Group Title: Entomology mimeo report
Title: Spray program for peaches and plums
Full Citation
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 Material Information
Title: Spray program for peaches and plums
Series Title: Entomology mimeo report
Physical Description: 4 leaves : ; 28 cm.
Language: English
Creator: Tisdale, W. B ( William Burleigh ), 1890-
Tissot, A. N ( Archie Newton ), b. 1897
University of Florida -- Dept. of Plant Pathology
University of Florida -- Dept. of Entomology
Publisher: University of Florida, Dept. of Plant Pathology and Dept. of Entomology,
University of Florida, Dept. of Plant Pathology and Dept. of Entomology
Place of Publication: Gainesville Fla
Publication Date: 1953
Copyright Date: 1953
Subject: Peach -- Diseases and pests -- Control -- Florida   ( lcsh )
Plum -- Diseases and pests -- Control -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: W.B. Tisdale & A.N. Tissot.
General Note: Caption title.
General Note: "9/25/53 Plant Pathology and Entomology"--Leaf 4.
 Record Information
Bibliographic ID: UF00090256
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 261135433

Full Text

Plant Patholo Mimo Reort -2
EntomologyMieo Report 54-1

W. B. Tisdale & A. N. Tissot

The most important diseases and insects of peaches and plums are common
to both crops in Florida, and control of these pests is a prerequisite to
quality fruit. In most localities of the state, brown-rot and scab are the
most important diseases of peaches and brown-rot is more important with plum.
The plum curculio, scales, stink bugs, and the peach tree borer are the most
common insect pests of these fruits.

Brown-rot causes fruit rot, blossom, spur, and twig blight. Rotting
mature fruit is the stage usually observed by growers. The rotting fruit
turns brown, and a mass of gray dust of spores grows on its surface. These
spores spread the disease to other fruit during wet weather. As the rotted
fruit dries out, it forms a "muimy" some of which remain hanging on the tree,
while others fall to the ground. In either case, the fungous parasite that
causes the rot lives over winter in the mummies and twigs and produces spores
in the spring that cause blossom blight. Infected blossoms are killed and
turn brown soon after they open. When weather conditions are favorable for
it, the fungus grows back into the spur and twigs, causing the fruit to shed,
and twigs to die. This stage of the disease combined with curculio damage
may cause total loss of the fruit. Fruits that escape infection in the blossom
stage or shortly afterward, often become infected about the time they reach

For satisfactory control of brown-rot, the mummied fruits and blighted
twigs should be removed from the trees and ground and destroyed before new
growth starts. Harrowing and discing orchards during the pink stage of the
blossoming period will help reduce early infection by destroying the spore
cups of the fungus coming from the mummies. Rotten fruit under the trees
should be picked up after harvest and destroyed. The trees should then be
sprayed thoroughly, as recommended in the spray schedule.

Scab attacks the fruit and twigs. It usually appears on the fruit about
4 to 6 weeks after the blossoms fall and continues to develop until the fruit
is ripe. In its early stages scab appears as small, circular, olive-green to
brown spots clustered on the upper surface. Where many spots have grown to-
gether, the fruit cracks and exposes it to brown rot. On the twigs, scab is
noticed as circular, yellowish-brown spots with dark gray to purple borders.
The spots may girdle the twigs and cause them to die. The disease appears
on the leaves in the form of brown, circular spots between the veins which
dry up and fall out, leaving circular holes in the leaves.

The plum curculio is largely,/*ip hisib e for the failure of peach and plum
trees to set and bear fruit. The/adlt is a had elled, brown beetle with a long
beak or snout on the front of th ead, Thqma e urculios cut crescent-
shaped slits in the fruit and la. eggs in tpm. these eggs hatch whitish,
legless grubs or larvae that fee&_a the tBsh of fruits. When the eggs
are laid in very young fruits the ~d of the 'bs causes the fruits to drop.
If the eggs are laid in fruits tha earl they may remain on the
trees but they will be "wormy" at

In former years lead arsenate was generally used against the plum curculio.


When infestations were heavy this insecticide sometimes failed to give satis-
factory control and there was always danger of injury to the leaves and young

The new organic insecticides have been tested in various peach growing
areas. Parathion and dieldrin have most consistently given satisfactory control
and they now are available for use against this pest. Parathion can be used
in all four of the curculio sprays in the schedule but dieldrin must not be
used later than the first cover spray. If dieldrin is used in the earlier
sprays parathion can be substituted in the second cover spray. The first
three curculio sprays prevent early infestations and dropping of the young
fruits. The last spray protects the ripening fruit and prevents it from being
wormy at harvest.

Stink bugs of various kinds sometimes attack peaches as they are nearing
maturity. The feeding of these insects causes small, dry, spongy areas to
develop just beneath the skin of the fruit. Parathion in the last cover sprpy
will help to control this pest. These stink bugs migrate to the peaches from
other plants growing in the orchard or nearby. When stink bugs are numerous
in the vicinity of peach trees it is advisable to spray or dust the cover crop
or other host plants of the bugs shortly before the peaches ripen. Five per-
cent chlordane dust or 10 percent toxaphene dust can be used and sprays made
from wettable powders or emulsifiable concentrates of these insecticides also
are effective.

Two scale insects are commonly found on peach and plum trees and both
are capable of seriously injuring or even killing the trees. Both are found
principally on the twigs and branches, though they may occasionally be found
on leaves or fruits. The San Jose scale is nearly round, and varies in color
from gray to smoky black. Heavily infested branches have a roughened, gray
appearance. The females of the white peach scale also are round in shape but
they are yellowish- or grayish-white in color, and the males are snow white.
Areas of bark infested with this scale appear as cottony patches on the trees.
The scales feed on sap which they suck from the tree and their feeding causes
first the twigs and later the branches to wither and die.

The dormant spray made from concentrated lime sulfur is used primarily
for disease control but it is effective against the scale insects also.
Parathion, likewise, is a good scalecide and if it is used in the spray
schedule for curculio control, the trees should remain quite free of scales
throughout the year.

The peach tree borer is a serious pest of the peach and every year it
causes the death of many trees. It is much less destructive to plum although
plum trees sometimes become infested. The peach tree borer moths may appear
at any time from spring to fall but most of the eggs are laid from July to
September. It is difficult to kill the borer within the bark so control
measures are designed to kill the adult moths or the young larvae before they
can enter the trees.

The parathion sprays used for curculio control will help to control the
peach tree borer. However, many of the peach tree borer eggs are laid after
the curculio sprays are discontinued so it is desirable to make additional
sprays for more complete borer control. Three sprays applied approximately
a month apart and beginning about July first should give adequate protection.


One-half pound of 15 percent wettable parathion in 25 gallons of water will
make a spray of suitable strength. DDT gives a longer residual effect than
parathion and it also may be used for borer control. Use one-half pound of the
50 percent wettable powder for 25 gallons of spray. The trunks and lower
branches should be thoroughly drenched with the spray but it is not necessary
to spray the tops of the trees unless they are infested with scale insects.

Paradichlorobenzene, sometimes called PDB, is used to control the peach
tree borer in more northern peach areas but it is not recommended for use in
Florida. It can be used safely only on trees which are fully dormant and if
used on growing trees the materials may cause serious injury to the bark or
even kill the trees.

Fortunately, it is possible to spray peaches and plums with a combination
of fungicides and insecticides and thus control both diseases and insect pests
at the same time. In order to be fully effective, it is necessary that the
sprays be applied at certain definite times. The different spray applications
are timed not by the calendar but by the stage of growth of the trees and fruits.
The times of application, the kinds and amounts of materials to be used, and
the pests against which the sprays are directed, are shown in the spray schedule
that follows. For early varieties of peaches it is probable that 4 applications
will be adequate. If rains are frequent, the 5th application may be necessary.
Sprays 3 and 4 in the schedule are the most important for curculio control. A
fair degree of control can be expected if they alone are used but more complete
protection will be obtained if sprays 2 and 5 also are used.

Best control of the diseases and insects is obtained when a power sprayer
is used for applying the spray but where one has only a few trees, it would be
impracticable to buy power sprayers for this purpose alone. In such cases, one
may use a bucket pump sprayer or even a knapsack spray pump provided a sufficient
length of pressure hose, an extension rod and suitable nozzle are used. The
bucket pump sprayer with an agitator is more satisfactory, because it is more
convenient, and a greater pressure can be developed and maintained than with a
knapsack sprayer. A 6-to-10 foot hose and a 4-foot extension rod should be
adequate to assure coverage of all parts of the tree. An adjustable nozzle
is desirable so that all sides of leaves, branches, and fruits can be covered
with the spray. Bucket pump and knapsack sprayers may be obtained from seed,
fungicide and insecticide dealers. Compressed air sprayers can be used but they
are not recommended for applying the spray materials used here. Some of the
fungicide and insecticide materials are insoluble, and simply remain suspended
in the water. They tend to settle rapidly, and as the compressed air sprayers
have no provision for agitation, the materials are likely to be applied very
unevenly. This may result in poor control of the pests or injury to the trees.
Spray should be applied as soon as possible after mixing and in no case should
diluted sprays be carried over for use the next day.


Time of Application Pests to Control Materials to use for 25
gallons of finished spray

1. Dormant Spray
Apply after leaves
have shed or before
buds begin to swell

2. Petal Fall Spray
Apply when most petals
have fallen.

3. Shuck Spray
Apply when most of
shucks have fallen
from fruit about
10 days after 2nd

4. First Cover Spray
Apply about 2 weeks
after the shuck spray.

5. Second Cover Spray
Apply about 2 or 3
weeks before

6. First Borer Spray
Apply about July 1

7. Second Borer Spray
Apply about August 1

8. Third Borer Spray
Apply about September 1

Brown rot and scab;
San Jose and white
peach scales

Brown rot and plum

Brown rot and scab;
Plum curculio

Brown rot and scab;
Plum curculio.

Brown rot and scab:
Plum curculio

Peach tree borer

Peach tree borer

Peach tree borer

Concentrated lime-sulfur
2 1/2 gallons: or Bor-
deaux (1 1/2 lbs copper
sulfate and 1 1/2 Ibs
hydrated lime.)

Wettable sulfur 1 1/2
Ibs. plus
Parathion wettable 15% -
1/2 lb. or Dieldrin
wettable 25% 1/2 Ib.

Same as 2

Same as 2

Wettable sulfur 1 1/2 Ibs.
Parathion wettable 15% -
1/2 lb.
(Do not use dieldrin in
this spray)

Parathion wettable 15% -
1/2 lb. or
DDT 50% wettable 1/2 lb.

Same as 6

Same as 6

Apply borer sprays only to trunks and lower branches of trees.

9/25/53 Plant Pathology
and Entomology 400 copies

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