,l'-dimethyl-4,4'-bipyridinium
ion) as potential chemical harvest aids for navy bean. Dinoseb alone
caused little or no desiccation. Ametryn, endothall, and paraguat

individually showed moderate desiccation.

Dale Robert Mutch

Inclusion of additives to herbicide sprays increased their
efficacy. The three-way combination of ammonium sulfate plus crap
oil markedly increased efficacy of herbicides ametryn, endothall, and
dinoseb. The two-way combination of paraquat plus ammonium sulfate

resulted in the greatest navy bean desiccation.

Greenhouse and field experiments were conducted to evaluate
additives to increase efficacy of dinoseb and endothall for potato
vine desiccation. Inclusion of additives resulted in slight increases
in endothall efficacy, however, desiccation was still poor. The
three-way c0mbination of dinoseb, plus ammonium sulfate, plus crop

oil markedly increased desiccation of potato vines.

In this study, paraquat showed the most promise as a chemical
harvest aid on navy bean. Ammonium sulfate at 9.0 kg/ha increased
efficacy of paraquat in the greenhouse and in the field. Field studies
indicate that paraquat at 0.6 kg/ha in combination with ammonium sulfate
at 9.0 kg/ha have no adverse effects on navy bean germination or seed

dry weight.

The three-way combination of ammonium sulfate plus crop oil plus
dinoseb can increase desiccation of potato vines without detrimental
effects on tuber quality. The combination of 9.0 kg/ha ammonium
sulfate plus crop oil at 2.3 L/ha plus l.4 kg/ha dinoseb gave
equivalent potato vine kill for 'Sebago' to 2.8 kg/ha dinoseb plus
2.3 L/ha crop oil. '

ACKNOWLEDGMENTS

I would like to express my greatest appreciation to Dr. Donald
Penner for his guidance, knowledge and friendship as my major

professor.

I would like to thank my wife Barbara for her encouragement
and support, my son Nicholas for giving me a reason to continue my

education, and my son Benjamin for his inspiration.

Special thanks is given to Frank Roggenbuck for his assistance

in my field plot experiments.

Lastly, I would like to thank my committee members, Dr. Richard

Chase and Dr. George Ayers for their expert guidance.

ii

TABLE OF CONTENTS

 

 

Page
LIST or TABLES ................. . . . . ... 1'v
INTRODUCTION ........ . . . . . . .......... l
CHAPTER l: LITERATURE REVIEW ........... . . . . 3
History of Harvest Aids ................ 3
Use of Ammonium Salts and Ethephon to Influence
Herbicide Efficacy . . . ........... 6
Current Need fOr Chemical Harvest Aids ........ 8
CHAPTER 2: POTENTIAL CHEMICAL HARVEST AIDS FOR NAVY BEAN
(PHASEOLUS VULGARIS) .......... . . . . l0
Abstract ....................... 10
Introduction ......... . . . . . ....... ll
Materials and Methods ................. l2
Results and Discussion ................ 14
Literature Cited ..... . ............. l8
CHAPTER 3: THE USE OF ADDITIVES TO INCREASE EFFICACY 0F
DINOSEB FOR POTATO (SOLANUM TUBEROSUM) FOR
VINE DESICCATION - - - - ...... . . 28
Abstract . . . .................... 28
Introduction . .................... 28
Materials and Methods ................. 29
Results and Discussion . . . . ............ 82
Literature Cited . .................. 55
CHAPTER 4: SUMMARY AND CONCLUSION ............. 42
LIST OF REFERENCES ..... ' ................ 44
APPENDIX .......................... 47

Table

LIST OF TABLES

Chapter 2

l.

Percent moisture content and visual injury of navy
bean plants following postemergence application
of ametryn averaged over rates of 0. 0, l. l, and
2.2 kg/ha applied with ammonium salts, ethephon,

or crop 01.] O O O O O I O O O O O O I O O O O O O 0

Percent moisture content and visual injury of navy
bean plants following postemergence application of
endothall averaged over rates of 0.0, 0.6, and l.0
kg/ha applied with ammonium salts, ethephon, or

crop oil . . . . . . ....... . . . . .....

Percent moisture content and visual injury of navy
bean plants following postemergence application of
dinoseb averaged over rates of 0.0, 0.8, and 1.7
kg/ha applied with ammonium salts, ethephon, or

crop oil . . . . . . . . . . . . . . . . ......

Percent moisture content and visual injury of navy
bean plants following postemergence application of

dinoseb with ethephon or crop oil ...... . . . .

Percent moisture content and visual injury of navy
bean plants following postemergence application of

dinoseb with ammonium sulfate or crop oil . . . . . .

Percent moisture content and visual injury of navy
bean plants following postemergence application of
paraquat averaged over rates of 0.0, 0.6, and l.l
kg/ha applied with ammonium salts, ethephon, or

crop oil ......................

Percent moisture content and visual injury of navy
bean plants following postemergence application of

paraquat with ammonium sulfate or X-77 . . . . . . .

Percent moisture content and visual injury of navy
bean pods and seeds following postemergence appli-
cation of paraquat, dinoseb, endothall, and ametryn
with additives ammonium sulfate, X- 77, or crop oil

iv

Page

19

20

2l

22

23

24

25

26

Table Page

9. Percent germination and seed dry weight of navy
bean plants following postemergence application
of paraquat, dinoseb, endothall, and ametryn
with additives ammonium sulfate, X-77, or crop 27
01

Chapter 3

1. Percent shoot moisture content and visual injury
of 20 cm tall 'Superior' potato vines averaged
over rates of 0.0 and 0.6 kg/ha of postemergence
application of endothall with ammonium salts,
ethephon and crop oil . . . . . . . . . . . ..... 35

2. Percent shoot moisture content and visual injury
of 20 cm tall 'Superior' potato vines averaged
over rates of 0.0, 0.8, and l.7 kg/ha of post-
emergence application of dinoseb with ammonium
salts, ethephon and crop oil . . . . . . . . . . . . 37

3. Percent shoot moisture content and visual injury
of 20 cm tall ‘Superior' potato vines treated
with postemergence application of dinoseb with
ammonium sulfate and crop oil ....... . . . . . 38

4. Percent shoot moisture content and visual injury
of 'Superior' 20 cm tall potato vines treated
with postemergence application of dinoseb with
ammonium sulfate and crop oil . . . . . . . . . . . . 39

5. Visual injury and tuber quality evaluated in the
field when 'Sebago' potato vines were treated
with postemergence applications of different
rates of dinoseb with ammonium sulfate and crop 40
oil . . . . . . . . . . . . . . . . . . . ......

6. Visual injury and tuber quality and specific gra-
vity were evaluated in the field on 'Monona'
potato vines treated with postemergence appli-
cations of dinoseb with ammonium sulfate, ethephon
and crop oil . . . . . . . . . . . . . . . . . . . . 41

Appendix

A-l. Percent moisture content and visual injury of
navy bean plants following postemergence appli-
cation of ametryn with ammonium salts, ethephon,
and crop oil .................... 47

A-3,

A-4.

A-5.

Percent moisture control and visual injury of navy
bean plants following postemergence application of
endothall with ammonium salts, ethephon and crop

Oi] O O O O O O O O I O O O O O O O 0

Percent moisture content and visual injury of navy
bean plants following postemergence application of
dinoseb with ammonium salts, ethephon and crop oil .

Percent moisture content and visual injury of navy
bean plants following postemergence application of
paraquat with ammonium salts, ethephon and X-77 . . .

Percent shoot moisture and visual injury of 'Super-
ior' potatoes following postemergence application
of endothall with ammonium salts, ethephon and

crop oil

Percent shoot moisture and visual injury of 'Super-
ior' potatoes following postemergence application

of dinoseb with ammonium salts, ethephon and

crop oil

vi

Page

48

Sl

53

INTRODUCTION

 

A chemical harvest aid is an agricultural chemical which
desiccates or defoliates existing vegetation to facilitate an early
or more timely harvest of a crop. The need for chemical crop de-
siccation is enhanced by prolonged wet periods in the Fall prior to
harvest, or when other management practices cause delay in normal

maturity. Navy bean (Phaseolus vulgaris L.), potato (Solanum tuber-

 

 

osum L.) (l2), soybean (Glycine max Merr L.) and sunflower (Helianthus

 

 

agggg§_L.) (3,5), are crops in Michigan where the use of a chemical
harvest aid could be beneficial. In Michigan, four contact herbicides
are registered for potato vine killing. Ametryn (2-(ethylamino)-4-
isopropylamino-G-methylthio)-§;triazine), endothall (7-oxabicyclo(2,2,
l)heptaine-2,3-dicarboxylic acid), dinoseb (2-sgcrbutyl-4,6-dinitro

phenol), and paraquat (l,l'-dimethyl-5,5'-bipyridinium ion) (35).

Michigan is the largest producer of navy beans in the United
States (24) and, currently, there are no registrations for use of
chemical harvest aids. However, in l977, when Michigan had a wet Fall,
approximately 70,000 acres were not harvested (24), a condition when

a chemical harvest aid could have reduced this loss.

In a recent survey, 67% of Michigan potato growers indicated they
used dinoseb for chemical vine desiccation (28). Paraguat causes
rapid vine kill, however, current registration prohibits its use on

potatoes to be stored or used for seed.

Paraquat has received a state label (24c) registration as a
harvest aid for soybean (3). Paraquat has also been used to accel-

erate drying for sunflower (3,5).

Herbicides used for desiccation purposes are generally contact
herbicides and more toxic to humans (35). Research with these
compounds should employ different techniques to increase their

efficacy while decreasing their rates.

The purpose of this research was to (a) evaluate several potential
chemical harvest aids and to determine efficacy of various ammonium
salts and ethephon (Z-chloroethyl) phosphonic acid) as additives for
increasing efficacy on navy bean, (b) evaluate several ammonium salts
and ethephon as additives to increase efficacy of dinoseb and endothall

for potato vine desiccation.

Chapter l

Literature Review

History of Harvest Aids

The value of early harvest of potatoes facilitated by vine
removal was recognized by Murphy (25), and Schultz and Folsom (27)
in l920. Research developed on the subject in the 1930's and l940's.

Tuber cracking during harvest of potatoes was observed in the
earlier work with vine killing. Werner and Dutt, in l940, reported
that root cutting or vine killing reduced cracking of late variety
"Triumph" potatoes (37). Many advantages for potato vine desic-
cation were reported by Callbeck (l5), desiccation prevented tuber
infection by late blight, prevented spread of virus diseases,
reduced number of oversized and knobby tubers, speeded skin maturity,
and facilitated and permitted timing of harvest. Binkley and Kunkel (8)
reported increased use of vine killers in Colorado for the purpose of

toughening tuber skins, and to reduce scuffing and mechanized abrasions.

In Maine, potatoes must be harvested during September and early
October to prevent possible losses to tubers by low temperatures (16).
When killing frosts do not occur, potato vines must be killed or
potatoes must be harvested with green vines. If late blight is
present, considerable losses can occur from late blight tuber rot when
potatoes are harvested with infected green vines (12). Vines need to

be killed two weeks prior to harvest to prevent tuber Skinning, or

bruising (7).

Hand pulling of potato vines was the first method of destroying
vegetative growth (7). However, as acreage increased, this method
soon became impractical. Noolery Machine Company developed a flame
potato vine burner which used 18 gallons of fuel per acre. Roto-
beating of vines became a practice of killing green vine growth (23).

These practices, however, were unsatisfactory.

The chemical revolution was just beginning in the 1940's. SUCh
compounds as sulfuric acid and copper sulfate were used experiment-
ally for potato vine desiccation (2). In the late l940's and early
1950's, ammonium sulfate was evaluated by potato researchers as a
potential chemical harvest aid at rates of 200 to 300 pounds per
acre (26,30). Vine killing with chemicals became an accepted
practice with the development of more complex organic compounds
such as substituted phenols and endothall (7-oxabicyclo 2,2,l heptane-
2,3-dicarboxylic acid) (2). The use of additives to increase
efficiency of herbicides was reported by Callbeck (l5), who used
crank case oil in combination with handy killer, green cross topkiller,

and Geigy‘s potato vine killer; (all sodium arsenite compounds).

In l946, Steinbauer (3l) reported occasional discoloration in
the vascular bundles of tubers from vines treated with sodium nitrate,
dinitrocresol, and phenol compounds. Other researchers also reported
vascular discoloration in tubers following use of chemical harvest
aids (l2,l5). Prince (26) reported that discoloration was confined
to the xylem elements of the vascular ring with the discoloration

being more dense on the stem side of the vessel end walls. Some early

investigations confused stem end browning with vascular discoloration
(l6). Folsom and Rich (l8) developed a "half-inch or l.3 cm depth"
method of cutting tubers to separate stem end browning from vascular
discoloration. Vascular discoloration extends greater than 1.3 cm

from point of stolon attachment, where stem ehd browning is confined to

the stem end portion of the tuber (l8).

Early researchers concluded that rapid vine killing resulted in
vascular discoloration (l6). However, Hoyman (2l) reported that
discoloration was caused by climatic conditions. Hoyman showed that
drought in combination with rapid vine desiccation resulted in dis-

coloration (2l).

Cotton (Gossypium hirsutum L.) has also been considered as a

 

potential crop for chemical harvest aids. Tharp (34) in l955, reported
2,968,973 acres of cotton were treated with defoliants or desiccants.
Desiccation or defoliation of cotton was important to prevent green
staining of the fibers (2). Barnes (7) reported that chemical harvest
aids may also be valuable for soybeans grown for seed. Chemical
harvest aids have also been Shown to reduce seed moisture in rice

(Oryza sativa L.) (20). Harvest aids applied to alfalfa (Medicago

 

sativa L.), various clovers (Trifolium L.), and birdsfoot trefoil

(Lotus corniculatns L.) reduced pod shattering when harvested for

 

seeds (22).

Several contact herbicides are now registered in Michigan for

potato vine desiccation. Phytobland oils or organic solvents are

recommended in combination with these herbicides to increase their
efficacy. With increased profits available from earlier harvests,
the use of chemical harvest aids has expanded to crops like soybean,

sunflower, and navy bean (5).

Use of Ammonium Salts and Ethephon to Influence Herbicide Efficacy

 

Ammonium sulfate, ammonium sulfamate, and ammonium thiocyanate,

applied at high rates have been classified as herbicides (4). How-

ever, using ammonium salts at low non-herbicidal rates in combination

with herbicides has increased herbicide efficacy.

Amitrol-T is a commercial product combining amitrole (3-amino-s;

triazole) with ammonium thiocyanate (35). Ammonium thiocyanate

increased amitrole translocation in quackgrass (Agropyron repens L.)

(l6). Ammonium ions could affect absorption and translocation of

picloram (4-amino-3,5,6-trichloropicolinic acid) in quava (Psidium

guajava L.) and dwarf bean (l7). Ammonium sulfate increased efficacy

of bentazon (3-isopropy-lfl;2,l,3 benzothiadizain-(4)-3fl;one, 2,2-
dioxide) and glyphosate (N-(phosphonomethyl) glycine) for yellow

nutsedge (Cyperus esculentus L.) control (33). Glyphosate activity

was enhanced when ammonium sulfate was used as an additive for purple

nutsedge (Cyperus rotundus L.) (32) and quackgrass control (10).

Early researchers hypothesized that the ammonium ions decreased

the pH of the herbicide spray, thus increasing absorption (29). How-

ever, Nilson and Nishimoto (39) reported that enhancement of picloram

absorption was not necessarily due to lowering the pH of the herbicide

solution. In addition, varying the pH of the spray solutions of

bentazon and glyphosate after addition of ammonium salts resulted
in no difference in efficacy of these herbicides for yellow nutsedge

control (33).

It has been reported by Good and Izawa (19) that ammonium ions
and methylamine prevent phosphorylation and increase the rate of
electron flow from plastoquinone to photosystem I. Herbicides and
ammonium ions may act at the same sites to increase desiccation to
the plant. Paraquat (l,l'-dimethyl-4,4'-bipyridium ion) removes
electrons from the electron transport system of photosystem I, thus

inhibiting the reduction of NADP to NADPH (l4).

However, herbicides and ammonium ions may also react at different
sites, but the combination may enhance the herbicidal effect. Suwan-
ketnikom (33), reported that single applications of bentazon at l.l
kg/ha did not provide adequate control of yellow nutsedge. However,
bentazon activity was greatly enhanced with the addition of ammonium
salts. Boger gt_§l, (ll) concluded that bentazon inhibited electron

flow in photosystem II.

Weissman (36) reported that ammonium ions suppressed both nitrate
and nitrite reductase levels in plant leaves, and may cause an increase
of nitrite accumulation. Ammonium ions, when applied in combination
with herbicides, may cause increased nitrite accumulation in plant

leaves above that for the herbicide applied alone.

Ethephon (2-chloroethyl phosphonic acid) has enhanced dicamba

(2,6-dichloro-gfanisic acid) efficacy (9). Ethephon increased basi-

petal translocation of 14C glyphosate in yellow nutsedge (33). This
report supports Binning gt_al, (9) hypothesis that ethelene released
from ethephon may alter source-sink relationships in plants and

increase basipetal movement of herbicides.

Current Need for Chemical Harvest Aids

 

In Michigan, a chemical harvest aid would be beneficial if
detrimental weather delayed planting and/or harvest. Chemical harvest
aids have been shown to reduce moisture content in soybean (38),
sunflower (5), and rice seed (20). Byg gt_al, (13) reported safe
harvest of short season soybeans at 13-14% seed moisture 4 to 5 days

earlier if paraquat was applied as a chemical harvest aid.

Paraquat has received a (24C) state label in Ohio and Michigan
for use as a chemical harvest aid for soybeans (3). Paraquat has
shown no adverse effects on germination of soybeans (38). An early
harvest and market delivery of soybeans brings a premium price
providing an incentive for use of chemical harvest aids. In addition,
the longer a crop stays in the field, the greater the danger of

inclement weather (5).

United States sunflower acreage has expanded rapidly, from
810,000 acres in 1976, to 2,753,000 acres in 1978, and an estimated
4,140,000 acres for 1979 (3). Earlier harvest of sunflower has many
advantages, (a) minimization of bird damage, (b) increased combine
efficiency, and (c) earlier winter wheat planting (3). Sunflowers

mature long before they are dry enough to combine. To prevent mildew

damage or for temporary storage, seeds should be below 12% moisture
content and for long term storage, seeds should be below 9.5%
moisture (5). Paraquat has shown promise as a chemical harvest aid

for sunflower (3,5).

Michigan grows 95% of the navy beans in the United States (24).
In 1977, when Michigan had a wet Fall, approximately 70,000 acres
of navy beans remained in the field (24). The use of a chemical
harvest aid could have reduced this loss. Michigan State University
has been researching the posSibility of erect-type navy bean varieties
which will allow for direct harvest. Adams (1) reported that these
new varieties may require the use of chemical desiccation prior to
harvest. In addition, Michigan bean growers will be increasing black
turtle dry bean acreage in 1980. This variety of bean has problems
of pod shattering and diseases at harvest (6). Chemical harvest aids
reduced pod shattering in small seeded legumes (22), and reduced
disease damage for potatoes (12). In Michigan, the greatest amount of

chemical harvest aids are used for desiccating potato vines (28).

Chapter 2
Potential Chemical Harvest Aids

for Navy Bean (Phaseolus vulgaris)

 

Abstract

At present, no chemical harvest aids are registered for use on

navy bean (Phaseolus vulgaris L.) in Michigan, although prevailing

 

weather conditions would frequently favor their use. Greenhouse and

field experiments were initiated to evaluate four contact herbicides

as potential Chemical harvest aids on navy bean. In the greenhouse

ametryn (2-ethylamino)-4(isopropylamino)-6-(methy1thio)-§7triazine)

at 1.1 and 2.2 kg/ha, dinoseb (2-(l-methylpropy1)-4,6-dinitrophenol)
at 0.8 and 1.7 kg/ha, endothall (7-oxabicyclo(2,2,l)heptane-2,3—dicar-

boxylic acid) at 0.6 and 1.0 kg/ha, and paraquat (l,l'-dimethyl-4,4'-
bipyridinium ion) at 0.6 and 1.1 kg/ha were applied to navy bean

plants and evaluated as desiccants seven days later. Variuos ammonium

salts and ethephon (2-chloroethyl) phosphonic acid) were evaluated as

adjuvants to increase efficacy in combination with the four contact

herbicides. Ametryn at l.l kg/ha, paraquat at 0.6 kg/ha, dinoseb at

1.4 kg/ha, and endothall at 0.6 kg/ha were applied to navy bean in a

field study. Ammonium sulfate, as a tank mix additive, at 9.0 kg/ha

was compared to herbicides alone or in combination with crop oil or

X-77 non-ionic surfactant (alkylaryl polyethylene glycol and free

fatty acids). Paraquat was the most effective desiccant or harvest

aid on navy bean. Ammonium sulfate at 9.0 kg/ha increased the efficacy

of paraquat in both the greenhouse and in the field. Field studies

10

11

indicated that this combination had no adverse effects on navy bean

germination or seed dry weight.

Introduction
A chemical harvest aid is an agricultural chemical which desic-
cates or defoiliates existing vegetation to facilitate an early or
more timely harvest of a crop. The need for chemical crop desiccation

is enhanced by prolonged wet periods in the Fall prior to harvest.

Michigan is the largest producer of navy bean in the United
States (9). Currently, no registrations exist for the use of chemical
harvest aids for this crop. However, in 1977 when Michigan had a
wet Fall, approximately 28,000 ha of navy bean were not harvested

(9). A chemical harvest aid could have reduced this loss.

Ametryn, dinoseb, endothall, and paraquat are all contact herbi-
cides that causes localized injury to plant tissue where contact
occurs (12). Paraquat has received a state label (24c) registration

as a harvest aid on soybean (Glycine max (L.) Herr.) (3). Paraquat

 

has also been used to accelerate drying in sunflower (Helianthus

 

annuus L.) (3). The herbicide paraquat has been tested for acceler-
ated drying of soybean and sunflower and has a restricted label use

for potato (Solanum tuberosum L.) vine killing (6).

 

Ammonium sulfate, ammonium thiocyanate, and ethephon may
increase absorption of herbicides. Ammonium thiocyanate increased
amitrole (3-amino-§;triazole) translocation in quackgrass (Agropyron

repens L.) (7). Ammonium sulfate increased absorption of 14C bentazon

12

(3-isopropyl-lfl;2,l,3 benzothiadiazin-(4)-3H;one 2,2-dioxide) and
14C glyphosate (N-phosphonomethyl)glycine) on yellow nutsedge (Cyperus

esculentus L.) (10). Ethephon increased absorption and basipetal

 

movement of 14C glyphosate in yellow nutsedge (10).

Ammonium ions prevent phosphorylation and increase rate of
electron flow from plastoquinone to photosystem I (8). Paraquat
removes electrons from the electron transport system of photosystem I,
thus inhibiting the reduction of NADP to NADPH (2). Calderbank (5)
reported that hydrogen peroxide produced during reoxidation of the
bipyridylium-free radical is the toxicant causing rapid injury of
the plant; also reactive hydroxyl radicals may be involved. Ammonium

ions may interact with herbicides that inhibit electron flow.

The purpose of this research was to evaluate several potential
chemical harvest aids and to determine efficacy of various ammonium

salts and ethephon as additives for increasing efficacy on navy bean.

Materials and Methods

 

'Seafarer' navy bean seeds were planted in greenhouse soil at the
rate of five sseds per 946-ml cup and after germination were thinned
to two plants per cup. Water was added to the soil daily with a
20-20-20 N-P-K Peters fertilizer solution at 100 ppm. The plants
were grown without supplemental lighting under a 14 h day until the
third trifoliolate leaf was completely expanded, the stage selected for

the treatment.

Ametryn was applied at 1.1 and 2.2 kg/ha, dinoseb at 0.8 and 1.7

kg/ha, endothall at 0.6 and 1.0 kg/ha, and paraquat at 0.6 and 1.1

13

kg/ha. All herbicide concentrations were applied at the rate of 347
L/ha. Crop oil 'Herbimax' was applied in combination with herbicides
at 2.3 and 4.6 L/ha. 'X-77' 1, a non-ionic surfactant was applied in
combination with herbicides at 1.2 and 2.4 L/ha. Ethephon and all
ammonium salts were applied in combination with herbicides at 4.5

and 9.0 kg/ha. Seven days after herbicide treatment, plants were
rated for visual injury, and fresh weights and dry weights determined.
The data presented are the means of two experiments with four repli-

cations per experiment.

A field study to evaluate the results obtained from the green-
house study was initiated on the Cliff Roggenbuck farm near Port
Hope, Michigan. 'Seafarer' navy bean were planted in four 76 cm by
l8.3 m rows per treatment. The experimental design was a randomized

complete block with four repliCations.

Ametryn at 1.1 kg/ha, dinoseb at l.4 kg/ha, and endothall at
0.6 kg/ha, and paraquat at 0.6 kg/ha were applied in 208 L/ha aqueous
spray. 'Herbimax' crop oil was applied in combination with herbicide
at 2.3 L/ha. 'X-77' non-ionic surfacant was applied with paraquat at
1.2 L/ha. Ammonium sulfate was applied in combination with herbicides
at 9.0 kg/ha. Seven days after treatment, the center two rows were
harvested in each plot. Desiccation was rated visually and 400 pods
were collected at random from each plot. The fresh weight of 100 pods
was determined after the seeds were removed. Samples of 100 seeds

were also weighed to determine harvest aid influence on seed weight.

1 Alkylaryl polyethylene glycol and free fatty acids

l4

Pods and seeds were dryed to 13% moisture and dry weights were
determined. Percent moisture content of both seeds and pods were
calculated. Seed germination was determined for 100 seeds of each

plot by Michigan Crop Improvement Association.

Results and Discussion

Ametryn was only moderately effective as a chemical harvest
aid on navy bean (Table l). The addition of ammonium phosphate,
ammonium thiocyanate, or ethephon only slightly increased the effi-
cacy of ametryn. Inclusion of a crop oil with ethephon plus ametryn
combination gave a significant increase in desiccation of navy bean.
Increasing the rate of crop oil application from 2.3 to 4.6 L/ha
applied solely with ametryn offered no greater efficacy than the 2.3
L/ha rate. The three-way combination of ammonium sulfate at 4.5 and
9.0 kg/ha and crop oil at 2.3 L/ha with ametryn markedly increased
desiccation of the navy bean plants and was the most effective
ametryn treatment (Table l). Averaged over all additive treatments,
the 1.1 kg/ha rate of ametryn application was not significantly

different from the 2.2 kg/ha rate.

In contrast, the efficacy of endothall averaged over all additive
treatments increased as the application rate increased from 0.6 kg/ha
to 1.0 kg/ha. The addition of crop oil concentrate to the spray
solution only slightly increased endothall efficacy (Table 2). All
of the additives except ammonium thiocyanate providely increased
endothall efficacy. Ammonium sulfate appeared to be slightly more
effective across a number of treatments than the other additives (Table

2).

l5

Averaged over all additive treatments, the 1.7 kg/ha rate of
dinoseb application was significantly more effective than the 0.8
kg/ha rate as a chemical harvest aid for navy bean. Hithout addi-
tives, dinoseb at both rates caused little or no desiccation of the
navy bean (Tables 4 and 5). The additives ranked as follows in
ascending order of effectiveness in increasing dinoseb activity:
ammonium phOSphate, ammonium sulfate, ammonium thiocyanate, and
ethephon. All were more effective than dinoseb plus only crop oil.
The three-way combination including crop oil was generally more
effective than the two-way combination of dinoseb plus ammonium salt

or ethephon (Table 3).

Examination of the three-way combination at specific rates of
dinoseb applications in combination with ethephon plus crop oil
provided no added advantage to the higher 1.7 kg/ha dinoseb appli-
cation rate (Table 4), whereas in the three-way combination of crop
oil plus ammonium sulfate plus dinoseb, increasing the dinoseb rate
from 0.8 kg/ha to 1.7 kg/ha also increased desiccation of navy bean

(Table 5).

Averaged over all additive treatments, the 1.1 kg/ha rate of
paraquat application was significantly more effective than the
0.6 kg/ha rate as a chemical harvest aid for navy bean. Ammonium
phoSphate, ammonium thiocyanate, and ethephon, applied at 4.5 and
9.0 kg/ha in combination with paraquat, failed to increase the
desiccation of navy bean plants by paraquat alone (Table 6). X-77

non-ionic surfactant, applied at 1.2 and 2.4 L/ha in combination

l6

with paraquat, significantly increased navy bean desiccation. How-
ever, there was no difference between the X-77 rates. Ammonium
sulfate applied at 4.5 and 9.0 kg/ha markedly increased efficacy of
paraquat over all other combinations. A triple combination of
ammonium sulfate at 4.5 and 9.0 kg/ha with 1.2 L/ha of X-77 and

paraquat reduced the ammonium sulfate enhancement (Table 6).

In the greenhouse study, increasing the paraquat rate from 0.6
to 1.1 kg/ha in combination with ammonium sulfate also increased

desiccation to the highest level observed in this study (Table 7).

In a field study to evaluate the results from the greenhouse
study under field conditions, dinoseb at 1.4 kg/ha proved to be
ineffective as a chemical harvest aid (Table 8). The addition of
X-77 to paraquat or crop oil to ametryn, dinoseb and endothall all
provided for greater desiccation than the herbicides alone. However,
the addition of ammonium sulfate to paraquat, ametryn, and dinoseb
provided much greater enhancement of desiccation than the X-77 or
crop oil (Table 8). This is exemplified in the reduction of the
percent moisture content of the navy bean pods from 47% in the control
to 28% by 0.6 kg/ha paraquat, 24% by 0.6 kg/ha paraquat plus X-77, to

13% by 0.6 kg/ha paraquat plus 9.0 kg/ha ammonium sulfate (Table 8).

Ammonium sulfate at 9.0 kg/ha in combination with paraquat at
0.6 k/gha, dinoseb at 1.4 kg/ha, endothall at 0.6 kg/ha and ametryn
at 1.1 kg/ha did not alter the percent germination compared to the
control. Ammonium sulfate at 9.0 kg/ha in combination with ametryn

at l.l kg/ha and endothall at 0.6 kg/ha resulted in a decrease in dry

17

weight of 100 seeds (Table 9). Ammonium sulfate at 9.0 kg/ha in
combination with paraquat at 0.6 kg/ha and dinoseb at 1.4 kg/ha did
not significantly affect seed dry weight (Table 9).

Turner and Loader (11) reported ammonium salts did not enhance
the activity of paraquat. However, their experiments were conducted

on guava (Psidium guajava L.), Poplar (Populus euroamericana L.) and

 

privet (Ligustrum ovalifolium L.). Bovey and Diaz-Colon (4) reported

 

that oil-soluble herbicides are more effective than paraquat on guava.

Ammonium salts have increased efficacy of many herbicides (ll).
Ammonium sulfate has particular advantages because of its low cost

and low mammalian toxicity.

In summary, paraquat at 0.6 or l.l kg/ha in combination with
ammonium sulfate at 9.0 kg/ha resulted in the most complete desic-
cation of navy bean plants. Field studies indicated that paraquat
at 0.6 kg/ha in combination with 9.0 kg/ha of ammonium sulfate had no

adverse effects on navy bean germination or seed dry weight.

10.

ll.

12.

18

Literature Cited

Anonymous. 1979. Herbicide to aid soybean dry down. Ag.
Chem. Age. Sept. - Oct. 32-33.

Ashton, F.M. and A.S. Crafts. 1973. Mode of action of
herbicides. John Wiley and Sons, Inc. 504 pp.

Assad, A.C. and F.E. Romans. 1979. Chemical harvest aid
assumes important role in six crops. Needs Today. Fall
1979:20-21.

Bovey, R.N. and J.D. Diaz-Colon. 1969. Effects of simu-
lated rainfall on herbicide performance. Need Sci. 17:154-157.

Ciderbank, A. 1969. The bipyridylim herbicides. Adv. in
Pest. Control Res. 8:127-235.

Chevron Chemical Company. Herbicide label for paraquat CL.

Donally, N.F. and S.K. Ries. 1964. Amitrol translocation
in Agropyron re ens increased by addition of ammonium
thiocyanate. SCTence 145-497-498.

Good, N.E. and Izawa. 1966. Uncoupling and energy transfer
inhibition in photophorylation. In current topics in Biogener.,
edited by Sandi, D.R., Vol. 1, ACEEEmic Press, New York.

292 pp.

Michigan Agriculture Statistics. 1978. Michigan Department
of Agriculture. 80 pp.

Suwanketnikom, R. 1978. Yellow nutsedge (Cyperus esculentus L.)
control with bentazon (3-isopropyl-lH-2,l,3-bensothiadiazin-4-(3H)-
one 2,2-dioxide) and glyphosate (N-(Ehosphonomethyl) glycine). .-
Ph.D. Dissertation, Michigan State University. 111 pp.

 

Turner, 0.0. and M.P.C. Loader. 1972. Some increases in
efficacy of foliage applied herbicidal salts due to addition
of ammonium ions. Proc. 11th Br. Need Control Conf. 654-660.

Need Science Society of America. 1979. Herbicide Handbook.
Champaign, IL 479 pp.

19

Table 1. Percent moisture content and visual injury of navy bean
plants following postemergence application of ametryn averaged
over rates of 0.0, 1.1, and 2.2 kg/ha applied with ammonium salts,

ethephon, or crop oil.

 

 

Additive Oil Visual Injury Moisture
Treatment Rate Rate Rating Content
(Additive) (kg/ha) (L/ha) (After 7 Days)a (%)
Control --- --- 0.0 ib 88 a
Ammonium 0 0 6.5 fgh 76 bcde
phosphate
4.5 0 7.5 de 75 cdef
9.0 0 7.0 efg 76 bcde
4.5 2.3 7.0 efg 74 def
9.0 2.3 6.5 fgh 76 bcde
Ammonium 0 0 6.5 fgh 76 bcde
sulfate
4.5 0 8.2 bcd 73 efg
9.0 0 8.8 bc 71 g
'4.5 2.3 9.8 a 66 h
9.0 2.3 9.8 a 66 h
Ammonium 0 0 6.5 fgh 76 bcde
thiocyanate
4.5 0 5.6 h 79 b
9.0 0 7.9 Cde 73 efg
4.5 2.3 6.4 gh 78 be
9.0 2.3 8.5 be 73 efg
Ethephon 0 0 6.5 fgh 76 bcde
4.5 0 7.2 efg 76 bcde
9.0 0 7.4 def 74 def
4.5 2.3 6.0 h 77 bcd
9.0 2.3 8.8 be 71 9
Crop 0 0 6.5 fgh 76 bcde
Oil 0 2.3 8.9 b 71 g
0 4.6 8.8 be 72 g

 

a Ratings were on a O to 10 scale; 0 = no injury, 10 = death.

b Means within colums for a given additive with similar letters are
not significantly different at the 1% level by Duncan's multiple
range test.

Table 2.

Percent moisture content and visual injury of navy bean

plants following postemergence application of endothall averaged

over rates of 0.0, 0.6, and 1.0 kg/ha applied with ammonium salts,

ethephon, or crop oil.

 

 

Additive Crop Oil Visual Injury Moisture
Treatment Rate Rate Rating Content
(Additive) (kg/ha) (L/ha) (After 7 Days)a (%)
Control --- --- 0.0 ib 82 a
Ammonium O 0 8.4 def 69 bcd
phosphate
4.5 0 9.8 ab 62 gh
9.0 O 7.8 egfh 70 bed
4.5 2.3 8.6 de 70 bcd
9.0 2.3 9.0 bcd 64 efg
Ammonium O 0 8.4 def 69 bcd
sulfate
4.5 0 8.9 cd 67 de
9.0 0 9.4 abc 64 efg
4.5 2.3 9.8 ab 66 cf
9.0 2.3 10.0 a 61 h
Ammonium 0 0 8.4 def 69 bed
thiocyanate
4.5 O 7.0 h 74 b
9.0 0 7.4 gh 72 bc
4.5 2.3 7.8 efgh 72 bc
9.0 2.3 8.9 cd 68 cde
Ethephon 0 O 8.4 def 69 bed
4.5 O 8.8 cd 66 ef
9.0 0 9.5 abc 64 efg
4.5 2.3 8.5 de 67 de
9.0 2.3 8.9 Cd 69 bcd
Crop 0 O 8.4 def 69 bcd
Oil 0 2.3 7.6 fgh 72 bc
0 4.6 7.5 gh 71 bc

 

a Ratings were 0 to 10 scale; 0 = no injury, 10 = death.

b Means within columns for a given additive with similar letters are not
significantly different at the 1% level by Duncan's multiple range

test.

21

Table 3. Percent moisture content and visual injury of navy bean
plants following postemergence application of dinoseb averaged
over rates of 0.0, 0.8, and 1.7 kg/ha applied with ammonium Salts,

ethephon, or crop oil.

 

Additive Crop Oil Visual Injury Moisture

 

Treatment Rate Rate Rating Content
(Additive) (kg/ha) ' (L/ha) (After 7 Days)a (%)
Control --- --- 0.0 jb 83 a
Ammonium 0 O 0.2 j 83 a
phosphate
4.5 O 5.5 i 77 c
9.0 0 7.4 ef 74 d
4.5 2.3 6.8 fg 74 d
9.0 2.3 7.5 ef 74 d
Ammonium O 0 0.2 j 83 a
sulfate
4.5 O 7.4 cf 74 d
9.0 O 5.8 hi 76 c
4.5 2.3 9.0 be 68 f
9.0 2.3 8.8 bc 69 e
Ammonium 0 O 0.2 j 83 a
thiocyanate
4.5 0 6.4 gh 76 c
9.0 O 8.9 bc 69 e
4.5 2.3 9.0 be 69 e
9.0 2.3 9.5 ab 65 h
Ethephon O 0 0.2 3 33 a
4.5 0 8.0 de 70 e
9.0 O 8.6 be 66 g
4.5 2.3 9.5 ab 66 g
9.0 2.3 10.0 a 62 i
Crop 0 O 0.2 j 83 a
Oil 0 2.3 5.5 i 78 b
O 4.6 5.2 i 79 b

 

a Ratings were on a O to 10 scale; 0 = no injury, 10 = death.

b Means within columns for a given additive with Similar letters are not
significantly different at the 1% level by Duncan's multiple range
test.

22

Table 4. Percent moisture content and visual injury of navy bean
plants following postemergence application of dinoseb with ethephon

or crop oil.

 

Dinoseb Ethephon Crop Oil Visual Injury Moisture
Rate Rate Rate Rating Content
(kg/ha) (kg/ha) (L/ha) (After 7 Days)a (%)

 

0.0 0.0 0.0 0.0 e 83 ab
0.0 4.5 0.0 2.0 d 80 be
0.0 9.0 0.0 2.5 d 79 c
0.0 0.0 2.3 0.0 e 84 a
0.0 0.0 4.6 0.0 e 84 a
0.8 0.0 0.0 0.5 e 82 ab
0.8 4.5 0.0 7.0 b 70 e
0.8 9.0 0.0 7.2 b 70 e
0.8 0.0 2.3 4.2 c 77 c
0.8 0.0 4.6 4.0 c 78 c
0.8 4.5 2.3 9.0 a 62 f
0.8 9.0 2.3 10.0 a 48 i
1.7 0.0 0.0 0.0 e 84 a
1.7 4.5 0.0 9.0 a 60 f
1.7 9.0 0.0 10.0 a 51 h
1.7 0.0 2.3 6.8 b 72 d
1.7 0.0 4.6 6.5 b 73 d
1.7 4.5 2.3 10.0 a 54 g
1.7 9.0 2.3 10.0 a 54 g

 

a Ratings were on a O to 10 scale; 0 = no injury, 10 = death.

b Means within columns for a given additive with similar letters are
not significantly different at the 1% level by Duncan's multiple
range test.

23

Table 5. Percent moisture content and visual injury of navy bean
plants following postemergence application of dinoseb with ammonium

sulfate or crop oil.

 

Dinoseb Ammonium sulfate Crop Oil Visual Injury Moisture
Rate Rate Rate Rating . Content
(kg/ha) (kg/ha) (L/ha) (After 7 Days)a (%)

 

0.0 0.0 0.0 0.0 hb 83 ab
0.0 4.5 0.0 0.0 h 84 a
0.0 9.0 0.0 0.0 h 85 a
0.0 0.0 2.3 0.0 h 84 a
0.0 0.0 4.6 0.0 h 84 a
0.8 0.0 0.0 0.5 h 82 bc
0.8 4.5 0.0 6.8 e 72 e
0.8 9.0 0.0 3.2 q 80 c
0.8 0.0 2.3 4.2 f 77 d
0.8 0.0 4.6 4.0 f 78 d
0.8 4.5 2.3 8.0 d 67 f
0.8 9.0 2.3 8.5 cd 64 g
1.7 0.0 0.0 0.0 h 84 a
1.7 4.5 0.0 8.0 d 66 f
1.7 9.0 0.0 9.0 bC 63 g
1.7 0.0 2.3 6.8 e 72 e
1.7 0.0 4.6 6.5 e 73 e
1.7 4.5 2.3 10.0 a 54 1
1.7 9.0 2.3 9.5 ab 60 h

 

a Ratings were on a O to 10 scale; 0 = no injury, 10 = death.

b Means within columns for a given additive with similar letters are
not significantly different at the 1% level by Duncan's multiple
range test.

24

Table 6. Percent moisture content and visual injury of navy bean
plants following postemergence application of paraquat averaged
over rates of 0.0, 0.6, and 1.1 kg/ha applied with ammonium salts,

ethephon, or crop oil.

 

Additive X-77 Visual Injury Moisture

 

Treatment Rate Rate Rating a Content
(Additive) (kg/ha) (L/ha) (After 7 Days) (%)
.6

Control --- --- 0.0 3 88 a
Ammonium O O 7.8 b 72 9
phosphate

4.5 O 3.8 ef 80 bcde

9.0 O 4.0 e 80 bcde

4.5 1.2 4.0 e 79 cde

9.0 1.2 2.0 hi 83 b
Ammonium O 0 7.8 b . 72 g
sulfate

4.5 O 9.2 a 66 h

9.0 0 ' 10.0 a 54 l

4.5 1.2 6.9 c 76 f

9.0 1.2 4.5 e 77 ef
Ammonium O 0 7.8 b 72 g
thiocyanate

4.5 0 6.5 cd 81 bcd

9.0 0 4.0 e 77 cf

4.5 1.2 6.2 cd 78 de

9.0 1.2 1.8 i 83 b
Ethephon O 0 7.8 b 72 g

4.5 0 6.9 c 76 f

9.0 0 5.8 d 77 ef

4.5 1.2 3.1 fg 82 be

9.0 1.2 2.8 gh 82 be
x-77 0 0 7.8 b 72 g

0 1.2 8.0 b 70 g
0 2.4 8.2 b 69 g

 

a Ratings were on a O to 10 scale; 0 = no injury, 10 = death.

b Means within columns for a given additive with similar letters are
not significantly different at the 1% level by Duncan's multiple
range test.

25

Table 7. Percent moisture content and visual injury of navy bean
plants following postemergence application of paraquat with ammonium

sulfate or X-77.

 

Paraquat Ammonium sulfate X-77 Visual Injury Moisture
Rate Rate Rate Rating a Content
(kg/ha) (kg/ha) (L/ha) (After 7 days) (%)

 

CT

0.0 0.0 0.0 0.0 i 88 a
0.0 4.5 0.0 0.0 i 87 a
0.0 9.0 0.0 0.0 i 87 a'
0.0 0.0 1.2 0.0 1 89 a
0.0 0.0 2.4 0.0 i 88 a
0.6 0.0 0.0 7.4 ef 68 cde
0.6 4.5 0.0 8.5 bc 58 fg
0.6 9.0 0.0 10.0 a 44 i
0.6 0.0 1.2 7.0 f 69 cd
0.6 0.0 2.4 7.5 ef 70 cd
0.6 4.5 1.2 6.0 g 74 C
0.6 9.0 1.2 1.0 h 82 b
1.1 0.0 0.0 8.2 cd 60 f
1.1 4.5 0.0 9.0 b 53 gh
1.1 ,9.0 0.0 10.0 a 33 j
1.1 0.0 1.2 9.0 b 50 h
1.1 0.0 2.4 9.0 b 51 h
1.1 4.5 1.2 7.8 de 67 de
1.1 9.0 1.2‘ 8.0 cde 62 cf

 

a Ratings were on a 0 to 10 scale; 0 = no injury, 10 = death.

b Means within columns for a given additive with similar letters are
not significantly different at the 1% level by Duncan's multiple
range test.

26

Table 8. Percent moisture content and visual injury of navy bean
pods and seeds following postemergence application of paraquat,
dinoseb, endothall, and ametryn with additives ammonium sulfate,

X-77, or crop oil.

 

 

Visual Injury Pod Seed
Rate Rating a Moisture Moisture
Treatment (kg/ha) (After 7 Days) (%) (%)
b
Control 0.0 0.5 f 47 ab 31 c
Paraquat 0.6 7.0 c 28 e 26 de
Paraquat + X-77 0.6 + 1.2 L/ha 8.5 b 24 f 20 gh
Paraquat + ammon-
ium sulfate 0.6 + 9.0 10.0 a 13 h 15 i
Dinoseb 1.4 , 2.5 e 45 b 35 b
Dinoseb + oil 1.4 + 2.3 L/ha 7.0 c 28 e 24 ef
Dinoseb + ammon-
ium sulfate 1.4 + 9.0 9.8 a 18 g 17 hi
Endothall 0.6 6.5 c 34 cd 31 c
Endothall + oil 0.6 + 2.3 L/ha 8.5 b 23 f 17 hi
Endothall + ammon-
ium sulfate 0.6 + 9.0 7.2 c 32 d 26 de
Ametryn 1.1 4.0 d 38 c 28 cd
Ametryn + oil 1.1 + 2.3 L/ha 4.5 d 35 Cd 24 ef
Ametryn + ammon-
ium sulfate 1.1 + 9.0 8.0 b 27 ef 22 fg
X-77 1.2 L/ha 0.5 f 49 a 40 a
Oil 2.3 L/ha 2.0 e 35 cd 28 cd
Ammonium sulfate 9.0 2.0 e 34 Cd 26 de

 

a Ratings were on a O to 10 scale; 0 = no injury, 10 = death.

b Means within columns with similar letters are not significantly
different at the 1% level by Duncan's multiple range test.

27

Table 9. Percent germination and seed dry weight of navy bean
plants following postemergence application of paraquat, dinoseb,

endothall, and ametryn with additives ammonium sulfate, X-77, or

 

 

crop oil.
Rate Germination Dry Height

Treatment (kg/ha) (%) (gm/100 seeds)
Control 0.0 ‘ 96 aa 18.6 ab
Paraquat 0.6 93 abc 16.6 d
Paraquat + X-77 0.6 + 1.2 L/ha 98 a 17.6 abc
Paraquat + ammonium

sulfate 0.6 + 9.0 96 a 17.5 abc
Dinoseb 1.4 88 c 17.8 abc
Dinoseb + oil 1.4 + 2.3 L/ha 90 be 17.7 abc
Dinoseb + ammoniun

sulfate 1.4 + 9.0 94 abc 19.2 a
Endothall 0.6 92 abc 17.3 bc
Endothall + oil 0.6 + 2.3 L/ha 93 abc 17.0 cd
Endothall + ammonium

sulfate 0.6 + 9.0 95 ab 17.4 bc
Ametryn 1.1 90 bc 18.5 ab
Ametryn + oil 1.1 + 2.3 L/ha 94 abc 17.8 abc
Ametryn + ammonium

sulfate 1.1 + 9.0 96 a 17.0 cd
X-77 1.2 L/ha 92 abc 18.8 a
Oil 2.3 L/ha 95 ab 18.4 ab
Ammonium sulfate 9.0 96 a 18.3 ab

 

a Means within columns with similar letters are not significantly
different at the 1% level by Duncan's multiple range test.

Chapter 3
The Use of Additives to Increase Efficacy of

Dinoseb for Potato (Solanum tuberosum) Vine Desiccation

Abstract
In Michigan, chemical vine desiccation is an important

management practice for late season potatoes (Solanum tuberosum L.).
A number of chemicals are registered, however, approximately 67%

of the growers apply dinoseb (Z-sggfbutyl-4,6-dinitrophenol) (4).
Greenhouse and field experiments were initiated to evaluate the
potential of ammonium salts and ethephon ((2-chloroethy1) phosphonic
acid) to increase the efficacy of chemical harvest aids on potato

vines.

Dinoseb and endothall (7-oxabicyclo(2,2,l)heptane-2,3-
diacarboxylic acid) were evaluated in combination with additives.
All treatments with endothall applied at 0.6 kg/ha resulted in
unsatisfactory desiccation to potato vines in the greenhouse.
Ethephon and ammonium sulfate increased efficacy of dinoseb in
greenhouse and field studies. The combination of ammonium sulfate
at 9 kg/ha plus 2.3 L/ha of crop oil plus 1.4 kg/ha dinoseb gave
equivalent potato vine kill to 2.8 kg/ha dinoseb plus 2.3 L/ha crop
oil.

Introduction

 

Chemical potato vine killing has developed as an essential

commercial practice for long season variety potatoes. It is

28

29

practiced mainly for five reasons: a) to reduce the spread of
virus diseases in seed potato fields, b) to control late blight
tuber rot, c) to allow harvesting the crop before freezing
weather, d) to control tuber size, e) to improve skin maturity
(2,3). In Michigan, a number of chemicals are registered for
potato vine desiccation, however, apporximately 67% of the growers

apply dinoseb (4).

Phytobland oils and organic surfactants are commonly used as
spray additives for chemical harvest aid contact herbicides.
With cultivars such as 'Sebago', however, potato vine killing often

requires a split application.

Inorganic salts as additives have been shown to increase
efficacy of herbicides, such as bentazon (3-i50pr0pyl-lfl:2,l,3
benzothiadiazin-(4)-3fl;one 2,2 dioxide) and glyphosate (N-(phos-
phonomethyl) glycine) for yellow nutsedge (Cyperus esculentus L.)
control (6). Ammonium sulfate has increased efficacy of dinitro

phenol herbicide, DNOC (4,6-dinitro-97cresol), and endothall (1.5).

The objective of this research was to evaluate potential
ammonium salts and ethephon as additives to increase efficacy of

dinoseb and endothall for potato vine killing.

Materials and Methods

 

'Superior' potatoes were grown in the greenhouse at 25 :_2c with-

out supplemental fluorescent 1ighting.. Potato seed pieces were

planted in 946-ml cups. After germination, vines were thinned to
two stalks per cup. New growth was continuously cut to keep only
two vines per pot. The potato plants were watered daily with 20-20-
20 (N-P-K) Peters fertilizer solution at 100 ppm to insure vigorous
vine growth. Careful watering prevented nutrient solution from
coming in contact with foliage. Potato vines were grown to 20 cm

tall prior to treatment.

Dinoseb at 0.8 and 1.7 kg/ha and endothall at 0.6 kg/ha were
applied to vigorous 20 cm tall vines. All herbicide concentrations
were applied at a rate of 347 L/ha. Crop oil 'Herbimax' was applied
in combination with herbicides at 2.3 and 4.6 L/ha. Ethephon and all
ammonium salts were applied in combination with herbicides at 4.5 and
9.0 kg/ha. Ten days after herbicide treatments, potato vines were
rated for visual injury; fresh weight and dry weights were determined.
The data presented are the means of two experiments with four repli-

cations per experiment.

To evaluate greenhouse results under field conditions, experimental
treatments in the field were applied to 'Sebago' potato vines at Mayne
Gruesbeck's farm in Eaton Rapids, Michigan. Potatoes were planted
May 14, 1979. Plots were three rows 86.4 cm wide and 4.6 m long with
a tuber spacing of 17.8 cm. A randomized complete block design with
four replications was used. Treatments were applied with handheld 002

pressurized sprayer applying 254 L/ha at 2.8 kg/cmz.

Dinoseb was applied at 1.4, 2.8, and 5.6 kg/ha to vigorous growing

vines on September 24, 1979. Ammonium sulfate was applied at 9.0 kg/ha.

31

Crop oil was applied at 2.3 L/ha. Ten days after application, vines
were rated for visual injury. The center row of each plot was
harvested by hand. Tuber skinning and vascular discoloration were
recorded from 25 randomly sampled tubers of each replication. Tuber
discoloration data was determined by cutting 25 tubers, once at

harvest and again 30 days after harvest.

To evaluate greenhouse results under field conditions, experi-
mental treatments in the field were applied to 'Monona' potato vines
at the Montcalm Experimental Farm in Entrican, Michigan. Potatoes
were planted May 16, 1979. Plot size was three rows 86.4 cm wide,
4.6 m long and a 25.4 cm tuber spacing. Each plot was arranged in
randomized complete block design with four replications. Treatments

were applied with a handheld sprayer applying 254 L/ha at 2.1 kg/cmz.

Dinoseb was applied at 1.4 kg/ha to vigorous growing vines on
August 13, 1979. Ammonium sulfate and ethephon were applied at 9.0
kg/ha. Crop oil was applied at 2.3 L/ha. Ten days after application,
August 23, 1979, visual injury ratings were taken. Potatoes were
harvested August 24, 1979, by a one-row mechanical harvester developed
at Michigan State University. “The center row of each plot was
harvested. Specific gravity, tuber skinning, and tuber discoloration
were recorded from random samples of tubers. Tuber discoloration
data represents averages of two separate cuttings of 25 tubers, one

at harvest and one 30 days after harvest.

32

Results and Discussion

 

In the greenhouse, endothall at 0.6 kg/ha was not an effective
desiccant on 'Superior' potato vines (Table 1). Ammonium phosphate,
ammonium thiocyanate, and crop oil in combination with endothall
did not satisfactorily increase desiccation of potato vines (Table
l). Ammonium sulfate applied at 9.0 kg/ha without added crop oil
increased efficacy of endothall to some degree. Ethephon at 4.5
kg/ha plus crop oil at 2.3 L/ha caused the greatest increase in

efficacy of endothall, however, desiccation was still poor.

Dinoseb at 1.7 kg/ha evaluated over all additive treatments
significantly increased potato vine desiccation more than 0.8 kg/ha
rate. Ammonium phosphate or ammonium thiocyanate alone or plus
crop oil in combination with dinoseb resulted in a moderate increase
in desiccation to potato vines compared to dinoseb alone (Table 2).
Ethephon or ammonium sulfate at 4.5 and 9.0 kg/ha in combination with
crop oil at 2.3 L/ha markedly increased the efficacy of dinoseb
(Table 2).

Examination of several rates of dinoseb application as shown in
Table 3 indicated that crop oil at 2.3 and 4.6 L/ha enhanced the
activity of dinoseb at 1.7 kg/ha. Ethephon at 9.0 kg/ha markedly
increased efficacy of dinoseb at both 0.8 and 1.7 kg/ha. Maximum
desiccation to potato vines resulted when ethephon at 9.0 kg/ha and

crop oil at 2.3 L/ha were combined with dinoseb at 0.8 and 1.7 kg/ha.

33

Ammonium sulfate at 9.0 kg/ha resulted in enhancement of
dinoseb efficacy at 1.7 kg/ha (Table 4). Ammonium sulfate at 9.0
kg/ha in combination with crop oil at 2.3 L/ha markedly increased
efficacy of dinoseb at both 0.8 and 1.7 kg/ha.

Similarly in field studies as shown in Table 5, the addition of
9.0 kg/ha of ammonium sulfate to dinoseb plus crop oil at 2.3 L/ha
increased the efficacy of dinoseb at 1.4 kg/ha rate to that observed
at the 2.8 kg/ha rate plus crop oil without ammonium sulfate. Dinoseb
alone at 1.4 and 2.8 kg/ha resulted in unsatisfactory vine desiccation
of 'Sebago' potatoes. Crop oil at 2.3 L/ha increased efficacy of
dinoseb at 2.8 kg/ha. The three-way combination of ammonium sulfate
at 9.0 kg/ha, crop oil at 2.3 L/ha and dinoseb at 1.4 and 2.8 kg/ha
resulted in no tuber skinning or tuber discoloration. Ammonium sulfate
at 9.0 kg/ha, crop oil at 2.3 L/ha in combination with dinoseb at 5.6
kg/ha completely desiccated potato vines, however, some tuber discolora-

tion resulted.

In another field study, dinoseb alone at 1.4 kg/ha resulted in
inadequate vine kill of 'Monona' potatoes (Table 6). Crop oil at 2.3
L/ha did not increase dinoseb efficacy at 1.4 kg/ha. Ammonium sulfate
at 9.0 kg/ha plus crop oil at 2.34 L/ha markedly increased efficacy
of dinoseb at 1.4 kg/ha without detrimental tuber skinning or tuber
discoloration (Table 6). Combinations of ethephon at 9.0 kg/ha plus
crop oil at 2.3 L/ha with dinoseb at 1.4 kg/ha also resulted in
markedly enhancement of dinoseb activity. However, this three-way Com-

bination resulted in tuber skinning, thus reducing tuber quality.

34

In this study, ammonium sulfate showed greatest potential as an
additive to increase efficacy of dinoseb. Greenhouse and field
studies indicate a three-way combination of ammonium sulfate plus
crop oil plus dinoseb can increase desiccation to potato vines
without detrimental effects on tuber quality. The combination of
9.0 kg/ha ammonium sulfate plus crop oil at 2.3 L/ha plus 1.4 kg/ha
dinoseb gave equivalent potato vine kill on 'Sebago' to 2.8 kg/ha
dinoseb plus 2.3 L/ha crop oil.

35

Literature Cited

 

Blackman, G.E., K. Holly, and H.H. Roberts. 1949. The
comparative toxicity of phytocidal substances. Symp. Soc.
Exp. Biol. 3:283-317.

Bonde, R. and E.S. Schultz. 1945. The control of potato
late-blight tuber rot. Am. Potato J. 22:163-167.

Schultz, E.S. and R. Bonde, and N.P. Raleigh. 1944. Early
harvesting of healthy seed potatoes for control of potato
disease in Maine. Maine Agr. Exp. Sta. Bull. 427.

Schultz, G.E., P. Rzewnicki, and D. Penner. 1979. Computer-
ization of herbicide use surveys. Need Sci. Soc. of Amer.
Abstract 285:133.

Simon, E.N. 1953. Mechanisms of dinitrOphenol toxicity. Biol.
Rev. 28, 453-479.

Suwanketnikom, R. 1978. Yellow nutsedge (Cyperus esculentus L.)
control with bentazon (3-isopropyl-1Hf2,1,3 benzothiadiazin-(4)-
3H-one 2,2-dioxide) and glyphosate (N-(phosphonomethyl) glycine).
PHID. Dissertation, Michigan State University. 111 pp.

 

36

Table 1. Percent shoot moisture content and visual injury of 20 cm
tall 'Superior' potato vines averaged over rates of 0.0 and 0.6 kg/ha
postemergence application of endothall with ammonium salts, ethephon

and crop oil.

 

 

Additive Crop Oil Visual Injury Shoot b
Treatment Rate Rate Ratinga Moisture Content
(Additive) (kg/ha) (L/ha) (After 10 Days) (%)
Control --- --- 0.0 f 91 ab
Ammonium 0 0 0.0 f 91 ab
phosphate 4.5 0 0.0 f 91 ab
9.0 0 4.0 c 88 bc
4.5 2.3 0.0 f 91 ab
9.0 2.3 4.0 c 88 bc
Ammonium O 0 0.0 f 91 ab
sulfate 4.5 0 2.0 e 90 ab
9.0 0 5.0 b 88 bc
4.5 2.3 0.0 f 91 ab
9.0 2.3 0.0 f 90 ab
Ammonium O 0 0.0 f 91 ab
thiocyanate 4.5 0 0.0 f 92 a
9.0 O 5.5 b 89 ab
4.5 2.3 0.0 f 91 ab
9.0 2.3 3.0 d 89 ab
Ethephon O 0 0.0 f 91 ab
4.5 O 5.8 b 88 bc
9.0 O 2.0 e 91 ab
4.5 2.3 7.5 a 86 c
9.0 2.3 4.2 c 89 ab
Crop 0 0 0.0 f 91 ab
Oil 0 2.3 0.5 f 90 ab
0 4.6 0.5 f 91 ab

 

a Ratings were on a 0 to 10 scale; 0 = no injury, 10 = death.

b Means within columns with similar letters are not significantly
different at the 1% level by Duncan's multiple range test.

37

Table 2. Percent shoot moisture content and visual injury of 20 cm
tall 'Superior' potato vines averaged over rates of 0.0, 0.8 and 1.7
kg/ha postemergence applications of dinoseb with ammonium salts,

ethephon, and crop oil.

 

 

Additive Crop Oil Visual Injury Shoot
Treatment Rate Rate Ratinga Moisture Content
(Additive) (kg/ha) (L/ha) (After 10 Days) (%)
Control --- --- 0.0 i 90 a
Ammonium 0 0 2.0 h 88 a
phosphate 4.5 0 5.8 bf 82 b
9.0 O 6.2 ef 80 bc
4.5 2.3 6.8 cde 78 de
9.0 2.3 9.2 a 68 g
Ammonium 0 O 2.0 h 88 a
sulfate 4.5 0 5.8 f 82 b
9.0 O 7.6 bc 76 cf
4.5 2.3 9.4 a 59 h
9.0 2.3 10.0 a 45 1
Ammonium O O 2.0 h 88 a
thiocyanate 4.5 O 5.8 f 82 b
9.0 0 7.8 b 74 f
4.5 2.3 6.4 def 79 cd
9.0 2.3 6.6 def 79 cd
Ethephon O O 2.0 h 88 a
4.5 0 7.2 bcd 76 ef
9.0 0 9.4 a 67 g
4.5 2.3 9.5 a 57 h
9.0 2.3 10.0 a 44 i
Crop O 0 2.0 h 88 a
Oil 0 2.3 4.5 g 82 b
0 4.6 4.0 g 82 b

 

a Ratings were on a 0 to 10 scale; 0 = no injury, 10 = death.

b Means within columns with similar letters are not significantly
different at the 1% level by Duncan's multiple range test.

38

Table 3. Percent shoot moisture content and visual injury of 20 cm
tall 'Superior' potato vines treated with postemergence application

of dinoseb with ethephon and crop oil.

 

 

Dinoseb Ethephon Concentrated Visual Injury Shoot

Rate Rate oil Ratinga Moisture Content

(kg/ha) (kg/ha) (L/ha) (After 10 Days) (%)
0.0 0.0 0.0 0.0 1 90 a
0.0 4.5 0.0 0.0 l 89 a
0.0 9.0 0.0 0.0 i 91 a
0.0 0.0 2.3 0.0 1 89 a
0.0 0.0 4.6 0.0 l 89 a
0.8 0.0 0.0 0.0 l 90 a
0.8 4.5 0.0 6.0 f 76 c
0.8 9.0 0.0 9.2 bc 57 ef
0.8 0.0 2.3 1.0 h 88 ab
0.8 0.0 4.6 0.0 1 89 a
0.8 4.5 2.3 9.0 C 60 e
0.8 9.0 2.3 10.0 a 22 g
1.7 0.0 0.0 4.0 g 84 b
1.7 4.5 0.0 8.5 d 65 d
1.7 9.0 0.0 9.5 b 54 f
1.7 0.0 2.3 8.0 e 67 d
1.7 0.0 4.6 8.0 e 68 d
1.7 4.5 2.3 10.0 a 22 g
1.7 9.0 2.3 10.0 a 21 g

 

fl

Ratings were on a O to 10 scale; 0 = no injury, 10 = death.

Means within columns with similar letters are not significantly
different at the 1% level by Duncan's multiple range test.

39

Table 4. Percent shoot moisture content and visual injury of 20 cm
tall 'Superior' potato vines treated with postemergence application

of dinoseb with ammonium sulfate and crop oil.

 

Dinoseb Ammonium sulfate Concentrated Visual Injury Shoot.
Rate Rate oil Ratinga Moisture Content
(kg/ha) (kg/ha) (L/ha) (After 10 Days) (%)

 

0.0 0.0 0.0 0.0 g 90 a
0.0 4.5 0.0 0.0 g 90 a
0.0 9.0 0.0 0.0 g 90 a
0.0 0.0 2.3 0.0 g 89 a
0.0 0.0 4.6 0.0 g 89 a
0.8 0.0 0.0 0.0 g 90 a
0.8 4.5 0.0 4.2 e 84 ab
0.8 9.0 0.0 6.5 d 74 c
0.8 0.0 2.3 1.0 f 88 ab
0.8 0.0 4.6 0.0 g 89 a
0.8 4.5 2.3 8.8 b 62 e
0.8 9.0 2.3 10.0 a 22 f
1.7 0.0 0.0 4.0 e 84 ab
1.7 4.5 0.0 7.5 c 70 d
1.7 9.0 0.0 8.8 b 62 e
1.7 0.0 2.3 8.0 c 67 d
1.7 0.0 4.6 8.0 c 68 d
1.7 4.5 2.3 10.0 a 26 f
1.7 9.0 2.3 10.0 a 22 f

 

Ratings were on a 0 to 10 scale; 0 = no injury, 10 = death.

Means within columns with similar letters are not significantly
different at the 1% level by Duncan's multiple range test.

40

Table 5. Visual injury and tuber quality evaluated in the field when
'Sebago' potato vines were treated with postemergence applications of

different rates of dinoseb with ammonium sulfate and crop oil.

 

 

Dinoseb Ammonium sulfate Crop Visual Injury Tuber Tuber
Rate Rate oil Ratinga Skinning Discoloration
(kg/ha) (kg/ha) (L/ha) (After 10 Days) (25 tubers) (25 tubers)
0.0 0.0 0.0 2.2 hb 1.0c 0.0d
0.0 9.0 0.0 4.3 g 0.0 0.0
1.4 0.0 0.0 6.0 f 0.0 0.0
1.4 0.0 2.3 7.0 e 0.0 0.0
1.4 9.0 0.0 7.2 e 0.0 0.0
1.4 9.0 2.3 9.0 be 0.0 0.0
2.8 0.0 0.0 8.0 d 0.0 0.0
2.8 0.0 2.3 9.0 bc 9.0 0.0
2.8 9.0 0.0 8.8 c 0.0 0.0
2.8 9.0 2.3 9.0 bc 0.0 0.0
5.6 0.0 0.0 9.0 be 0.0 0.2
5.6 0.0 2.3 9.5 ab 0.0 0.4
5.6 9.0 0.0 9.5 ab 0.0 0.3
5.6 9.0 2.3 10.0 a 0.0 0.4

 

Ratings were on a 0 to 10 scale; 0 = no injury, 10 = death.

Means within column with similar letters are not signifantly different
at the 1% level by Duncan's multiple range test.

Ratings were on a 0 to 3 scale; 0 no skinning, l = low skinning,

2 = moderate, 3 severe.

d Ratings were on a 0 to 3 SCale; O = no discoloration, 1 = low,
2 - moderate, 3 severe..

41

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Chapter 4

Summary and Conclusion

Greenhouse and field experiments were conducted to evaluate
ametryn, dinoseb, endothall, and paraquat as potential chemical
harvest aids for navy bean. Dinoseb alone caused little or no
desiccation. Ametryn, endothall, and paraquat individually showed

moderate desiccation.

The inclusion of additives to herbicide sprays increased their
efficacy. The three-way combination of ammonium sulfate at 4.5 or
9.0 kg/ha and crop oil at 2.3 L/ha with ametryn markedly increased
desiccation of navy bean plants and was the most effective ametryn
treatment. All of the additives except ammonium thiocyanate pro-
vided increased endothall efficacy on navy bean plants. The three-
way combinations of dinoseb or ethephon plus ammonium salts plus
crop oil were generally more effective than the two-way combinations.
Ammonium sulfate applied at 4.5 and 9.0 kg/ha markedly increased
efficacy of paraquat. Paraquat applied at 1.1 kg/ha in combination
with ammonium sulfate provided the greatest navy bean desiccation.
Field studies indicate paraquat at 0.6 kg/ha in combination with 9.0
kg/ha or ammonium sulfate had no adverse effects on navy bean ger-

mination or seed dry weight.

Greenhouse and field experiments were conducted to evaluate
ammonium salts and ethephon as additives to increase efficacy of

dinoseb and endothall for potato vine killing. In the greenhouse

42

43

ethephon at 9.0 kg/ha plus crop oil at 2.3 L/ha was the most
effective of the ethephon treatments, however, desiccation was
still poor. Ethephon or ammonium sulfate at 4.5 and 9.0 kg/ha plus
crop oil at 2.3 L/ha markedly increased the efficacy of dinoseb for’
'Superior' potato vines. In the field, ethephon at 9.0 kg/ha, plus
crop oil at 2.3 L/ha in combination with dinoseb at 1.4 kg/ha en-
hanced herbicide activity on 'Monona' potato vines. However, this
three-way combination resulted in tuber quality damage, ammonium
sulfate at 9.0 kg/ha plus 2.3 L/ha of crop oil enhanced efficacy

of dinoseb at 1.4 kg/ha for 'Monona' and 'Sebago' potato vines.

These studies indicate the three-way combination of ammonium-
sulfate plus crop oil plus dinoseb can increase desiccation of
potato vines without detrimental effects on tuber quality. The
combination of 9.0 kg/ha ammonium sulfate plus crop oil at 2.3 L/ha
plus 1.4 kg/ha dinoseb gave equivalent potato vine kill for 'Sebago'

to 2.8 kg/ha dinoseb plus 2.3 L/ha crop oil.

The study indicates that the combination of ammonium sulfate
plus paraquat can be effectively used as a chemical harvest aid for
navy bean. The three-way combination of ammonium sulfate, plus crop
oil, plus dinoseb allow use of lower dinoseb rates for potato vine

desiccation.

LIST OF REFERENCES

10.

11.

12.

13.

14.

15.

44

Adams, M.N. 1979. Erect-type bean varieties where are we?
Unpublished data.

Addicott, Fredrick 1., and Ruth Stocking Lynch. 1957. De-
foliation and desiccation: Harvest aid practices. Advances
in Agronomy. IX: 68-93.

Anonymous. 1979. Herbicide to aid soybean dry down. Agri-
chemical Age: Sept.-0ct. 32-33.

Ashton, F.M. and A.S. Crafts. 1973. Mode of action of herb-
icides. John Wiley and Sons, Inc. 504 pp.

Assad, A.C. and E. Romans. 1979. Chemical harvest aid assumes
important role in six cr0ps. Needs Today: Fall 20-21.

Austin, Richard. 1980. Agriculture Agent, Shiawassee County,
Michigan. Personal communications.

Barnes, E.E. 1945. Soybean Dig. 5 (9), 8.

Brinkley, A.M. and R. Kinkel. 1949. The effect of chemical vine
killers on yield and quality of red McClure and bliss triumph
potatoes. Am. Potato J. 25:371-376.

Binning, L.K., D. Penner, and N.F. Meggitt. 1971. The effect
of 2-chloroethyl phosphonic acid on dicamba translocation in
wild garlic. Need Sc. 19:73-75.

Blair, A.M. 1975. The addition of ammonium salts or a phOSphate
ester to herbicides to control Agropyron repens. Need Res.
15:101-105.

 

Boyer, P., B. Beese, and R. Miller. 1977. Long-term effects
of herbicides on the photosynthetic apparatus: An investigation
on bentazon inhibition. Need Res. 17:61-67.

Bonde, R. and E.S. Schultz. 1945. The control of potato late-
blight tuber rot. Am. Potato J. 22:164-167.

Byg, D.M. and E.N. Stroube, K.T. Kmetz, and R.C. Belt. 1976.
Effect of induced field drying on soybean seed quality. Am.
Soc. Agric. Eng. Annu. Meet. Paper No. 76-1554.

Claderbank, A. 1968. The bipyridylim herbicides. Adv. in Pest
Control Res. 8:127-235.

Callbeck, R.C. 1948. Current results with potato vine killers
in Prince Edward Island. Am. Potato J. 25:225-233.

16.

17.

18.

19.

20.
21.

22.

23.

24.

25.
26.

27.

28.

29.

30.

31.

45

Cunningham, C.E., P.J. Eastman, and Michael Goven. 1952.
Potato vine killing methods as related to rate of kill. vas-
cular discoloration, and virus disease spread. Am. Potato J.
29:8-16.

Donally, N.E. and S.K. Ries. 1964. Amitrole translocation in
Agropyron re ens increased by the addition of ammonium thio-
cyanate. Science. 145:497-498.

Folsom, 0., and A.E. Rich. 1940. Potato tuber net-necrosis
and stem-end borwning studies in Maine. Phytopath. 30:313-332.

Good, N.E. and Izawa. 1966. Uncoupling and energy transfer
inhibition in photophorylation. In Current Topics in Bioener-
getics. Edited by Sanadi, P.R.J., Vol. 1, Academic Press,

New York, 292 pp.

Hinkle, D.A. 1953. Southern Heed Conf. Proc. 6:72.

Hoyman, N.G. 1948. Potato vine killers (Abstract) Am. Potato
J. 25:52. '

Jones, L.G. 1954., Chemicals for pre-harvest drying or
spray-curing. Calif. Agr. Exp. Sta. Circ. 423.

Kendrick, J.B., Jr., and J.E. Swift. 1972. Defoliation and
other harvest aid practices. Univ. of California. 34 pp.

Michigan Agriculture Statistics. 1978. Michigan Dept. of
Agriculture. 80 pp.

Murphy, P.A. 1921. Can. Dept. Agr. Bull. 44.

Prince, A.E. 1948. Potato top killing. Maine Agr. Exp. Sta.
Bull. 460:36-37.

Schultz, E.S. and D. Folsom. 1920. Transmission of mosaic
disease of Irish potatoes. J. Agr. Res. 19:315-337.

Schultz, C.E., P. Rzenwnicki, and D. Penner. 1979. Computer-
ization of herbicide use surveys. Heed Science Society of
Am. (Abstract). 285:133.

Simon, E.N. 1953. Mechanisms of dinitrophenol toxicity.
Biol. Rev. 28:453-479.

Skogley, C.R. 1953. Results with various chemicals for potato
vine killing. Am. Potato J. 30:140-142.

Steinbauer, G.P. 1946. Potato vine killing. Maine Agr. Exp.
Sta. Mimeo Report.

32.

33.

34.

35.

36.

37.

38.

39.

46

Sumunnamek, U. and C. Parker. 1975. Control of Cyperus rotundus
with glyphosate: The influence of ammonium sulfate and’other
additives. Need Res. 15:13-19.

 

 

Suwanketnikom, R. 1978. Yellow nutsedge (C erus esculentus L.)
control with bentazon (3- isopropyl- 1H- 2, l ,B—Eensot TadTazin-(4)-
3H-one 2, 2- dioxide) and glyphosate (NlphOSphonomethyl) glycine).
PR'.D Dissertation, Michigan State University.

Tharp, N.H. 1956. Summary of harvest aid chemical use on
cotton. U.S. Dept. of Agr.

Need Science Society of America. 1979. Herbicide Handbook.
Champaign, 111. 479 pp.

Neissman, 0.5. 1972. Influence of ammonium and nitrate nutrition
on enzematic activity; Plant Physiol. 49:138-141.

Nerner, H.0. and J.0. Putt. 1941. Reduction of cracking of
late crop potatoes at harvest time by root cutting or vine
killing. Am. Potato J. 18:189-208.

Whigham, D.K. and E.N. Stoller. 1979. Soybean desiccation
by paraquat, glyphosate, and ametryn to accelerate harvest.
Agrom. J. 71:630-633.

Wilson, B.J. and R.K. Nishimoto. 1975. Ammonium sulfate
enhancement or picloram activity and absorption. Need Sci.
22:289-296.

APPENDIX

47

Table A-1. Percent moisture content and visual injury of navy bean plants following
postemergence application of ametryn with ammonium salts, ethephon and

 

 

 

 

crop oil.
AmmoniumTSans
Ametryn PhOSphate Sulfate Thiocyanate Ethephon Crop Oil Visual Injury Moisture
Rate Rate Rate Rate Rate Rate Rating Content
(kg/ha) (kg/ha) (kg/ha) (kg/ha) (kg/ha) (L/ha) (After 10 Days)a (%)
o o o o o o 0.0 hb 88 a
0 4.5 O 0 0 O 0.0 h 88 a
0 9.0 O 0 O O 0.0 h 87 ab
0 O 4.5 O 0 0 0.0 h ‘ 87 ab
0 O 9.0 0 O 0 0.0 h 88 a
0 0 O 4.5 0 0 0.0 h 88 a
0 0 0 9.0 0 0 0.5 h 86 ab
0 0 0 0 4.5 O 0.5 h 86 ab
0 0 O 0 9.0 O 1.0 h 82 be
0 O 0 0 0 2.3 0.0 h 89 a
0 O O O 0 4.6 0.0 h 89 a
1.1 0 O O 0 0 8.2 cd 65 jklm
2.2 0 0 0 O O 4.8 g 76 de
1.1 4.5 0 0 0 0 8.0 cde 66 ijklm
1.1 9.0 0 0 O 0 7.2 def 71 efghi
2.2 4.5 0 0 O O 7.0 ef 71 efghi
2.2 9.0 O O O O 6.8 cf 72 efgh
1.1 O 4.5 0 0 0 8.5 bc 64 jklm
1.1 0 9.0 0 0 0 9.2 abc 62 1mno
2.2 0 4.5 O O 0 8.0 cde 69 ghij
2.2 0 9.0 O 0 0 8.5 bc 65 jklm
1.1 0 0 4.5 0 O 4.0 a 78 cd
1.1 O 0 9.0 0 0 8.8 abc 63 klmn
2.2 O O 4.5 O O 7.2 def 7O fghi
2.2 O 0 9.0 0 O 7.0 cf 71 efghi
1.1 0 0 4 0 4.5 0 8.0 cde 69 ghij
1.1 O O 0 9.0 O 6.9 of 72 efgh
2.2 0 0 0 4.5 O 6.5 f 73 defg
2.2 O 0 O 9.0 0 8.0 cde 67 hijkl
1.1 O O 0 0 2.3 9.0 abc 62 1mno
1.1 0 0 O O 4.6 8.8 abc 63 klmn
2.2 0 O O 0 2.3 8.8 abc 64 jklm
2.2 O 0, 0 0 4.6 8.8 abc 63 klmn
1.1 4.5 0 O O 2.3 5.0 g 75 def
1.1 9.0 0 O O 2.3 4.0 g 78 cd
2.2 4.5 O 0 0 2.3 9.0 abc 61 mno
2.2 9.0 O 0 0 2.3 9.0 abc 63 klmn
1.1 0 4.5 O O 2.3 9.5 ab 57 pq
1.1 O 9.0 0 0 2.3 9.5 ab 58 nop
2.2 0 4.5 O 0 2.3 10.0 a 54 O
2.2 0 9.0 0 0 2.3 10.0 a 54 O
1.1 O O 4.5 0 2.3 4.2 g 78 cd
1.1 0 0 9.0 O 2.3 8.0 cde 69 hij
2.2 O 0 4.5 0 2.3 8.5 be 68 hijk
2.2 0 O 9.0 0 2.3 9.0 abc 63 klmn
1.1 0 0 0 4.5 2.3 4.0 g 76 de
1.1 0 0 0 9.0 2.3 9.0 abc 61 mno
2.2 0 O O 4.5 2.3 8.0 cde 68 ghijk
2.2 0 0 0 9.0 2.3 8.5 bc 66 ijklm
a

Ratings were on a 0 to 10 scale; 0 I no injury, 10 . death.

Means within columns with similar letters are not significantly different at the 1%
level by Duncan's multiple range test.

48

Table A-2. Percent moisture content and visual injury of navy bean plants following.
postemergence application of endothall with ammonium salts, ethephon and

crop oil.
’AmmonTfim SaTts

 

 

Endothall Phosghate Sulfate ThiocyanateT'Ethephon Crop Oil Visual Injury Moisture

Rate Rate Rate Rate Rate Rate Rating Content
(kg/ha) (kg/ha) (kg/ha) (kg/ha) (kg/ha) (L/ha) (After 7 Days)a (%)

o o o o o o 0.0 hb 82 a

O 4.5 O 0 0 O 0.0 h 82 a

0 9.0 O 0 0 0 0.0 h 83 a

O 0 4.5 0 0 0 0.0 h 81 ab

0 0 9.0 0 O 0 0.0 h 83 a

0 O 0 4.5 0 O 0.0 h 84 a

O 0 O 9.0 0 O 0.0 h 84 a

O 0 O 0 4.5 O 0.0 h 82 a

0 0 0 0 9.0 O 0.0 h 84 a

O O O O O 2.3 0.0 h 83 a

O 0 O O O 4.6 , 0.0 h 83 a
0.6 O O O O 0 ' 8.0 cdef 64 fgh
1.0 0 O O 0 O 8.8 abcde 60 hi
0.6 4.5 0 0 O 0 9.5 ab 58 ij
0.6 9.0 O 0 O O 6.5 fa 70 cde
1.0 4.5 O 0 O O 10.0 a 47 no
1.0 9.0 0 0 0 O 9.2 abc 57 j
0.6 O 4.5 O 0 0 8.8 abcde 62 gh
0.6 O 9.0 O O O 8.8 abcde 62 oh
1.0 0 4.5 0 O O 9.0 abcd 58 ij
1.0 0 9.0 O 0 O 10.0 a 46 no
0.6 0 0 4.5 O O 6.0 g 74 bc
0.6 O O 9.0 O O 7.5 ef 68 cdef
1.0 0 0 4.5 0 0 8.0 cdef 65 efgh
1.0 O 0 9.0 0 O 7.2 fg 67 cdefg
0.6 0 O 0 4.5 O 7.5 cf 67 cdefg
0.6 0 O 0 9.0 0 9.0 abcd 59 hi
1.0 O 0 O 4.5 0 10.0 a 50 lm
1.0 0 O 0 9.0 O 10.0 a 49 mn
0.6 O 0 O O 2.3 6.5 fg 73 cd
0.6 0 O O O 4.6 6.0 g 74 be
1.0 0 O O 0 2.3 8.8 abcde 61 hi
1.0 O 0 0 0 4.6 9.0 abcd DU ni
0.6 4.5 0 O 0 2.3 8.2 bcdef 64 fgh
0.6 8.0 O 0 O 2.3 8.0 cdef 66 defg
1.0 4.5 0 O O 2.3 9.0 abcd 63 fgh
1.0 9.0 O 0 O 2.3 10.0 a 44 o
0.6 0 4.5 0 O 2.3 9.5 ab 59 hi
0.6 0 9.0 0 O 2.3 10.0 a 56 jk
1.0 O 4.5 O 0 2.3 10.0 a 57 3
1.0 0 9.0 0 0 2.3 10.0 a 45 o
0.6 0 O 4.5 -»0 2.3 6.0 g 74 be
0.6 0 O 9.0 0 2.3 7.8 def 68 cdef
1.0 O 0 4.5 0 2.3 9.5 ab 60 hi
1.0 O 0 9.0 O 2.3 10.0 a 53 kl
0.6 O O O 4.5 2.3 7.0 fg 70 cde
0.6 0 O 0 9.0 2.3 9.0 abcd 62 gh
1.0 0 0 0 4.5 2.3 10.0 a 48 no
1.0 O O O 9.0 2.3 8.8 abcde 63 foh

 

aRatings were on a 0 to 10 scale; 0 - no injury, 10 - death.

6 . . . 8
Means within columns with similar letters are not Significantly different at the 18

level by Duncan's multiple range test.

49
Table A-3. Percent moisture content and visual injury of navy bean plants following
""“"" post emergence application of dinoseb with ammonium salts, ethephon, and

crop_oi1.
Ammonium Salts
Dinoseb Phosphate Sulfate Thiocyanate Ethephon Crop Oil Visual Injury Moisture

 

Rate Rate Rate Rate Rate Rate Rating Content
(kg/ha) (kg/ha) (kg/ha) (kc/ha) (kg/ha) (L/ha) #(After 7 Days 1° (1.)
O O O 0 O 0 0.0nD 8386
O 4.5 0 O 0 O 0.0n 83ab
0 9.0 O O 0 O 0.0n 84a
0 O 4.5 0 0 0 O.on 84a
0 0 9.0 O O O 0.0n 85a
0 O O 4.5 O 0 0.0n 84a
0 O O 9.0 O O 0.0n 85a
0 O O O 4.5 0 2.01m 80cd
O 0 O O 9.0 O 2.5k1 79d
0 O 0 O O 2.3 0.0n 84a
0 O O O O 4.6 0.0n 84a
0.8 0 0 O 0 0 0.5mm 826C
1.7 O O O O O 0.0n 84a
0.8 4.5 0 O O 0 3.5jk1 79d
0.8 9.0 0 0 O 0 7.5cdefg 689h
1.7 4.5 0 O 0 0 7.5cdefg 689h
1.7 9.0 O O 0 O 7.2defg 69gb
0.8 O 4.5 0 0 0 6.8fgh 72f
0.8 0 9.0 0 O O 3.2k1 80cd
1.7 0 4.5 0 0 0 8.0bcdefg 66hi
1.7 O 9.0 O 0 0 8.Sabcdef 63ij
0.8 0 O 4.5 0 O 5.0ij 76e
0.8 0 0 9.0 O O 9.0abcd 60jk1
1.7 O O 4.5 O 0 7.8bcdefg 689h
1.7 O 0 9.0 0 O 8.886cde 62ijk
0.8 O 0 0 4.5 O 7.0efg 709
0.8 O O 0 9.0 O 7.2defg 709
1.7 O 0 0 4.5 O 9.0abcd 60jkl
1.7 0 0 O 9.0 0 10.0a 51n
0.8 O O 0 O 2.3 4.2jk 77d
0.8 0 0 O 0 4.6 4.0jk 78d
1.? 0 0 O 0 2.3 6.8fgh ' 72f
1.7 O 0 0 0 4.6 6.59hi 73f
0.8 4.5 0 O O 2.3 5.2hij 76c
0.8 9.0 0 O O 2.3 6.8fgh 72f
1.7 4.5 O O O 2.3 8.Sabcdef 641
1.7 9.0 O O 0 2.3 8.2abcdefg 67gb
0.8 O 4.5 O O 2.3 8.0bcdefg 67gb
0.8 O 9.0 O O 2.3 8.5abcdef 64i
1.7 O 4.5 O O 2.3 10.0a 54m
1.7 O 9.0 0 0 2.3 9.5ab GOJkl
0.8 0 O 4.5 O 2.3 8.8abcde 64i
0.8 0 O 9.0 O 2.3 9.0abcd 63ij
1.7 O 0 4.5 O 2.3 9.2abc 60jkl
1.7 O 0 9.0 0 2.3 10.0a SZmn
0.8 O 0 O 4.5 2.3 . 9.0abcd 6213K
0.8 O O O 9.0 2.3 10.0a 480
1.7 O O O 4.5 2.3 10.0a 54m
1.7 O O O 9.0 2.3 10.0a 54m

 

a Ratings were on a O to 10 scale; 0 a no injury, 10 - death.

b Means within columns with similar letters are not significantly different at the 1%
level by Duncan's multiple range test.

50

Table A-4. Percent moisture and visual injury content of navy bean plants following
postemergence application of paraquat with ammonium salts, ethephon and

X-77.
Ammonium Salts

 

Paraquat Phosphate Sulfate Thiocyanate Ethepnon X-77 Visual Injury

Moisture

 

Rate Rate Rate Rate Rate Rate Rating Content
(kg/ha) (kg/ha) (kg/ha) (kg/ha) (kg/ha) (L/ha) (After 7 Days)a (%)
o o o o o o 0.0 kb 88 ab
0 4.5 O O O O 0.0 k 88 ab
0 9.0 0 O 0 O 0.0 k 87 ab
0 O 4.5 O 0 O 0.0 k 87 ab
0 0 9.0 0 0 O 0.0 k 87 ab
0 0 0 4.5 O O 0.0 k 89 a
O O O 9.0 O O 0.0 k 86 abc
O 0 O O 4.5 0 0.0 k 86 abc
O 0 0 0 9.0 0 0.5 jk 82 abcde
O 0 0 O O 1.2 0.0 k 89 a
0 0 0 0 0 2.4 0.0 k 89.9
0.6 0 0 O 0 O 7.4 cdef 68 jk
1.1 0 O O O O 8.2 bc 60 no
0.6 4.5 O O O 0 0.5 jk 34 abcd
0.6 9.0 O 0 0 0 1.5 ij 80 cde
1.1 4.5 0 O O O 7.0 cdef 7O jk
1.1 9.0 0 0 0 0 6.5 def 73 ij
0.6 0 4.5 0 0 0 9.0 ab 58 no
0.6 O 9.0 O 0 O 10.0 a 44 q
1.1 0 4.5 0 0 0 9.5 a 53 op
1.1 O 9.0 0 0 O 10.0 a 33 r
0.6 O O 4.5 O O 6.8 cdef 72 ij
0.6 0 0 9.0 0 O 7.0 cdef 72 ij
1.1 0 0 4.5 0 0 6.2 efg 74 hi
1.1 0 0 9.0 0 0 1.0 jk 82 abcde
0.6 0 0 0 4.5 O 6.8 cdef 72 ij
0.6 O O O 9.0 0 7.2 cdef 72 ij
1.1 O O 0 4.5 0 7.0 cdef 71 ij
1.1 O O O 9.0 O 4.5 h 77 efg
0.6 O O O 0 1.2 7.0 cdef 70 jk
0.6 0 O 0 0 2.4 7.5 cde 69 jk
1.1 0 O 0 O 1.2 9.0 ab 50 pg
1.1 O O 0 0 2.4 9.0 ab 51 pq
0.6 4.5 O O O 1.2 0.5 jk 82 abcde
0.6 9.0 O 0 0 1.2 0.0 k 87 ab
1.1 4.5 O O O 1.2 7.5 cde 67 k1
1.1 9.0 o o o 1.2 4.0 h 76 fgh
0.6 0 4.5 O O 1.2 6.0 fg 74 hi
0.6 0 9.0 O 0 1.2 1.0 jk 82 abcde
1.1 O 4.5 O O 1.2 7.8 bcd 67 kl
1.1 0 9.0 O O 1.2 8.0 DC 62 mn
0.6 0 O 4.5 0 1.2 6.5 def 72 ij
0.6 O O 9.0 O 1.2 1.0 jk 82 abcde
1.1 0 0 4.5 0 1.2 6.0 fg 74 hi
1.1 O 0 9.0 O 1.2 2.5 i 80 cde
0.6 0 0 0 4.5 1.2 1.2 jk 82 abcde
0.6 0 0 O 9.0 1.2 1.0 jk 82 abcde
1.1 O 0 0 4.5 1.2 5.0 gh 75 gh
1.1 O O O 9.0 1.2 4.5 h 78 ef

 

a Ratings were on a O to 10 scale; 0 = no injury, 10 a death.

Means within columns with similar letters are not significantly
level by Duncan's multiple range test.

different at the 1%

51

Table A-5. Percent shoot moisture and visual injury of 'Superior' potatoes following
postemergence application of endothall with ammonium salts, ethephon and
crop oil.

 

Ammonium Salts
Endothall PhOSphate Sulfate Thiocyanate Ethephon Crop Oil Visual Injury Shoot
Rate Rate Rate Rate Rate Rate Rating a Moisture
(kg/ha) (kg/ha) (kg/ha) (kg/ha) (kg/ha) (L/ha) (After 10 Days) (%)

 

 

O’

O 0 0 O O 0 0.0 f 91 abc
O 4.5 O O O O 0.0 f 91 abc
O 9.0 0 O O O 0.0 f 91 abc
0 0 4.5 O (O O 0.0 f 90 abc
0 0 9.0 O 0 0 0.0 f 91 abc
0 0 O 4.5 O 0 0.0 f 93 ab

0 O O 9.0 O O 0.0 f 94 a

O 0 0 O 4.5 O 0.0 f 92 ab

0 0 0 O 9.0 O 0.0 f 92 ab

0 0 0 O O 2.3 0.0 f 91 abc
O 0 O O O 4.6 0.0 f 91 abc
0.6 O O O 0 O 0.0 f 91 abc
0.6 4.5 0 O 0 0 0.0 f 90 abc
0.6 9.0 0 O O O 4.0 c 86 cde
0.6 O 4.5 O 0 O 2.0 e 89 abcd
0.6 O 9.0 O 0 0 6.0 b 84 ef
0.6 O O 4.5 O 0 0.0 f 92 ab
0.6 0 O 9.0 O 0 5.5 b 85 de
0.6 0 O O 4.5 O 5.8 b 85 de
0.6 O 0 O 9.0 O 2.0 e 89 abcd
0.6 0 O O 0 2.3 0.5 f 90 abc
0.6 O O O O 4.6 0.5 f 90 abc
0.6 4.5 O 0 O 2.3 0.0 f 91 abc
0.6 9.0 0 O 0 2.3 4.0 c 86 cde
0.6 0 4.5 O O 2.3 0.0 f 90 abc
0.6 0 9.0 0 O 2.3 0.0 f 90 abc
0.6 0 O 4.5 0 2.3 0.0 f 92 ab
0.6 O O 9.0 0 2.3 3.0 d 87 bcde
0.6 O O O 4.5 2.3 7.5 a 80 f
0.6 O O O 9.0 2.3 4.2 c 86 cde

 

a Ratings were on a 0 to 10 scale; 0 I no injury, 10 - death.

b Means within columns with similar letters are not significantly different at the 1%
level by Duncan's multiple range test.

52

 

 

 

 

Ig_lg“§;§. Percent shoot Noisture and visual injury of 'Superior' potatoes, following
postemergence application of dinoseb with ammonium salts, ethephon, and
crop oil.

__ ATINnonJiITn: Sa 1 t3“ "—
Dinoseb Phosphate Sulfate Thiocyanate EthEphEn Crop Oil Visual Injury Shoot
Rate Rate Rate Rate Rate Rate Rating a Moisture
(kg/ha) (kg/ha) (kg/ha) (kg/ha) (kg/ha) (L/ha) (After 10 Days) (%)
0 O O 0 O O 0.0 mb 90 a
O 4.5 0 O O 0 0.0 m 89 ab
0 9.0 0 O O O 0.0 m 90 g
0 O 4.5 O 0 0 0.0 m 90 a
0 O 9.0 0 0 0 0.0 m 90 a
0 0 0 4.5 O 0 0.0 m 92 a
O 0 O 9.0 O O 0.0 m 91 a
O O 0 O 4.5 O 0.0 m 89 ab
0 0 O O 9.0 O 0.0 m 91 a
O O . O O O 2.3 0.0 m 89 ab
0 O O O 0 4.6 0.0 m 89 ab
0.8 O 0 0 0 0 0.0 m 90 a
1.7 0 O O 0 O 4.0 jk 84 cd
0.8 4.5 O 0 O O 3.8 k 86 bc
0.8 9.0 O 0 O O 4.0 jk 86 bc
1.7 4.5 0 0 0 0 7.8 g 69 fg
1.7 9.0 0 O 0 0 8.5 cf 63 ijk
0.8 0 4.5 0 0 O 4.2 jk 84 cd
0.8 O 9.0 O O O 6.5 hi 74 e
1.7 O 4.5 O O O 7.5 g 70 fg
1.7 O 9.0 O 0 0 8.8 de 62 ijk
0.8 O O 4.5 O 0 3.8 k 86 bc
0.8 O O 9.0 O O 6.2 hi 76 e
1.7 O O 4.5 O O 7.8 g 68 fgh
1.7 0 0 9.0 0 O 9.5 abc 55 m
0.8 0 0 O 4.5 O 6.0 i 76 e
0.8 0 0' 0 9.0 0 9.2 bcd 57 lm
1.7 0 0 O 4.5 0 8.5 cf 65 hij
1.7 O O O 9.0 O 9.5 abc 54 m
0.8 O 0 O 0 2.3 1.0 1 88 ab
0.8 0 O 0 0 4.6 0.0 m 89 ab
1.7 O O O O 2.3 8.0 fg 67 fgh
1.7 O 0 O O 4.6 8.0 fg 68 fgh
0.8 4.5 0 O O 2.3 4.5 1 82 d
0.8 9.0 0 0 0 2.3 8.5 cf 66 ghi
1.7 4.5 O 0 O 2.3 9.0 cde 60 k1
1.7 9.0 0 0 0 2.3 9.8 ab 50 n
0.8 O 4.5 O 0 2.3 8.8 de 62 ijk
0.8 0 9.0 O 0 2.3 10.0 a 22 op
1.7 O 4.5 0 O 2.3 10.0 a 26 o
1.7 0 9.0 0 O 2.3 10.0 a 22 op
0.8 0 0 4.5 O 2.3 6.2 hi 74 e
0.8 0 O 9.0 0 2.3 6.8 h 72 ef
1.7 0 O 4.5 O 2.3 6.5 hi 74 e
1.7 0 O 9.0 O 2.3 6.5 hi 74 e
0.8 O 0 O 4.5 2.3 9.0 cde 60 k1
0.8 O O O 9.0 2.3 10.0 a 22 op
1.7 O 0 O 4.5 2.3 10.0 a 22 0p
1.7 O O O 9.0 2.3 10.0 a 21 £L_.__.

 

Ratings were on a O to 10 scale; 0 8 no injury, 10 = death.

Means within columns with similar letters are not significantly different at the 1:
level by Duncan's multiple range test.

4a

”I1111111111111411111“