AGRICULTURAL RESEARCH CENTER MONTICELLO
Monticello ARC Research Report 1977-1 .. December 8, 1976.
COMMERCIAL PEACH INSECT AND DISEASE C8MAENiE TIONS
J. C. Ball and 1W, .rench1,2
'u^ ^ 7 Hor:da
Commercial peach production in north Florida wouldvinotJ e 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 constant attack by a variety of pests. A good dis-
ease 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, fungi-
cides and improved spray equipment available to him. Nevertheless, spray-
ing 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:
STIMING: The foliage and tree should have a protective covering of
fungicide and insecticide at all times, from the pre-blossom stage until
fruit harvest. 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 controlled 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 peach scale.
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 move-
ment 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 noz-
zled to deliver the gallons as determined from Table III.
1Assistant Entomologist and Associate Plant Pathologist
S2This research report was prepared in collaboration with R. S. Mullin,
Extension Plant Pathologist; and J. Brogdon, Extension Entomologist.
RATES: Fungicides and insecticides are recommended at specific rates
which have been found to be effective and non-phytotoxic under Florida con-
ditions. 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 Ibs. per 100 gallon of water
when spraying dilute (2 gallons per tree). If the sprayer when traveling
2 MPH is found to be delivering 1 gallon of water per tree -hen 3 Ibs. 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, Parathion 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
SPRAY NOTES: The following spray schedule (Table I) will give commer-
cial control of important disease and insect pests. The rates given in
Table III are based on dilute formulations with 2 gallons water being ap-
plied per tree. One half to 1 gallon would normally be required to adequate-
ly 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 and 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
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
infected 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 diseases being spread by insect vectors. Unless annual surveys
are conducted and diseased trees removed, an infected orchard would rapidly
Control recommendations are: (1) to remove all affected trees immed-
iately 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 1180 for 40 minutes. W
Bacterial Spot: This spray program does'not control bacterial spot,
a disease 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 tempera-
tures below 500F 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 effective against brown rot. If rainy weather occurs at harvest
use lb. Benlate in 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 hydrocooler during operation. Flush and clean hydro-
cooler every 1 or 2 days.
Wax Treatment: Botran (2-3 ppm on fruit) plus Benlate (lppm on fruit)
incorporated into a wax treatment following chlorinated (25-50 ppm) hydro-
Rust: Peach rust, like bacterial spot, causes greater damaging injury
on weak trees than on those of high vigor. In central Florida orchards, es-
pecially 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.
White Peach Scale: White peach scale is one of the most destructive
pests on peaches in Florida. Heavy infestations will kill branches and en-
tire trees. The scale is found mainly on the trunk and older wood. They
secrete a waxy covering that is relatively impervious to pesticides; there-
fore, 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 craw-
ler 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.
Mites: Spider mites are generally not a problem in north Florida or-
chards; 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 increase, high populations can appear, seemingly overnight,
and the grower should constantly monitor his orchard paying particular atten-
tion to trouble spots. Spraying should be done before mite populations be-
come too high, as these are difficult to control; however, the grower should
also avoid unnecessary treatments. Use Kelthane, Plictran, or Systox at
recommended rated (Table III) and observe time limitations (Table II). Use
high volume sprays as thorough coverage is essential for good control.
Parathion, Guthion, and Systox are especially toxic to humans and should
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 no 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
Thiodan and Systox are moderately toxic to bees and can be used in the
vicinity of bees. However, these materials should not be spray 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 0
*San Jose scale or Ethion-oil scale. W
# able I (continued)
NAME AND TIME
NO. OF SPRAY
After all petals
are off and before
peach is showing.
or Benlate (see
remarks) or Liquid
or Captan or
Mainly for brown rot prob-
lem:areas. Apply several
sulfur or Benlate sprays
during bloom to reduce
blossom blight damage.
Benlate 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
Spary tree thoroughly
including trunk and larger
Do not apply Thiodan
more than 2 times during
the fruiting season.
4. Shuck-fall or Brown rot, Wettable sulfur or
first cover... Scab Benlate or Captan.
(3/4 shucks off)
Tarnished plant Penncap M4 or Guthion Penncap M should not be
bug, Southern or Imidan. applied more frequently
green stinkbug, than 14 days apart.
5. Second cover Brown rot, Wettable sulfur or' Do not apply Thiodan
14 days later5 Scab. Benlate or Captan within 30 days of
Lesser peach Thiodan. harvest, or Guthion
borer. within 21 days of har-
Tarnished Penncap M4 or vest, or Imidan within 14
plant bug, Guthion or days of harvest.
So. green Imidan.
6. Third cover... Brown rot. Wettable sulfur or For preharvest control
14 days later or Captan or Benlate. of brown rot apply 1 or
4 weeks before Plum Curculio, Same as 2nd 2 sprays of Benlate be-
harvest of each So. green cover spray, ginning 3 weeks before
variety. stinkbug. harvest.
NAME AND TIME
PESTS CONTROLLED AND MATERIAL
NO. OF SPRAY RECOMMENDED' REMARKS
7. Fourth cover... Brown rot. Dusting sulfur 80% Do not apply Penncap M
Two weeks before Captan or Benlate. or Imidan within 14 days
harvest of each Plum Curculio, Penncap M4 or Imidan. of harvest.
variety. So. Green stinkbug.
8. Fifth cover... Brown rot. Dusting sulfur 80% Sevin can be applied up
Preharvest one or Captan or Benlate to one day of harvest
week before Plum Curculio, Sevin. on peaches and 3 days
harvest of each So. green of harvest on nectarines.
9. Sixth cover... Brown rot. Benlate If weather is hot and
Pre-harvest dry, it may not be nec-
one day before cessary to use Benlate
harvest. in this spray.
10. 1st borer spray..
After all fruit
White peach scale
POST HARVEST SPRAYS
Lesser peach Thiodan
Peach tree borer.
White peach Parathion or Guthion
scale. or Diazinon.
Thoroughly wet scaffold
limbs, trunk, and soil
at base of tree to control
Apply 2 sprays 2 weeks
apart when crawlers are
11. 2nd borer spray... Lesser peach Thiodan Apply Lorsban only once
30-45 days after tree borer, per season. Registered
1st borer spray. Peach tree borer. Lorsban on peaches 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
Pa.athion and Guthion. Liquid lime-sulfur for scale control rate: 12 gal/100 gal.
1 See Table II for residue tolerances and limitations for pesticides recommended.
2 See "Spray Notes" page 2.
3 During cool weather Parathion will not give effective control and Penncap M, Guthion,
or Imidan should be used.
4 Penncap M is a slow release formulation of methyl-parathion with longer residual activity
to provide extended control.
5 For best control of scab during wet weather, a 7 day fungicide spray interval should
RESIDUE TOLERANCES AND LIMITATIONS FOR PESTICIDES RECOMMENDED FOR
PEACHES AND NECTARINES
IN THIS PUBLICATION.
INTERVAL BETWEEN LAST APPLICATION AND
HARVEST. AND OTHER RESTRICTIONS.*
Nectarine Peach Nectarine Peach
Benlate 15.0 15.0 No time limit. Do not graze treated
Do not graze treated orchards, orchards.
Max. 1 lb. per acre per appli- No time limit.
cation. 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.
application as spray; 3.6 Ibs. per application as spray;
as dust. 3.6 Ibs. as dust.
Captan 50.0 50.0 No time limit. No time limit at 5 Ibs.
Postharvest same as peaches. per acre.
1 day at 6 Ibs. per acre.
Postharvest 1 to 1.2
Ibs./100 gal. spray or
dip. Recharge when vol.
down 25% with .5 lb. for
each 25 gal. added.
hDiazinon 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,
Max. 5.7 Ibs. per acre per 11.5 Ibs. per acre per
Guthion 2.0 2.0 21 days 21 days
Imidan 5.0 10.0 14 days 6 Ibs. max. per acre 14 days
Kelthane 10.0 10.0 14 days 14 days
Liquid none none Apply during dormancy or delayed dormance.
Lorsban 0.05 Do not apply within 14
days of harvest. Do not
allow spray to contact
fruit. Do not graze meat
or dairy animals in
Parathion 1.0 1.0 Do not apply more than 5 Ibs. Parathion 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 har-
vest. Do not graze or feed
cover crops from treated
INTERVAL BETWEEN LAST APPLICATION AND
CHEMICAL TOLERANCES (PPM) HARVEST, AND OUHER RKESRIKIIUNS.-
Plictran 4.0 4.0 Do not apply more than 9 bs/acre per season. Do not
tank mix with spray oils. Do not apply within 4 wks.
of spray oils. Do not graze or feed livestock on cover
crops growing in treated areas.
Sevin 10.0 10.0 3 days 1 day
3-9.7 lbs/100/A spray or 10-60 Ibs/A dust.
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.
AMOUNT OF PESTICIDE REQUIRED PER 100 GALLONS
2X 5X 1OX
Gallons of water per tree:
Gallons of water per acre:
Chemical Pounds of wettable powder per 100 gallons.
Benlate 50% WP 0.50 1.0 2.5 5.0
Botran 75% WP 1.00 2.0 5.0 10.0
Captan 50% WP 2.00 4.0 10.0 20.0
Ferbam 75% WP 2.0 4.0 10.0 20.0
Guthion 25% WP 1.25 2.5 6.25 12.5
Imidan 50% WP 1.5 3.0 7.5 15.0
Kelthane 85% WP 2.0 4.0 10.0 20.0
Parathion 15% WP 2.0 4.0 10.0 20.0
Plictran 50% WP* .25 .38 -- --- ----
Sevin 50% WP 2.0 4.0 10.0 20.0
Sulfur, wettable 80% 6.0 12.0 30.0 60.0
Thiodan 50% WP 1.5 3.0 7.5 15.0
Chemical Ounces of emulsifiable concentrate/100 gal.
Diazinon AG500 4 Ibs/gal E.C. 16 32 80 160
Ethion 4 Ibs/gal. E.C. 16 32 80 160
Guthion 2 Ibs/gal E.C. 20 40 100 200
Kolthane 4 Ibs/gal E.C. 16 32 80 160
Liquid lime-sulfur* scale insects 12 gal. -- --
leaf curl 6 gal. -- --
blossom blight 1 gal. -- -- ---
Lorsban 4 Ibs/gal E.* 96 -- -- --
Parathion 4 Ibs/gal 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 informa-
tion 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
1 oz. = approximately 30 milliliters
1 lb. = 16 ounces
.1 lb. = 1.6 ounces
.4 lb. = 6.4 ounces
.8 lb. = 12.8 ounces