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43

.E22

no.l84

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CONNECTICUT

Agricultural Experiment Station

NEW HAVEN, CONN.

BULLETIN 184, DECEMBER, 1914.

SPRAY treatment, ETC., for ORCHARDS.

CONTENTS.

Page

Officers and Staff 2

Spray Treatment, etc., for

Orchards 3

Winter Treatment 3

Pruning as a Control Measure 3

Winter Spraying 4

What to Use 5

Lime-Sulphur Mixtures . 5

Miscible Oils 6

Lime-Sulphur versus Misci-
ble Oils 6

Page

Summer Spraying 6

Apple 6

Pear 8

Peach 8

Plum 8

Cherry 9

Quince 9

Directions for Making Spray

Mixtures 10

Cautions 11

The Bulletins of this Station are mailed free to citizens of Con-
necticut who apply for them, and to others so far as the editions
permit.

CONNECTICUT AGRICULTURAL EXPERIMENT STATION.

OP'KICERS AND STAFF".

BOARD OF CONTkOl..
His Excellency, Simeon E. Baldwin, ex-officin, President.

Prof. H. W. Conn, Vice President Middletown

George A. Hopson, Secretary Wallintrford

E. H. Jenkins, Director and Treasurer Xew Haven

Joseph W. Alsop Avon

Wilson H. Lee Orange

Prank H. Stadtmueller Elmwood

James H. Webb • • Hamden

Administration.

E. H. Jenkins, Ph.D., Director and Treasurer.
Miss V. E. Cole . Librarian and Stenographer.
Miss L. M. Brautlecht, Bookkeeper and Stenographer.
William Veitch, 7n charge of Buildings and Grounds.

Chemistry.

Analytical Laboratory. John Phillips Street, M. S., Chemist in Charge.
E. Monroe Bailey, Ph.D., C. B. Morison, B.S.,
C. E. Shepard, G. L. Davis, Assistants.
Hugo Lange, Laboratory Helper.
V. L. Churchill, Sampling Agent.
Miss E. B. Whittlesey, Stenographer.

Proteid Research.

T. B. Osborne, Ph.D., Chemist in Charge.
Miss E. L. Ferry, M.S., Assistant.

IBotany.

G. P. Clinton, Sc.D., Botanist.
E. M. Stoddard, B.S., Assistant Botanist.
Miss E. B. Whittlesey, Herbarium Assistant.
G. E. Graham, General Assistant.

Entomology.

W. E. Britton, V 11. T)., Entomologist ; State Entomologist.
B. H. Walden, B.Agr., First Assistant.
Q. S. Lowry, B.Sc, I. W. Davis, B^Sc,

M. p. Zappe, B.S. Assistants.
Miss F. M. Valentine, Stenographer.

Forestry.

Walter O. Filley, Forester; also State Forester

and State Forest Fire Warden.
A. E. Moss, M. F., Assistant Station Forester.
Miss E. L. Avery, Stenographer.

Plant Breeding.

H. K. Hayes, M.S., Plant Breeder.
C. D. Hubbell, Assistant.

Vegetable Growing.

Howard F. Huber, B.S.

SPRAY TREATMENT, ETC., FOR ORCHARDS.

By W, E. Britton, Entomologist, and
G. P. Clinton, Botanist.

This bulletin has been prepared to meet a constant and grow-
ing demand for information regarding the general spraying
of orchards in Connecticut. More specific and detailed ac-
counts of the various insect and fungous pests of orchards
may be found in the Spray Calendar and in the reports of this
Station, especially those of the Entomologist, the Botanist, and
in "Tests of Summer Sprays on Apples and Peaches", Reports
1910, page 583, and 1911, page 347. Some of these are out
of print and can no longer be supplied.

If the orchardist finds troubles not readily recognized by
means of the publications just mentioned, or if they are new
to him, he should send specimens to the Station for identifica-
tion and for advice about treatment. All such specimens
should be placed in a strong paper, wood or metal box, so as
not to be crushed in the mails. All communications are an-
swered when the sender's name and address accompany
specimens.

WINTER TREATMENT.

Pruning as a Control Measure.

In most peach and apple orchards it is the usual practice to
prune before spraying the dormant trees, especially before the
March spraying with lime-sulphur or with miscible oil. All sur-
plus wood may then betaken out, thus leaving less bark surface to
be covered with the liquid. If the trees are attacked by San
Jose Scale or any other kind of scale insect, the worst infested
branches should be removed. All branches showing injury
from the attack should be headed back in order to get a strong-
er growth from fewer buds.

Winter pruning is even more essential for fungous troubles
than for insects. Of course one of the chief reasons for
pruning is to take out unnecessary and interfering branches
and shape up the tree, with resulting improved dry air drain-
age whereby infection by fungi is lessened, but even more

4 CONNECTICUT EXPERIMENT STATION BULLETIN 184.

important is the removal of dead limbs and twigs and those
showing diseased areas and cankers in the bark, as all these
are frequently the carriers of the winter stage of injurious
fungi. When it is not advisable to remove the cankered
branch or trunk, the infected area should be carefully removed
by cutting clear to the healthy bark and scraping out all the
intermediary tissues. These scraped areas and the cut ends
of the larger branches should be painted over when dry with
white lead or coal tar.

After this pruning has been done the tree should be thor-
oughly coated with spray. It is a good practice to bum all
diseased or infected branches w^hich have been cut from the
trees.

For the blight on pear, also on apple and quince when they
are seriously affected by this bacterial disease, winter pruning
is especially desirable, since the re-inoculation of the germs in
the freshly cut surfaces is then much less likely than during the
growing season. Even in winter, however, it is best to cut oft
the branches some distance below the diseased parts and wipe
the pruning tool frequently with a cloth moistened in carbolic
acid or corrosive sublimate solution, to kill any accidentally
attached germs.

For cherries and plums attacked by black knot, pruning in
late fall or in winter before the winter spore stage starts to
germinate is likewise desirable. Cutting out the knots has not
been found very satisfactory, so all infected branches should
be cut off several inches below any signs of the knot. A\'hen
possible, it is best to commence this pruning with the young
trees as it sometimes requires severe treatment to remove all
knots. This should be kept up each year until the knots fail
to reappear. In case the tree is severely cut back, additional
pruning is needed from time to time to re-shape the tree, remove
water sprouts, etc. The knots should be carefully gathered up
and burned before spring. Watch should be kept of wild
cherry and plum trees in the neighborhood, lest they serve as a
means of infection.

Winter Spraying.

Spraying of orchard trees, when dormant, was first made
necessary in Connecticut from ten to fifteen years ago by the

WINTER SPRAYING. 5

prevalence of the San Jose Scale, which ruined many peach
■orchards and seriously damaged apple orchards. Winter
spraying is practiced for the purpose of destroying insects
rather than fungi, though one fungus, the peach leaf curl, may
also be controlled by this treatment.

Besides the San Jose Scale, certain other pests, such as the
leaf blister mite on pear and apple, the clover mite which may
be found on any kind of trees, the pear Psylla on pear, the
green apple aphis and the rosy apple aphis on apple, may all be
wholly or partially controlled by the winter treatment.

For most of the insect troubles mentioned above, the
trees may be sprayed as soon as the leaves drop in November,
or just before the buds open in April. The fall application will
probably kill more San Jose scales than the spring application,
because they are not then protected by their winter covering
and often the naked young may be seen crawling about until
December 1st. Where trees are badly infested with San Jose
Scale, it is usually advisable to spray twice, once in November
and again in April, as the second will often cover parts of the
tree that were missed by the first treatment.

For peach leaf curl, however, the early spring treatment is
advisable, and some newly-hatched aphids will then be killed
which were not present on the trees at the time of the Novem-
ber application.

What To Use.
Lime-Sulphur Mixtures.

The best all-round spray for peach, plum and all young and
smooth-barked trees is the lime-sulphur mixture. In some of
the larger orchards this is made on the place which, no doubt,
is the cheapest and best way, if the size of the orchard war-
rants the outlay for the plant. In most cases, however, the
owner will prefer to purchase his lime-sulphur, and he can
buy the commercial liquid lime-sulphur in any desired quanti-
ty, ready to dilute and apply, and be fairly certain of procur-
ing a good article. This commercial lime-sulphur should test
about 33°B and it should be diluted at the rate of one part
in nine parts of water.

There are now on the market several dry lime-sulphur mix-

6 CONNECTICUT EXPERIMENT STATION BULLETIN 184.

tures which claim a great saving in freight by not shipping the
water. Some of these are sulphides of basic elements other than
lime, and they will probably prove good insecticides and pos-
sibly fungicides, without causing injur}' to the trees, but they
are still more or less in the experimental stage.

Miscible Oils.

If one has large and old apple trees with rough bark and
badly infested with San Jose Scale, he may be able to rid them
of the scale quicker by spraying with one of the so-called sol-
uble or miscible oils, such as "Scalecide", "Carboleine" or
"Jarvis Compound" than with lime-sulphur, because the oils
have a greater penetrating power and will go into the cracks
and crevices. It will also moisten the pubescent twigs and
"crawl" around them. These oils should be diluted at the rate
of one part to fifteen parts of water.

Lime-Sulphur versus Miscible Oils.

The oils are not so good fungicides as is lime-sulphur and,
when they do not mix freely with water, are liable to cause
injury and should not be used. There is no danger of injuring
dormant trees with the lime-sulphur mixtures. Moreover
newly hatched scales will establish themselves readily on bark
which was sprayed with oil preparations in the spring, but they
do this very sparingly on bark treated with lime-sulphur :
consequently, if any are present they are found on the new
growth^ — twigs, leaves, or fruit.

At the Station farm, Mt. Carmel, in the old and neglected
orchard of about fifty trees, some of which were badly infested,
the San Jose Scale has been controlled satisfactorily for four
years by the use of lime-sulphur, — no miscible oil ever having
been used. The trees are now nearly free from scale, but for
two years they were given both fall and spring treatments.

SUMMER SPRAYING.
Apple.
In the average apple orchard only two summer spray treat-
ments need be given, the first soon after the blossoms fall and
the second from three to four weeks later, tlie spray being lead

SUMMER SPRAYING. ■ J

-arsenate (3 lbs. of the paste, or l^^ lbs. dry, in 50 gallons of
water) to kill the codling moth or apple worm which is always
present; and usually combined with some fungicide such as
commercial L. & S. (1>4 gallons). The beginner should fol-
low this simple treatment until he learns what special troubles
lie needs to control, and unless somewhat familiar with spray-
ing practices, he may be confused by the more complicated
•combination formulas and directions for controlling the various
pests. He should begin at the bottom and "work up".

For the orchardist more experienced in spraying and iden-
tifying- insect and fungous pests, we recommend the following
three treatments, or such as he may need, for controlling the
particular enemies of his orchard :

(1). In certain localities and in certain seasons, canker
worms, bud moths, tent-caterpillars and brown-tail moths may
do great damage. In case any or all of these are present the
worms feed on the unfolding leaves, and a spray of lead arsen-
ate should be given before the blossom buds open, though not
until there is considerable expanded leaf-surface to hold the
poison. If scab and rust are prevalent, a fungicide, preferably
Bordeaux mixture, 4-4-50, should be added to the poison for
this treatment, or if the insects mentioned above are not
troublesome, it may be used alone.

(2). After the blossoms fall the experienced orchardist
Avill use a fungicide, preferably dilute lime-sulphur, 1^ gallons
in 50 gallons of water." Where there is little danger of rus-
scting the fruit, weak Bordeaux mixture (which is a better
fungicide) 1-4-50, may be used instead of lime-sulphur. Lead
arsenate should be added in either case. If there is a prospect
of considerable damage from aphlds, leaf-hoppers, scale-
insects, red-bugs, or pear Psylla, a 40 per cent, nicotine solu-
tion, Yz pint per barrel, may be added to the combination with-
out injury to the foliage and without impairing the insecticidal
or fungicidal properties of the mixture.

(3). The combined fungicide-insecticides just mentioned
may be used for the June or third spra3ang but the nicotine may
not then be necessary. This third spraying" takes care of the
second brood of codling moth, late chewing insects, etc., also
the sooty blotch, late scab and various fruit specks and rot
fungi.

s connecticut experiment station bulletin 184.

Pear.

As a rule pears do not require so much summer spraying as
apples and the treatments are given for specific troubles. It
may be advisable to apply poison for codhng moth, pear slug
and other leaf-eating insects, and a fungicide, preferably Bor-
deaux, to control leaf blight and scab. Occasionally nicotine
may be needed to control plant bugs or the pear Psylla. The
applications should be made at the same three periods as for
apples ; namely, on the unfolding leaves before the blossoms
open, just after the petals fall, and about three weeks later.

In case pear blight is serious despite the winter pruning,
summer pruning, with especial care not to spread infection by
means of the pruning tools, is sometimes desirable.

Peach.

Peach foliage seldom needs to be sprayed with poison. In
Connecticut orchards the peach sawfly has caused partial defo-
liation and in such cases one spraying with lead arsenate (2 lbs.
paste in 50 gallons water) should be given about the middle of
June. This may be added to the self-boiled lime-sulphur,
w'hich is the safest fungicide for controlling scab and brown
rot. -

Scab can usually be controlled by two treatments, — one on
the young fruit about the middle of May, and another the
middle of June, while rot is often largely pre^•ented by two
treatments about the middle of June and July. Three treat-
ments, about the middle of each of these months, will take
care of both troubles fairly well. Summer spraying is most
advisable in case of such badly rotting varieties as Champion,
etc., or when Elberta, etc., scab badly. It has hardly come into
general practice in this state, but deserves more attention than
has yet been given it. Atomic Sulphur has proved as satis-
factory in our experiments as the self-boiled lime-sulphur in
controlling these two fungi.

Plum.

Plum orchards may need to be sprayed occasionally witli
poison to prevent damage from canker worms or other leaf-
eating insects. Some writers recommend this treatment against

SUMMER SPRAYING. V

curculio, but probably the jarring method of control will usu-
ally be found more satisfactory.

For the control of brown rot the fruit should be thinned,
and after harvest all mummies should be gathered and destroyed.
While spraying is not entirely satisfactory, largely because the
spray does not adhere readily to the smooth fruit, it may be
desirable in certain cases. The first treatment should be made
with self -boiled lime-sulphur on the fruit when about half
grown, and be followed by a second, third, and possibly fourth
spraying in case of late ripening varieties, at intervals of ten
to fourteen days. The last spraying should be made about
seven to ten days before picking, and can be made with com-
mercial lime-sulphur, 1-150, if there is any danger of sediment
on the fruit interfering with its sale. In case of leaf an-
thracnose, the spraying should be started earlier. See Cherry.

Cherry.

Rarely is it necessary to spray cherries except for the con-
trol of brown rot on the sweet varieties, and for this purpose
the self-boiled lime-sulphur should be used, the same as direct-
ed for plum.

In case the leaf spot "anthracnose" is troublesome, the spray-
ing should be made earlier than for brown rot, the first applica-
tion being made on the young leaves just after the petals falU
followed by one or two others at intervals of ten to fourteen
days.

Occasionally there may be damage from the pear or cherry
slug, in which case' a weak lead arsenate mixture (say 2 lbs. in
50 gallons) may be applied. Unless the insects are present,
however, it may well be omitted.

Quince.

Quince trees, like apples, should be sprayed with lead ar-
senate and a fungicide, preferably Bordeaux mixture. Three
treatments, as for scab of apple and pear, are usually desirable.
These help to control rust, black rot, leaf blight, and such
chewing insects as are present. Summer pruning for the
bacterial blight may be desirable in some cases.

10 CONNECTICUT EXPERIMENTAI. STATION BUI.I.ETIX 184.

DIRECTIONS FOR MAKING SPRAY MIXTURES.

Commercial Lime-Sulphur. Any of the commercial lime-
sulphur mixtures on the market testing about 33° B. may be
used for spraying fruit trees. For winter treatment these
are usually diluted with one part of the mixture to 9 parts of
water. For summer treatment the dilution is usually l/i to l^/i
gallons to 50 gallons water.

Self-Boiled Lime-Sulphur. This is a home-made mixture
prepared as follows : Eight pounds of fresh lime are started
slaking in a barrel with a little water (warm water preferably
in cool weather), and when the mass has begun to heat, eight
pounds of sulphur flour are quickly sifted in and thoroughly
stirred with the slaking lime. This, at the consistency of a
rather thick paste, is allowed to heat for fifteen minutes from
the time the sulphur is added, when it is cooled down with
additional water. The mixture is stirred and strained into the
spray barrel, to remove the coarser sediment, and diluted to
the fifty gallons.

Usually three barrel lots can be made at a time in an ordin-
ary barrel by using three times the amount indicated above.
This amount furnishes more heat and makes a little better
mixture than when made up in single barrel lots. A third of the
amount is then used with a barrel of water.

Bordeaux Mixture. Four pounds of copper sulphate are
dissolved in hot water or by suspending the crystals in a coarse
bag in a half barrel of water. Four pounds of fresh lime are
slaked in a small amount of water, and then strained into the
spray barrel about half filled with water. To this is then added
the half barrel of dilute copper sulphate.

When several barrels are needed, stock solutions can be
made up as follows: The copper sulphate is dissolved in a
barrel at the rate of one pound to one gallon of water, and the
lime, after slaking, is diluted so that it also contains one [xmnd
per gallon of water. Then, when needed, four i;allon> of the
lime water, after stirring thoroughly, arc strained into the
spray barrel, this half filled with water, and t'our gallons of
the copper solution, furtlier diluted to make about half a Iiarrel.
are poured into this.

RECEIPTS FOR SPRAYING MIXTURES. 11

Lead Arsenate. This poison is manufactured in both paste
and powder form. The paste form is generally preferred for
orchard work, but it dries and becomes lumpy if kept from
oiie year until jthe next. ' It also corrodes metal containers.
The paste contains fifty per cent, wafer and should be used in
the proportions of 3 lbs. in 50 gallons of water. It is best to
first mix it thoroughly with a small amount of water before
putting into the spray tank: t

Dry or powdered lead arsenate will keep indefinitely in a dry
place. In spraying, use just half as much as of the paste form,
or 1^ lbs, in 50 gallons of water. The dry lead arsenate may
be thrown into the spray tank after it has been filled with
liquid, and it will be readily moistened and distributed.

Both paste and powdered lead arsenate may be used in con-
nection with lime-sulphur, Bordeaux mixture, or nicotine solu-
tion and larger quantities of arsenate may be used if desired.

Nicotine Solutions. Several of these are now sold contain-
ing forty per cent, or more of nicotine, usually in the form of
sulphate. For most kinds of aphids one-half pint to a barrel
of water is sufficient, but the amount may be much increased or
doubled without danger of causing injury. Nicotine solutions
may be safely used in combination with lead arsenate, Bor-
deaux mixture, or lime-sulphur; with any one or with all of
them.

Miscible Oils. Several brands are now on the market, and
for dormant spraying each should be diluted at the rate of one
part in 15 parts water. The contents of each original package
should be thoroughly mixed or shaken before attempting to
dilute any portion of it. As a rule, it is unnecessary and in-
advisable to mix miscible oils with other spray materials.
Such oils are chiefly used on dormant trees.

CAUTIONS.

Before beginning to spray, know what you are spraying for.
If you have troubles which you cannot identify, send speci-
mens to the Station and get information and advice.

Never spray any fruit tree while in bloom. It kills your
best friends, the honey bees, which pollinate the flowers and

12 CONNECTICUT EXPERIMENT STATION BULLETIN 184.

help to increase the yield of fruit. The spray will also injure
the delicate floral organs, so that fruit will not set.

Be careful about using any kind of spray not advocated here,
especially on peach and Japan plum foliage, which are especial-
ly susceptible to spray injury.

If miscible oils do not mix readily and thoroughly with
water on diluting, they should be discarded, as there is danger
of injuring the trees.

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Connecticut

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