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The Effect of Certain Spraying Materials on
the Abscieeion of Fruit and Foliage of

the Apple and Sour Cherry

THESIS

Submitted to the Faculty of the Michigan State
College of agriculture and applied Science
in partial fulfillment of the require-
mente for the degree of
Master of Science.

By
Walter Curtis Dutton
July 1925 ““

THESiS

 

 

-1-
_£ntroduction

The prevalence of fungus diseases
and insect pests is responsible fer the use of
tungicides and insecticdes on fruit plants. It
is evident, then, that the first consideration in
selecting a spraying material is that it shall be
effective in pest control. However, there are other
factors that must be considered and an important
one is the question of foliage injury.

Foliage injury has been recognized
and discussed as long, perhaps, as plants have been
sprayed. The literature of spraying contains many
references to spray injury and among them are
excellent descriptions of various types of injury,
studies of the components of spraying materials
that cause or retard injury and of environmental
factors that favor its deve10pment.

.A complete review of the literature
with a bearing on spray injury will not be attempted
here but a brief discussion of some of the work
which has a direct application to the studies to
be reported in this paper may well be included.

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Review of Literature

Grandall (3)* has described two
types of bordeaux injury on apples: -- "Brown-
spotting" and Yellowing". He states that the
brown-spotting is the more common but less serious
form of injury as leaves are not entirely destroyed
by it as when affected by yellowing. The yellow-
ing frequently caused serious injury but could
not be definitely connected with any particular
set of environmental conditions. Crandall (3),
Hedrick (6). Adams (1), and others all agree that
moisture, as rain, fog or dew, must be present in
order for bordeaux injury to develop, the usual
observation having been that injury generally
follows a rainy period or develops most seriously
in rainy seasons.

Hedrick (6) and Adams (1) state that
the degree of injury is in preportion to the amount
of copper sulphate in the bordeaux. Pickett (10)

I"Reference is made by number to "Literature Cited"
pp. 135-136.

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observed that the amount of foliage injury seemed
to be directly proportional to the number of appli-
cations. Hedrick (6), Adams (1). Cooper (4),
Grandall (3) and others state that bordeaux injury
cannot be prevented or even reduced to any degree
by the use of excess lime. Crandall‘s work,
however, indicated that after-applications of

milk of lime would reduce injury, though COOper

(4) and Pickett (1) were unable to get any benefit
from such treatments. .

Iellowing or the yellow-leaf type
of bordeaux injury may occur, according to Adams
(1), within two weeks after the application and
subsequent defoliation may continue with any
protracted wet period. Crandall (3) found that
yellowing was more likely to occur in June and
July than either earlier or later. Hedrick (5)
concluded that loss injury is likely to develop
when bordeaux is applied in dry weather.

Lime-sulphur Injggy. Injuries to
foliage caused by lime-sulphur have not been studied

so extensively as those caused by bordeaux but

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there are a few valuable contributions. Safro (11)
found that the true lime-sulphur injury is due
primarily to the calcium polysulphides and to a
less extent to the calcium thiosulphate and that
any other compounds (referring to original ingred-
ients or decomposition products of lime-sulphur)
present either before or after applications are
harmless. Young (16) has found that lime-sulphur
is strongly alkaline when applied and then changes
to a slightly acid condition. wallace (14) con-
cluded that the action of lime-sulphur in causing
injury differs fundamentally from that of bordeaux.
Lime-sulphur injury, he believes, is caused before
the solution has dried on the tree and while it

is still very caustic. That capper sulphate used
in combination with lime-sulphur is unsafe is in-
dicated by the work of Morse (9) who found that the
combination caused severe foliage injury and russet-
ing of the fruit. Thatcher and Streeter (13)

state that when acid lead arsenate is mixed with
lime-sulphur solution, a definite chemical change

  
   

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takes place forming some lead sulphide and arsen-
ate of lime and that such change probably in-
creases the danger of foliage injury. The addi-
tion of hydrated lime, casein and other materials
retard this change and should consequently reduce
foliage injury.

Injury by spraying materials fre-
quently occurs seriously on leaves that have been
injured mEbhanically, by insects or by fungi,
particularly apple scab. In such instances, spray
injury occurs when otherwise there probably would
be none. Such injury has been observed and reported
by Wallace (14), Crandall (3). Cooper (4). Horse {8).
and Whetsel (15). It has been caused by various
materials -- lime-sulphur, bordeaux, lead arsenate,
sulphur-lead dust and cepper dust. The toxic
material evidently penetrates the leaf through the
break in the cuticle and epidermis caused by the
previous injury, and then spreads out through the
leaf tissues, the leaf showing a circular or
'irregular brown area somewhat larger than the

original'fungal or mechanical lesion.

weather and Foliage Injury; ~-
The conditions which make the leaf more resistant
or more susceptible to foliage injury by various
materials have not been well established. In this
connection, wallace (14) found little evidence
to show that wet weather during or following
application of the spray (lime-sulphur) very
materially favors foliage injury but did think
that the nature of the season previous to spraying
might influence the leaf structure in such a way
that it might be resistant or susceptible to lime-
eulphur injury. Hedrick (5) has stated that it
seems reasonable to suppose that leaves and fruit
have less resistant power against the action of
copper poisons when.wet weather prevails than dur-
ing dry weather and offers in support of this the
statements of’Kohl (6) that "cuticle is much

thinner when the plant is grown in moist atmosphere”;

of Lothelier (7) that "it (the cuticle) may entirely

disappear when grown in a saturated atmosphere;
and of Bain (2) that remarkable differences are
found in the cuticle of the apple and peach leaves

in accordance with the weather. Bain's conclusions
were that eXposure to any atmospheric conditions
that have a tendency to increase transpiration,
results in an increased thickness of cuticle.
Abscission of Fruit. -- Another
angle of spray injury which has received atten-
tion only recently is that of abscission of fruit
following the use of certain spraying materials.
Sanders (12) discusses this in.some detail. He
reports experiments beginning in 1915 in Nova
Scotia, in which the use of lime-sulphur as a
summer spray has definitely reduced the quantity
of apples produced and that the same thing was
reported from British Columbia in 1919. The size
of fruit from lime-sulphur sprayed trees was
smaller than with bordeaux. He gives evidence to
show that changing from lime-sulphur to bordeaux
or capper-lime dust resulted in a large increase
in production in the Annapolis Valley, and also
found that lime-sulphur applied to the fruit alone
~or to the upper surface of leaves caused no ab-

normal drop of fruit but where line-sulphur was

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applied to the under surface of the leaves that
most of the apples dropped and concludes that the
damage is the result of absorption of lime-sulphur
through the under surface of the leaf. This
injury, he found, did not result from preblossom
applications of lime-sulphur and only a limited
amount from the calyx application but when applied
in the two-weeks application, the fall of fruit
was always heavy.

iject of Investigations. -- A study
of the reports of investigations just cited brings
out some very interesting facts and, although some
ferms of injury and the degree to which they may
develop have been recOgnized, together with some
of their contributing factors, the literature still
leaves much doubt as to the actual amounts of leaf-
fall that may be expected to occur with a given
material with various fruits and different weather
conditions. More complete information is desirable
with regard to the conditions under which injury
occurs and to the relation of environmental factors

to resistance or susceptibility of leaves to injury

as well as the influence of tree vigor to the de—
veloPment of injury. Furthermore, the comparative
susceptibility of various kinds of fruit to injury
by different materials has not been completely
established.

The investigations reported in this
paper were planned and carried through to obtain
information along the lines just mentioned, with
special reference to conditions prevailing in

Michigan 0

gresentation of Data.

The studies reported in this paper
were made in connection with a number of individual
experiments with apples and cherries at various
places in Michigan. A description of each individual
experiment will first be given with a statement
of materials, strengths, methods of application,
methods of obtaining records and a tabular state-
ment of results, without discussion. A general dis-

cussion will then follow, bringing together and

discussing comparable material from the individual
experiments. In connection with this discussion
will be considered some of the environmental condi-
tions and factors which probably have had a direct
bearing on the results.

Various materials will be mentioned
in the description and discussion of the several
experhments and in order to avoid a complete ex-
planation in each instance the following definition
of terms is inserted. Lime-sulphur, unless other-
wise specified, refers to the standard, commercial
liquid concentrate testing 32 to 33 degrees Beaume.
Bordeauxl refers to a mixture of copper sulphate,
lime and water.«-The formula is usually given, as
8-8-100. The first figure always refers to
cepper sulphate (pounds), the second to lime
(pounds), and the third to water (gallons). The
kind of lime used will usually be given in paren- '
thesis. Lead arsenate means ordinary commercial
lead arsenate powder without spreader. Where lead
are nate paste was used it will be mentioned
as such. The statement of dilutions of lime-sul-

phur, lead arsenate, etc., as 3 gals. in 100,

-11-

2 lbs. in 100, or 2—100 mean that the number of
gallons or pounds of material mentioned were mixed
with enough water to make 100 gallons of spray.

mess of 1m Preliminarily
to the description of the experiments and the dis-
cussion of the results it seems desirable to des-
cribe and define certain types of injury that may
be referred to rather frequently.

nguries Resulting from the Use of
fiime-sulphur Alone or in Combination with Acid
Lead Arsenate. -- When lime-sulphur and acid lead
arsenate are used together on apples two types of
injury may occur. The first will be referred to
(in this paper as the "yellow-leaf" type of injury
and it is generally conceded that this injury is
caused by water soluble forms of arsenic which
result from the reaction between lime-sulphur and
acid lead arsenate. This injury, in the early
stages, appears as brown spots. These may be few
or many in number and may vary in size from very
small to one-quarter inch or more in size. The
leaves gradually turn yellow, due to the loss of
chlorophyll, and abscise. When this type of injury
develops the leaves usually reach the yellow stage

in one week to ten days or possibly two weeks

- 12 -

after an application of lime-sulphur and lead
arsenate and so far as the writer has observed,
there is no recurrence of this injury until after
another application of spray.

The other type of injury resulting
from the use of lime-sulphur and lead arsenate
will, in this paper, be referred to as the "brown
leaf" or "scald" type of injury and is undoubtedly
caused by the lime-sulphur itself and therefore
might occur when lead arsenate is not used with
the lime-sulphur. With this, there are no definite
lesions but a portion of the leaf, usually the tip
or a margin where the material has concentrated
before drying, is killed. If the injury is severe
the entire leaf may be killed or when it is only
slight there may simply be a few pots anywhere on
the leaf. Areas killed in this way are frequently
invaded by saprophytic fungi. Just how this in-
jury occurs is not well understood but may possibly
be correlated with the fact that lime-sulphur is
strongly alkaline before it dried. The same or at
least, similar types of injury occur under widely I

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different conditions, first when the lime-sulphur
on the foliage dries very slowly and second, when
lime-sulphur is applied to foliage when the temper-
ature is high. In the first, it may be assumed
that the lime-sulphur remains strongly alkaline
until it dries and thus the period during which
injury might occur is greatly extended. On the
other hand, with high temperature it may be that
the process of injury is accelerated by the high
temperature.

Lime-sulphur will often cause rather
serious injury to apple leaves that bear deep
seated scab lesions, the lime-sulphur penetrating
into the leaf and spreading out through the leaf
tissues through the scab lesions. The portion of
the leaf killed by the lime-sulphur is brown and
the brown area is usually circular in form and
larger than the original lesion. This type of
injury may not cause defoliation, but frequently
does when severe.

Bordeaux Injury. -- Bordeaux is
responsible for different types of injury to the
foliage and fruit of trees as described by Crandall

 

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- 14 -

(5) but only one type will be considered in this
paper as having been responsible for foliage
abscission in the apple and cherry. This is the
form generally referred to as the "yellow leaf"
bordeaux injury. This is first evident as small
purplish spots on the surface of the leaf, these
spots soon turn brown and the leaf begins to turn
yellow, the green color usually disappearing last
'from immediately around the brown lesions. Leaves
injured in this way, particularly those of the cherry
closely resemble cherry leaves affected by leaf-
spot. In fact, close examination is usually
necessary to differentiate between the effects of

bordeaux injury and cherry leaf spot.

garment 1e

 

Defoliation by;Lime-eulphur and
Egrdeaux in Montmorencygand English Morello Cherries,
1923. An orchard of Montmorency and English Morello
cherries on the College grounds at East Lansing was
used in 1923 to compare lime-sulphur and bordeaux
in their effect on leaf-fall. The trees were 14
years old, under cultivation and in fair vigor.
Material and Applications. Two
materials only were used, lime-sulphur and bordeaux,
and at the following strengths.
1. Lime-sulphur, 3 gal. in 100.
2. Bordeaux, 8-14-100 (hydrated lime).
Lead arsenate powder, 2 lbs. in
100, was used with both for all applications. The
spraying was done with a spray gun and with about
275 pounds pressure. The schedule and dates of
applications follow. 1. Petal-fall, Kay 29;
2. Two-weeks, June 8; and 3. Pour-weeks, June 24.
Each material was used regularly
for all applications except that a few trees in
the lime-sulphur plot were sprayed with bordeaux

at the two-weeks application.

- 15 -

Record of Leaf-fall. Leaf counts
were made five times and recorded on tags attached
to the spur or shoot in question. Spur leaves
were recorded on.Montmorency, and shoot leaves on
English Mbrello trees as they produce very few spurs
under ordinary conditions. The counts were made
at the following dates. June 5, July 11, August
13, September 7 and October 4.

The October 4 leaf count was not
made on the lime-sulphur sprayed trees of English
Morello due to severe. infestation by leaf-
spot with the consequent defbliation. This was
the result of omitting the after-harvest appli-
cation. The September 7 count was not made in
the Montmorency trees that were sprayed alternately
with lime-sulphur and bordeaux. The data for both

varieties are presented in Table l.

 

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-18..

Experiment 2.

The delation of Various Spraying and
Dustingjnaterials to Leaf-fall in the Montmoreney
CherryI Traverse CityI 1923. Records were obtained
at Traverse City in 1923, in connection with ex»
teneive leaf-spot control experiments, to determine
the amount of defoliation caused by several spraying,

and dusting materials when used for the regular
summer treatments on the Montmorency cherry. This
work was done in the Titus Brothers orchard about
four miles north of Traverse City. The trees were
mature, growing on sandy soil and under thorough
cultivation and generally in good vigor. The trees
from.which the redords were taken in 1924 had been
unifonmly treated in 1923. There was practically
no leaf-spot in 1924 so that the study of leaf;
fall in relation to spray injury was in no way
Complicated by the effects of leaf-spot.

Schedule of Applications and Mater-
飧£h_ The regular summer spraying schedule was
‘used. The various applications were made at the

following dates.

 

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1. Petal-fall, June 4 and 5.

2. Two-weeks, June 18 and 19.

3. Four-weeks, July 3.

3a. Special. July 10. Duets only.
4..lfter-harvest. July 27.

For applications 2 and 3 the dust
applications were split and one side of trees
dusted one week earlier than the date indicated
for those applications. This constituted half
applications on alternate sides of the trees at
intervals of one week rather than complete appli-
cation at intervals of two weeks. The spraying
applications were completed each time at the period
indicated.

The spraying materials were applied
with a spray gun with 250 to 275 pound pressure.
The dusting was done with a large power duster.

The materials and the strengths at
which they were used were as follows: --

l. Lime-sulphur, 3 gal. in 100,
and lead arsenate, 2 lbs. in 100. All applications.

2. Bordeaux, 6-10-100 (hydrated

- 20 -

lime), and lead arsenate, 2 lbs. in 100. All
applications.

3. Lime-sulphur, 3-100, for appli-
cation 1, 2 and 4, and bordeaux, 6-10-100, for
application 3. Lead arsenate used with both ma-
terials.

4, Bordeaux, 5-10-100, for

application 1, lime-sulphur, 3-100, for applica-
tions 2, 3 and 4. Lead arsenate used with both
materials.

5. Pyrex, 18 lbs. in 100. All
applications.
_ 6. Copper dust, 20% monohydrated
00pper sulphate, 10% lead arsenate, and 70% hyh
drated lime.

7. Sulphur-lead dust, 90% sulphur
and 10% lead arsenate.

8. Check, no treatment.

Leaf-fall Records. Leaf counts were
made on shoots at three periods as follow: June
15. July 20, September 10. I

The record of defoliation is pre-
sented in Table 2.

 

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Lies-sulphur,
5-100, and
lead arsenate,

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Bordeaux, 30
10-100, and
lead arsenals,
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Liam-sulphur,

 

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arsenate,

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SulfiUCT-lead
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- 22 -

Experiment 3.

Defoliation by Lime-sulphur and
Bordeaux in the Montmorency Cherry, East Lansing;
1224; The comparative test of lime-sulphur and
bordeaux in the College orchard made in 1923 on
Montmorency and English Morello was repeated,with
slight changes, on Montmorency in 1924.

. Materials and applications. The two
materials, lime-sulphur and bordeaux, were used
as follows:

1. Lime-sulphur, 3 gal. in 100.
2. Bordeaux, 6-6-100 Ilump lime).

Lead arsenate was used with both
for all applications.

They were applied according to the
regular four application schedule and at the dates
here indicated. 1. Petal-fall, June 5; 2. Two-
weeks, Jun 18; 3. Four-weeks, July 2; 4. After-
harvest, August. 20.

Record of Leaf-fall. Leaf counts

were made at four periods and recorded on tags

in the usual way. Spurs were used. The counts
were made as follows: June 20, July 15, August
20, and October 4.

The record of defoliation appears

in, Table 3e

 

 

-25...

Experiment 4.

The Relation of Tree Vigor to Sue-
ceptibilipy to Bordeaux Injggy_in the Montmorengy
Chergy, Traverse City, 1923. In 1922 at Traverse
City a number of materials were used for the con-
trol of cherry leaf-spot, some of which gave good
results and others very poor so that some trees
lost very few leaves and others were badly defoli-
ated. In 1923 a plot sprayed with bordeaux ran
across all the plots of 1922, so that trees that
had been defoliated in varying degrees in 1922 re-
ceived uniform spraying treatment with bordeaux
in 1923. Other phases of management, as cultiva-
tion, fertilization and pruning were uniform.

The bordeaux was applied according to
the regular four application schedule consisting
of the petal-fall, two-weeks, four-weeks and after-
harvest applications. The bordeaux was made
according to the 6-10-100 (hydrated lime) fonmula.

Records of Leaf-fall. The compara-
tive amounts of defoliation were determined by

counting the number of leaves persistent on shoots

-26..

on September 12 and at the same time recording the
number of leaves that had dropped by counting the
leaf-scars. These records were obtained from one
group of trees which, in 1922 had lost very little
foliage and from another group which in 1922 had
lost about 75% of the leaves by mid-summer. The

results of these counts are presented in Table 4.

-27-

Table 4. The Relation of Vigor to Susceptibility
to Bordeaux Injury in the Montmorency Cherry,

_Traverse City, 1923.

 

   
 
 

Condition of the
trees in 1922.

No. Original No.Leaves
Shoots No. Persistent Leaf-
Txamined Leaves Sept.12 Fall.
(Aver.) (Aver.)

 

Badly defoliated 201 9.5 8.1 1.4

Slightly defoli- 197 9.4 8.4 1.0
ated

 

 

 

 

 

 

 

Experiment 5.

The delation of the Vigor to
Susceptibilitypto Bordeaux Injggy in the Early
Richmond CherpypEast Lansingl 1924. In 1924 a
group of 12 Early Richmond trees in the College
orchards at East Lansing were used to study the
relation of tree vigor to the development of
bordeaux injury. The trees were of mature age, in
low vigor and had been making very short terminal
growth and forming very few spurs.

Tpeatment in 1924. Just before the
blooming period in 1924 six of the twelve trees
were given a heavy application, 5 pounds per tree,
of nitrate of soda. This was broadcast under the
trees and well beyond the epread of the branches.
There were frequent rains so that it was quickly
taken into the soil. The other six trees were left
without any nitrate.

Cultural treatments and spraying were
uniform for both lots. They were all sprayed four
times according to the regular summer schedule which

included the petal-fall, two-weeks, four-weeks and

- 29 -

afteryharvest applications. 6-6-100 bordeaux (lump
lime) and lead arsenate, 2 lbs. in 100, were used
for all applications.

The application of the nitrate of
soda resulted in a greatly increased growth , --
the shoot growth was greater, the leaves were
larger,thicker and darker green in color.

“ecord of Leaf-fall. The leaf-fall
records were obtained from terminal shoots as the
trees had been in such low vigor that very few
spurs had been formed. Leaf counts were made at
five periods as follows: June 28, July 25,
September 4, and October 5.

The data are presented in Table 5.

fl”

 

-31-

Expe riment 6_._

The Effect of Shading,.Method of
Application, and Materials on the:§pscission of
Leaves of the Apple, East Lansing, 1923. A
block of young trees of Bladwin and Red Canada
on the College grounds at East Lansing was used in
1923 to determine the relation of several factors
to the absciseion of leaves. These trees had been
planted four years at the beginning of the experi-
ment and were in good vigor but not bearing fruit.
Information along several lines was desired in
connection with this experiment, among which were
the relation of shading, the portion of the leaf
covered with spraying materials, and of several
materials and different strengths of materiils to
leaf-fall.

Materials and Strengths. Three
materials and the strenghts at which they were
used were as follows: --

l. Lime-sulphur, 2} gal. in 100.

2. Bordeaux, 8-8-100 (lump lime).

3. Bordeaux, 5.10-100, (hump lime).

4. Sulfocide, 1 to 150.
5. Check, no treatment.
The materials were all applied with
a good bucket pump, using a fine vermorrel nozzle.
No arsenate of lead was used.
Details of Methods and Treatments.
Three methods of application and a check as follow,
were used.
1. Upper surface only of leaves
sprayed.
2. Lower surface only of leaves
sprayed.
3. Upper and lower surfaces both
sprayed.
4. Check, no spray.

The trees were divided into approxi-
mate quarters for each treatment listed and when
the spraying material was being applied oiled sheets
were used to prevent the spray from reaching the
limbs where it was not desired. With certain mater-

ials only one method of application was used, --

complete coverage of both upper and lower surfaces --
and in such instances one-half the tree was sprayed
and the other half used as a check.

“1th lime-sulphur, certain trees were
left fully exposed to light and sunshine, one was
semi-shaded, and a third was fully shaded. Shading
as used here means the exclusion of direct sunlight
only. The shading designated as "semi-shade" was
accomplished by supporting over and around the tree
screens made of lath with the inter-spaces equal
to the width of the lathe. The so-called "full-
shade" was accomplished by supporting over and
around the tree a cover of heavy white muslin.

. Some difficulty was encountered in
applying the sprays to leaves that were to be
sprayed on the underside only as it is obviously
impossible to spray the undersurface of the leaf
without some spray going on up and falling on the
upper surface of adjacent leaves. It was also
difficult when spraying the upper surface only to
prevent some material from getting on the lower side.
In an effort to avoid these difficulties the actual
dosage in either case was probably less than on

the same surface of leaves which were completely

covered above and below.
, Dates of.4pplication and Leaf-counts.
The trees were sprayed three times as follows:

1. May 29; 2. June 8; 3. August 16.

The leaf-fall was recorded by
placing tags on spurs and recording the number of
leaves persistent at intervals. Counts were made
on the days here listed. June 1, July 16, August 7,
September 19, October 1.

The extent of defoliation and the
periods when it occurred are shown in Table 7 for

Baldwin and in Table 8 for Red Canada.

- 35 -

A detailed list of materials,

method of application and degree of shading follows

in Table 6.
Table 6.

Materials and Methods Used on Baldwin

and Red CanadaLpEast Lansing, 1923.

 

terial

xposure
to light

 

me-sulphur,
é—lOO

 

orm

*Variety o

f

'Upperleaffisur-
face only.Lower
leaf surface
only. Upper and
lower.

one Ck e

 

imehsulphurfi

i-lOO.

(gami-
shade

 

imine-- sulphur
2%-100

 

shade

f;apple and the por-

tion of leaves e rs ed.
--—1;nnrnmr—-—Tfifi}1fifimny——-—t

A
pper leaf sur-

face only.
Iower leaf
surface only.
Upper and lower
Check.

 

pper leaf sur-
face only.Lower
leaf surface
only. Upper and
lower.

Che Oke

 

Upper leaf sur-
face only.Lower
leaf surface
only. Upper and
lower.

Check.

 

Ordeaux,
-8-100

ormal

 

ordeaux,
6-10-100

ordeaux,

-150

ormal

Upper leaf sur-
face only.Lower
leaf surface
only. Upper and
lower.

Check.

Check

Upper‘léaf sure -
face only.Lower
leaf surface
only. Upper and
lower e

Check.

 

Upper and lower pper and lower -

Check

 

ormal

Upper and lower

 

Check

 

(

 

V

.. \lhu

 

 

I

.

 

. v
(‘1‘!
»

 

 

! 3..
v

 

 

 

 

§§periment 7.

ébscission of’Leaves on Baldwin
Apple, Belding, 1923. Records were obtained from
Baldwin apple trees in 1923 at the Hall Orchards,
Inc., at Balding. The Trees were mostly 20 to 22
years old and were growing in sandy loam soil with
thorough cultivation during spring and early summer
followed with a cover cr0p in late summer.
Materials and Application. A
number of materials were used as follows. I
1. Bordeaux, 6-18-100 (hydrated lime).
2. Limeysulphur, 2% gal. in 100.
3. Lime-sulphur, 2% gal. in 100,
and calcium caseinate, 1% 1b.
in 100.
4. Lime-sulphur, 2% gal. in 100,
and hydrated lime; 15 lbs. in
100.
5. Limeesulphur, 2% gal. in 100 fer
the pro-blossom applications;
90-10 sulphur-lead dust for all

post-blossom applications.

 

 

6. Sulphur-lead dust, 90% sulphur,
10% lead arsenate.

7. Check, no treatment.

Lead arsenate at the rate of 2 lbs.
in 100 was used with all the spraying materials
for all applications except the prepink,

The spraying materials were applied
with a spray gun with the pressure usually about
275 pounds. The operator usually worked from the
top of the sprayer except fer the last application,
when the trees were sprayed from the ground, inside
and outside. The dusting materials were put on
with a large power duster and usually during the
late evening or early morning when there was little
or no wind.

The schedule of applications con-
sisted of the prepink, pink or cluster, petal-fall,
two weeks and second brood applications according to
the regular schedule of applications recommended for

Michigan conditions.

Record of Abscission. The compara-
tive amount of defoliation caused by the various
materials was determined by counting the number of
leaves persistent on spurs on October 3. The
spurs studied were mostly on two and three year
old wood and none of them had borne blossoms in
1923. The results of the counts are presented in

Table 9e

Table 9. Leaves Persistent Under Various Treatments

on Spurs of the Baldwin Apple, Balding, October 31,

 

 

 

 

1923.
Becords from Total No. Average
flTreatment Trees Spurs Leaves per
Counted epur
l. Bordeaux \ 3 498 1994 4.0
2. Lime-eil- .rz 553 2205 3.9
phur
5. Lime-sul- . s 575 1826 3.1
phur and cal-
cium casein-
ate
4. Lime-sulphur 3 483 1918 3.9
and hydrated
lime
5. Combination: 3 315 1267 4.0
lime-sulphur
and dust
6. Sulphur-lead 3 344 1603 4.6
dust
7. Check 1 412 1925 4.6

 

 

 

 

 

 

 

- 42 -
Experiment 8.

Abscission of Fruit and Leaves of
the Baldwin AppleJ Beulah, 1925. The effect of lime-
sulphur and bordeaux on the abscission of the fruit
and foliage of the Baldwin apple was studied in
1923 in the Joseph Smeltzer orchard near Beulah,
Benzie County. The trees were large, mature, uni-
form and all bloomed heavily in the spring of 1923.

Materials and Applications. Two
materials, lime-sulphur and bordeaux, were used.
The lime-sulphur was diluted at the rate of 2%
gallons in 100 and the bordeaux was made according
to the 6-12-100 (hydrated lime) formula. Lead
arsenate paste, at the rate of 6 pounds in 100
was used with both materials.

The trees all received the pink,
petal-fall, two-weeks and second brood sprays.

A aPray gun was used with the sprayer operating
at 350 pounds pressure. The spraying was done
from the ground and all trees were sprayed both
inside and outside. The operator first sprayed
outwards from near the center of the tree,
,th°r°u8hly covering the underside of the leaves
and all inner portions of the tree then worked

around the outside of the tree and completed the

COVOIQSQ.

-45..

Record of.dbscission. The effect of
the two materials on the abscission of fruit and
foliage was obtained by determining the numbers
of apples and leaves persistent on spurs on
September 13. Counts were made, for fruit records,
from spurs that had blossomed in the Spring of
1923 and fer leaf records,from spurs that had not
borne blossoms in 1923. The selection of record
spurs was strictly random, Studies were made of
two groups of spurs on each tree: first, those
around the outside of the tree where the exposure
to sunlight was good and where they probably did
not receive a heavy dosage when.the trees were
sprayed from the inside and second, those around
the lower inside portion of the tree where they
were shaded considerably and where they received
the full benefit of the material applied from the
center of the tree. Records were obtained from
four trees under each treatment and leaf and fruit
records were from the same trees. The record spurs
were evenly distributed around the trees. All
spurs of both classes were within 4 to 7 feet from
the ground. The spurs from the outside or perio
phery of the tree will hereafter be referred to as

- 44 -

"outside'spurs and those from the inner part of

the tree as "inside" spurs. The data obtained in
these counts are presented in Table 10. No

effort was made to determine the original number
of blossoms or leaves borne by each spur but on the
bordeaux sprayed trees careful observation indi-
cated that practically no leaves had fallen except
the rudimentary leaves at the base of each spur.
Rather heavy defoliation occurred a little later
as the result of bordeaux injury which developed

after the counts were made.

-45-

Table 10o

Fruit and Leaves Persistent on Spurs of

the Baldwin Apple at Beulah, September 13, 1923.

 

 

 

 

 

 

 

 

 

 

 

 

Fruit Lime-sulphur Bordeaux
Inside Outside Inside Outside
Total number spurs 459 1211 791 932
examined
Spurs that lost all 82 44 43 26
fruit (percent) .
Spurs that held part 18 56 57 74
of fruit (percent)
Average number apples 1.06 1.11 1.16 1.22
per Spur that held
fruit
Number apples matured on 19 62 66 90
any 100 spurs that
bore blossoms ,
Foliage Inside Outside Inside|0utside
Total number Spurs 411 404 410‘\W‘ 403
examined
Total number leaves 1503 1727 1937 2078
persistent
Average number leaves 3.6 4.2 4.7 5.1
pper spur

 

 

 

- 45 -
Egperiment 9.

The Relation of the Composition of
Bordeaux to the Abscission of’Leives of the AppleL
East Lansing, 1924. EEYEMY93r,QlthE993 91138992
Island Greening and Duchess (Oldenburg) were used
in 1924 fer a series of tests to determine the
effect on leaf-fall of bordeaux made with varying
amounts of cOpper sulphate and lime and with cer-
tain impurities in the lime. Answers were sought
to several definite questions. Is foliage injury
increased by increases in the amount of copper sul-
phate used? with the amount of copper sulphate
constant will extra lime reduce innury? Will
injury be greater if the lime is high in Magnesia?

Methods and Materials. Each tree
was divided into three portions, one of which was
smaller than the others and was used as a check.
The other larger portions were sprayed with bordeaux
mixture, each of a different formula. The treat-
ments were paired so that a tree of Duchess re-
ceived the same treatments as a Rhode Island
tree. Oiled sheets were used to prevent the spray

from reaching branches that were not to be sprayed.

- 47 -

”he materials were applied with a
good bucket pump, using a fine vermorrel nozzle.
The spray was always applied completely covering
both upper and lower surfaces of the leaves.

The materials and the strengths at

which they were used were as follows:

1. One tree each of Duchess and Bhode Island.

1. Bordeaux, 2-2—100.

2. Bordeaux, 2-4-100.

3. Check, no treatment.

11. One tree each of Duchess and Rhode Island.

1. Bordeaux, 8-8-100.

2. Bordeaux, 8-16-100.

3. Check, no treatment.

III. One tree each of Duchess and Rhode Island.

1. Bordeaux, 8-8-100.

2. Bordeaux, 8-8-100, in which
magnesium oxide was substituted for 40% of the lime
(calcium oxide).

3. Check, no treatment.

17. One tree each of Duchese and Rhode Island.

1. Bordeaux.8-N-100. Lime used in

just sufficient quantity to precipitate all copper

- 43 -

as indicated by the use of the potassium permanga-
nate test.

2. Colloidal capper hydroxide
(Hooker) 1-5000.

3. Check, no treatment.

Chemically pure materials and rain
water were used for making all the mixtures in this
experiment.

Dates of Applications and Leaf-
couhts. Two applications were made: 1. June 23,
and 2. July 24.

The leaf-fall records were obtained
by the usual tag method. ccunts were made at
four periods: June 26, July 23, August 20 and
October 3.

The record of leaf-fall is shown in
Table 11 for Duchess and in Table 12 for Rhode
Island.

Table 11. Tue eels

 

 

 

 

Materials and decor
Strengths 8 Hr
l. Bordeaux, ;
2-8-100 23
2. bordeaux, ‘
2-4-100 25

 

fi w—w—w

 

3. Check for
1 an (1 f;

 

4. Bordeaux,
8-6—100.

 

5. Bordeaux,

 

8-16-100 331

l

6. Check for g
4 and F. xiii

 

 

7. Bordeaux,
_ 84109

 

8. bordeaux,
8-8-1CO

(Lime,40f"-
m_g. oxide) V?

 

9. Check for
7 2,1110) (i.

14

 

10. Iordenux,
8-N-100, (On.
to infiltralize
Cu.)

H

._ .___.JL. . _....-_._. A

,p.

 

Cu.Hydroxide
1-5000

2

5 ;

 

12. Check for
10 and 11.

 

 

0 L

l__

 

1131b 16 1:3 e

 

Materials and
Strengths

 

1

l. Bordeaux,
2-3-100

 

2. Bordeaux,
2-4-100

_Wfi

 

3. Choc; for

‘ '\
l ‘ciiiCl .3

 

@. Bordeaux,
.8-8-100

 

(5. 1201‘ deaux,

8-16:100

 

6. Check for
4 {lild 50

 

7. Bordeaux,
8-8-100

 

8. bordearx,
8-8-100 (Lit
4Qf-hg.oxid4

 

. ChemziOr
7 and 8
10. Bordeaux,
8-LI-100, (Ct
to neutrali:
Cu.)

 

11. Colloidal
Cu. Hydro xid
1-50090

 

12. Check for.
10_3nd 11t_‘

 

 

 

. ',»-..Dr."|

“I Lug ?L,D.'\r, -

 

-51-

Experiment 10

The Effect of Various Spraxing
Treatments on the abscission of the Foliage and
Fruit in the Appl§.gmcrrice. 1924. A twelve
year old apple orchard at Morrice was used in 1924
for a :series of tests to determine the effect
of spraying materials on the abscission of leaves
and fruit. The trees were in good vigor and had
been in alfalfa sod for two years, the alfalfa
usually has been out and left on the ground or
placed around the trees as a mulch. This work was
conducted along two lines. The first, a compara-v
tive test of several materials and combinations
of materials in Which the application was made in
the regular and usual manner, and the second, a
comparison of so-called weak and strong lime-
sulphur and weak and strong bordeaux in which both
strengths of each material were applied at three
different rates. These were termed light, moderate
and heavy applications.

Materials Used and Methods of

Application. In the general comparative test the

 

following named materials were used and at the

dilutions stated.

1.
2.

5.

4.

5.

6.

8.

- 52 -

Lime-sulphur, 2% gals. in 100.
Lime-sulphur, 2% gal. in 100,
plus calcium caseinate, 1 1b.

in 100.

Lime-sulphur, % gal. in 100,
plus lump lime, 10 lbs. in

100.

Dry-mix sulphur-lime mixture,

16 lbs. sulphur, 8 lbs. lump
lime, 1 1b. calcium caseinate
and water to make 100 gals.
Lime-sulphur, 2% gals. in

100 for the pre-blossom applica-
tions and dry-mix sulphur-lime
for the post-blossom applications.
Colloidal sulphur (Tisdale)*, Q

8310 in 1000
Dolloidal sulphur (Herbert and

Herbert)**, 10 lbs. in 1000

Check, no treatment.

*This materials was furnished by .L.~E.Tisdale.
of the Crap Protection Institute.

** This material was manufactured by Herbert &

Herbert, Inc.

9 55 -

Lead arsenate powder at the rate
of 2 lbs. in 100 was used with all materials for all
applications except the prepink. Nicotine sulphate
at the rate of 1 pint in 100 was used with all
materials in the petal-fall application.

-These materials were all applied in
the usual and regular way. The exact procedure
was varied to meet conditions prevailing at any
time, wind being the principal determining factor.
Each tree or at least each row was completed as
a unit. The spraying was all done from the ground
with a spray gun with a disc aperture of 9/64 inch.
The pressure was maintained quite unfairly at
300 to 510 pounds.

In the portion of the work comparing
different concentration and rates of application”
the materials were used as follows.

1. "weak" lime-sulphur, 1i gals. in
100, and lead arsenate li-lbs. in 100.

2. "Strong" lime-sulphur, 3 gals. in 100,
and lead arsenate, 3 lbs. in 100.

3. "Weak" bordeaux, 2-4—100, and lead
arsenate, 1 lb. in 100.4

4. "Strong" bordeaux. 6-12-100, and
lead arsenate 3 lbs. in 100.

The lead arsenate was used at the rates
indicated for all applications except the prepink.
Nicotine sulphate was used in the petal-fall applica-
tion. The spraying was all done from the ground with a
spray gun with a disc aperture of l/8 inch. The pressure
was maintained at 500 to 310 pounds. The general method
of application was the same as described for the first
part of the experiment, in that each tree or at least each
row was completed as a unit but a special method was
used to insure uniformity in applying each material at
different rates. .

Both materials at each strength were
applied at three different rates, which have been termed
as ”light". "moderate“, and "heavy" applications. Weak
lime-sulphur, for example, was used on three rows; one
row received the light application, another the
moderate, and the third the heavy application. This
was accomplished by a special method, which may be
described as follows. The spraying'was begun on the
"heavy" row and all three were given a uniform. light
application. The "light" row was sprayed no more. By
the time the three rows were sprayed the materials on

the first and second rows sprayed had dried and they

-55-

were immediately sprayed Just as before so that the
dosage was double that on the lightly sprayed row.
As soon as the materials had dried from the second covering,
the first row was again sprayed with the same light
application. The final result was that one row received
one light application, another row two light applications
and the third row three light applications. This
constitutes what has been arbitrarily termed "light"
"moderate" and fiheavy" applications. The moder-
ately sprayed trees, then, received twice, and
the heavily sprayed trees approximately three
times asmany gallons of diluted materials as the
lightly sprayed row. It follows then that the
comparative amounts of diluted materials applied
to trees receiving light, moderate, and heavy
applications varied as l, 2 and 3. Strong lime-
sulphur, weak bordeaux and strong bordeaux, were
all applied exactly as described for the weak lime-
sulphur.

Comparative Amounts of active
Ingredients. Since the rates of application for
each material varied as l, 2 and 3 and bordeazx
and lime-sulphur were each used at two concentra-

tions it is evident that there were differences

- 55 -

in the amounts of actual active ingredients applied
to each row and by considering together the dosage
and strength of material it is possible to deter-
mine the comparative amounts used. For example,
the rows sprayed with light applications of weak
and strong lime-sulphur received equal quantities
of diluted materials but the rows sprayed with
the strong lime-sulphur received twice as much
actual lime-sulphur since the diluted material was
twice as strong. Other examples, could be worked
out on the same basis. The comparative amounts
of active ingredients under each treatment are
shown in Table 13. in which is also included the
comparative amounts of diluted materials. The
treatment giving the smallest amount is assigned
the value of 1.

Schedule and Dates ofépplications.
The materials for all the work were applied accord-
ing to the following shcedule and at the dates
indicated: 1. Prepink, May 2 and 3; 2. Pink,
May 16 and 16; 3. Petal-fall, June 6 and 7; 4.
Two-weeks, June 19 and 20; 5. Second brood,

August 12 and 13.

-57-

Tablg_13. Comparative Amounts of Active Ingredients.

 

I

 

 

 

 

 

 

 

terials and Rate of Comparative amounts of
Strengths Application. Diluted Active
Materials ingredie ntjs_..

Weak lime-sulphur, Light 1 l
I} olOO. Ioderat 8 2
Heavy 3 3

Strong lime-sul- Light I 2
phur, it - 100. Moderate 2 4
Heavy 3 6

Weak bordeaux Light I l
2-4-100. Moderat 2 2
'Heavy 3 3

Strong bordeaux Light 1 3
6-12-100. Mbderate 2 6
Heavy L 3 9

 

 

 

 

 

The schedule here used is the standard treatment
recommended for hearing apple trees in Michigan.

Abscission of Leaves and Fruit.
Data were obtained concerning the abscission of
leaves for Hubbardston and Wagener. All suchre-
cords were from spurs which did not bear blossoms
in the spring of 1924. A continuous record, was
made for Hubbardston throughout the season by
means of tag records. Observations were made at
the following periods.

1. June 10, 11 and 12. Tags
placed and original number leaves recorded.

2. June 28 and 29. About two weeks
after the two-weeks applications.

3. August 4 and 5. Just before the
second brood spray and immediately after an epidemic
of bordeaux leaf injury.

4. September 2 and 3. Three weeks
after second brood spray.

5. September 29 and 30. Final
count and tags collected. The leaf abscission

records for Wagoner were made for most of the spray

treatments by counting the number of leaves persis-
tent on a large number of spurs on August 26. This
record included all defoliation which had occurred

during the summer.

The data for Hubbardston are presented
in Tables 14 and 15, and for wagener in Table 16.

“ecords pertaining to the abscission
of fruit were obtained for Jonathan and Hubbardston.
Individual spur records were made by placing tags
on spurs and recording there on the number of buds
or apples present at the time each record was
made. counts were made as follows: ~-

1. In pink or cluster stage.

2. Just after the firSt drop.

3. Soon after the June dr0p.

The first count indicated the original
number of buds in each cluster, the second the
number of apples persistent after the first drOp
and the third the number persistent after the
June drap. The term "First droP' as used here
may be defined as the abscission of fruit which
occurs within ten days or two weeks after petal-fall

-60..

and the "June drop" as that usually occurring
during late June or early July.

The fruit abscission records for
Jonathan are presented in Tables 17 and 18 and for

Hubbardston in Tables 19 and 20.

 

 

22......

a...

Jun-4.

n- Wi‘ affirm-III!

.qoe

lfibr.
-mhowar,

nausea .OOthne
ouch .
.oa.

 

CD

0
LO
LO
u)
m
H

 

.‘1
e
"f‘ U.)

) 4..
kriPanmWw

 

(O ‘34
.

D.)

0

fl

C)

H

 

 

 

. e
“a u. If)
U Q L‘
r—i l—i

HQ‘U
O

{“fo-

OCJH

m.a mum esfl n
m.w hue NHH m mpsmmaow
m.w now own H
m.m «mmu Heb epoa

pawns

ooanw
.mpw1emsm
whoa win
a ‘
ooa-m -c
.xsnvcmon

m4b 1 2.
a. (.79:

 

seem paupnflm9o_
hog mmbwm‘
mmuses4 mwpoa

 

 

 

docfléuro
wszom .oh

 

mama

 

seawsoflags;

mpedmspu
can
dmwhmme

 

 

.emma .mOHsaou emamge sesame; may ms

Hammuman do mammsp,mma

.xee

we; 93w.

omen Seam cosqflpdoa

macheha mo panama sea

.mH.oHpea

 

 

- 72 -

Discussion.

u'he individual experiments have
been described and the results stated without any
discussion or interpretation. The hext step.
then, is to bring toyether comparable material
from the these experiments and if possible to
draw some definite conclusions from the studies
and comparisons. This is done in the following

pages.
Specific Consideration.

THE SOUR CHERRY

The Amount of Ioliar.Abscission
Caused by Several Spraying Materials.

Lime-sulphur. Sour cherries were
sprayed with lime-sulphur in three distinct ex-
periments in 1923 and 1924. The varieties used
were Montmorency and English Morello; the locations
were widely separated, one at Traverse City and
the other at East Lansing; the weather conditions
varied between locations and from season to season;

the lime-sulphur was used at two strengths, 2%

- 7:5 -

gals.in 100 and 3 gals. in 100; and the number of
applications varied.

The foliage on trees sprayed with
line-sulphur showed, with only one exception, no
definite injury which was the result of the lime-
sulphur. The one exception was at Traverse City
when one of the early applications caused the
tips of some leaves, where the lime-sulphur had
accummulated, to lose the natural green color and
to assume a creamy white appearance but without
any killing or breaking down of the leaf tissues
and apparently with no leaf-fall which could be
traced to this injury. The leaves develOped
their natural green color later.

The exact total amounts of leaf-
fall during the summer in the various experiments

is here shown.

East Lansing, 1923 ACTUAL PERCENT.

(from.Table 1)
.Montmorenoy (from spurs) 0.2 3.2
English.Morello (from shoots) 0.9 7.5

Traverse City, 1923
(from Table 2).
inontmorency (from shoots) 0.9 7.6

-74..

East Lansing, 1924
(from Table 3). Actual Percent

Montmorency (from spurs) 0.8 15.0

Records of normal leaf-fall are
difficult to get from unsprayed cherry trees be-
cause of the usual defoliation by leaf-spot, but
satisfactory records were obtained with Montmor-
ency at Traverse City in 1923, as leaf-spot injury
of consequence did not develop. The leaf-fall
on the unsprayed trees was 0.9 leaf from shoots
(Table l ). This is what may be called normal
leaf-fall and incidentally is exactly the same as
that on trees sprayed with lime-sulphur. Since
the amount of abscission in the other experiments
is closely in line with that in the Traverse Uity
orchard it is evident that little foliar abscission
will result directly from the proper use of lime-
sulphur on sour cherries under Michigan conditions.

Bordeaux. Trees of the sour cherry
were sprayed with bordeaux in the same experiments.
under the same conditions and with the same varie-
ties mentioned for lime-sulphur. In addition,
bordeaux was used on Early Richmond at East Lansing

in 1924.

In every experiment, regardless of
location, variety, weather conditions, strength
of material or number of applications bordeaux
caused foliage injury and defoliation. The injury
which was responsible for the leaf-fall was always
of the yellow-leaf type; in some instances it was
light, in others severe. The statements of total
leaf-fall during the summer in the various experi-
ments follows.

East Lansing, 1923,

(from Table 1) Actual Percent
Montmcrency, (from spurs) 4. .
English Morelloafrom shoots) 9.5 79.3

Traverse City, 1923
(from Table 2)
lucntmorency (from shoots) 1.6 l 3.0

East Lansing, 1924
(from Tables 3 and 5).

Montmorency (from spurs) 2.8 59.5
Early nichmond, not nitrated
(from shoots) 6.3 45.5

These results indicate definitely
that serious foliage injury and defoliation are
very likely to follow the use of bordeaux on

sour cherries in Michigan. This statement is
supported further by numerous observations in
experiments not herein discussed.

Pyrox. A commercially prepared
material containing bordeaux and lead arsenate
sold under the brand name of Pyrox was used on
Montmorency at Traverse City in 1923. The use
of this material resulted in very heavy leaf-fall
during mid- and late summer. The injury was the
typical yellow-leaf kind caused by bordeaux. The
total leaf-fall for the summer period as taken
lrom.Table 2 follows. The amount of defoliation
on unsprayed trees is also shown.

Actual Percent

Pyrox (from shoots) 6.5 BI.
Check (from shoots) 0.9 7.7

'Sulphur Dust and Qgpper Dust. The
dusts which were used on fiontmorency at Traverse
City in 1923 caused practically no injury and the
foliage had the same appearance and texture as
normal unsprayed foliage. The amounts of leaf-
fall, as compared with that on untreated trees was

as follows (from Table 2).

- 77 -

Actual Percent

 

Copper dust (from shoots) 0.9 8.5
Sulphur dust (from shoots) 0.7 6.4
Check (from shoots) 0.9 7.7

Alternation of Materials -- 1535?.
sulphur and Bordeaux. At Traverse City and East
Lansing in 1923 changes of materials were made
during the season in some instances. Bordeaux
was substituted for lime-sulphur in one plot at
Traverse City in the petal-fall application and
in another in the four-weeks application.
at East Lansing bordeaux was substituted for lime-
sulphur in the two-weeks application. nontmorency
was the variety at both places. in each instance
the change of material resulted in foliage injury
and an epidemic of yellow leaves in one week to
ten days later. The comparative amounts of leaf-
fall follow.

Actual Pfiercent

Traverse City (from table 2)
Lime-sulphur, Applic.
1, 2 b 4; bordeaux,

 

applic. 39 « . . 106 1500
Bordeaux, applic. l;
Lime-sulphur, applic.
2, 3. & 4. 1.5 14.0

East Lansing. (from: Table 1).
Lime-sulphur, applic. 1
and 3; bordeaux, applic. 2. 1.7 32.6

 

In another instance with anglish
Morello at East Lansing in 1923, a tree was accid-
entally sprayed with both lime-sulphur and bordeaux
in the same afternoon. Almost complete defoliation
followed as well as injury to the bark and young
cherries. Many instances were reported from various
parts of the state during that season where severe
foliage injury followed a change from one material
to another. The injury apparently was not correlated
with a change in one way, as from.lime-sulphur to
bordeaux or vice versa as it was known to have
occurred with both. It was very evident that there
‘was some reaction between certain constituents of
the two materials to form a soluble and toxic

compound.

Nutritive Condition of the Tree in
Relation to Bordeaux Injggz;

Some attention was given to the.
question of tree vigor in the sour cherry and
its relation to the deve10pment of bordeaux
injury. In other words, is a cherry tree in one
plane of nutrition more likely to suffer from
bordeaux injury than trees in other conditions?

-79-

Trees in low vigor have been very generally ob-
served as being more susceptible to injury by lea:-
spot and it seemed desirable to determine if the
same condition is true with regard to bordeaux
injury.

Studies were made in two orchards,
one at Traverse uity in 1923 (Experiment 4) and
one at East Lansing in 1924(Experiment 5). The
condition of the trees at Traverse Gity may be
described as follows. One group had been badly
defoliated in 1922 by leaf-spot and were in a weak
condition in the spring of l923; the others had
been only slightly defoliated and were in ndrmal
condition. Analyses of spurs and shoots collected
in early spring from other trees in similar condi-
tion showed the two groups to have had comparable
amounts of total nitrogen but the reserve of starch
and sugars was very low in the trees defoliated
in 1923*. This was the condition at the beginning
of the growing season but just what it was during he

~summer when defoliation occurred is not know. At

*Mlon. 151p. Sta. 3p. Bale 147s p. 70

-80-

East Lansing in 1923 the trees were in a unifbrmly
low condition of vigor to begin with but the
nutritive state of one lot was changed by a heavy
application of nitrate of soda in the early spring
so that vegetative growth was accelerated during
the summer. In one instance then, the tree had
been on an equal plane to begin with but one lot
had the carbohydrate reserves lowered as a result
of defoliation. In the other, the trees were in
an equally low plane of vigor but one group was
changed by the use of nitrate of soda. There were
undoubtedly differences in the nutritive condition
of the two groups in each experiment, but what this
difference was is not known.

All trees in each experiment, as
stated in the description of the experiments, were
sprayed uniformly. The results, taken from Tables

4 and 5, may be summarized as follows.

 

_Arctual is re ent .
antmorency at Traverse City

Trees in low carbohydrates in

spring of 1923 1.4 14.7
Normal trees 1.0 10.6

Early Richmond, Last Lansing
Nitrated trees 10.1 67.?
Normal trees 6.3 4710

The evidence is not extensive or
conclusive enough to allow the drawing of any de-
finite conclusions but it indicates that the
nutritive condition of the tree has some relation
to its susceptibility or resistance to bordeaux

injury.
W

The Amount of Foliar abscission Causedgz

Various Materials.

Lime-sulphur. Two general types
of injury on apples resulting from the use of lime-
sulphur and acid lead arsenate have been described
in preceding paragraphs and both have occurred
during the course of the work herein reported.
Equally complete records, however , were not obtained
for both.

Yellowaleaf Injury. Lime-sulphur
and lead arsenate were used at Balding, Experiment
in 1923 in comparison with the same materials to
which had been added certain materials intended to
retard the reaction between the lime-sulphur and

lead arsenate and consequently to reduce the amount

-82-

of injury. Excess lime was used in one instance
and calcium caseinate in another. Sulphur dust
was also used in comparison with the other materials.
Very little injury developed at any time except
after the last application when the trees were
sprayed from the inside as well as outside. About
two days after this application yellow leaves were
in evidence in many plots. The comparative amounts
of defoliation were determined by counting the
leaves persistent on spurs early in October. The
original number ofleaves present on the spurs was
not determined but the check tree may be assumed
as being normal as scab infestation on the foliage
was not severe and had caused little or no defbliatiau
A summary of the material presented
in Table 9 follows, showing the number of leaves
persistent on spurs at the first of October.
Check 4.6
Sulphur-lead dust 4.6

Combination schedule of
lime-sulphur and sulphur

amt 40°
Lime-sulphur plus lime 3.9
Lime-sulphur 3.9

Lime-sulphur plus calcium
caseinate 3.1

- 33 -

‘he loss of foliage was not severe
with most of the materials but the results give
some comparative effects.

Another and extensive experiment
was started at uorrice where it was planned to
obtain more definite data but the work in that
particular orchard was given up because of loss
of the crap from frost injury. General observa-
tions were made in another orchard on the same
farm where several combinations were used. They
indicated that excess lime with lime-sulphur and
lead arsenate did not appreciably reduce the amount
of yellow-leaf injury. The use of calcium casein-
ate, however, did seem to lessen this injury.

The observations there were made on Rhode Island
and Stark. The trees were sprayed at every
application from the ground, inside and outside,
and yellow leaves were present in numbers follow-
ing all post-blossom applications. The total
amount of leaf-fall was greater than at Balding.

At Beulah in 1923 records were
obtained from Baldwin to determine the comparative
amountsof injury caused by lime-sulphur and bor-
deaux. The injury on lime-sulphur sprayed trees

was of the yellow-leaf type and develOped mostly

after the two-weeks application. In early

-84-

September outside spurs on lime-sulphur trees had
an average of 4.2 leaves per spur as compared with
5.1 on bordeaux trees. The number present on the
bordeaux trees was probably about normal for that
time of year and under conditions that had prevailed
in that orchard.

The results obtained from the
young trees at East Lansing in 1923 were rather
inconclusive but indicate that lime-sulphur alone
does not cause much injury under weather conditions
that prevailed that season. The data presented
in Table 7 show that Baldwin trees spriyed with
lime-sulphur (complete application and normal
exposure) lost no more leaves than unsprayed
trees with normal exposure. Red Canada (Table 8)
with a complete application of lime-sulphur
lost 2.3 leaves per spur in comparison with 1.0
for the check.

Brown-leaf or Scald Type of Injugy.
The injury that developed on apples in 1924 was
almost entirely of the type described as brown-
leaf or scald, as the leaves did not turn yellow
before they were abscised but became brown as if

scalded. When the injury was severe the leafpfall.

- 35 -

when less severe or only slight the leaf persisted
but frequently a portion of the leaf broke off
so that many persistent leaves were not entire.
The extent of this type of injury was studied in
the orchard at Morrice (Exp. 10) with Hubbardstcn
and Wagener. In this experiment, the work was
divided; first, a general comparison of several
materials and combinations and second, a comparison
of different strengths of lime-sulphur and bordeaux
applied at various rates. The results for the
first will be discussed here, the second will
be considered later.

The materials used in the first
part of the work may be separated into three
groups; '-

1. Lime-sulphur.

2. Lime-sulphur to which some materid.
‘wae added to lessen injury of certain types.

3. Materials with sulphur as the

active agent but present as free sulphur.

In the first two groups the sulphur

- 35 -

was present in what may be termed an "active" form
as it is in solution in the form of polysulphides
and thiosulphate. In the third group, the sulphur
'was present in a relatively "inert” form, as free
sulphur and colloidal sulphur.
The total defoliation resulting

from injury of the brown-leaf or scald type occurr-
ing with each of the materials when used on.Hubb-

ardston was as follows. The data are taken from

 

Table 14.
Group ls
gctual Percent
Lime-sulphur 3.4 43.0
Group 20
Lime-sulphur with excess lime 3.7 48.6
Lime-sulphur and calcium
caseinate 4.4 55.6
Group 3..
' Drybmix sulphur-lame 2.4 30.7
Dry-mix and lime-sulphur
(combination schedule) 2.0 25.3
Colloidal sulphur (Tisdale) 1.9 24.3
Colloidal sulphur (Herbert &
Herbert) 2.5 32.0

Check, no treatment 1.8 23.0

A studybf these results shows that
the so-called inert materials caused much less
leaf-fall than the active materials. The active
materials all caused much more leaf-fall than the
inert materials but in the group where excess lime
and calcium caseinate were added the injury was
noticeably greater than where lime-sulphur was
used alone. Lead arsenate was used with all
materials but it seems safe to disregard it here
as there is no reason to believe that it was
involved in the injury that deveIOped.

Records were also obtained for
wagener for part of the materials used in the
general comparative tests. A summary of these
data, taken from Table 16, follows. The'records
here lhow the number of leaves persistent on
spurs at the end of the summer and in comparing
the results from the several materials it is
necessary to assume that the original number
of leaves per spur averaged about the same for

all treatments.

- 88 -

Group 1. Leaves persistent
Lime-sulphur 2.6
Group 2.
Lime-sulphur and calcium
caseinate 1.4
Group 3.
Dry-mix sulphur-lime 2.6

The results here are comparable
with those on Hubbardston except that there is
no difference between the final effect of the
inert material (dry-mix) and lime-sulphur alone.
There is no evidence at hand to explain this
difference but it may be suggested that some leaf-
fall may have occurred where dry-mix was used
as a result of scab infection on the foliage.
This was rather severe in this plot.

In general, the results indicate
that under conditions favorable for the deve10p-
ment of brown -leaf injury the so-called inert
materials, as dry-mix sulphur-lime and colloidal
sulphur will cause relatively little defoliation;
That lime-sulphur without the addition of special
materials will cause considerably more and enough

to be considered serious; and that the use of lime-

sulphur to which has been added excess lime or
calcium caseinate will result in severe leaf-fall.
Comparative Amount of Leaf-fall
Following Yellow- and Brown-leaf_gypes of Injggz.
A comparison of the amounts of leaf-fall occurring
in 1923 when conditions were favorable for the
yellow-leaf type and in 1924 whennthey were favor-
able fbr the brown-leaf type, shows in general
that the latter may be more severe when certain
materials are used. Companng the amounts of the
two kinds of injury caused by any one of the
three groups of materials just discussed shows
some interesting facts. The inert materials
(dry-mix, colloidal sulphur and sulphur-lead dust)
may be expected to cause relatively little injury
of either type. Lime-sulphur and lead arsenate
will cause both but with strength of material and
application uniform the brown-leaf injury will
likely be more severe than the yellow-leaf. The
addition of excess lime to the lime-sulphur and
lead arsenate combinations resulted in a slight

reduction in leaf-fall when yellow-leaf injury

prevailed but increased leaf-fall when conditions
were favorable for the development of the brown-
leaf injury. The relation of calcium caseinate
to yellow-leaf injury is rather doubtful but
brown-leaf inmury was definitely increased by
adding it to the lime-sulphur.

The Relation of'Weather Conditions

 

to the Development of Brown-leaf Injury. The
type of foliage injury developing on apples in
1924 was, as previously stated, different from
the usual injury following the use of the
lime-sulphur and lead arsenate spray, that is,
the yellow-leaf type which is probably the result
of soluble arsenic. This brown-leaf injury was
observed generally in many parts of Michigan in
1924, it was seen in southern Ohio on varieties
typical of that district and it was reported as
being very severe in the apple growing districts
of Pennsylvania. The fact that it occurred in
widely separated districts, on many varieties and
with many growers using various methods of appli-
cation and brands of spraying materials automati-
cally eliminates the possibility that it may have
been the result of faulty application or impro-
perly made spraying materials. The nature of the

injury indicated that it was in some way connected
with tender foliage which was not resistant to the
caustic action of lime-sulphur and in this connec-
tion it has been stated in the introductory para-
graphs that the nature of the season has a very
definite relation to the type of leaf, particularly
affecting the development of the cuticle.

On the basis of these observations
and facts, it seemed desirable to study the weather
conditions that prevailed in 1924 in districts
where this brown-leaf injury was known to have
been rather serious. The weather of 1924 was
compared with that of 1923 since none of the brown
leaf injury was observed during that year.

Records are presented in Table 21 fer the months
of May and June for certain conditions of the
weather at East Lansing, hichigan, Columbus, Ohio,
and harrisburg, Pennsylvania. These records
were obtained from the stations of the United
States Weather Bureau at each place. The study
was confined to May and June as it is during
these months that most of the leaf-growth on
spurs takes place.

A study of the data in Table 21

shows consistent differences for both months at
all stations. The mean temperature was consis-
tently lower in 1924, the total precipitation and
the number of days with rainfall were greater for
1924, the percentage of possible hours of sunshine
was consistently lower and the mean humidity was
higher in 1924 than in 1923. These conditions
were such that, with other things equal, leaves
grown in 1924 would be more tender than those of
1923 and consequently would be more susceptible
to the caustic action of freshly applied lime-
sulphur. This statement has no reference to the
brown-leaf injury following applications of lime-
sulphur when the temperature is high.

Bordeaux: There is only one type of injury
resulting from the use of bordeaux which has been
observed as responsible for leaf-fall in the apple
in the course of the experiments herein discussed.
Unless otherwise specified any reference will be
to the yellow-leaf injury.

Bordeaux was used in several
experiments in various orchards. At Balding in
1923 (Exp. 7) records were obtained from Baldwin.
In that one orchard the average number of leaves
persistent on spurs on October 3 on bordeaux
sprayed trees was 4.0 as compared with 4.6 fer
unsprayed trees. (Table 9) In this experiment,
then, the leaf-fall resulting from bordeaux injury
was insignificant. At Beulah in 1923 (Exp. 8)
and on Baldwin again, bordeaux had caused no
apparent injury as late as September 13 but con-
siderable injury and defoliation did occur a little
later. At East Lansing, 1923, (Exp. 6) the use
of 8-8-100nbordeaux (with complete application)
resulted in a total leafzfall on Baldwin (Table 7)
of 5.0 leaves per spur as compared with 1.6 leaves

for checks. On Red 0anada trees (Table 8)in the

-95-

same experiment a like treatment resulted in the
loss of 6.6 leaves per spur as compared with 1.3
for the check. In another experiment at East
Lansing in 1924 (Exp. 9) the use of 8-8-100 bordeaux
on Duchess (Table 11, Items 4 and 7) caused nearly
complete defoliation in comparison with a loss

of one-third to about one-half the leaves on
checks (Items 6 and 9). The leaf-fall in the

last period (ending October 3) with this variety
was heavy on sprayed and unsprayed alike. With
Rhode Island, in this experiment, (Table 12,

Items 4 and 7) the 8-8-100 bordeaux caused leaf-
fall to the extent of 6.9 and 7.3 leaves per

spur as compared to 2.4 and 3.2 for the checks
(Items 6 and 9). At Morrice in 1924(Exp. 10) a
moderate application of 6-12-100 bordeaux caused
injury and defoliation to the amount of 2.1

leaves per spur as compared with 1.8 for the check.
Considerable defoliation was caused, however, on
the check by a heavy infestation of scab on the
foliage so that the leaf-fall on the check must

be considered greater than normal. wagener in

the same orchard (Table 16) with like treatment

had 3.6 leaves persistent on spurs at the end
of the summer as compared to 4.6 and 4.7 under
other treatments where there was little injury.

A study of these results as whole
show that the use of bordeaux on apples may
frequently result in some abscission of leaves
but the injury frequently occurs so late in the
season or to such a small extent that the .
effect on the tree may be relatively less serious
than when heavy defoliation takes place early
in the season.

The Relation of Strength material
and date of application to the Development of
Foliage Injugyfiin the Apple. The second part of
Experiment 10 consisted of a comparison of two
strengths each of lime-sulphur and bordeaux, and
each applied at three different rates. The
results of this work are summarized and discussed
in the following paragraphs and in this connection
there are several angles to be considered: --
the strength of the material, the rate of applica-
tion, and the relative amounts of actual active
materials present. Lime-sulphur and bordeaux
will each be considered by itself and not compared,

one with the other.

- 97 -

Lime-sulphur. Two strengths of
lime-sulphur were used, 1% - 100, and 3 - 100.
These have been termed "weak" and "strong".

Each strength was applied at three rates which
have for convenience and in a.relative way been
called, "light”, "moderate", and "heavy" appli-
cations. Records of leaf-fall were obtained in
detail for Hubbardston and in less detail for
Wagener.

A comparison of weak lime-sulphur
and strong lime-sulphur, with equal dosage shows
definitely that the strong caused great injury.
and defoliation. This is shown for Hubbardston
(from Table 15) in the following tabulation in

which is stated the total» leaf-fan.under each

 

treatment.
Dosage Weak Strong
Light 1.8 (22%) 3.6 (43.91)
Moderate 2.8 (36%) 6.1 (63.0%)

 

With Wagoner the results (from

- 98 -

Table 16) are stated in terms of the number of

leaves persistent on spurs at the end of summer.

 

Dosage Weak Strong_
Light 4.6 2.1
Moderate 3.2 1.9
Heavy 2.6 0.8

 

A comparison of results of differ-
ent rates of application but with the strength
of material the same shows conslusively that an
increase in dosage results in a greater amount of
injury. This is shown clearly for both Hubbardston
and Wagoner in the tabulations just preceding this
paragraph.

The relation of the relative amounts
of actual lime-sulphur to the degree of leaf-
fall is shown fer Hubbardston in Figure l. The
amount ofactual lime-sulphur applied to any tree
was of course determined by two other factors:

strength of material and rate of application. The

graph in rigure 1 shows that leaf-fall is very
closely proportional to the number of units of
lime-sulphur used.

It should be made clear at this
point that the results stated in this section of
the discussion apply only to the brown-leaf
type of lime-sulphur injury and not to the yellow-
leaf kind.

Bordeaux. Comparisons similar to
these made for lime-sulphur may also be made with
bordeaux. ‘The weak bordeaux was made by the 2-4-
100 formula and the strong by the 6-12-100 for-
mula and both were applied at three rates; --
light, moderate, and heavy applications.

The amount of defoliation on bor-
deaux sprayed trees, regardless of strength of
materials or dosage, was rather light and was
the result of epidemic of yellow leaves that
occurred in late July and early August. The
results for Hubbardston (from Table 15) and
fer Wagener (from Table 16) are presented in the
following tabulations.

The total leafbfall from spurs
for Hubbardston is first.

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- 100 -

 

Dosage Weak Strong

Light 1.1 (14.4%) 2.1 (26.5%)
Moderate 1.6 (21.1%) ' 2.1 (27.1%)
Heavy 1.8 (23.0%) 1.5 (19.w%)

The number of leaves persistent on
spurs of wagener at the end of summer is shown in

thesecond.

Dosage Weak Strong,

Light 4.7 3.8
Moderate 4.4 3.6
Heavy 4.0 3.8

 

Studied on the basis of strength
of material it is found that with equal dosage
the strong bordeaux usually caused slightly
greater leaf-fall.

From.the point of view of rate
of application, each increase in dosage of the
weak bordeaux caused slightly more foliage injury

- 101 -

with both varieties but the results were not so
consistent with the strong.

The relation of the comparative
number of units of cepper in bordeaux to the
amount of leaf-fall is not very definite as
shown in Figure 2 and in fact the differences
are so small that it is evidently unsafe to draw
any conclusions from the results of this work with
bordeaux, under the conditions that prevailed in
that orchard during the season when the work
was done. Under other conditions, more favorable
for bordeaux injury, the results might have
been entirely different.‘

The comparative amounts of defolia-
tion under the various treatments is also shown
for both Hubbardston and wagener in a series of
photographs taken on September 23. This is shown
in the photOgraphs in two ways: -- first, by
general views of the trees to show the density
of the foliage .mass, and second, by close-up
views of a few spurs to show the comparative
numbers of leaves present. The photographs of the
trees and spurs of Hubbardston are shown in
Figures 3 and 4 and for Wagoner in Figures 5 and
6.

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-107-

The question of strength of mater-
ials and rate of application cannot be decided
entirely on the basis of foliage injury. The
combination that is best to use is the one that
will give satisfactory pest control with a
minimum of foliage injury. Results obtained in
connection with these experiments, but not dis-
cussed in this paper, show that with lime-sulphur,
a medium concentration and moderate rate of appli-
cation gave the most satisfactory results, consider-
ing both pest control and foliage injury. With
bordeaix it was found that the strength can be
reduced considerably below that generally used
and still get satisfactory scab control. The
results, however, with regard to foliage injury
as stated in fbregoing paragraphs were not de-
finite but so much russeting of the fruit occurred

that the use of ordinary bordeaux does not seem

advisable.

The Effect of Spraying Materials on the

Abscission of the Fruit in the
9321.2:

Records were obtained in two ex-

periments, one in 1923 and the other in 1924 to

- 108 -

determine if spraying materials affect the ab-
scissionof young apples. This work was done in
two orchards and with three varieties.

The work in 1923 was with mature
Baldwin trees at Beulah. One lot of trees was
sprayed with lime-sulphur and the other with
bordeaux. The details of methods are discussed
in Experiment 8. The results (from Table 10)
which are summarized here show a definite diff-
erence between the effects of the two materials.
The comparison here is made in terms of the number
of apples matured on any 100 spurs that bore

blossoms in the spring.

 

Material Inside Spurs Outside Spurs
Lime-sulphur 19 62
Bordeaux 66 90

 

The percentage of spurs on bore
deaux trees, both inside and outside, that retained
fruit was much higher than on lime-sulphur trees
and the average number of apples on these spurs

was higher for the bordeaux trees.

- 109 -

The work in 1924 was done at
Morrice in connection with Experiment 10.
Records were obtained from Jonathan and Hubb-
ardston.

The date for both varieties from
the general comparative test will be considered
first. The results for Jonathan (from Table
17) is condensed and presented in the following
tabulation. The figures given are for the final

count made after the June drop.
Spurs Apples; Apples on

 

Retaining' per 100

Material fruit .-Spur (Spurs
Limeesulphur 61% 1.2 73
Lime-sulphur plus

lime 90% 1.5 155
Lime-sulphur plus 7

calcium caseinate 53% 1.2 63
Dry-mix sulphur-

line. 81% 1.4 115

Dry-mix and lime-
sulphur -- comm.

schedule. 85% 1.7 135
Colloidal sulphur

(Tisdale) 48% 1.4 57
Colloidal sulphur

(Herbert 5

Herbert). 79% 1.6 125

 

This data shows that lime-sulphur

- 110 -

and lime-sulphur plus calcium caseinate reduced
the final set of fruit much below lime-sulphur
plus lime, dry-mix for all or part of the applica~
tions and colloidal sulphur (Herbert and Herbert).
The results of the other colloidal sulphur was
about the same as the first two mentioned. Refer-
.snce to Table 17 shows a peculiar effect where
lime-sulphur plus calcium caseinate was used.
The first drop was relatively light but the June
drapwas very heavy so that the final set was
less than with lime-sulphur alone. The fruit set
on the check trees is given in Table 17 but no
mention has been made of this in the discussion
because of severe injury to the young fruits by
scab.

The results for Hubbardston (from
Table 19) for the general comparative tests are
condensed and presented in the following

tabulat ion.

 

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m erg-«go: n seq; use 2... 0?!

 

 

Spurs Apples Apples
Retaining per on 100

Haterial Fruit Spur Spurs
Lime-sulphur 55% 1.2 42
Lime-sulphur plus

lime. 40% 1.0 40
Lime-sulphur

plus calcium

caseinate 43% 1.0 43
Dryhmix sulphur

lime. 50% 1.0 so
Dry-mix and

lime-sul-

phur, com

bination

schedule 49% 1.1 53
Colloidal sul-

phur (Tie-

dale) 50% 1.1 55
Colloidal

sulphur

(Herbert

5 Herbert) 50% 1.2 60

 

The final fruit set with Hubbards-
ton with all treatments was lower than the poorest
on Jonathan and the differencesaro so small that
conclusions would seem unreliable.

Fruit-set records were also obtained
for both varieties from the comparison of weak

and strong materials applied at various.1ate£d

 

 

‘7,

,

- eteiassisc x

 

_,_n

tumours-ts:

 

     

 

- 112 -

The results with Jonathan from Table 18 may be

stated as follows.
Spurs Apples Apples

 

 

Retaining per on 100
Material Fruit S ur S urs
Week Eight uppre . M
lime- Moderate " 29% 1.0 29
sulphur Heavy 7 56% 1.4 50
strong Light 2 27% 1.0 27
lime- Moderate 7 55% 1.1 36
sulphur Heavy ' 15% 1.0 13
Weak Light 7 97% 1.5 145
bordeaux Moderate " 62% 1.4 so
Heavy 7 50% 1.0 50
Light 7 89% 1.7 151
Strong Moderate " 72% 1.1 79
Bordeaux Heavy " 78% 1.6 124

 

No effort will be made to correlate
strength of materials and rates of application
with fruit-set and the results are very irregular
but a comparison of the lime-sulphur group as a
whole with the bordeaux group shows a distinct
difference in results in favor of bordeaux.

‘he results with Hubbardston
(from Table 18) follow.

w: as “is none _..

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- 113 -
Spurs Apples Apples
Retaining Per on 100

Material Fruit S ur Spurs
Vial: Light applic. 513’ 1.5 66

 

 

 

/o

lime- Moderate ‘ 29% 1.0 29
sulphur Heavy " 30% 1.4 50
Strong Light 7 21% 1.0 27
lime- Moderate " 33% 1.1 36
sulphur Heavy 7 15% 1.0 15
Weak L1 ht ” 97 1.5 145
bordeaux.Mo erate 7 62 1.4 86

Heavy " 50 1.0 50
Strong Light 7 59 1.7 151
bordeaux.Moderate " 72 1.1 79

Heavy " 78 1.6 124

 

The results with Hubbardston are
again very irregular but a comparison of the two
groups as a whole indicates that a heavier set
may be expected on trees sprayed with bordeaux
than with lime-sulphur.

The results with regard to the
relation of spraying materials to the abscission
of apples are not such that definite conclusions
are justified but there is very good evidence
that lime-sulphur will, with some varieties at
least, cause a heavier abscission of fruits than
occurs where bordeaux or some of the less active

forms of sulphur are used.

  

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- 114 -

Some General Considerations with Regard
to Foliage Injurg.

The Relation of 1'ime of Application
to Time Develgpment of Foliage Injggyz, A study
of the data presented in the several tables, in
which a comparison is made of the dates of appli-
cation and the periods when leaf-fall occurred,
brings out some interesting facts which may in a
general way be stated as follows. Brown-leaf
and yellow-leaf injuries following the use of
lime-sulphur and lead arsenate both develop soon
after an application but may not develop after
all applications. Bordeaux injury of the yellow-
leaf kind may develOp soon after an application
but may also be delayed indefinitely.

These facts are illustrated in
four graphs presented in Figures 7, 8 and 9.

In Figure 7 are presented the results with Mont-
morency cherry at East Lansing in 1923 (Experiment
1 and Table 1). The graph shows clearly that
lime-sulphur caused no injury of consequence and

that bordeaux caused practically no injury until

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- 11 5-

1ong after the last application which was made on
June 24. The first injury of consequence occurred
in early September and continued through the
month. In Figure 8 are presented in graphic
ferm the results with Montmorency at East Lansing
in 1924 (EXperiment 3 and Table 3). Lime-sulphur
again caused relatively little injury and bordeaux
very little until late in the last record period.
In £1igure 9 are shown the results
obtained at morrice in 1924 with the Hubbardston
apple (Experiment 10 and Tables 14 and 15). The
applications earlier than the two-weeks are not
shown as no injury was observed previous to that
time and careful observations indicated that the
leaf-fall on bordeaujkprayed trees was probably
only normal as no de inite injury resulting from
bordeaux was seen until much later. Definite
injury did develop, however, in the lime-sulphur
plot and the total leaf-fall for the first period
is an expression of the normal fall plus that
resulting from line-sulphur injury. No further
leaf-fall occurred on the lime-sulphur sprayed
trees until immediately after the second-brood
spray when severe injury developed, but there was

110 recurrence of injury or defoliation after that

11eriod. The bordeaux trees, on the other hand,

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- 116 -

lost some leaves as a result of bordeaux injury
which developed shortly before the second-brood
application. No leaf-fall occurred on bordeaux
sprayed gross after that application.

In other experiments as at Beulah
in 1923 (Experiment 8) the only injury observed
in bordeaux sprayed trees developed in late
September while the injury on lime-sulphur sprayed
trees occurred immediately after the two-weeks
and second-brood sprays. In work at Balding in
1922, which has not been discussed in this paper,
bordeaux injury was not seen until late September
and early October.

The conclusion to be drawn, then,
from these studies is that injury of either type
on trees sprayed with lime-sulphur and lead
arsenate may be expected to deve10p shortly after
an application and that there will be no recurrence
until after another application but with bordeaux
the injury and accompanying leaf-fall may not and
usually does not occur until a considerable
time after any particular application. Bordeaux
injury may also continue in a gradual way or
recur in epidemic form with another application.

Just what the factors ass that may

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- 117 -

be responsible for these conditions are not fully
understood but the discussion in the paragraphs
that follow immediately may throw some light on

the subject.

The Relation of Weather Conditions to
the Development of Foliage Injury.

Definite studies have not been made
to determine just what conditions are favorable
for the development of the yellow-leaf type of
injury following the use of the lime-sulphur and
lead arsenate spray but since this injury was
uncommon in 1924 it may be assumed that the state
of weather and plant growth that prevailed then
was not favorable for such injury but it is not
possible to state just what really does favor
its deve10pment. Certain conditions of the weather
for a portion of the summer of 1924 have been
presented in the foregoing pages. The conditions
that apparently favor the deve10pment of brown-
leaf injury have already been fully discussed and
will not be repeated here.

In the course of these investigations

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- 118 -

and in connection with many other experiments,
bordeaux injury to the foliage of the apple and
cherry has been observed in many degrees. It
has not been possible to correlate every epidemic
with some meteorological condition and in fact,
all the injury seen has not developed in epidemic
ferm but in a gradual way. There has been one
definite observation, however, which is that nearly
every severe and definite epidemic of yellow leaves
resulting from the use of bordeaux has been pre-
ceded by a period of foggy weather or light rains
with relatively high temperature and further
these epidemics have occurred in seasons or in
the portion of a season when rainfall was relatively
light.

A number of instances may be cited.
In 1919 at Grand flapids cherries and plums were
_ Sprayed with bordeaux. The summer was extremely
dry but rather heavy defoliation occurred follow-
ing light showers in late afternoon and evening
so that the foliage remained wet, probably, all

night. At Traverse Oity with Montmorency cherries

- 119 -

foggy weather with rather high temperature but no
rain of consequence was followed by an epidemic
of yellow-leaf injury. At East Lansing in 1923
(Experiment 1) Montmorency cherries were sprayed
with bordeaux. On August 30 a heavy fog occurred
with temperature about normal. The leaf-count
made on September 7 showed a leaf-fall of 1.4
leaves per spur and the full effect of the
epidemic had not been felt at that date. No
precipitation of consequence had occurred during
August. In 1924 at East Lansing heavy fogs occurred
on September 17, 18, 20 and 21. For the

last two dates the fog began in the evening of
the 20th and continued until nearly the middle

of the forenoon of the 2lst. This fog was very
heavy and the temperature was high. The mean
lowest temperature for the month was 46.5 de-
grees F. while the minimum temperature for the
morning of “eptember 21 was 58 degrees F. This
was fellowed by an epidemic of yellow leaves on
both apples and cherries. At merrice in 1924
with apples the only time that defoliation on.bor-
deaux Sprayed trees occurred was in early

August. About ten days earlier a light rain had
fallen in the evening, so that the trees remained

wet during the night.

All the defoliation caused by
bordeaux injury cannot be accounted for in this
way but, as previously stated, all the severe
epidemics of yellow leaves followed the condi-
tions described and the evidence seems to justi-
fy the conclusion that yellow bordeaux injury on
apples and cherries in Michigan is most likely
to deVelOp during periods when fogs or light rains
preval.and when the temperature is relatively
high; 1

Strength and composition of Bordeaux
in Relation to thegevelopment of Injggz; ‘Various
fermulae were used for making the bordeaux used
in the several experiments with cherries but they
were not compared directly in any single experiment
so that it will not be possible to make any definite

comparisons. The general conclusion, however,

from a study of the results is that bordeaux at

any of the strengths used may cause considerable
injury, and defbliation.

“ith apples, there were three

- - 121 -
opportunities to study the effect of different
strengths of bordeaux. At Morrice (Experiment
10) 2-4-100 and 6-12-100 bordeaux were used but
without any significant differences in results.
Two strengths were used at East Lansing in 1923
(Experiment 6) on Baldwin and Red Canada.
The formulae were 8-8-100 and 6-10-100 and the
stronger material caused slightly greater defolia-
tion on both varieties than the weak,

In 1924 a more complete test was
made to determine the effect of different amounts
of copper sulphate and different ratios of lime.
This was with Rhode Island and Duchess at East
I'ansing (Experiment 9). I.

The results for Duohess (from
Table 11) and for “hode Island (from Table 12)
may be summarized as follows. This injury is
expressed in terms of total leaf-fall from spurs

for the season.

~ 122 -

 

Material Duchess Rhode Island
Bordeaux, 2-2-100 7.4(5.9) 6.6(4.2)
Bordeaux 2-4-100 7.2(1.9) 5.3(2.5)‘
Check 5.6(0.8) 3.0(0.4)
Bordeaux 8-8-100 8.4(1.7) 6.9(2.1)

Bordeaux 8-16-100 4e9‘1e5) 7e1‘2e1)
Check 2.9(1.0) 2.4(O.9)
Bordeaux 8-8-100 7.6(2.4) 7.3(3.8)
Bordeaux 8-8-100 (Dalomitec) 8.3(2.l) 7.6(4.7)
Check 4e2‘1e2) 3e2‘2e0)
Bordaaux b‘N’lOO 7e3‘7e0) 7.1(6e9)
Colloidal copper hydroxide 3.9(1.7) 5.1(1.2)
Check. 3.3(O.8) 2.2(l.2)

 

The leafffall during the last period,
iending October 3, may have been affected to a certain
extent by frost injury so in order to avoid this com-
plication the amount of the leaf-fall occurring

up to August 20, the end of the second period, is
given in parentheses for each item. (An analysis
of the data in this tabulation results in

nothing definite except that bordeaux with only
enough lime to precipitate the cepper is unsafe

and that colloidal copper hydroxide caused, in this
instance, no foliage injury of consequence.

The only conclusion that can be

drawn from this discussion of strengths of bordeaux

- 123 -

in relation to foliage injury is that even when
the concentration is low severe injury may de-
velop. However, the work along this line is
not extensive enough or the results definite
enough to permit the statement that reducing
the amount of cOpper sulphate or increasing that
of lime will or will not reduce the degree of
foliage injury and defoliation. ‘

The Relation of Shading to Lime-
Sulphur Ingggy; The results obtained from the
work where trees were shaded in comparison with
unshaded trees (Experiment 6) were inconclusive
and such that it is not possible to state any
definite conclusions. There were no significant
differences in leaf-fall under the several con-
ditions or with spraying and no spraying and in
every instance was light.

Method of Application and Foliage
Injury. One object of the work in Experiment 6
was to detenmine if the method of application
effects in any way the amount of foliage injury
and leaf-fall. The materials were applied in

- 124 -

three ways: -- to the upper leaf surface only, to
the lower leaf surface only, and to both the upper
and lower surfaces.

The results with lime-sulphur on
Baldwin (Table 7) were entirely inconclusive but
with Red Canada (Table 8) the amount of injury
increased with the different treatments in the
order following: upper surface only, lower
surface only, and upper and lower surfaces. The
leaf-fall on the check was slightly less than
where the upper surface only was sprayed. These
results, however, are to be considered as
indicative of what may occur rather than as con-
clusive evidence.

With bordeaux, 8-8-100, on Baldwin
(Table 7) the degree of leaf-fall increased in the
order given for the several treatments: -- check
(1.6), upper surface only (3.3), lower surface
only (3.8), and both upper and lower surfaces
(5.0). With Red Canada (Table 8) the results were
in the same order except that the leaf-fall where
sprayed on the lower surface only was less than
for the upper surface only. The amounts of de-
foliation per spur for the several treatments were

as follows: -- check (1.3), upper surface only

(3.3), lower surface only (2.1), and both upper

and lower (6.6). The results here must again be
considered as indicative rather than conclusive
as there were factors, other than method of
application, that may have affected the results.
Comparative Susceptibility_gf

Cherries and Apples to Injury by Spraying
IMaterials. A study of the results of the several

 

 

experiments with apples and cherries shows that
there are rather distinct differences in the tol-
erance of the two fruits to lime-sulphur and
bordeaux. Sour cherries, under Michigan condi-
tions, do not seem to be subject to either of the
two types of injury resulting from the use of
lime-sulphur ahd acid lead arsenate but are quite
susceptible to injury by bordeaux. .Apples, on
the other hand, are quite susceptible to both
types of injury that may result from the use of
lime-sulphur and lead arsenate. Injury following
the use of bordeaux is also likely to occur on
apples but usually to a less serious extent and
frequently so late in the season that the effect
of the defoliation following the injury may not be

- 126 -

of so much consequence as if the injury had

developed early in the season.

- 127 -
Summagy

The studies reported in this paper
were made in connection with ten individual
experiments on apples and sour cherries. These
experiments were with trees of various ages, of
several varieties, located in different parts of
the state, and in two season that were widely
different with regard to weather conditions. The
conclusions drawn from these studies are summarized
in the following paragraphs.

Foliage injury of two distinct types
has been obserfed on the apple following the use
of lime-sulphur and lead arsenate. The first and
perhaps most common is the yellow-leaf injury which
develops within one to two weeks after an appli-
cation. This injury is probably eaused by soluble
forms of arsenic resulting from reaction between
lime-sulphur and acid lead arsenate. The other
injury has been called the brown-leaf or scald type
and it also deve10ps soon after an application.
This injury is supposedly caused by the lime-
sulphur itself and therefore might deve10p when

it is used alone without lead arsenate. Leaf-fall

- 128 -

may follow both types of injury.

Bordeaux may cause on apples and
cherries what has been called yellow-leaf injury.
There are other types but they have not been ob-
served to cause defoliation. Leaves affected in
this way look very much like those attacked by
certain leaf-spot diseases, as cherry leaf-spot.

The sour cherry shows large diff-
erences in susceptibility to injury by various
spraying and dusting materials. Lime-sulphur
has caused very little injury to the foliage
and no serious leaf-fall. Bordeaux has frequently
been responsible for heavy defoliation. Injury
following the use of sulphur dust and capper dust
has not been observed on the sour cherry in Michi-
gan. Pyrox has caused very heavy defoliation.
Changing from lime-sulphur to bordeaux or vice versa
has resulted in quite severe foliage injury. The
conditions under which such injury is likely to
develOp are not fully understood.

There is evidence that there is
some relation between the.nutritive condition

of the tree and its susceptibility to bordeaux

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-129-

injury but just what the conditions are that favor
injury have not been determined.

The apple also varies in its suscep-
tibility to injury by different materials but in
a different way from the sour cherry. Both types
of injury which may follow the use of lime-sulphur
and lead arsenate have been observed. Bordeaux
injury also occurs on the apple. Sulphur and
copper dusts have not caused any foliage injury.
The addition of excess lime to the lime-sulphur-
lead arsenate combination seems to decrease slightly
the amount of yellow-leaf injury but to increase
that of the brown-leaf type. Calcium caseinate
has caused a definite increase in the amount of
brown-leaf injury and its relation to the yellowb
leaf type has not been fully determindd. Dry-
mix sulphur-lime and colloidal sulphurs cause re-
latively little defoliation.

Yellow-leaf injury probably occurs
on the apple more frequently than the brown-leaf

but the latter may be more severe when conditions

are favorable for its development.

- 130 -

Brown-leaf injury seems to occur
under conditions that favor the growth of a tender
leaf, that is, one with a light cuticle. Some of
the conditions that evidently favor this are low
temperature, with much precipitation at frequent
intervals, relatively little sunshine, and high
humidity.

Brownpleaf lime-sulphur injury in
the apple was more severe with strong lime-sul-
phur than with weak; it was also greater with each
increase in dosage, and varied closely withthe
actual amount of lime-sulphur concentrate used per
tree regardless of the dilution or rate of applica-
tion. Little or no correlation could be established,
under the same conditions. between the amount of
yellow-leaf bordeaux injury and the strength of
the bordeaux, the rate of application or the actual
amount of capper applied per tree.

Abscission of the fruit in the apple
is affected byaspraying materials, the results
varying with different varieties. The exact

relation of all materials to this phenomenon has

1a sagas-1:5 u: as. duets) any

    

- 131 -

not been established but the results indicate de-
finitely that lime-sulphur may, under some condi-
tions and with some varieties cause an abnormal
drop of fruit. The effect of the addition of excess
lime or calcium caseinate to lime-sulphur has
not been determined fully. Bordeaux and the less
active sulphur sprays, as dry-mix sulphur-lime and
colloidal sulphur apparently do not cause an
abnormal drop.
The length of time after an applicatial

before injury develops varies with the material.
Yellow-leaf and brown-leaf injury on lime-sulphur
sprayed trees both develop within one to two weeks
after an application and have not been observed
to recur until after another application. Yellow-
1eaf bordeaux injury may occur soon.after an
application but usually has not developed until

some time after and may continue or recur.

The relation of weather conditions

to the time of development of injury on lime-sul-
phur sprayed trees is not clear, but the appearance
of bordeaux injury of the yellow-leaf type in epidemic
ferm usually follows a period of heavy fogs or

light rains with the temperature relatively high.

- 152 -

All bordeaux injury to the foliage, however,
cannot be explained in this way.

The relation between the strength
and composition of bordeaux and the degree of
foliage injury has not been established but it
was observed that injury occurred on both apples
and cherries regardless of the strength or composition
of this bordeaux.

‘he effect of shading on the occurrence
of lime-sulphur injury on apples was not determined
as there was so little leaf-fall udder any condition
that comparisons were impossible.

The results obtained with regard to
method of application in relation to leaf-fall
indicate, with both lime-sulphur and bordeaux, that
injury is more likely to occur when the under sur-
face only is sprayed than when the upper surface
only is covered and still more may follOw a complete
application to both surfaces. The results, however,
are indicative rather than conclusive.

Differences were found in the suscep-

tibility of the sour cherry and the apple to various

- 153 -

types of injury. The cherry seems very resistant to
lime-sulphur injuries, but susceptible to bordeaux
injury. The apple is susceptible to both types of
lime-sulphur injury and to bordeaux injury but with
bordeaux defoliation is likely to be much less severe
and to occur at less critical periods than with the

cherry.

~134-

Acknowledgments.

The writer is indebted to Professor
V. R. Gardner for many vaulable suggestions and
helpful criticisms; also to Professor F. 0.

Bradford and Dr. J. W. Crist.

1.

2.

3.

4.

5.

6.

7.

8.

- 135 -

pytoraturo Cited
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Trans. Peninsular Hort. Soc. pp. 82-87 (1922)
Bain, S. M. The action of copper on leaves with
special attention to the injurious effects of
fungicides on peach foliage. Tenn. Sta. Bul.
Vol. 15, No. 2: 1-108. (1902)
Crandall, C. S. Bordeaux.mixture. Ill. Agr.
Exp. Sta., Bul. 155. pp. 201-296 (1909)
000per, J. R. Spraying experiments in
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Rodrick, U. P. Bordeaux injury. 5. Y. Agr.
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Kohl, F. G. Die Transpiration dor Pflanzen
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Morse, 7. J., and Shapovalov, M. Apple Spraying

.experiments in 1914. Me. Agr. fixp. Sta. Bul.

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Pickett, B. S., at al. Field experiments in
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Safro, U. I. An investigation of lime-sulphur
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pp. l-ll. (1922).

Thatcher, R. W., and Streeter, L. R. Chemical
studios of the combined load arsenate and lime-
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521. pp. 1-20. (1924).

Wallace, E. Spray injury induced by lime-sul-
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Whetzel, R. H. Apple scab and foliage injury.
Proc. R. Y. State Hort. Soc. pp. 76-78. (1924).
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Annals Mo. Bot. Gard. 9:403-435. (1922).

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