AGRICULTURAL RESEARCH CENTER MONTICELLO
Monticello ARC Research Report BB1980-1 January 9, 1982.-- '
HUME LIDKAK 1
COMMERCIAL PEACH INSECT AND DISEASE RECO NATIONS
W. J. French 2 S-U, oV.'f
Commercial peach production in north Florida would not be possible without
effective disease and insect control. Although the peach has a relatively short
development period in Florida, the fruit as well as the tree is subjected to con-
stant attack by a variety of pests. A good disease and insect control program
is important, not only in protecting the maturing fruit but in maintaining the
trees' vigor season after season. Today's peach grower is fortunate to have
effective insecticides, fungicides and improved spray equipment available to him.
Nevertheless, spraying for pest control is no easy task. Attention must be
given to many details, some seemingly unimportant. Many times the difference
between a successful and unsuccessful spray program depends on three factors:
TIMING: The foliage and tree should have a protective covering of fungi-
cide and insecticide at all times, from the pre-blossom stage until fruit har-
vest. After the fruit is harvested, then the problem of proper timing becomes
very important because of the intervals between sprays and the nature of the
pests attacking the tree at this time. The white peach scale is normally con-
trolled until harvest by the insecticides applied to protect the fruit. After
harvest, when insecticides are applied at less frequent intervals, they should
be timed to coincide with the "crawler" stage of each generation of the white
COVERAGE: Economic pest control is dependent on uniform coverage of the
tree with the correct pesticide dosage. Many growers who have been applying
dilute sprays are using air-blast equipment capable of applying low volume sprays
of 10x (apply oil sprays at dilute rate only). When sprays are concentrated
2x or more, there is little possibility of movement of spray solution from the
point where the droplet hits the tree; therefore, accurate calibration and
placement of the spray is even more critical for successful pest control.
The sprayer should travel at 1 2 miles per hour and should be nozzled
to delivery the gallons as determined from Table III.
RATES: Fungicides and insecticides are recommended at specific rates which
have been found to be effective and non-phytotoxic under Florida conditions.
Professor of Plant Pathology
2This research report was prepared in collaboration with Gary Simone, Extension
Plant Pathologist and H. Cromroy, Extension Engomologist.
Changing formulations or spray volume without changing the amount of material
used can give too much or too little toxicant. It is therefore important to:
(1) know required amount of formulation to apply per tree; (2) know the gallons
of spray per tree the machine will deliver at a given rate of travel; (3) know
the amount of chemical to add per tank. Examples: The recommended rate of
Thiodan 50% WP is 1 lbs. per 100 gallons of water when spraying dilute (2 gal-
lons per tree). If the sprayer when traveling 2 MPH is found to be delivering
1 gallon of water per tree, then 3 lbs. of Thiodan 50% WP would be required per
100 gallons of water or 15 Ibs. per 500 gallons of water. The product label
tells you how much active ingredient is in the formulation. For instance, Para-
thion 15% WP listed in the guide contains 15% actual parathion. If a formulation
is used with a different percent actual parathion, the amount put in the spray
tank must be adjusted accordingly.
SPRAY NOTES: The following spray schedule (Table I) will give commercial
control of important disease and insect pests. The rates given in Table III
are based on dilute formulations with 2 gallons water being applied per tree.
One half to 1 gallon would normally be required to adequately cover a mature tree
during the early season sprays, gradually increasing to 2 gallons per tree at
full foliage. If heavy populations of white peach scale are encountered during
the dormant season, an Ethion-oil combination spray can be used instead of a 3%
oil spray. Prepare by mixing 1 pint of Ethion 46% emulsifiable concentrate in
100 gallons of water. To this add 3 quarts of 80-90% oil emulsion concentrate.
High volume sprays should be used when white peach scale populations are heavy.
Scale population can build rapidly from very low levels; therefore postharvest
sprays must be maintained.
This section will discuss only those problems not covered in the spray
PHONY PEACH: Phony peach is a disease of peaches that is spread from in-
fected peach or wild plum trees to healthy peach trees by leafhoppers. Without
technical training it is difficult to identify infected trees in the early stages
of this disease. When in doubt, consult your county agent, extension plant
pathologist, or extension fruit specialist.
The longer the diseased trees remain in the orchard, the greater the chance
of disease being spread by insect vectors. Unless annual surveys are conducted
and diseased trees removed, an infected orchard would rapidly become unprofitable.
Control recommendations are: (1) to remove all affected trees immediately
after detection; (2) remove all wild plum trees within a minimum of 400 yards of
all commercial orchards by spraying with Ammate or 2,4,5-T in the spring after
leaf-out; (3) use nursery stock certified to be free of phony; (4) nursery stock
suspected of harboring phony can be made phony-free by soaking plants in water
held at 118 for 40 minutes.
BACTERIAL SPOT: This spray program does not control bacterial spot, a dis-
ease which has not been a serious problem in Florida. When bacterial spot appears,
it is often associated with adverse cultural conditions which cause tree stress,
i.e. low fertility, spray burn, etc.
POST HARVEST DECAYS: The two principal decays of peaches are brown rot and
Rhizopus rot. Both rots can be checked by cooling the fruit to temperatures be-
low 50F throughout the marketing period. Botran 75W added to the hydrocooling
water at a rate of 1 lb/100 gallons water will control Rhizopus. Benlate is ef-
fective against brown rot. If rainy weather occurs at harvest, use lb. Benlate
in the hydrocooler along with Botran. Do not use Benlate in place of Botran. Add
1 lb. Botran and lb. of Benlate to each additional 100 gallons of water to the
hydrocooler during operation. Flush and clean hydrocooler every 1 or 2 days.
WAX TREATMENT: Botran (2-3 ppm on fruit) plus Benlate (1 ppm on fruit)
incorporated into a wax treatment following chlorinated (25-50 ppm) hydrocooler
RUST: Peach rust, like bacterial spot, causes greater injury on weak trees
than on those of high vigor. In central Florida orchards, especially those low
in nitrogen, rust may appear in early June and cause heavy defoliation by mid-
summer. The disease usually develops later in north Florida and seldom warrants
control measures. Sulfur may provide some control.
CATFACING INSECTS: The early sprays for catfacing insects (stinkbug,
tarnished plant bug) are extremely important. Rapid growth of leaves and fruit
at this time has the effect of reducing the amount of pesticide contacted by
the insects between spray intervals. Therefore, the petal fall and shuck-fall
sprays must be timed very accurately, so that untreated surfaces do not remain
exposed to attack.
WHITE PEACH SCALE: White peach scale is one of the most destructive pests
on peaches in Florida. Heavy infestations will kill branches and entire trees.
The scale is found mainly on the trunk and older wood. They secrete a waxy
covering that is relatively impervious to pesticides; therefore, for sprays to
be effective, they should be applied when the vulnerable "crawler" stage is
present. Crawlers are the motile larvae that hatch from eggs laid beneath the
scale covering. They are barely visible to the naked eye, and are best seen
with a lOx hand lens. After hatching, the crawlers leave the protection of the
female covering to search for a place to settle. The protective wax covering is
secreted after the first moult which occurs around 7-9 days after hatching.
During the fruiting period, routine sprays keep the scale under control.
At post-harvest and on non-bearing trees, sprays should be timed to the crawler
stage. Treat when crawlers first appear and apply a second spray two weeks
later (a third spray may be necessary 2 wks. later if crawlers are still hatching).
Use either Guthion, Parathion, or Diazinon in a dilute spray to obtain complete
coverage of the trunk and branches
To find infestations, look for white cottony tufts on the trees. These are
cocoons of male scales. Once found, the grower should inspect the tree every
week for egg laying and crawler hatch.
If white peach scale is not controlled in the summer and fall, high popu-
lations may overwinter necessitating a dormant spray. The need for a dormant
spray is a last resort and should not be considered a routine part of the
scale control program. For one thing, the scale overwinter as protected adult
females and the amount of mortality achieved from dormant sprays can be rela-
tively low. In addition, by the time dormant or delayed dormant sprays are
applied, much of the damage (dead wood) caused by the scale will have already
Greater detail on the life cycle and scouting for white peach scale can be
found in ENT-38, "White Peach Scale in Florida" by J. C. Ball and J. E. Brogdon,
Fla. Coop. Ext. Ser., IFAS, Univ. of Florida, Gainesville, FL 32611.
Peach Tree Borer (PTB) and Lesser Peach Tree Borer (LPTB): These borers
feed in the bark of the tree. They are frequently associated with pruning cuts
and lesions made by farm equipment; however, such wounds are not necessary for
successful penetration of the borers. The PTB attacks the trunk from about 6"
above the soil to 3" below the soil. The LPTB is found on the upper trunk and
scaffold limbs. LPTB moths first emerge around March and continue at fairly con-
stant levels through October. The major PTB flight occurs in late summer and
fall, with peak emergence in late September early October. To be effective,
borer sprays should thoroughly wet the trunk and larger branches. Early season
control of LPTB is probably achieved by the preharvest cover sprays; however,
if the grower has a persistent heavy infestation even after proper application
of post-harvest borer sprays, a pre-harvest Thiodan spray should be applied
(observe proper days-to-harvest interval). The most effective timing of borer
sprays in Florida has not been worked out and that presented in this guide
represents a maximum schedule.
In Georgia, research has indicated that Lorsban applied in the first week of
August will control PTB and also white peach scale. In addition, a rate of 1 1/2
qts/100 gal instead of 3 qts provides control in young orchards or at lower borer
populations. These findings have not been confirmed under Florida conditions.
Mites: Spider mites are generally not a problem in north Florida orchards;
however, sporadic, heavy infestations do occur and in some orchards or parts of
orchards, they can be a yearly problem. Because of the mites' rapid rate of in-
crease, high populations can appear, seemingly overnight, and the grower should
constantly monitor his orchard, paying particular attention to trouble spots.
Spraying should be done before mite populations become too high, as these are
difficult to control; however, the grower should also avoid unnecessary treat-
ments. Use Kelthane, Plictran, or Systox at recommended rates (Table III) and
observe time limitations (Table II). Use of high volume sprays as thorough coverage
is essential for good control.
Many pesticides including Parathion, Penncap M, Guthion, and Systox are
especially toxic to humans or for other reasons "Restricted Use" materials to
be applied only by properly trained and equipped operators. Read the precau-
tions and warnings on pesticide labels. Store pesticides in original labeled
containers out of reach of children, pets, and livestock. Store all pesticides
in a secure area, under lock and key. Dispose of left-over spray materials and
all empty containers safely and promptly. Do not reuse empty pesticide containers.
Follow the recommended dosage and waiting period to avoid excess residues and
possible injury to plants and animals. Avoid drift of pesticides to adjacent
areas. Do not be responsible for further polluting our environment.
TOXICITY TO HONEYBEES
Lorsban, Penncap M, Parathion, Guthion, and Sevin are highly toxic to
honeybees. Severe losses of bees can be expected if these materials are used
when bees are in the orchard at time of application or for 24 hours thereafter.
Thiodan and Systox are moderately toxic to bees and can be used in the
vicinity of bees. However, these materials should not be sprayed directly on
the bees in the field.
Kelthane and Ethion are relatively non-toxic and can be used around bees
with a minimum of injury.
Table I. PEACH SPRAY SCHEDULE SUGGESTED FOR COMMERCIAL PLANTINGS
NAME AND TIME
PESTS CONTROLLED AND MATERIAL
NO. OF SPRAY RECOMMENDED REMARKS
1. Dormant... Leaf curl. Ferbam If scale is a problem, 1
After all leaves application lime-sulfur
are off and before for San Jose scale; 2
buds begin to swell applications of 3% oil or
in late winter. *White peach Liquid lime- Ethion-oil spray 14 days
scale sulfur or 3% oil apart for white peach
*San Jose scale or Ethion-oil2 scale.
2. Blossom... Blossom blight. Wettable sulfur Apply several sulfur or
or Benlate (see Benlate sprays during
remarks) or bloom to reduce blossom
Liquid lime- blight damage. Benlate
sulfur. resistant strains of
fungi may develop and become
a serious problem. Benlate
resistance may develop
where Benlate is used
throughout the season.
Alternate fungicides to
reduce the buildup of
3. Petal-fall... Scab Wettable sulfur
After all petals or Captan or
are off and before Benlate.
peach is showing. Tarnished plant Parathion or Spray tree thoroughly,
bug. Guthion or including trunk and larger
Lesser peach Thiodan.
tree borer Do not apply Thiodan more
than 2 times during the
4. Shuck-fall or Brown rot, Wettable sulfur
first cover... Scab or Benlate or
(3/4 shucks off) Captan.
Tarnished plant Penncap M or Penncap M should not be
bug, So. green Guthion or applied more frequently
stinkbug, Plum Imidan or3 than 14 days apart.
5. Second cover Brown rot, Wettable sulfur Do not apply Thiodan with-
14 days later Scab. or Benlate or in 30 days of harvest, or
Captan Guthion within 21 days of
Lesser peach Thiodan. harvest, or Imidan within
borer. 14 days of harvest or
Tarnished Penncap M or Parathion within 14 days
plant bug, Guthion or of harvest.
So. green Imidan or
Table I. (continued)
NAME AND TIME
NO. OF SPRAY RECOMMENDED REMARKS
6. Third cover Brown rot. Wettable sulfur For preharvest control
14 days later or or Captan or of brown rot apply 1
4 weeks before Benlate. or 2 sprays of Benlate
harvest of each Plum Curculio, Same as 2nd beginning 3 weeks
variety. So. green cover spray. before harvest.
7. Fourth cover... Brown rot. Dusting sulfur Do not apply Penncap
Two weeks before 80% or Captan or M, Parathion or Imidan
harvest of each Plum Curculio, Benlate. Penncap within 14 days of
variety. So. green stink- M4, Imidan or harvest.
8. Fifth cover... Brown rot. Dusting sulfur Sevin can be applied
Preharvest one 80% or Captan up to one day of har-
week before Plum Curculio, or Benlate. vest on peaches and 3
harvest of each So. green Sevin. days of harvest on
variety. stinkbug. nectarines.
9. Sixth cover... Brown rot. Benlate If weather is hot
Preharvest one and dry, it may not
day before har- be necessary to use
vest. Benlate in this spray.
10. POST HARVEST SPRAYS
1st borer spray... Lesser peach Thiodan Thoroughly wet scaf-
After all fruit tree borer, fold limbs, trunk, &
is harvested. Peach tree borer. soil at base of tree to
White peach scale White peach Parathion or control borers.
sprays... scale. Guthion or Apply 2 sprays 2 weeks
Diazinon apart when crawlers
11. 2nd borer spray... Lesser peach Thiodan Apply Lorsban only
30-45 days after tree borer, once per season.
1st borer spray. Peach tree Lorsban or Registered on peaches
borer. Thiodan only.
12. 3rd borer spray... Peach tree Thiodan Thoroughly wet trunk to
30-45 days after borer crotch and soil at base
2nd borer spray. of tree.
*White peach scale and San Jose scale are usually controlled
by the cover sprays of
Parathion and Guthion. Liquid lime-sulfur for scale control rate: 12 gal/100
1See Table II for residue tolerances and limitations for pesticides recommended.
2See "Spray Notes" page 2.
3During cool weather Parathion will not give effective control and Penncap M, Guthion
or Imidan should be used.
4Penncap M is a slow release formulation of methyl-parathion with longer residual
activity to provide extended control.
5For best control of scab during wet weather, a 7 day fungicide spray interval
should be followed.
RESCUE TOLERANCES AND LIMITATIONS FOR PESTICIDES RECOMMENDED FOR
PEACHES AND NECTARINES IN THIS PUBLICATION.
INTERVAL BETWEEN LAST APPLICATION AND
CHEMICAL TOLERANCES (PPM) HARVEST, AND OTHER RESTRICTIONS.*
Nectarine Peach Nectarine Peach
Benlate 15.0 15.0 No time limit. Do not graze treated or-
No time limit.
Max. 1 lb. per acre per
Botran 20.0 20.0 1 day 1 day
Max. 5 Ibs. per acre per Max. 1 lb. per 100 gal. per
application as spray; 3.6 Ibs. application as spray; 3.6
as dust. lbs. as dust.
Captan 50.0 50.0 No time limit No time limit at 5 Ibs. per
Postharvest same as peaches. acre.
1 day at 6 lbs. per acre.
Postharvest 1 to 1.2 Ibs./
100 gal. spray or dip. Re-
charge when vol. down 25%
with .5 lb. for each 25 gal.
Diazinon 0.75 0.75 10 days 20 days
Ethion 1.0 1.0 Do not apply within 30 days of harvest. Do not apply more
than twice during fruiting season.
Ferbam 7.0 7.0 Do not apply later than Do not apply within 21
immediately after bloom. days of harvest. Max. 11.5
Max. 5.7 lbs. per acre per lbs. per acre per applica-
Guthion 2.0 .2.0 21 days 21 days
Imidan 5.0 10.0 14 days 6 lbs. max. per acre 14 days 6 Ibs. max. per
per application. acre per application
Kelthane 10.0 10.0 14 days 14 days
Liquid none none Apply during dormancy or delayed dormancy.
Lorsban 0.05 Do not apply more than once
per season. Do not apply
within 14 days of harvest.
Do not allow spray to con-
tact fruit. Do not graze
meat or dairy animals in
Parathion 1.0 1.0 Do not apply more than 5 Ibs. active per acre per year.
Do not apply within 14 days of harvest.
Penncap M 1.0 1.0 Do not use more than 5 Ibs.
active per acre per year.
Do not apply later than 14
days before harvest. Do not
graze or feed cover crops
from treated orchards.
INTERVAL BETWEEN LAST APPLICATION AND
CHEMICAL TOLERANCES (PPM) HARVEST, AND OTHER RESTRICTIONS.*
Plictran 4.0 4.0 Do not apply more than 4.5 lbs. active per acre per season
or more than 4 times. Do not tank mix with spray oils. Do
not apply during the same season that a summer spray oil is
used. Do not graze or feed livestock on cover crops growing
in treated areas.
Sevin 10.0 10.0 3 days 1 day
Sulfur none none No time limit. No time limit.
Systox 0.75 0.75 Do not apply within 30 days of harvest. Do not apply more
than three applications per season.
Thiodan 2.0 2.0 Do not apply within 30 days of harvest. Do not apply more
than twice during fruiting season.
*Rates are expressed as active ingredient.
TABLE III. AMOUNT OF PESTICIDE REQUIRED PER 100 GALLONS.
Dilute (IX) 2X 5X lOX
Gallons of water per tree: 2 1 .4 .2
Gallons of water per acre: 200 100 40 20
Chemical Pounds of wettable powder per 100 gallons.
Benlate 50% WP
Botran 75% WP
Captan 50% WP
Ferbam 75% WP
Guthion 25% WP
Imidan 50% WP
Kelthane 18.5% WP
Parathion 15% 1WP
T~~~~~~~ 1 f-A- Cf0 ~
rllctran U50 wr .j--.Jo --- --- --
Sevin 50% WP 2.0 4.0 10.0, 20.0
Sulfur, wettable 80% 6.0 12.0 30.0 60.0
Thiodan 50% SP 1.5 3.0 7.5 15.0
Chemical Ounces of emulsifiable concentrate/100 gal.
Diazinon AG500 4 lbs/gal. E.C. 16 32 80 160
Ethion 4 lbs/gal. E.C. 16 32 80 160
Guthion 2 Ibs/gal. E.C. 20 40 100 200
Kelthane 4 Ibs/gal. E.C. 16 32 80 160
Liquid lime-sulfur* scale insects 12 -- -- -
leaf curl 6 -- -- -
blossom blight 1 -- -- -
Lorsban 4 Ibs/gal. E.C.* 96 -- --
Parathion 4 lbs/gal. E.C. 10 20 50 100
Penncap M 2 Ibs/gal. 32 64 160 320
Systox 2 Ibs/gal E.C. 16 32 80 160
Thiodan Miscible 2 Ibs/gal* 48 -
*Use as dilute only.
This schedule is a guide to aid the grower; however, all pertinent information
relating to the pesticides cannot be included. It is the responsibility of
the grower to read the label for information on restrictions and correct use.
Use of a pesticide inconsistent with the label is illegal.
1 pint = 16 oz. = 473 milliliters
1 qt. = 32 oz. = 2 pints
1 gal. = 128 oz. = 4 qts. = 8 pints
S1 oz. = approximately 30 milliliters
1 lb. = 16 ounces
.1 lb. = 1.6 ounces
.4 lb. = 6.4 ounces
.8 lb. = 12.8 ounces