Integrated orchard management guide for commercial apples in the Southeast.

              2006 Integrated Orchard Management Guide
for Commercial Apples in the Southeast
Alabama Cooperative
Extension System
Auburn University
University of Arkansas
Division of Agriculture
Cooperative Extension Service
University of Arkansas
Clemson Cooperative
Extension Service
Clemson University
University of Georgia Cooperative
Extension Service
University of Georgia
North Carolina Cooperative
Extension Service
North Carolina State University
University of Tennessee
Agricultural Extension Service
University of Tennessee
Poison Control Centers and Emergency Facilities
PESTICIDE POISONING – Symptoms of pesticide poisoning may include
headache, blurred vision, weakness, nausea, cramps, diarrhea, and chest discomfort.
If any of these symptoms occur during or after mixing or applying pesticides or if an
unintended unprotected exposure such as a spill occurs, stop work at once and take
appropriate action. If pesticide is spilled on the skin, immediately wash the area
thoroughly with large amounts of soap and water. If pesticide is in the eye, flush the
eye for 15 minutes in running water. If pesticide is inhaled, move to open, clean air.
If pesticide is ingested, rinse out the mouth. Follow all label first aid directions. Give
CPR if indicated. Get help. Contact your physician or poison control center (listed
below or on WPS safety poster). Transport the victim to the closest medical
care facility. Take the pesticide container or the label with you, or have others search
for the label and get it to the facility.
Most pesticide poisonings are due to overexposure to organophosphate and
carbamate insecticides. Investigation indicates these are the result of misuse,
disregard for safety precautions, and lack of proper hygiene during mixing and
application. Ninety percent of occupational exposure is through the hands. Use
neoprene or butyl rubber gloves. Rubber boots prevent acute exposure from spills
and chronic exposure from accumulation of residues in materials of boots and shoes.
STATE-DESIGNATED POISON CENTERS
ALABAMA
Regional Poison Control Center 800-292-6678
The Children’s Hospital of Alabama 205-933-4050 (business)
1600 7th Ave South
Birmingham, AL 35233-1711
ARKANSAS
Poison and Drug Information Center 800-482-8948
University of Arkansas for Medical Sciences
4301 West Markham-Slot 522
Little Rock, AR 72205
GEORGIA
Georgia Regional Poison Control Center 800-282-5846
Grady Memorial Hospital 404-525-3323 (for the deaf)
80 Butler Street South East 404-616-9000 (business)
Atlanta, GA 30335-3801
NORTH CAROLINA
Carolinas Poison Center 800-848-6946 (in NC)
Carolinas Medical Center 800-222-1222 (nationally)
1000 Blythe Blvd 704-355-4000 (business)
Charlotte, NC 28232-2861
SOUTH CAROLINA
Palmetto Regional Poison Control Center 800-922-1117
College of Pharmacy 803-777-1117 (local)
University of South Carolina 803-777-7909 (business)
Columbia, SC 29208
TENNESSEE
Southern Poison Control Center 901-528-6048
848 Adams Ave.
Memphis, TN 38103
2006 Integrated Orchard Management Guide for Commercial Apples in the Southeast
Table of Contents
Pest and Orchard Management Program . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Tree Row Volume: A Model for Determining Spray Volume . . . . . . . . . 27
IPM Practices for Selected Pests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Pesticide Resistance Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Effect of pH on Pesticide Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Orchard Floor Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Apple Pollination, Honey Bees, and Pesticides . . . . . . . . . . . . . . . . . . . . 38
Soil and Plant Analysis Guidelines for Southeastern Apple Production . 39
Fertility Management Recommendations for Apples . . . . . . . . . . . . . . . . 40
Relative Effectiveness of Fungicides . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Relative Effectiveness of Insecticides and Miticides . . . . . . . . . . . . . . . . 43
Toxicity of Pesticides to Beneficial Arthropods . . . . . . . . . . . . . . . . . . . . 45
Weed Response to Preemergence Herbicides . . . . . . . . . . . . . . . . . . . . . 46
Weed Response to Postemergence Herbicides . . . . . . . . . . . . . . . . . . . . . 47
Fungicides and Bactericides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Insecticides and Miticides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Herbicides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Growth-Regulating Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Vertebrate Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Pesticide Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
EPA Registration Numbers of Various Materials . . . . . . . . . . . . . . . . . . . 75
Recommendations for the use of agricultural chemicals are included in this
publication as a convenience to the reader. The use of brand names and any
mention or listing of chemical products or services in this publication does
not imply endorsement by the Cooperative Extension Service nor
discrimination against similar products or services not mentioned.
Individuals who use agricultural chemicals are responsible for ensuring
that the intended use complies with current regulations and conforms to the
product label. Be sure to obtain current information about usage
regulations and examine a current product before applying any chemical.
For assistance, contact your local Extension Agent.
Senior Editor: Jim Walgenbach, Extension Entomologist, NC State
University
Section Editors:
Insect Management Jim Walgenbach
Cultural/Growth Regulators Steve McArtney
Disease Management Turner Sutton
Vertebrate Management Dave Lockwood
Weed Management Wayne Mitchem
Contributors
Alabama South Carolina
John McVay
Arlie Powell
Ed Sikora
Entomology
Horticulture
Plant Pathology
Bob Bellinger
Mike Hood
Desmond Layne
Guido Schnabel
Safety
Apiculture
Horticulture
Plant Pathology
Arkansas Tennessee
John Boyd
Pat Fenn
Donn Johnson
Curt Rom
Weed Science
Plant Pathology
Entomology
Horticulture
Steve Bost
Edward Burgess
Frank Hale
Dave Lockwood
John Skinner
Plant Pathology
Safety
Entomology
Horticulture
Apiculture
Georgia North Carolina
Phillip Brannen
Keith Delaplane
Paul Gulliebeau
Dan Horton
Harold Scherm
Plant Pathology
Apiculture
Safety
Entomology
Plant Pathology
Steve McArtney
Wayne Mitchem
Mike Parker
Bill Sullivan
Turner Sutton
David Tarpy
Steve Toth
Jim Walgenbach
Horticulture
Horticulture
Horticulture
Zoology
Plant Pathology
Entomology
Entomology
Entomology
1
Pest and Orchard Management Program
DORMANT
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Cultural Management
Control tree density, size,
and shape for better light
and spray penetration.
Conduct annual dormant
pruning in central leader
trees and appropriate high-density
orchards.
***** The younger the trees, the closer to bud break
they should be pruned. Prune older and
bearing trees first; prune 1- to 2-year-old
nonbearing trees during the month before
dormant bud break.
Provide proper nutrition
for moderate tree growth
and good fruit quality.
Collect soil samples;
establish and maintain a good
lime and fertility program.
Apply late winter fertilizer to
young, nonbearing trees, and
half rate to mature, bearing
trees.
***** See Fertility Management section (page 40)
for complete sampling, fertilizer rates, and
application methods. Apply full rate to young,
nonbearing trees to promote good tree growth.
Increase lateral bud break
and lateral shoot
development on last
year's leader growth to
encourage scaffold limb
development.
Bag last year's leader growth
3 to 4 weeks before
anticipated dormant bud
break.
***** See Growth-Regulating Chemicals section
(page 61) for details.
Plant Growth Regulators
Control water sprout
regrowth near pruning
cuts and on tops of large
scaffold limbs exposed to
light by heavy dormant
pruning.
Tre-Hold A-112 See comments. Use 10,000 ppm (10
oz/gal) as a "sponge-on"
application.
12 0 See Growth-Regulating Chemicals section
(page 61) for complete recommendation
details. The need for this practice depends on
heaviness of pruning, size of cuts, and
potential growth vigor. Effectiveness depends
on COMPLETE coverage.
Control burr knot
formation.
Gallex ** Paint directly from can,
full strength, on burr
knots.
See Growth-Regulating Chemicals section
(page 61) for recommendation details.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
2
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Disease Management
Reduce inoculum of apple
scab fungus.
Shred leaves with flail
mower.
***** May also help reduce inoculum of fungi that
cause Brooks spot, Alternaria blotch, and
Glomerella leafspot.
Reduce inoculum of
black, white, and bitter rot
fungi.
Prune out dead wood and
mummied fruit.
***** Pruning is extremely important to reduce the
likelihood of these diseases. Don’t stockpile
prunings near orchard. Remove and burn, or
chip with a flail mower.
Reduce inoculum of fire
blight bacteria.
Prune out cankers and old
fire blight strikes.
**** Will also reduce inoculum of black rot, white
rot, and bitter rot.
Reduce inoculum of
powdery mildew fungus.
Prune out silver-colored
terminals.
*** Particularly useful on young trees of a
susceptible cultivar.
Improve control of cedar
apple and quince rusts.
Scout orchard, adjacent
woods, or borders for red
cedar, and remove.
***** Complete removal of red cedar in areas where
cedars are not common may eliminate need for
fungicide sprays for these diseases.
Create good conditions
for drying fruit and
foliage; improve spray
penetration.
Prune to open trees. ***** Pruning is extremely important for good
disease control inside the canopy and in the
tops of large trees.
Weed Management
Control seedling
perennials and winter
annuals.
Apply glyphosate or
paraquat to control emerged
winter annuals.
*****
+++++
See product label. See product label. Apply nonselective postemergence herbicide
alone (spring). When control from this breaks
and summer weeds are 2-3 inches tall, apply a
nonselective preemergence herbicide. This will
likely be in early May, but may vary from year
to year. Delaying PRE herbicide application
results in residual control later in the summer.
Reduce dandelions. 2,4-D amine ++++ 1 qt 1.0 lb 48 60 Apply at least 2 weeks before bloom to control
flowering weeds. Reduces competition with
apple blossoms to enhance bee pollination.
Control of flowering weeds will also help
control tarnished plant bug.
3
SILVER TIP
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Disease Management
Control fire blight. Bactericides
copper hydroxide
copper oxychloride sulfate
Bordeaux
++++
++++
++++
See label.
See label.
See label.
See label.
See label.
See label.
This treatment will help control fire blight in
blocks of trees of a susceptible cultivar where
fire blight has been a problem. It will not
eliminate need for streptomycin. Applications
later than 0.25- to 0.5-inch green tip may result
in injury. Most effective if applied dilute.
Control black rot. Fungicides
Captan 50W or
4L
++++
++++
——
4 lb
2 qt
96
96
00
An important spray for black rot control in
Georgia. Warning: Captan will cause injury
when used with or too close to oil applications.
Control crown rot
(collar rot).
Fungicides
Ridomil Gold EC or WSP ++++ See label. 12 1
Ridomil and Aliette applications are
recommended on cultivars propagated on
susceptible rootstocks planted in heavy or
poorly drained soils. Apply Ridomil in the
spring before growth starts, and repeat
application after harvest. Apply 3 to 5
applications of Aliette a year. Make first
application of Aliette after leaf emergence.
Note: Ridomil and Aliette must be applied on a
preventive basis. Treatment of trees exhibiting
symptoms will not prevent further symptom
development.
Aliette 80WDG or 80 WSP ++++ e to 1½ lb 2 to 5 lb 12 14
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
4
GREEN TIP TO ½-INCH GREEN
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate Per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Disease Management
Control scab.
See discussion in
Fungicides and
Bactericides (page 49)
for information on
postinfection control
program.
Fungicides
Syllit 65 W +++++ ½ to ¾ lb 2 to 3 lb 48 7
Vangard 75WG +++++ 1.25 oz 5 oz 12 72 Vangard tends to be most active at cool
temperatures.
Vangard 75WG
+ mancozeb
80 WP or
75 DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
¾ oz
¾ lb
¾ lb
0.6 qt
¾ lb
3 oz
3 lb
3 lb
2.4 qt
3 lb
12
24
24
24
24
72
77
77
77
77
Scala SC +++++ 1.75 to 2.5 oz 7 to 10 oz 12 72 Scala SC is not compatible with captan.
Scala SC
+ mancozeb
80 WP or
75 DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
1.25 oz
¾ lb
¾ lb
0.6 qt
¾ lb
5 oz
3 lb
3 lb
2.4 qt
3 lb
12
24
24
24
24
72
77
77
77
77
Sovran 50WG +++++ 1 to 1.6 oz 4 to 6.4 oz 12 30
Flint 50WG +++++ — 2 to 2.5 oz 12 14
Pristine 38W +++++ — 14.5 to 18.5
oz
12 0
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
GREEN TIP TO ½-INCH GREEN (Continued)
5
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate Per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Rubigan 1E
+ captan 50 WP
or
+ mancozeb
80 WP or
75 DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
3 to 4 oz
¾ lb
¾ lb
¾ lb
0.6 qt
¾ lb
8 to 12 oz
3 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
30
77
77
77
77
Do not use captan within 2 weeks of an oil
spray.
Although resistance of the apple scab fungus to
the DMI fungicides Nova, Rubigan, and
Procure has not been confirmed, some growers
have experienced problems in the Southeast in
controlling scab when using these fungicides.
Growers who have had this problem should use
a program that begins with two sprays of Syllit,
Vangard, or Scala, followed by two sprays of
Flint or Sovran. The fifth spray, which should
occur around petal fall, can include a DMI
fungicide, but it needs to be combined with a
full rate of captan or captan + mancozeb or
metiram to ensure scab control. A DMI
fungicide at this time will help control powdery
mildew, especially on mildew-susceptible
varieties, and cedar apple and quince rust if
captan is used alone.
Nova 40W
+ captan 50 W
or
+ mancozeb
80 W or
75 DF or
F4
or
+ Polyram 80 DF
+++++
+++++
+++++
+++++
+++++
1¼ to 2 oz
¾ lb
¾ lb
¾ lb
0.6 qt
¾ lb
5 to 10 oz
3 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
14
77
77
77
77
Procure 50WS
+ captan 50 W
or
+ mancozeb
80 W or
75 DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
1 to 2 oz
¾ lb
¾ lb
¾ lb
0.6 qt
¾ lb
4 to 8 oz
3 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
14
77
77
77
77
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
6
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Insect Management
Control scales and reduce
overwintering European
red mite and rosy apple
aphid eggs.
Improve scale and rosy
apple aphid control
Insecticides
Oil
Oil +
Lorsban 4E
or
Supracide 2E
or
Esteem 35WP
or
Diazinon 50WP
or
Danitol 2.4EC
or
Asana XL
or
Ambush 2E
or
Warrior
+++++
++++
+++++
+++++
+++++
++++
+++
+++
++++
2 gal
2 gal
½ to 1 pt
1 to 2 pt
–
1.0 lb
2b to 5a oz
2 to 5.8 oz
1.6 to 3.2 oz
0.64 to 1.28 oz
8 gal
8 gal
2 to 4 pt
4 to 8 pt
4 to 5 oz
4 lb
10b to 21a oz
4.9 to 14.2 oz
6.4 to 12.8 oz
2.56 to 5.12 oz
12
12
96
12
12
24
24
12
12
24
0
0
DD
DD
45
21
14
21
PF
21
Use a superior-type or highly refined summer
oil applied dilute for best results. If the oil
application is delayed until tight cluster to
pink, use a refined oil or reduce a superior
type to ½ to 1 gal/100 gal. Do not use captan
within 2 weeks of an oil application.
An insecticide with oil may be added at this
time in orchards experiencing problems with
scales or climbing cutworms. In some blocks,
applications of Lorsban, Asana, and Ambush
no longer control rosy apple aphid due to
resistance. Neither Asana nor Ambush will
control mites or scales.
Note: Pyrethroids, including Asana, Ambush,
Danitol, and Warrior will not control scales.
These products are highly toxic to predatory
mites and often lead to flare-ups of European
red mite populations.
Initiate Oriental Fruit
Moth (OFM) monitoring
program.
Erect pheromone traps ***** Erect pheromone traps by green tip to detect
first emergence. See section on IPM Practices
for Selected Pests (page 29) for monitoring
information.
Mating disruption of
OFM.
Pheromones
Isomate Rosso +++++ 100 dispensers /acre
If insecticides are used for first generation
OFM control at petal fall, mating disruption of
OFM can be delayed until May or June.
See section on “Mating Disruption” in IPM
Practices for Selected Pests (page 31).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
TIGHT CLUSTER TO PINK
7
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Disease Management
Control scab. Fungicides
Same fungicides as used
in green-tip spray except
do not use Vangard
75WG or Syllit 65W. If
two sprays of Sovran or
Flint have been used,
switch to a nonstrobilurin
fungicide.
Control powdery mildew. Fungicides
Nova 40W
Rubigan EC
Bayleton 50DF
Procure 50WS
+++++
++++
++++
+++++
1¼ to 2 oz
3 to 4 oz
½ to 2 oz
1 to 2 oz
5 to 10 oz
8 to 12 oz
2 to 8 oz
4 to 8 oz
24
12
12
12
14
30
45
14
These are the most important sprays for the
control of powdery mildew.
Control cedar apple rust
and quince rust.
Fungicides
Nova 40W
Rubigan 1EC
Bayleton 50DF
mancozeb 80W or
75DF or
F4
Polyram 80W
Ferbam Granuflo
+++++
+++++
+++++
+++++
+++++
+++++
+++++
++++
1¼ to 2 oz
3 to 4 oz
½ to 2 oz
¾ lb
¾ lb
0.6 qt
¾ lb
½ lb
5 to 10 oz
8 to 12 oz
2 to 8 oz
3 lb
3 lb
2.4 qt
3 lb
2 lb
24
12
12
24
24
24
24
24
14
30
45
77
77
77
77
7
Do not use Ferbam within 7 days of an oil
spray.
Control black rot and
frogeye leafspot.
Captan 50W or
4L
++++
++++
1 ½ to 2 lb
¾ to 1 qt
6 to 8 lb
3 to 4 qt
96
96
00
Captan alone will not control powdery mildew
or rust diseases.
Insect Management
Initiate codling moth and
leafroller monitoring
program.
Erect pheromone traps. ***** Erect traps now because moths begin to
emerge near bloom. See section on IPM
Practices for Selected Pests (page 29) for
information on monitoring programs.
8
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv
Interval
100 gal Acre (days) Comments
Insect Management
Control rosy apple
aphid.
Insecticides
Actara 25WDG
Assail 30SG
Calypso 4F
Thiodan 3EC, Phaser 3EC
Diazinon 50W
Dimethoate 4EC/400
Danitol 2.4EC
+++++
+++++
+++++
+++
++++
++++
+++++
–
–
–
b qt
1 lb
½ to 1 pt
2.6 to 4.3 oz
4.5 oz
2.5 to 4 oz
2 to 4 oz
2 b qt
4 lb
2 to 4 pt
10.6 to 21.3 oz
12
12
12
24
24
24
24
35
7
30
21
21
28
14
Pink stage is the best time to control rosy
apple aphid. Caution: Rosy apple aphid
resistance to Thiodan, Diazinon,
Dimethoate, and Danitol has been observed
in some orchards. See Rosy Apple Aphid
resistance section (page 35).
Assail may be used during bloom if sprays
are applied before or after bees are in the
orchard. Assail residues on leaves or
flowers are not toxic to bees, but avoid
spraying when bees are in the orchard.
Control plant bugs
and spotted tentiform
leafminer (STLM).
Maintain clean ground-cover.
Insecticides listed for
rosy apple aphid will aid in
plant bug and leafminer
control if plant bugs are
readily seen.
***** In many instances, a clean groundcover
eliminates the need for insecticides to
control bugs. If there is a history of plant
bug problems, a second application at petal
fall will improve control. The need for
insecticides specifically targeting STLM at
this time is questionable because first
generation mines rarely exceed threshold
levels.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
9
BLOOM
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Cultural Management
Loosen bags on leaders to
acclimate for 2 to 3 days;
then remove bags from
leaders and spray with
Promalin.
Leader bags must be
removed when new lateral
growth is 1 to 3" long.
***** See Growth-Regulating Chemicals section
(page 61) for complete details.
Do leader selection and
strip whorl on dormant
headed tree leaders.
Select new shoot for
central leader and remove
competing shoots from
first four nodes below new
leader shoot.
Plant Growth Regulators
Improve fruit shape and
increase fruit weight of
Red and Golden
Delicious (can be used
only on varieties that have
dominant calyx ends).
(BA+GA 4 + 7)
Promalin
Perlan
+++
+++
1 to 2 pt
1 to 2 pt
12
4
None
See Growth-Regulating Chemicals section
(page 61). Apply as a fine mist application
at 40 to 50% of Tree Row Volume (TRV)
water rate between king bloom opening and
full bloom.
Increase lateral bud break
and lateral shoot growth
on 1-year-old leader
growth as a tool to
encourage scaffold limb
development, especially
on those that were bagged
before bud break.
Promalin
Perlan
+++++
+++++
250 to 500
ppm
(1 to 2 pt)/10
gal
125 to 500
ppm
(0.5 to 2 pt)/
10 gal
12
4
None Apply to last year's leader growth with a
handheld nozzle. See Growth-Regulating
Chemicals section (page 61).
Make one application when orchard trees
have 1 to 3 inches of new growth.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
10
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Disease Management
Control scab, rusts, and
mildew.
Fungicides
Same fungicides as
recommended in tight
cluster stage.
Avoid sprays in full bloom if possible. Do not
overextend application intervals.
Control fire blight. Bactericides
streptomycin 4.8 to 8 oz 1½ to 2½ lb 12 50
Begin application at first bloom and continue at
3- to 4-day intervals until petal fall.
Streptomycin sprays protect only those
blossoms open at time of application. It is very
important to continue spraying through “rat-tail”
bloom, especially on susceptible varieties.
See discussion under Resistance Management
section (page 34) for timing sprays according
to conditions favorable for infection.
Insect Management
Protect pollinators. Do not apply insecticides
during bloom.
***** Keep orchard floor free of flowering weeds.
This will increase pollination activity in the
trees and lessen bee activity after apple bloom.
Disrupt mating of codling
moth.
Pheromones
Isomate CTT
CheckMate CM-XL 1000
++++
++++
(# dispensers)
200/acre
120-200/acre
Do not use mating disruption in blocks of less
than 5 acres. Pheromone dispensers should be
hung before moths begin to emerge, with
hanging completed by petal fall. Also,
supplemental sprays with an insecticide may be
necessary under moderate to high population
densities. See section on IPM Practices for
Selected Pests (page 29).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
PETAL FALL
11
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Cultural Management
Reduce fruit corking. Solubor +++ 1 lb
at first cover
If boron is low in leaf sample or cork spot has
been a problem in past years, a second and
third application may be used. Dilute
applications are necessary for good uptake. See
Fertility Management section (page 40).
Reduce fruit corking and
bitter pit.
calcium nitrate
or
calcium chloride
+++
+++
3 lb
2 lb
beginning at
first cover
Repeat calcium sprays in each cover spray all
season. Calcium nitrate may contribute to
unwanted leaf nitrogen levels and vegetative
growth. Do not apply calcium chloride when
temperatures are above 85ºF, and DO NOT
tank mix with Solubor. All calcium sprays
should be applied dilute for maximum
response, especially for bitter pit control in the
late season cover spray when fruit are
becoming waxy. See Fertility Management
section (page 40).
Plant Growth Regulators
Reduce fruit russetting on
susceptible cultivars (esp.
Golden Delicious).
(GA4+7)
Pro-Vide
Novagib
++++
++++
10
oz/appl.
20-26
oz/appl.
12
4
None At petal fall, begin the first of four applications
at 10-day intervals. See Growth-Regulating
Chemicals section (page 61) for complete
recommendations.
Thin fruit to reduce crop
load and encourage return
bloom.
Depends on cultivar, fruit
size, and thinning chemical
selected. Applications
timed from petal fall to
about 8 mm would be
applied during this time.
+++++ See Thinning
Chart.
Check label for specific
thinning chemical(s) to
be used.
See Chemical Fruit Thinning Spray and Apple
Thinning recommendations chart in Growth-
Regulating Chemicals section (page 64).
Initiate vegetative growth
control applications.
Apogee ++++ Use at TRV
calculated
A.I./acre.
12 45 See Apogee table in Growth-Regulating
Chemicals section (page 66).
12
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Disease Management
Control scab. Scout for secondary scab. ***** If primary scab is controlled by petal fall or
first cover, switch to captan. If secondary scab
is detected early, dodine, Rubigan, Nova, or
Procure can be effectively used in a
postsymptom treatment. See discussion under
Fungicides and Bactericides (page 49).
Control summer diseases
(general).
Fungicides
captan 50W or
4L
2 lb
1 qt
8 lb
4 qt
96
96
0
0
If Rubigan, Nova, or Procure is used in this
spray, increase the rate of Captan 50W to 6 to 8
lb/acre or Captan 4L to 3 to 4 qt/acre and
extend interval to 10 to 14 days, or follow
combination sprays with lower rates of captan
or metiram in 5 to 7 days with full rate of
captan or combinations of captan plus
mancozeb or metiram. Captan and metiram at
petal fall or first cover generally give better
fruit finish than mancozeb. If the first cover
spray occurs after May 15, include 8 to 12
oz/acre of Topsin M70WP with captan for
sooty blotch or flyspeck control as directed in
second and later cover sprays below. Use
captan in orchards where black rot is a
problem.
captan 50W or
4L
+
Polyram 80 W or
mancozeb
80W
75 DF
4F
+++++
+++++
+++++
+++++
+++++
1¼ lb
0.62 qt
¾ lb
¾ lb
¾ lb
0.6 qt
5 lb
2½ qt
3 lb
3 lb
3 lb
2.4 qt
96
96
96
96
77
77
77
77
Sovran 50WG +++++ 1.0 to 1.6 oz 4.0 to 6.4 oz 12 30 Sovran and Flint will also control apple scab
and powdery mildew.
PETAL FALL (continued)
13
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Control summer diseases
(general) (continued).
Flint 50WG +++++ — 2.5 to 3.0 oz 12 14
Pristine 38W +++++ — 14.5 to 18.0 oz 12 0
Control Brooks fruit spot. Fungicides
Use fungicides listed for
summer diseases or use
fungicide combinations
listed under green tip.
+++++
Petal fall through third cover sprays are the
most important sprays for Brooks spot control.
Nova, Rubigan, and Procure have very little
Brooks spot activity. If Nova, Rubigan, or
Procure are used, combine them with a full rate
of protectant.
Control powdery mildew. Fungicides
Bayleton 50DF +++++ 0.5 to 2 oz 2 to 8 oz 12 45
If Nova, Rubigan, or Procure are no longer
used, include Bayleton for mildew control on
susceptible cultivars.
Control cedar apple rust. Fungicides
Ferbam Granuflo ++++ ½ lb 2 lb 24 7
If captan alone is used in these sprays, include
Ferbam where cedar apple rust is a problem.
Insect Management
Preventively control
European red mite,
spotted tentiform
leafminer, and white
apple leafhopper.
Control European red
mite.
Insecticides
Agri-Mek 0.15EC
+
oil
Apollo SC
Savey 50WP
Zeal 72WDG
FujiMite5EC
Envidor 2SC
+++++
+++++
+++++
+++++
+++++
++++
2.5 oz
S
S
S
S
S
10 oz
4 oz
3 oz
2 to 3 oz
1 to 2 pt
16 to 18 oz
12
12
12
12
12
12
28
45
28
28
14
7
An application of Agri-Mek at petal fall should
provide season-long suppression of these pests.
A paraffinic spray oil (0.25% or 1 gal/acre)
must be tank mixed to ensure Agri-Mek’s
activity. Do not use captan 2 weeks before or
after applying oil with Agri-Mek.
Apollo and Savey are most effective if applied
at petal fall or first cover. Apply FujiMite,
Zeal, or Envidor between petal fall and third
cover or when mites reach one adult per leaf.
FujiMite will also control leafhoppers. See
page 35 for resistance management of
European red mite.
14
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Control plum curculio. Insecticides
Guthion 50WP
Imidan 70WP
Avaunt 30WG
Actara 25SDG
Assail 30SG
Calypso 4F
Clutch 50WDG
Sevin 50WP
+++++
+++++
+++++
+++++
++++
++++
+++
++++
½ lb
¾ lb
–
–
–
1 to 2 oz
–
½ lb
2 lb
3 lb
5 to 6 oz
4.5 to 5.5 oz
8 oz
4 to 8 oz
3 oz
1 lb
48h, 14d
24
12
12
12
12
12
12
21
7
28
35
7
30
14
3
Adults enter orchards before or near petal fall.
A preventive spray is recommended to
minimize damage on fresh market apples. Cool
weather during this period may extend adult
activity, which may require a second
application. Read about re-entry interval for
Guthion in the Insecticides and Miticides
section (page 52).
Control Oriental fruit
moth.
Insecticides
Guthion 50WP
Imidan 70WP
Avaunt 30WG
Sevin 50WP
Assail 30SG
Calypso 4F
Clutch 50WDG
+++++
+++++
++++
++++
++++
++++
+++
½ lb
¾ lb
–
½ lb
–
1 to 2 oz
–
2 lb
3 lb
5 to 6 oz
2 lb
5 to 8 oz
4 to 8 oz
3 oz
48h, 14d
24
12
12
12
12
12
21
7
28
3
7
30
14
Oriental fruit moth has become more important
in apples in recent years. An insecticide applied
between 500 and 600 degree days (DD) after
biofix will control the first generation. Read
about re-entry interval for Guthion in
Insecticides and Miticides Section (page 52).
Control San Jose scale. Insecticides
Dimethoate 4EC/400
Diazinon 50WP
Guthion 50WP
Esteem 0.86EC
Centaur 70WP
Assail 30SG
summer oil
+++++
+++++
++++
+++++
++++
++++
+++
½ to 1 pt
1 lb
½ lb
–
–
–
–
2 to 4 pt
4 lb
2 lb
4 oz
34.5 oz
8 oz
1 to 2%
48
24
48h, 14d
12
12
12
12
28
21
21
45
14
7
0
Where scales are a problem, apply an
insecticide for first generation crawlers, which
are active from petal fall through third cover.
Yellow crawlers can be detected by wrapping
double-stick tape around infested limbs after
bloom and inspecting weekly. Caution:
Diazinon or oil applied with captan or Captec
may cause phytotoxicity.
Control white apple
leafhopper.
Insecticides
Sevin 50WP
Actara 25WDG
Assail 30SG
Calpyso 4F
Provado 1.6F
Avaunt 30WG
+++++
+++++
+++++
+++++
+++++
+++++
½ lb
–
–
0.5 to 1 oz
1 oz
–
2 lb
2 to 2¾ oz
2.5 to 4.0 oz
2 to 4 oz
4 oz
5 to 6 oz
12
12
12
12
12
12
1
35
7
30
7
28
Threshold level for first generation white apple
leafhopper is 1 nymph per leaf. Thinning
apples with Sevin during this time controls
leafhoppers. Leafhoppers may be present from
petal fall to second cover spray.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
15
PETAL FALL (continued)
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Control spotted
tentiform leafminer.
Insecticides
Lannate 90SP
Actara 25WDG
Provado 1.6F
SpinTor 2SC
Assail 30SG
++++
++++
++++
+++++
++++
¼ lb
–
1 to 2 oz
–
–
1 lb
4.5 oz
4 to 8 oz
5 to 8 oz
1.1 oz
72
12
12
4
12
14
35
7
7
7
Threshold level for first generation leafminer is
one mine per leaf, but rarely do populations
reach this level this early in the season.
Control rosy apple
aphid.
Insecticides
Provado 1.6F
Actara 25WP
Assail 30SG
Calypso 4F
Dimethoate 4EC/400
Danitol 2.4EC
+++++
+++++
+++++
+++++
++++
++++
2 oz
4.5 oz
–
0.5 to 1.0
½ pt
2.6 to 5.3 oz
4 to 8 oz
4.5 oz
2.5 to 4.0 oz
2 to 4 oz
2 pt
10.6 to 21.3
oz
12
12
12
12
48
24
7
35
7
30
28
14
If an insecticide was not applied for rosy apple
aphid at pink, or if control was poor, an
insecticide should be applied. Caution:
Diazinon applied with captan or Captec may
cause phytotoxicity or russetting.
Control green fruitworm. Insecticides
Guthion 50WP
Imidan 70WP
+++++
+++++
½ lb
¾ lb
2 lb
3 lb
48h, 14d
24
21
7
Green fruitworms are not a common pest:
Apply an insecticide at petal fall if larvae are
observed.
Weed Management
Control weeds. Check orchards for weed
populations.
***** Identify weed problems so herbicide program
can be adjusted for summer weed control.
Apply Pre + Post
herbicide. See herbicide guide. ***** See product labels. See product labels.
Apply when summer weeds are 2 to 3 inches
tall. Delaying application of preemergence
herbicides until early May extends summer
weed control.
Suppress clover bloom
to protect bees from
insecticide sprays.
2,4-D ***** 1 qt 48 60 Apply 2,4-D 7 to 10 days before spraying
insecticides to suppress clover and avoid
killing bees.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
16
FIRST COVER
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Disease Management (Same fungicides as used in Petal Fall Spray)
Insect Management
Control codling moth. Monitor codling moth adult
activity.
Insecticides
Guthion 50WP
Imidan 50WP
Intrepid 2F
Rimon
Danitol 2.4EC
Esteem 35WP
Assail 30SG
Calypso 4F
CYD-X
*****
+++++
+++++
+++++
+++++
+++++
+++
++++
++++
++++
½ lb
¾ lb
–
–
–
–
–
1 to 2 oz
–
2 lb
3 lb
10 to 16 oz
20 to 40 oz
16 to 21a oz
4 to 5 oz
4 to 8 oz
4 to 8 oz
1 to 3 oz
48h, 14d
24
4
12
24
24
12
12
4
21
7
14
14
14
45
7
30
0
See IPM Practices for codling moth (page
29) to determine how to minimize insecticide
applications for codling moth control.
Most insecticides generally provide 2 weeks’
control, so do not be concerned if pheromone
trap counts remain high 1 week after spraying.
If using Intrepid, Rimon, or Esteem for first
generaton codling moth, 2 applications at 14-
day intervals should be made, the first at 100-
200 DD. Do not make more than 2 applications
of Esteem per season.
CYD-X is a virus that controls only codling
moth. Frequent applications (7-14 days) at low
rates (1 to 2 oz per acre) have worked well in
field trials.
Control rosy apple
aphid, plum curculio,
white apple leafhopper,
spotted tentiform
leafminer, and San Jose
scale.
Monitor orchards for these
insects.
Insecticides
(See Petal Fall section,
page 11)
***** Infestations of these insects may occur anytime
from petal fall to the second cover spray. Early
detection is important for effective control.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
17
SECOND COVER AND LATER SPRAYS
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Cultural Management
Reduce fruit corking and
bitter pit.
calcium nitrate
calcium chloride
+++
+++
3 lb
2 lb
See information listed in Petal Fall to First
Cover sections (pages 11 through 16) and
Fertility Management section (page 40).
Provide proper nutrition
for moderate tree growth
and good fruit quality.
Apply second half of fertilizer to
mature, bearing trees if crop
load is present, as soon as
frost/freeze danger is past
(approx. second cover).
Collect leaf samples in July to
mid-August for leaf analysis.
++++
+++++
See Fertility Management Recommendations
section (page 40) for fertilizer use suggestions
and complete recommendations.
See Fertility Management Recommendations
section (page 40) for complete details.
Achieve proper tree
training, and control tree
size and density for good
light and spray
penetration.
Select lateral limbs, strip whorls,
establish wide crotch angles
with toothpicks or clothespins,
and prop limbs to good limb
angles (60-90º for central leader
trees and 75-85º below vertical
for high density, slender,
spindle-type trees).
Do detailed young tree
management (deshoot, position
limbs, tie up leader growth)
every 6 to 8 weeks until full tree
size and bearing are achieved
(especially for high density
orchards).
++++
++++
Tree training is mandatory to develop proper
lateral branching and limb position.
Summer pruning is a necessary extension of
tree training begun earlier. Summer pruning
helps contain tree size and density, and proper
limb selection and positioning encourage
flower initiation.
Remove water sprouts.
Do leader manipulation, such as
summer bending or snaking,
every 18 inches of terminal
growth extension.
++++
++
Removing upright water sprout growth reduces
tree density, allowing greater spray penetration
and better light distribution for fruit quality and
color development. Summer pruning and
removal of water sprouts also help control
sooty blotch and flyspeck.
18
Goals Options
Relative 1
Effectiveness(+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Plant Growth Regulators
Thin to reduce crop load
and encourage return
bloom.
Depends on cultivar, fruit
size, and thinning chemical
selected. Application time
from approximately 9 mm
and larger would be applied
from second cover on.
+++++ See
thinning
chart.
See Chemical Fruit Thinning Sprays (page 62)
and Apple Thinning Recommendations chart
(page 64) in Growth-Regulating Chemicals
section.
Enhance return bloom. Naphthaleneacetic acid
(NAA)
+++ See NAA Table in PGR
Section (page 65).
Control ground suckers
around base of trunk.
Tre-Hold A-112 Sprout
Inhibitor
Also use herbicides approved
for sucker control. See
comments in Herbicide
section (page 59) for Rely,
Gramoxone.
++++ Use 10,000 ppm (10
oz/1 gal) as a low-pressure,
large-droplet
handgun application.
12 0 See Growth-Regulating Chemicals (page 66)
for specific recommendation details.
Delay preharvest fruit
drop and delay fruit
maturity.
ReTain +++++ 2 oz One 333-
gram
pouch per
acre (50
grams
a.i.).
12 21 Apply a single application 4 weeks before
normal start of harvest for each variety. Fruit
maturity and harvest date will be significantly
delayed. See Growth-Regulating Chemicals
(page 67) for recommendation details.
Delay or reduce
preharvest fruit drop or
both.
Preload NAA (Fruitone-N) ++++ 2 oz 4 days 4 Apply multiple applications of 5 ppm each
week for the 4-week period prior to the normal
start of the harvest period for each variety.
NAA + 4 to 8 oz 4 days 4 Temporarily suppress any fruit drop by
applying 10 to 20 ppm (depending on variety)
of NAA. A second application can be applied 7
to 10 days later. See Growth-Regulating
Chemicals section (page 67) for
recommendation details.
SECOND COVER AND LATER SPRAYS (continued)
19
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Reduce fruit russetting
in susceptible varieties.
Pro-Vide 10SG
Novagib
(continue applications started
at petal fall)
++++
++++
60-100 g
20 oz per
acre/appl
12
4
0 See Petal Fall to First Cover sections and
Growth-Regulating Chemicals section
(page 61) for recommendation details.
Reduce fruit cracking of
susceptible varieties
(e.g., Stayman).
Pro-Vide 10SG +++ 100-200 g 12 0 Begin applications in early to mid-June or
as soon as cracking is observed. Repeat at
3-week intervals until harvest. See Growth-
Regulating Chemicals section (page 61) for
details.
Novagib +++ 2 to 4 pt per
acre/appl
4
Promote lateral
branching of current
season’s growth.
Promalin +++ 0.8 oz/gal of
water (125 ppm)
12 None See Growth-Regulating Chemicals section
(page 61) or recommendation details.
Disease Management
Control summer diseases
(white rot, bitter rot,
black rot, sooty blotch,
flyspeck, black pox).
Scout orchard.
Prune out fire blight strikes.
*****
*****
Apply cover sprays at 10- to 14-day
intervals. Use a 10-day interval during wet,
rainy periods. If Topsin M is not used in
cover sprays, it is important to combine
captan with sufficient ziram to increase
fungicide rate to 8 to 10 lb/acre in order to
control sooty blotch and flyspeck. Be sure
to observe 77-day preharvest interval when
using metiram or mancozeb. When using a
combination of captan and ziram, use
approximately equal rates of each. Use
captan where there is a history of white rot.
Fungicides
captan
50W
4L
+++++
+++++
2 lb
1 qt
8 lb
4 qt
96
96
0
0
ziram 76DF or 76WDG ++++ 2 lb 8 lb 48 14
Thiram 65W ++++ 1.7 lb 6.8 lb 24 0
Sovran 50WG +++++ 1.0 to 1.6 oz 4.0 to 6.4 oz 12 30 A maximum of four applications and 25.6
oz of Sovran 50WG can be used per acre
per season. It is weak on black pox.
Flint 50WG +++++ – 2.5 to 3.0 oz 12 14 A maximum of four applications and 11 oz
of Flint 50WG can be used per acre per
season. It is weak on black pox.
20
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Control summer diseases
(continued).
Pristine 38W +++++ – 14.5 to 18.0
oz
12 0 A maximum of four applications and 72 oz
of Pristine can be used per acre per season.
Pristine has activity on strains of the
Alternaria blotch fungus that are resistant to
Sovran and Flint. It is weak on black pox.
captan
50 W
4L
+
Topsin M70WP +++++
2 lb
1 qt
2 to 3 oz
8 lb
4 qt
8 to 12 oz 96 1
ziram 76DF or 76WDG
+
Topsin M70WP +++++
2 lb
2 to 3 oz
8 lb
8 to 12 oz 48 14
thiram 75WDG
+
Topsin M70WP
+++++
2 lb
2 to 3 oz
8 lb
8 to 12 oz
24 0
captan
50 W
4L
+
metiram 80DF
or
mancozeb 75DF
+
Topsin M70WP
+++++
2 lb
1 qt
¾ lb
¾ lb
2 to 3 oz
8 lb
4 qt
3 lb
3 lb
8 to 12 oz 96
77
77
77
Metiram and mancozeb cannot be used
within 77 days of harvest.
captan
50 W or
4 L
+
ziram 76DF, 76WDG or
thiram 65WDG
+
Topsin M70WP
+++++
1 lb
½ qt
1 lb
1 lb
2 to 3 oz
4 lb
1 qt
4 lb
4 lb
8 to 12 oz 96 14
If thiram is used in this combination, the
REI is 96 hours and the PHI is 0 days.
Suppress necrotic leaf
blotch on Golden
Delicious.
ziram 76W or WDG
thiram 75WDG
zinc oxide 39.8%
+++++
++++
+++++
1 to 2 lb
1 to 2 lb
4 to 8 lb
4 to 8 lb
1 pt
48
24
0
14
0
0
Sprays from mid June through early August
are most important.
SECOND COVER AND LATER SPRAYS (continued)
21
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Control powdery
mildew.
Scout orchard. ***** Determine need for additional fungicides
based on the number of infections on newly
unfolded leaves.
Control Alternaria
blotch.
Sovran 50WG
Flint 50WG
+++++
+++++
1 to 1.6 oz 4 to 6.4 oz
2.5 to 3 oz
12
12
30
14
Make first application of Flint or Sovran
around third or fourth cover (mid June).
Apply two additional applications at 10- to
14-day intervals. These applications will
also control other summer diseases on
Delicious. Use in conjunction with a
preventive mite management program.
Insect Management
Control codling
moth.
Monitor pheromone traps
weekly for adult activity.
Insecticides
(See First Cover.)
***** See IPM practices for codling moth (page
29) and Oriental fruit moth (page 30) to
determine the need for and timing of
insecticide sprays.
Insecticides provide 2 weeks’ control, so do
not be concerned if trap catches remain high
1 week after spraying. Keep trap bottoms
clean, and replace lures monthly.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
22
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
interval
100 gal Acre (days) Comments
Control Oriental fruit
moth.
Monitor pheromone traps
weekly for adult activity.
Insecticides
Guthion 50WP
Imidan 70WP
Intrepid 2F
Rimon 0.83EC
Danitol 2.4EC
Assail 70WP
Calypso 4F
Mating Disruption
Isomate-M100
Isomate Rosso
CheckMate OFM-F
*****
+++++
+++++
++++
+++++
+++++
++++
++++
+++++
+++++
+++++
½ lb
¾ lb
–
–
–
–
1 to 2 oz
2 lb
3 lb
12 to 16 oz
20 to 40 oz
5 to 6 oz
1.7 to 3.4 oz
4 to 8 oz
100
160
0.3 to 2.5 oz
48h, 14d
24
4
12
12
12
12
21
7
14
14
28
7
30
See IPM practices for Oriental fruit moth
(page 30) to determine the need for and
timing of insecticide sprays. Oriental fruit
moth has become more important on apples
in recent years, particularly later generations
in August and September.
Under moderate to low OFM populations,
pheromone treatment should begin just
before emergence of third generation adults
(late June to early July). When OFM
populations are high, begin mating disruption
just before emergence of second generation
adults (late May to early June).
Control tufted apple
bud moth.
Monitor pheromone traps
weekly for adult activity.
Thin fruit to avoid
excessive clustering.
*****
****
See IPM Practices for tufted apple bud moth
(page 31) to determine the proper timing of
insecticide applications.
Clustering of fruit is conducive to higher
levels of tufted apple bud moth injury.
Insecticides
Intrepid
SpinTor 2SC
Danitol 2.4EC
Avaunt 30WDG
Rimon 0.83EC
+++++
+++++
+++++
++++
++++
–
–
–
–
–
6 to 12 oz
4 to 8 oz
10.6 to 21.3 oz
5 to 6 oz
20 to 40 oz
4
4
24
12
12
14
7
14
28
14
See Insecticide Resistance Management
section (page 35) for tufted apple bud moth
(TABM). Insecticide sprays for TABM are
recommended only in orchards with a history
of damage. See section on IPM practices for
tufted apple bud moth to properly time
sprays.
Bacillus thuringiensis
Dipel 2X
CryMax
XenTari
+++
¼ to ½ lb
¼ to ½ lb
¼ to ½ lb
1 to 2 lb
1 to 2 lb
1 to 2 lb
4
4
4
0
0
0
For best results apply Bacillus thuringiensis
(Bt) products at no less than 2X
concentration. If using Bts, it is important
to monitor codling moth with pheromone
traps because Bts do not control codling
moth.
SECOND COVER AND LATER SPRAYS (continued)
23
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Control apple maggot. Erect red sticky spheres in
early June to monitor
adults.
**** Apple maggot has increased in importance
in recent years and is particularly a problem
in orchards near unsprayed orchards and/or
following a year in which many orchards
did not receive a full-season spray program,
but still had some fruit in the orchard. Erect
sticky traps on outside rows nearest
abandoned orchards or other sources of
flies. Check weekly. Threshold level is one
fly per trap per week. If flies are still caught
2 weeks after spraying, apply again. Adults
can emerge from June through August.
Insecticides
Guthion 50WP
Imidan 70WP
Assail 30SG
Calypso 4F
Clutch 50WDG
Provado
Surround WP
+++++
+++++
++++
++++
++++
+++
+++
½ lb
¾ lb
–
1 to 2 oz
–
–
–
2 lb
3 lb
8 oz
4 to 8 oz
6 to 8 oz
4 to 8 oz
20 to 50 lb
48h, 14d
24
12
12
12
12
4
21
7
7
30
14
7
–
Apply insecticides at 10- to 14-day intervals
during apple maggot flight.
Apply Surround at 7- to 14-day intervals, or
after a heavy rain, because thorough,
uniform, and consistent coverage is
important. Rate of Surround will vary with
tree size.
Control white apple
leafhopper or potato
leafhopper.
Insecticides
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Avaunt 30WG
Dimethoate 4EC/400
Clutch 50WDG
Centaur 70WP
+++++
+++++
+++++
+++++
+++++
+++
+++++
+++++
1 oz
–
–
0.5 to 1 oz
–
½ pt
–
–
4 oz
2 to 2¾ oz
2.5 to 4.0 oz
2 to 4 oz
5 to 6 oz
2 pt
2 oz
34.5 oz
12
12
12
12
12
48
12
12
7
14
7
30
28
28
14
14
Threshold level for second brood nymphs
(which occur in late July to early August) is
one nymph per leaf. Treatment will
eliminate the need to treat for adults
immediately before harvest. Generally, low
rates of insecticides will control
leafhoppers.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
interval
(hours)
Preharv.
interval
100 gal Acre (days) Comments
24
Control spotted
tentiform leafminer.
Insecticides
Lannate 90SP
SpinTor 2SC
Vydate 2L
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Clutch 50WDG
++++
+++++
++++
+++
++++
++++
++++
++++
¼ lb
–
1 to 2 pt
2 oz
–
–
0.5 to 1 oz
–
1 lb
4 to 8 oz
4 to 8 pt
8 oz
4.5 oz
2.5 oz
2 to 4 oz
3 oz
72
4
48
12
12
12
12
12
14
0
14
7
14
7
28
14
A threshold level of two mines per leaf for
second generation larvae (June to July) should
be used to dictate the need for STLM control.
Control of third generation larvae (August)
may be necessary on late-maturing cultivars if
populations exceed 4 mines per leaf. Many
orchards have high levels of parasites by this
time. Insecticides are more effective against
sap-feeding mines than tissue feeders.
Control green apple
and spirea aphids.
Insecticides
Dimethoate 4EC/400
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Clutch 50WDG
+++++
+++++
+++++
+++++
+++++
+++++
½ pt
1 to 2 oz
––
0.5 to 1 oz
–
2 pt
4 to 8 oz
4.5 oz
2.5 to 4.0 oz
2 to 4 oz
2 oz
48
12
12
12
12
12
28
7
35
7
28
14
Threshold level for green apple aphid is 50%
infested terminals. Control is most important
on young trees and in dwarf plantings. On
mature trees, a higher threshold is tolerable.
Control Comstock
mealybug.
Insecticides
Diazinon 50WP
Dimethoate 4EC
Actara 25WDG
Assail 30SG
+++++
+++++
+++
+++++
1 lb
½ pt
––
4 lb
2 pt
4.5 oz
4 to 8 oz
24
48
12
12
14
28
35
7
Applications should be made near the third
cover spray. Comstock mealybug has become
a problem in some orchards where
organophosphate use has been reduced or
eliminated, where postbloom pyrethroid use
has increased, or both.
Control woolly apple
aphid.
Insecticides
Dimethoate 4EC/400
Diazinon 50W
+++
+++
½ pt
1 lb
2 pt
4 lb
48
24
28
21
In recent years woolly apple aphid has
increased in many areas. Above-ground
infestations are of greatest concern on
younger trees.
Control redbanded
leafroller.
Insecticides
Bacillus thuringiensis
Guthion 50WP
Imidan 70WP
Intrepid 2F
SpinTor
+++
++++
++++
+++++
+++++
¼ lb
½ lb
¾ lb
–
–
1 lb
2 lb
3 lb
8 to 10 oz
4 to 8 oz
12
48h, 14d
24
4
4
0
21
7
14
7
Redbanded leafroller is a sporadic problem. If
damage is done, it is usually by the last
generation, which lays eggs from mid August
to mid September.
Control lesser apple
worm.
Insecticides
Guthion 50WP
Imidan 70WP
Intrepid 2F
+++++
+++++
+++++
½ lb
¾ lb
–
2 lb
3 lb
10 to 16 oz
48h, 14d
24
4
21
7
14
Lesser apple worm is a sporadic pest of
importance in isolated areas. If damage
occurs, it is usually by the third generation,
which occurs in August.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
SECOND COVER AND LATER SPRAYS (continued)
25
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Control dogwood borer. Insecticides
Lorsban 50W,
4E
Thiodan 3EC
Asana XL
++++
+++++
+++
+++
3 lb
1.5 qt
a qt
2.0 to 5.8 oz
–
–
–
–
96
96
24
24
28
28
21
21
Apply insecticides with a handgun sprayer to
the trunk, especially to burr knots and graft
unions. Moths can lay eggs from mid May
through July, so treatment in mid to late May
is optimal. Lorsban should be applied with a
handgun sprayer from no more than 4 ft or
with a shielded sprayer to prevent drift onto
foliage or fruit.
Control European red
mite and two-spotted
spider mite.
Monitor trees for mite activity. ***** See IPM practices for European red mite.
European red mite and two-spotted spider
mite threshold levels before July are 7 mites
per leaf (85% infested leaves) and 10 mites
per leaf (90% infested leaves) during July and
August. If populations are near threshold
level and Stethorus punctum is present,
recheck in 3 to 4 days to determine if
biological control reduces mite populations.
In orchards with Alternaria blotch, a
threshold of 2 mites per leaf (70 to 75%
infested leaves) should be used to minimize
stress to trees.
Miticides
Acramite 50WS
Nexter 75WP
Apollo SC
Savey 50DF
Zeal 72WDG
Envidor 2SC
Kelthane 50WP
Vendex 50W
Danitol 2.4EC
wettable sulfur
summer oil
+++++
+++++
+++++
+++++
+++++
+++++
++++
++++
++++
+
++
–
–
–
–
–
–
¾ to 1½ lb
¼ lb
–
1 ½ to 3½ lb
½ to 1 gal
¾ to 1 lb
4.4 oz
4.0 oz
3.0 oz
2 to 3 oz
16 to 18 oz
3 to 6 lb
2 lb
16 to 21.6 oz
5 to 15 lb
½ to 1% soln.
12
12
12
12
12
12
12
48
24
12
12
7
25
45
28
28
14
7
14
14
7
0
If Apollo or Savey were used at petal fall, do
not reapply at this time. Use the higher rate of
Kelthane on large trees. Do not expect
complete control with a single application of
oil or sulfur. These materials must be applied
multiple times for best results. Applying a
highly refined summer oil when mite
populations are beginning to increase (first
and second covers) will help suppress
European red mite infestations. Do not apply
captan 2 weeks before or after an oil spray.
SECOND COVER AND LATER SPRAYS (continued)
26
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Weed Management
Spot-treat with herbicide
to control difficult-to-manage
perennial weeds.
glyphosate ***** See Weed Response to
Herbicide table
(pages 46 to 48).
Apple trees are especially sensitive to
glyphosate applied in late summer and fall.
Avoid contacting tree bark and especially
foliage.
.
POSTHARVEST
Goals Options
Relative 1
Effectiveness (+)
or
Importance (*)
Rate per2 Re-entry
Interval
(hours)
Preharv.
Interval
100 gal Acre (days) Comments
Plant Growth Regulators
Control fruit storage scald. DPA ++++ 2½ pt per one gal of
water as a dip or spray to
harvested fruit.
See Growth-Regulating Chemicals section (page
61) for complete details.
To maintain apple flesh
firmness, fruit acidity and
minimize scald
SmartFresh See Growth-Regulating Chemicals section (page
61) for complete details.
Weed Management
Apply POST or PRE +
POST herbicide.
See herbicide guide. *** See herbicide guide. See product labels. In areas where heavy populations of winter
annual weeds are present, apply herbicide as part
of vole management program. Application of a
fall preemergence herbicide will delay the spring
herbicide application to early May or later.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
27
Tree Row Volume (TRV):
A Model for Determining Spray Volume
The TRV model is a simple and objective method of determining (1) the volume of tree
canopy on an acre of orchard, regardless of row spacing, tree size, age, or other factors;
and (2) the dilute application water rate and chemical quantity for dilute (1X)
applications or concentrate chemical load per acre needed to effectively spray each
particular orchard, regardless of pruning and tree canopy density.
The TRV concept rests on these assumptions: Each row of trees is a wall of foliage, and
water and chemical loads required can be related to the volume and density of foliage
within that wall. Only three measurements must be made:
(1) The distance between rows of trees; (2) the maximum tree height to be sprayed; and
(3) the spread from drip line to drip line, which must be accurately measured to at least
the nearest foot. In addition, an assessment of tree density is needed to calculate the
TRV of an orchard.
Using these measurements, the TRV of any orchard can be calculated using the
following formula:
Step 1: 43,560 sq ft/acre = feet of row/acre
distance between rows (ft)
Step 2: Feet of row/acre (from Step 1) X tree height (ft) X cross-limb spread (ft) =
cu ft of foliage/acre.
Steps 1 and 2 determine the volume of foliage canopy per acre in the orchard.
Step 3: Select one of the numbers from Table 1 that best indicates the canopy density
of each separate orchard or block.
The cubic feet of foliage volume from Step 2 and the tree density established in Step 3
are used to calculate the water volume required per acre for a dilute spray application to
provide maximum chemical load with a dilute airblast sprayer (applied to runoff).
canopy
Step 4: cu ft of foliage/acre density gallons of dilute solution
(from Step 2) X (from Step 3) = to be applied per acre for
1,000 cu ft a maximum application
Example
Consider an orchard that has rows spaced 25 feet apart, trees 20 feet high, a spread of 17
feet from drip line to drip line, and a tree density of 0.85.
Step 1: 43,560 ft2
25 ft = 1,742.4 ft
Step 2: 1,742.4 ft X 20 ft X 17 ft = 592,416 cu ft
Step 3: Density has been given as 0.85 gal/1,000 cu ft
Step 4: 592.416 cu ft X 0.85 gal = 503.5 gal/acre will apply a dilute
1,000 cu ft application to runoff.
However, general pesticide applications are not applied to runoff. Using 70 percent (0.70)
of the “to runoff” calculated rate reduces the dilute application just to the point of drip, or
what we call “pesticide dilute.” Table 2 gives the adjustments to the “TRV calculated
water rates for dilute to runoff” water application rate for various chemicals used and types
of spray applications. The 503.5 gallons per acre in the example above is used to illustrate
the adjustments in Table 2.
Table 1. Canopy density adjustments in tree row volume (TRV) model.
0.70 gal/1,000 cu ft Trees extremely open, light visible through entire tree, less
than 15 scaffold limbs per tree or young tree.
0.75 gal/1,000 cu ft Trees very open, 18 to 21 scaffolds per tree, light penetration
throughout tree, healthy spurs within tree canopy.
0.80 gal/1,000 cu ft Trees well pruned, adequate light in trees for healthy spurs
throughout trunk and scaffold limbs, many holes or openings
in foliage where light is visible through tree.
0.85 gal/1,000 cu ft Trees moderately well pruned, reasonable spur population
within canopy, tree thick enough that light is not visible
through bottom b of tree.
0.90 gal/1,000 cu ft Trees pruned minimally, spurs inside canopy are weak due to
limited light, very few openings where light is visible
throughout the tree.
0.95 gal/1,000 cu ft Little or no pruning, spurs dead or very weak in canopy, very
little light visible throughout the tree.
1.00 gal/1,000 cu ft Tree unpruned, extremely thick, no light visible anywhere
through tree canopy, trees more than 20 ft high.
28
Table 2. Adjustments in tree row volume (TRV) calculated water rates per acre for
various chemicals and types of spray applications.
Type of spray and chemical
application
% of the calculated TRV
dilute to runoff gallonage to
be used for a dilute
application
Actual gallons/acre to
be used in previous
TRV example orchard
1Pre-petal fall dilute pesticide
application (adjusted because
of incomplete foliage
development)
56 282
Dilute pesticide application
(from petal fall on and all
other applications not
specifically mentioned)
70 352
ProVide and Promalin
(as a fine mist)
40 to 50 201 to 252
Spur Red Delicious thinners
and dormant oil applications
100 504
Thinners for other varieties 70 to 90 352 to 453
Vegetative growth inhibitor 80 to 90 403 to 453
Preharvest Ethrel plus stop-drop
spray
100 to 120 504 to 605
1To use this reduced gallonage requires accurate nozzling to top of trees and good air displacement within trees (i.e.,
reduced tractor speed).
Table 3. How to calculate concentrate application rates.
Concentrate
pesticide
application
(3X water rate)1
Dilute pesticide TRV gallonage = 352 gal/acre = 117 gal/acre
Concentrate rate 3X
Concentrate
pesticide chemical
load per acre
(2X to 4X)2
Rate of pesticide Dilute pesticide
per 100 gal x TRV gal/acre = 2.0 X 352 = 7.1 lbs/acre
100 gal 100
5X or greater3 Rate of pesticide Dilute pesticide
per 100 gal x TRV gal/acre x 0.8 = 2.1 X 352 X 0.8 = 5.6 lbs/acre
100 gal 100
1Assume the example orchard was to be sprayed at 3X concentration.
2Rate per 100 gal dilute. Example based on 2.0 lb pesticide/100 gal.
3This adjustment for concentrate application (5X or greater) should be made if spraying conditions are good and trees are
properly matched to the sprayer. Adequate spray coverage cannot be assumed with concentrate application if sprays are
applied during windy conditions or to thick, oversized trees.
Table 3 demonstrates how the chemical load and water volume for concentrate sprays can
be easily calculated from the TRV model.
The TRV model is accurate for dilute and concentrate chemical applications with
conventional airblast sprayers, using water volumes as low as 150 gallons per acre. Below
this gallonage, the physics of droplet size and impingement on the foliage can become a
limiting factor in obtaining effective deposition on trees. Thus, if the TRV model
calculates a water application rate of less than 150 gallons per acre, a 150 to 200 gallon
rate should be considered a minimum in a conventional airblast sprayer, or be sure you are
using a concentrate engineered sprayer (higher air speed) that will ensure adequate
impingement of the spray solution on the tree surfaces at low water volume.
Dwarf High-Density Orchards
Dwarf high-density orchards represent a special situation for TRV applications. Most high
density orchard TRV water application rates calculate out at well below the minimum
desirable gallonage for good droplet impingement (below 150 gallons/acre). We have
consistently found improved efficacy of pesticide application and improved time
efficiency by calibrating for double the TRV. This raises the water application rate above
the minimum desirable gallonage, and then you must drive every other row middle to
reduce actual water volume per acre of orchard back to true TRV calculated rate.
Pesticides are applied on a normal interval, alternating drive middles.
The reality of sprayer calibration and nozzling for chemical applications is that until the
proper chemical load is appropriately delivered and deposited on leaf and fruit surfaces,
the spray you apply cannot be considered an effective pesticide application.
29
IPM Practices for Selected Pests
Plum Curculio
Plum curculio adults overwinter in leaf litter in and around orchards. In the spring when
the daily maximum temperature exceeds 70ºF, adults emerge, mate, and lay eggs under
fruit skin. This occurs near bloom, petal fall, or both, and an insecticide application at
petal fall is important to minimize damage when adults are present. Adults are ¼-inch-long
weevils with a curved snout; they are mottled black, gray, and brown with two
bumps on each wing cover and a white marking across the back. Eggs hatch within a few
days after being laid and feed in the fruit. The mature larva is ¼-inch long, white, slightly
curved, and legless. Damage on apples is usually observed as feeding or oviposition scars
and is cosmetic. There are two generations per year.
Scouting and Control: After bloom, check twice weekly for plum curculio adults for
feeding and egg-laying scars. Typically, an insecticide at petal fall and first cover (if adult
emergence is protracted) is used for control. However, additional insecticides should be
applied if any new damage is observed.
Plum Curculio Degree-Day (DD) Model
A degree-day model can help growers prepare for plum curculio emergence and
determine the end of adult movement in the spring. Once buds swell, note the second date
when air temperature exceeds 70ºF (biofix) and begin accumulating daily degree days
(DD) (base 50ºF) using the DD table for codling moth on page 33 (base 50oF). Adults
enter orchards from 50 to 400 DD after biofix. Damage occurs from 100 to 700 DD after
biofix. Summer generation adults begin emerging after 1,100 DD and can cause damage
until harvest.
Apple Maggot
Historically, the apple maggot has been a sporadic pest of apples in the southeastern U.S.,
but when it does occur it can cause considerable damage. The apple maggot usually
completes one generation per season, but two generations are known to occur in some
years. Adult flies emerge from overwintering pupae in the soil from June through
September, with the major emergence period being from mid July to early August. About
7 days after emergence, flies become sexually mature and mate, after which females
deposit eggs under the skin of apples by puncturing apples with their ovipositor. After a
few days a small maggot hatches from the egg, and the maggot tunnels within the fruit.
When mature, the maggot exits the apple, drops to the ground, and burrows into the soil,
where it completes development and forms a pupa. The pupa is the overwintering stage,
and it emerges as a fly the following summer. Although the majority of overwintering
pupae emerge the following spring, some pupae do not emerge for 2 to 4 years.
Weather conditions are important in dictating the timing and length of fly emergence.
Pupae overwintering in lighter soils and in sunny areas emerge before those in heavier
soils and shady areas. Sufficient soil moisture is also necessary for flies to emerge from
soil-borne pupae; drought delays or prevents many flies from emerging. Abandoned
orchards (or even a few nonsprayed trees) and wild hawthorn trees are potential sources of
large numbers of flies and are a threat to commercial orchards located within at least 400
yards.
Monitoring and Control: Monitor apple maggot adults with red sticky spheres alone or in
combination with a volatile bait. Baited spheres catch two to four times as many adults as
nonbaited spheres. In orchards with no history of maggot injury, a minimum of three red
spheres should be placed on the outside row of an orchard closest to the suspected source
of flies (e.g., abandoned orchard). Hang spheres in trees with fruit, but remove fruit
adjacent to the sphere so that the sphere is clearly visible. Apply an insecticide within 7 to
10 days after catching the first fly, and repeat applications at 10- to 14-day intervals while
adults are active.
Codling Moth
Codling moths begin to emerge and mate during April or early May, depending on
location. Eggs generally begin to hatch near the first cover spray, and soon larvae tunnel
into and feed inside fruit. The mature larvae are similar to Oriental fruit moth larvae, being
½-inch long and pinkish-white with legs. Unlike the OFM, codling moth larvae do not
have an anal comb.
Codling Moth Degree-Day Model
Base a decision to spray insecticides against coding moth on pheromone trapping and the
codling moth degree-day model. Use pheromone traps to determine the starting point of
the model (biofix) and to gauge the intensity of populations. The degree-day model
predicts percent of adult emergence and egg hatch for each of the three to four generations
of codling moth that annually occur in the Southeast.
To use the model, begin to accumulate degree days when male flight begins in the spring,
which is referred to as biofix. The biofix date is determined with pheromone traps to detect
the first sustained catch of two or more moths in the spring. Traps should be placed in
orchards near the tight cluster stage of bud development, and checked one to two times per
week. Traps should be hung at a density of one trap per 10 acres of orchard. Traps hung in
the upper third of the canopy often catch more moths than those in the lower canopy. Once
biofix is determined, degree days are calculated daily. It is only necessary to check traps
once per week after biofix is determined. The table on page 33 should be used to
determine the number of degree days occurring at various maximum and minimum daily
temperatures.
First Generation: Recommendations are provided for low and moderate to high population
densities. Low-density orchards are those with less than 0.5 percent of the fruit damaged
30
the previous year and pheromone trap catches that do not exceed 10 moths per trap per
week anytime before the accumulation of 200 DD after biofix.
In low-density orchards, make a single insecticide application at 350 DD after biofix. In
moderate- to high-density orchards, apply two insecticide applications 14 days apart, the
first at 150 to 250 DD after biofix: 150 if using a product which depends primarily on
ovicidal activity for control (i.e., Confirm or Intrepid), and 250 if using an insecticide that
has contact activity against larvae (i.e., organophosphate or pyrethroid).
Relationship between degree-day accumulations from biofix and percentages of
codling moth adult emergence and egg hatch.
Cumulative
Degree Days
% Adult
Emergence
% Egg
Hatch
Cumulative
Degree Days
% Adult
Emergence
% Egg
Hatch
0 (biofix)
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1,000
1,050
1,100
1,150
1,200
1,250
1
5
15
27
40
52
63
72
80
87
91
95
97
98
99
99
100
0
1
2
5
8
13
18
26
35
0
0
0
0
0
3
9
18
30
42
54
64
73
81
87
92
95
97
98
99
100
0
1
2
3
6
1,300
1,350
1,400
1,450
1,500
1,550
1,600
1,650
1,700
1,750
1,800
1,850
1,900
1,950
2,000
2,050
2,100
2,150
2,200
2,250
2,300
2,350
2,400
2,450
2,500
2,550
43
52
60
68
77
80
85
89
92
95
97
99
0
2
4
7
10
15
20
25
31
38
45
52
59
65
10
15
21
28
36
45
63
62
69
75
81
85
89
92
95
94
99
100
3
5
8
12
16
21
27
31
Second Generation: Recommendations are provided for extremely low, low, and
moderate to high population densities. Extremely low-density orchards may not require an
insecticide application (i.e., pheromone trap catches never exceed three moths per trap
per week between 900 to 1,900 DD after biofix for codling moth or 800 to 1,600 DD
after biofix for Oriental fruit moth). Low-density orchards require one insecticide
application at approximately 1,250 DD. These orchards may have no sign of damage by
first generation larvae and trap catches between 3 to 7 moths per trap per week between
900 to 1,450 DD after biofix. Moderate- to high-density orchards will have fruit damage,
higher pheromone trap catches requiring two insecticide applications 14 days apart starting
about 1,250 DD after biofix.
Third Generation: Apply an insecticide at 2,250 DD after biofix if pheromone trap catches
exceed 5 moths per trap per week after 1,900 DD after biofix or if fruit damage caused by
second-generation larvae is observed.
Exceptions to the Model: Where codling moth populations are extremely high and where
pheromone trap catches remain high between generations, additional insecticide
applications may be necessary. This often occurs in orchards adjacent to an abandoned
orchard or where old bins are placed near an orchard. Insecticides recommended for
codling moth have sufficient residual activity so that applications made at 14-day intervals
usually provide adequate protection.
Oriental Fruit Moth
Oriental fruit moths begin to emerge and mate before apple bloom, and eggs begin to
hatch at petal fall. Variable spring temperatures cause erratic emergence and egg-laying by
first-generation moths. The larvae feed on shoot tips and inside apple fruit. The mature
larva is 1/2-inch long, pinkish-white, and has an anal comb and legs. The only way to
distinguish between Oriental fruit moth and codling moth larvae is to use a hand lens to
examine mature larvae for the presence of an anal comb. Codling moth larvae do not have
an anal comb.
Oriental Fruit Moth Degree-Day Model
Base a decision to spray insecticides against Oriental fruit moth on pheromone trap catches
and a DD model. The biofix is determined in the same manner as for the codling moth.
Use pheromone traps to determine the starting point of the model and to gauge the
intensity of populations. The degree-day model predicts adult emergence and egg hatch for
the first three generations of the four or five generations that occur in the Southeast.
However, generations overlap in the late season, which makes the degree-day model less
useful later in the season.
The table on page 33 uses daily maximum and minimum temperatures to determine daily
DDs for Oriental fruit moth (base 45ºF). Place traps in the orchards near the green-tip
stage of bud development, and check one to two times per week. Hang traps at eye-level at
a density of 1 trap per 10 acres of orchard. Check traps weekly after the biofix date.
First-Generation OFM: Control of the first generation is often important to prevent first-generation
damage and to reduce populations of subsequent generations. First-generation
egg laying is usually low on apple, and only one insecticide application between 400 and
500 DD after biofix is necessary, which usually coincides with petal fall.
31
Second-Generation OFM: If first-generation control was successful, second-generation
populations are usually very low. Extremely low-density orchards may not require an
insecticide application (i.e., pheromone trap catches never exceed 3 moths per trap per
week between 800 to 1,600 DD after biofix). In low-density orchards (3 to 7 moths per
trap per week caught between 800 and 1,500 DD), make a single insecticide application
at 1,400 DD. Moderate- to high-density orchards will have fruit damage, higher
pheromone trap catches, or both, and may need two insecticide applications 14 days apart
starting at 1,100 DD.
Third-Generation OFM: An insecticide is recommended at 2,200 DD after biofix if
pheromone trap catches exceed 5 moths per trap per week at 1,900 DD after biofix and if
there is fruit damage caused by the second generation.
Fourth-Generation OFM: Because of overlapping generations late in the season, it is
difficult to predict when egg hatch of the fourth generation begins. However, continuous
egg laying can occur from August through October, and the use of pheromone traps are
the best method to determine the potential for late-season damage. Apply an insecticide
within 7 to 10 days of a pheromone trap threshold of 10 moths per trap per week.
Maintain spray intervals on a two-week (complete) or 5- to 7-day (alternate-row-middle)
schedule for as long as the threshold is exceeded.
Tufted Apple Bud Moth
The tufted apple bud moth (TABM) is the most important leafroller occurring in the
Southeast. TABM completes two generations per year, with egg laying occurring during
June (first generation) and August and September (second generation). Larvae feed on
leaves and fruit, with fruit damage usually observed as surface feeding. However,
second-generation larvae often feed within the calyx end of fruit. Unless an individual
orchard has a history of damage by this insect, it is doubtful that special precautions need
to be taken. Timing is critical to the successful management of this pest. Depending on
the type of insecticide used and the intensity of the TABM population, one or two
applications during each of the two generations may be necessary. Maintain a clean
orchard floor, particularly in the early spring before bloom, to minimize TABM
populations by removing the food source for overwintering larvae. New apple sucker
growth and broadleaf weeds are important food sources in the spring. In recent years
TABM populations have been reduced to very low numbers because of new insecticides
used in many orchards
Tufted Apple Bud Moth Degree-Day Model
A TABM degree-day model similar to that of the Oriental fruit moth and codling moth
has been tested and modified for populations in the Southeast. For calculating degree
days from maximum and minimum daily temperatures, use the Oriental fruit moth table
on page 33 (45oF). Place TABM pheromone traps at the tight cluster to pink stage of bud
development at a density of 1 trap per 20 acres of orchard. Biofix is the first date on
which a sustained catch occurs and may vary from 2 to 15 moths per trap over a one-week
period. The cumulative number of degree days from the point of biofix is used to
predict percentage of egg hatch and to time insecticide applications against the first
generation.
First-Generation Recommendation: When population densities are sufficiently high or if a
short residual insecticide is used, two insecticide applications per generation are necessary;
make the first application at about 10 percent egg hatch, which occurs between 800 and
900 DD after biofix, and the second application 14 days later. Where populations are low
or if using a long residual insecticide, one application per generation should be made, and
this can occur anytime between 10 and 30 percent egg hatch of the first generation, or
from 800 to 1,200 DD after biofix.
Second-Generation Recommendation: Depending on variety and harvest date, make one or
two applications for second-generation control. For cultivars harvested by early
September, a single application at 10 percent egg hatch will usually suffice; this coincides
with the accumulation of about 2,600 DD after biofix (early to mid-August). Second-generation
egg hatch can sometimes extend into late September, so a second application
may be made in late August or early September on varieties harvested after mid-
September.
Mating Disruption
Mating disruption programs consist of emitting relatively large amounts of sex pheromone
into an orchard environment to disrupt the normal mate-location process. Mating
disruption prevents mating and the subsequent laying of fertile eggs, which effectively
reduces populations below economically damaging levels. It is effective only in blocks of
5 acres or more. In apples, mating disruption is registered for control of both codling moth
and Oriental fruit moth. Oriental fruit moth is much easier to control with mating
disruption compared with codling moth; against moderate to high codling moth
populations, both mating disruption and insecticides should be used. Time insecticide
applications to coincide with egg hatch of the target pest. High population densities of
Oriental fruit moth have been successfully controlled with pheromones alone. Mating
disruption will not control infestations resulting from immigrating fertilized female moths;
hence, mating disruption alone is not recommended in blocks located adjacent to a
likely source of immigrating moths (i.e., abandoned orchards or bin storage areas).
Pheromone Dispensers: A number of companies market pheromone dispensers for mating
disruption, including hand-applied dispensers that emit pheromones for a relatively long
period and sprayable products that last for shorter periods and need to be reapplied.
Isomate-CTT is a common codling moth pheromone dispenser that lasts for the entire
growing season. Use approximately 150 to 200 dispensers per acre, with the lower rates
recommended in orchards where mating disruption has been previously used or with very
low population densities. Isomate-M100 (100 dispensers per acre) and Isomate Rosso (160
dispensers per acre) are Oriental fruit moth pheromone dispensers that last about 85 and
140 days, respectively. Under low population densities, it is possible to reduce OFM
dispenser rates to approximately 75 percent of the full rate. Suterra Inc. makes a sprayable
32
pheromone product for the Oriental fruit moth, with residual activity of 4 to 5 weeks;
hence, these products need to be reapplied at 4- to 5-week intervals.
Timing of Applications: For the codling moth, place pheromone dispensers in the orchard
before adults begin to fly in the spring. First emergence of adults usually begins during
late bloom or petal fall of Delicious cultivars. Hence, dispensers should be hung by petal
fall. For codling moth, best results are obtained when dispensers are hung in the upper
third of the canopy.
The Oriental fruit moth begins to emerge near green tip of Delicious cultivars, so for
season-long control dispensers should be in the orchard by this time. However, if an
insecticide effective against Oriental fruit moth is used at petal fall, it will control the first
generation. It is possible to delay placement of Isomate-M100 until just before emergence
of second- or third-generation adults (950 and 1850 DD after biofix, respectively). This
delayed placement should prevent the need for a second application of Isomate M100
dispensers, which may otherwise be necessary on later maturing cultivars. If using
sprayable pheromones for mating disruption, make the initial application when hand-applied
dispensers are applied.
Monitoring Insects: Checking fruit for larval damage is critical to determining the
effectiveness of mating disruption and the need for rescue sprays. Monitoring adult
populations of codling moth and Oriental fruit moth with pheromone traps is strongly
recommended to provide baseline information on population density, to monitor the
effectiveness of mating disruption, and to improve the timing of mating disruption and
insecticide treatments. Good monitoring is an important part of achieving successful
results. Effective pheromone mating disruption treatments will shut down trap catches of
male moths. However, pheromone trap monitoring should not be used as the sole method
of measuring efficacy. Also remember that mating disruption is species specific, so
monitoring of other insect pests is also important.
European Red Mite Management
Several beneficial arthropods can help keep European red mite (ERM) populations below
damaging levels. The most common in the Southeast are the phytoseiid mite (Amblyseius
fallacis) and the a complex of generalist predators (e.g., lady beetles and lacewings).
However, recent research in North Carolina suggests that neither of these predators
overwinters to any significant degree within orchards, so they must be reestablished in
orchards in the spring. Hence, practices that delay the buildup of ERM and enable
predators to increase before mites become a problem will favor biological control. The
two most effective practices are applying a delayed dormant oil spray and avoiding
insecticides toxic to these predators.
Monitoring Mite Populations: Use a regular monitoring program to follow the buildup of
mite populations and to determine if and when supplemental applications of a miticide
are necessary to avoid economic damage. Monitor each contiguous block of apples
weekly beginning when adult mites first appear (which may vary from mid May to early
July). Within each block, examine 5 leaves from each of 10 trees with a visor lens or hand
lens. Rather than counting the total number of mites on each leaf, record the number of
leaves infested with one or more mites, and estimate the mite density on a per-leaf basis
from the table below.
Determining the Need for Miticides: When mite populations reach a density of 5 to 10
mites per leaf (80 to 90 percent infested leaves) decide whether to use biological control or
a miticide to prevent mites from increasing to higher densities. For biological control with
Stethorus punctum to occur, the ratio should be 2.5 S. punctum to 1 ERM. S. punctum
should be sampled by counting the number of adults and larvae observed during a timed 3-
minute search around the periphery of mite-infested trees. S. punctum larvae must almost
always be present if this predator is to control mites. Count the actual number of A. fallacis
on sample leaves with a visor lens. If the ratio of A. fallacis to ERM is between 1 to 5 and
1 to 15, biological control is possible. If neither predator is present at sufficient levels for
biological control to occur, and mite populations are between 5 to 10 mites per leaf, apply
a miticide.
In areas where Alternaria blotch is a problem on Delicious apples, biological control is
usually not an option. In the presence of Alternaria blotch, mite populations must be
maintained a very low levels to avoid high levels of Alternaria and premature defoliation.
If preventive control measures are not used, a modified threshold level of 1-2 mites per
leaf should dictate the need for miticides.
Relationship between European red mite densities per leaf and percentage of mite-infested
leaves.
% Mite-Infested
Leaves
(>1 mite/leaf)
Expected No.
Mites per Leaf
% Mite-Infested
Leaves
(>1 mite/leaf)
Expected No.
Mites per Leaf
40
45
50
55
60
65
0.7
0.9
1.1
1.3
1.6
2.0
70
75
80
85
90
95
2.6
3.4
4.7
6.8
11.4
26.4
33
Codling moth degree days (50oF lower base, 88oF upper base) at various daily maximum
and minimum temperatures.
Max 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96
Min
20 0 1 1 2 2 3 3 4 5 5 6 7 8 9 9 10 11 12 13 14 15 15
22 0 1 1 2 2 3 3 4 6 6 6 7 8 9 10 10 11 12 13 14 15 15
24 0 1 1 2 2 3 4 4 6 6 7 7 8 9 10 11 11 12 13 14 15 16
26 0 1 1 2 2 3 4 4 6 6 7 7 8 9 10 11 12 12 13 14 15 16
28 0 1 1 2 2 3 4 4 6 6 7 8 8 9 10 11 12 13 14 15 15 16
30 0 1 1 2 2 3 4 5 6 6 7 8 9 10 10 11 12 13 14 15 16 16
32 0 1 1 2 3 3 4 5 6 6 7 8 9 10 11 11 12 13 14 15 16 17
34 0 1 1 2 3 3 4 5 6 7 7 8 9 10 11 12 13 14 14 15 16 17
36 0 1 1 2 3 4 4 5 6 7 8 8 9 10 11 12 13 14 15 16 17 17
38 0 1 1 2 3 4 4 5 6 7 8 9 10 11 11 12 13 14 15 16 17 18
40 0 1 2 2 3 4 5 6 6 7 8 9 10 11 12 13 14 15 16 17 17 18
42 0 1 2 2 3 4 5 6 7 7 8 9 10 11 12 13 14 15 16 17 18 19
44 0 1 2 3 3 4 5 6 7 8 9 10 11 12 13 14 15 15 16 17 18 19
46 0 1 2 3 4 5 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
48 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 20
50 1 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
52 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
54 - 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
56 - 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
58 - - 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
60 - - - 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
62 - - - - 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
64 - - - - - 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
66 - - - - - - 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
68 - - - - - - - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
70 - - - - - - - - 18 19 20 21 22 23 24 25 26 27 28 29 30 31
72 - - - - - - - - - 20 21 22 23 24 25 26 27 28 29 30 31 32
74 - - - - - - - - - - 22 23 24 25 26 27 28 29 30 31 32 33
76 - - - - - - - - - - - 24 25 26 27 28 29 30 31 32 33 34
80 - - - - - - - - - - - - 26 27 28 29 30 31 32 33 34 35
Oriental fruit moth degree days (45oF lower base, 91oF upper base) at various daily
maximum and minimum temperatures.
Max 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96
Min
20 1 1 2 2 3 4 4 5 6 7 8 9 9 10 12 12 13 14 15 16 17 17 18 19
22 1 1 2 2 3 4 4 6 7 7 8 9 10 11 12 12 13 14 15 16 17 18 18 19
24 1 2 2 2 4 4 5 6 7 7 8 10 10 11 12 12 14 15 15 16 18 18 19 20
26 1 2 2 3 4 5 5 6 7 7 8 10 10 11 12 13 14 15 16 16 18 18 19 20
28 1 2 3 3 4 5 5 6 7 8 9 10 10 11 13 13 14 15 16 17 18 19 20 20
30 1 2 3 3 4 5 5 6 7 8 9 10 10 12 13 13 15 16 16 17 19 19 20 21
32 1 2 3 3 4 5 6 6 8 8 9 10 11 12 13 14 15 16 17 18 19 19 20 21
34 1 2 3 3 4 6 6 7 8 8 10 11 11 12 14 14 15 17 17 18 19 20 21 21
36 1 2 3 3 5 6 6 7 8 9 10 11 11 13 14 14 16 17 18 19 19 20 21 22
38 1 2 3 4 5 6 6 7 9 9 10 11 12 13 14 15 16 17 18 19 20 21 21 22
40 1 2 3 4 5 6 6 8 9 9 10 11 12 13 15 15 16 18 18 19 20 21 22 23
42 1 3 4 4 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
44 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
46 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
48 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
50 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
52 - 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
54 - - 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
56 - - - 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
58 - - - - 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
60 - - - - - 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
62 - - - - - - 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
64 - - - - - - - 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
66 - - - - - - - - 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 35
68 - - - - - - - - - 23 24 25 26 27 28 29 30 31 32 33 34 35 36 36
70 - - - - - - - - - - 25 26 27 28 29 30 31 32 33 34 35 36 37 37
72 - - - - - - - - - - - 27 28 29 30 31 32 33 34 35 36 37 38 38
74 - - - - - - - - - - - - 29 30 31 32 33 34 35 36 37 38 39 39
78 - - - - - - - - - - - - - 31 32 33 34 35 36 37 38 39 40 40
80 - - - - - - - - - - - - - - 33 34 35 36 37 38 39 40 41 41
34
Pesticide Resistance Management
General Considerations
Pesticide resistance is a shift in the genetics of a pest population that allows individuals
within a previously susceptible population to survive. Resistant pest populations have
inherited traits that reduce their susceptibility to individual pesticides or groups of
pesticides. Resistance develops in all agricultural pest groups–insects, mites, fungi,
bacteria, nematodes, and weeds. Pesticide-resistant individuals are initially quite rare in
pest populations. However, when a new pesticide is first used, a very low number of
individual pests never previously exposed to the novel chemistry can be expected to be
resistant. The frequency of resistant genes to novel chemistries varies tremendously, but
history makes it clear that resistant individuals should be expected to be present in all
pest groups. By the nature of the process, resistance most often develops to pesticides
that are initially very effective and frequently used.
Pesticide resistance management is an effort to slow or prevent the development of
resistance. It relies on pest management and pesticide-use strategies to prolong the
effective life of pesticides. Resistance management is difficult, especially in high-value
crops like fruit, where high quality standards and limited numbers of registered pesticides
make the task more challenging.
Managing resistance requires an understanding of the factors that influence its
development. Selection is the process of pesticide-induced selection for resistance. With
regular pesticide use, those rare individuals that are naturally resistant survive and
reproduce more successfully than their susceptible peers. Resistance
frequency refers to the proportion of a pest population that is resistant. Cross resistance
refers to a type of resistance in which a pest population develops resistance to more than
one pesticide within a chemical family (e.g., organophosphate insecticides, EBDC
fungicides, etc.). Multiple resistance involves multiple, independent resistance
mechanisms, which often lead to resistance to chemicals from different families (i.e.,
organophosphate and carbamate insecticides, dodine and DMI fungicides). Resistance
stability is a key factor in managing resistance. Stability is an estimate of how well
resistance persists in a pest population once the pesticide is no longer used. The rate of
reversion to a susceptible state varies enormously. But when pesticide use ceases,
selective pressure for resistance is removed, and over time resistance will often be
reduced. Resistance stability estimates may allow limited use of resistance-prone
compounds.
It is important to emphasize that control failures do not confirm resistance. Other factors
(poor timing, sprayer calibration or coverage, wash-off, high pH in spray tank water,
inappropriate materials, etc.) should be eliminated as causes for control failures before
resistance is seriously considered. Factors influencing the development of resistance can
be grouped into biological and management categories. Biological factors include pest
reproductive rate, mobility of the pest species into and out of untreated areas, and genetic
factors such as number of resistance mechanisms, resistance frequency and intensity, and
resistance stability. Management factors that influence resistance development include
how materials are applied, how often they are used, how long they persist in the field,
treatment thresholds, and strategies for using available pesticides. Resistance management
efforts study specific pest-pesticide interactions and focus on practical strategies that
growers can implement.
Pest management is practical and works in concert with pesticide-use strategies to lessen
resistance selection by facilitating prudent, as-needed pesticide use. Pesticide-use strategies
work best when implemented as a new pesticide comes into commerce. Pesticide
manufacturers, IPM scientists, and growers have come to recognize that using resistance
management from the beginning works best. Collecting baseline susceptibilities, defining
probable resistance problems beforehand, and proposing pesticide-use strategies to forestall
resistance development are the province of manufacturers and IPM scientists. Biologically
and economically sound resistance management plans offered pre-sale give growers the best
hope for managing resistance. Pesticide-use strategies are often grouped as follows: (1)
management by moderation, (2) rotation and mixtures, and (3) saturation.
Moderation means limiting the use of a pesticide. Moderation is employed in concert with
IPM practices, such as using treatment thresholds, spraying only specific pest generations
or growth stages, maintaining unsprayed wild host reservoirs to act as refuges for
genetically susceptible individuals, using pesticides with shorter residual or lower toxicity
to important beneficial populations, etc. Moderation should be used to the fullest extent that
will provide commercially acceptable control.
Rotation, and in some cases mixtures, are the bulwarks of pesticide-use strategies since an
individual pest is less likely to be resistant to two or more differing classes of toxins. In
theory, most individual pests resistant to one pesticide will be killed when exposed to a
different class of toxin. Rotations depend on having effective, labeled materials with
different modes of action. Material cost is a key practical consideration that favors rotation.
Mixtures of fungicides have been used successfully to combat disease resistance, although
cost lessens the attractiveness of this approach. Mixtures of insecticides and miticides have
typically performed poorly. Rotation is seen as the desired approach for insecticides,
miticides, and some fungicides.
Saturation, the use of higher pesticide rates to control resistant individuals, is the least
attractive resistance management approach, although it has been used to manage resistance
to DMI fungicides. Saturation is generally a last resort, when there are no other effective,
labeled alternatives. In this scenario, higher rates will often provide control for a time,
although at greater cost. Synergists, chemicals that increase the toxicity of pesticides, have
sometimes been effective in boosting the efficacy of resistance-prone pesticides. As with
simple rate increases, saturation with synergists typically provides only short-term benefits.
35
Insecticide Resistance Management Strategies
In the southeastern United States, the tufted apple bud moth, codling moth, rosy apple
aphid, and European red mite have developed resistance to one or more pesticides.
Although codling moth and mite resistance are not widespread in the Southeast, problems
in other parts of the U.S. indicate the importance of employing sound pesticide use
patterns to prevent resistance development in this region.
Tufted Apple Bud Moth
The tufted apple bud moth has developed resistance to organophosphate insecticides,
most notably Guthion and Imidan. However, Intrepid, SpinTor, Avaunt, Rimon, and
Danitol are effective alternatives. Along with Bacillus thuringiensis products, these
products provide growers with a diversity of options with different modes of action to
manage TABM.
The recommended strategy is this: Do not use the same insecticide (or insecticides with
the same mode of action) against successive generations. For example, if Intrepid is used
against the first generation in year 1, then Avaunt, Rimon or SpinTor should be used
against the second generation. Against the first generation in year 2, do not use the same
insecticide used to control the second generation in year 1. When selecting an insecticide,
one should consider other insects that also may need to be controlled.
Rosy Apple Aphid
The rosy apple aphid has developed widespread resistance to Lorsban, and control
failures with Thiodan, Asana, Ambush, Diazinon, and Dimethoate have become more
common in recent years. Among the neonicotinoid insecticides, suspected failure with
Actara has been observed. However, all the neonicotinoids (i.e., Actara, Assail, Calypso,
Clutch, and Provado) have a similar mode of action and should be considered the same
material for rotation purposes.
The two best times to control rosy apple aphid on apple are 1) tight cluster to pink and 2)
petal fall. Do not apply any insecticide more than once during this time frame, and if
possible do not use the insecticide used for rosy apple aphid control more than once
during the period when the aphids may occur in apple orchards (through the third or
fourth cover spray).
European Red Mite
Avoiding unnecessary miticide applications is the most effective strategy for minimizing
the potential for resistance development. A delayed dormant oil application is highly
recommended to suppress overwintering populations of European red mite and to
improve the potential for biological control to maintain mite populations below damaging
levels. On Delicious cultivars, which are susceptible to alternaria blotch and where
preventive control or low threshold levels are recommended for control of European red
mite, there is a high potential for the development of resistant populations. To reduce this
potential, in addition to a delayed dormant oil application, only one of the following
options should be used in a given year, and the same option should not be used in two
consecutive years.
Preventive Strategies Curative Strategies
• Agri-Mek + oil at petal fall
• Apollo or Savey at first or second cover
• Zeal at first or second cover
• Envidor at first or second cover
• Acramite at 2 mites per leaf
• Nexter at 2 mites per leaf
Resistance Management Strategies for Plant Pathogens
Resistance of plant pathogens to pesticides has become widespread over the past 25 years
as site-specific (systemic) chemicals have been developed and used on many crops and
against many pathogens. The broad spectrum protectants (such as captan and mancozeb)
that were used previously had multiple sites of activity in the target pathogens, greatly
reducing the likelihood of resistance development.
Resistance has become a problem in the U.S. in only three pathogens that affect apples
during the growing season: Venturia inaequalis, cause of apple scab; Erwinia amylovora,
cause of fire blight; and Pseudomonas syringae pv. papulans, cause of blister spot.
Resistance of V. inaequalis to dodine (Syllit, initially sold as Cyprex) was first reported in
New York in 1969. It has subsequently been reported in several states in the Northeast and
Midwest but has not been found in orchards in the Southeast. Resistance of V. inaequalis
to the benzimidazole fungicides [benomyl (Benlate) and thiophanate methyl (Topsin M)]
was reported shortly after their introduction in 1971 and became widespread in the eastern
U.S., including the Southeast, in the mid-1970s. As a consequence they are no longer
recommended for apple scab control in the Southeast. The ergosterol biosynthesis
inhibiting fungicides [fenarimol (Rubigan), myclobutanil (Nova), triflumazole (Procure)]
were first introduced in the late 1980s, and reduced sensitivity of V. inaequalis has been
reported or suspected in a number of orchards in the Northeast and Midwest but is not
widespread. Resistance of the fire blight bacterium, E. amylovora, to streptomycin (Agri-mycin
17, Streptrol) is widespread in several states but has not been reported in the
Southeast. Resistance of P. syringae pv. papulans has been confirmed in an orchard in
Tennessee.
To avoid resistance development, minimize the use of fungicides and bactericides in which
resistance is likely to develop. Additionally, combine site-specific fungicides with
protectant fungicides that have broad spectrum activity. Limit dodine applications to two
to three per year. In areas where dodine resistance first became a problem, it was often
used 10 to 12 times throughout the growing season. Similarly, limit streptomycin use for
fire blight control to two to four times a year. Make applications only during times
favorable for infection. These periods are characterized by open blossoms, dew or rainfall
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greater than 0.01 inch, an average daily temperature of 60º F or greater, and the
accumulation of at least 198 degree-hours greater than 65º F since the first blossoms
opened. Use the ergosterol biosynthesis inhibiting fungicides only in combination with
broad spectrum protectants, such as captan or EBDC fungicides. Avoid post symptom
applications of site-specific fungicides, such as dodine and the DMI fungicides, because
this sets up an ideal situation for selection of resistant strains. Good orchard sanitation
practices to maintain pathogen populations at low levels is also an important component
of a resistance management program.
Managing Weeds and Preventing the Development of
Herbicide Resistance
Although weed resistance to herbicides is not discussed as often as resistance in insects
and pathogens, cases of weed resistance to herbicides do exist. For example, pigweed and
goosegrass are resistant to dinitroanaline herbicides (Prowl and Surflan), and
Johnsongrass is resistant to carboxylase herbicides (Fusilade DX). Resistance may not be
detected for several years because these resistant weeds produce seed, and then
subsequent generations must establish. Two factors that contribute to the development of
herbicide-resistant weeds are applying herbicides multiple times during the year and
using herbicides that have the same mechanism of control for several consecutive
growing seasons.
Because apples are a perennial crop and have limited herbicide options, techniques like
crop rotation and mechanical cultivation to prevent resistance in annual crops are not
feasible. However, some of the following strategies can help prevent resistance from
developing:
1. Use herbicides ONLY when necessary.
2. Rotate herbicides with different modes of action. For example, do not use simazine
(Princep, Simazine) continuously. Consider other preemergence broadleaf
herbicides. Also avoid making more than two applications of the same herbicide in
the same year.
3. Scout orchards regularly to identify weeds. Respond quickly to changes in weed
population by controlling weeds before they spread through the entire orchard.
4. Use nonselective postemergence herbicides in your weed management program.
Effect of pH on Pesticide Activity
Although the pH of spray water does not directly affect resistance development, it can
affect the activity of some pesticides. In most instances the label warns of this effect.
These include dimethoate, phosmet, malathion, azinphosmethyl, formetanate, ethephon,
NAA, and possibly others. When these materials, except NAA, are exposed to a pH
above 7.5, they undergo hydrolysis and break down to products that are either less
effective or not effective. Excessively acidic conditions may limit uptake of NAA and,
therefore, its effectiveness. The actual rate of breakdown depends on solubility and
temperature and the total quantity broken down during a given period. For example,
captan is hydrolyzed very quickly at alkaline pHs, but because it is very insoluble, the
impact of pH is negligible unless captan is allowed to stand around for a week or more.
This is also true for chlorothalonil. Hydrolysis increases with increased temperature. If
the time in the spray tank is limited by applying pesticides immediately, then the
quantitative amount broken down is limited.
Additives to the spray tank can also be a factor. Calcium chloride, especially when
concentrated in the tank and applied in a low volume spray, can increase the pH. The
greater the concentration, the greater the alkalinity. The manufacturing process for
calcium chloride leaves residues of free lime (calcium hydroxide). The greater the purity
of the calcium chloride, the lower the content of calcium hydroxide and the lower the
effect on pH.
The water source can be a factor. Although most wells, streams, and rivers in the
southeastern growing region are mildly acidic (6.7 plus or minus 0.2) there are
exceptions; therefore, check pH a few times before regular use. Ponds are more likely to
be alkaline, especially those high in algae and other organisms. These ponds undergo
diurnal pH changes as result of dissolved carbon dioxide. Levels greater than 10 have
been observed. Alkalinity contributed by CO2 is weakly buffered and readily changed by
acidifying agents.
Although not pH-related, some pesticides can be affected by other contaminants in the
water. For example, fenbuconazole, not labeled on apples, is greatly reduced in
effectiveness by suspended particulates. Still other compounds like 2,4-D and
azoxystrobilurin can be very difficult to wash out of the tank and can have a deleterious
effect on apples at very low concentrations.
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Orchard Floor Management
The best strategy for managing the orchard floor is to use a noncompetitive grass alley
with a vegetation-free strip in the tree row. The vegetation-free strip can be established
and maintained with herbicides as described in this section. The permanent grass sod
between the tree rows will minimize soil erosion, increase soil aeration and
permeability, and support equipment movement through the orchard during wet weather.
The vegetation-free strip eliminates competition for water and nutrients, minimizes tree
damage or loss from voles during the dormant season, and provides some radiant heat
from the soil surface should a spring frost or freeze occur. Herbicides are directed at the
soil and weeds underneath the tree.
The vegetation-free strip method is superior to all other orchard floor management
options. Vegetation under the tree competes for nutrients and water, resulting in reduced
growth, yield, and size of fruit. Another option is the use of organic mulches in the tree
row. Examples of mulching materials include straw, wood chips, and grass residue from
mowing. These mulches will suppress weed emergence, but weed removal by some
means will still be necessary. Mulches can improve the water-holding capacity of some
soils. However, there are several concerns regarding the use of organic mulches. The
most significant problem is that mulches create an ideal habitat for voles. Also,
additional nitrogen may be needed to support the microorganisms that drive
decomposition of organic mulches. In poorly drained or water-logged soils, organic
mulches increase the likelihood of phytophthora root rot. Mulches can be expensive and
difficult to obtain. Synthetic mulches made from polyethylene, polypropylene, or
polyester can be placed in the tree row around the base of the trunk or as a narrow strip
down the row. Some newer synthetics allow water and air to pass through the mulch.
Herbicide Considerations
To ensure proper herbicide use, always read the manufacturer*s label before application.
All statements on the manufacturer’s label take precedence over any recommendations
in this publication.
It is important that herbicide application equipment be properly calibrated to ensure that
herbicides are applied at the correct rate. For questions about calibrating your sprayer,
contact your county’s Cooperative Extension agent.
Remember that herbicides are applied as a directed spray along each side of the tree
row. Flat fan nozzles are most widely used for applying herbicides. They provide
excellent spray coverage of weeds and come in several sizes with capabilities to apply a
range of spray volumes. Some manufacturers make flat fan nozzles that minimize spray
drift, allowing low pressure spraying. Investing in such spray nozzles decreases the
likelihood of off-target herbicide movement.
It is advisable to apply white latex paint to the bottom 2 to 3 feet of the tree trunk of
newly planted trees before applying herbicides. Painting the tree trunks reduces the
potential for winter as well as herbicide injury, especially from postemergence
herbicides. Dip a car wash mitt (wear rubber gloves underneath the mitt) in paint and rub up
and down the tree trunk until it is completely painted.
Several herbicides are registered for use in apple orchards. Some are preemergence
herbicides that control weeds that have not emerged, and others are postemergence
herbicides that control emerged weeds. Preemergence herbicides control germinating weed
seeds but usually do not give acceptable control of emerged weeds. Rainfall is needed to
properly activate preemergence herbicides. Rainfall within 7 to 14 days after application
activates most herbicides; however, best control occurs when water (rain or irrigation) is
added within a few days of application. The desired amount of time for rainfall after
application varies by herbicide. Refer to the manufacturer’s label for specific information.
Postemergence herbicides control emerged weeds and are most effective when applied to
actively growing weeds. Weeds under stress from drought or mowing may not be
adequately controlled by postemergence herbicides. If weeds are stressed from drought,
delay herbicide application until after adequate rainfall when weeds are no longer wilted. If
weeds have been mowed, wait several days to allow regrowth before applying herbicides.
Symptoms of herbicide activity may not be noticeable for up to 14 days after application of
glyphosate, sethoxydim, clethodim, or fluazifop (Roundup, Poast, Select, or Fusilade DX,
respectively). Effects of glufosinate, paraquat, and 2,4-D (Rely, Gramoxone Max, and
Orchard Master, respectively) are noticeable in 1 to 3 days. Some postemergence herbicides
require the addition of a surfactant or crop oil to improve herbicide activity. Remember,
surfactants and crop oil differ from one another and may not be interchangeable.
Herbicide Application Timing
The goal of an effective weed management program is to eliminate weed competition the
first 6 to 8 weeks after bud swell and keep the area under the trees weed-free through
harvest. Timing of preemergence (PRE) herbicide application is important in accomplishing
this goal. It has been typical to make a single PRE herbicide application in the spring
followed by postemergence (POST) herbicide applications in the summer as needed.
However, it can be difficult to spray underneath limbs loaded with fruit in mid and late
summer. With appropriate PRE herbicide timing, POST herbicide applications in mid and
late summer can be avoided. Listed below are several PRE herbicide timing options.
1. Fall/Spring Split. One approach is to apply a PRE herbicide with a nonselective burn-down
herbicide (glyphosate or paraquat) in the fall after harvest (November). The fall
application will generally provide PRE control into the early summer. When fall PRE
treatment breaks and emerging weeds get 2 to 3 inches tall, another PRE herbicide
application with a burndown herbicide should be applied. Fall herbicide application may be
helpful in managing voles. In areas where erosion is a concern this option may not be
acceptable.
2. Delayed Preemergence. This approach requires a burndown herbicide application in
March. The burndown herbicide eliminates winter annual weeds until summer annual
weeds emerge in early to mid May. Once summer annual weeds get 2 to 3 inches, apply a
burndown with a PRE herbicide.
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Postemergence herbicides may be necessary to control escaped weeds or certain problem
weeds like Bermudagrass, Johnsongrass, and mugwort.
It is important to scout orchards regularly to determine weed species present. Scouting
allows growers to recognize the need to control escaped weeds with a timely herbicide
application and for early identification of difficult-to-control weeds. Early identification
of problem weeds can prevent them from becoming established in the orchard. If
problem weeds are noticed for the first time in an orchard, they need to be removed
before they produce seed. This can be done by hand or with a spot treatment with a
nonselective postemergence herbicide like glyphosate, paraquat, or glufosinate
(Roundup WeatherMax, Gramoxone Max, or Rely, respectively). Scouting also gives
growers an opportunity to recognize poorly controlled weeds so their weed management
program can be adjusted. Another aspect growers should consider is the potential for
infestations of weeds from around the border of the orchard. Weeds in these areas
produce seeds that will find their way into the orchard.
Chemical Mowing
Some herbicides can be used at sublethal doses to suppress orchard floor vegetation.
Timing and rate will vary with the vegetation present. Generally, tall fescue can be used
as the guiding species, because it is a major component in most orchards. Optimum
timing for suppression is when tall fescue has 3 to 6 inches of new growth in the spring.
The following herbicides and rates are suggested: Roundup WeatherMax at 4 fluid
ounces, generic glysophate products at 5 to 6 fluid ounces, and Poast 1.5E at 1 to 1.25
pints per acre. Chemical suppression of grasses should be done only to healthy, well-established
sod. Refer to product labels for details.
Weed Management in Newly Planted Trees
Eliminating weed competition is an important part of minimizing posttransplant stress to
newly planted trees. Research has shown that weed competition can reduce tree growth
and development by 50 percent. Newly planted orchards are not nearly as competitive
with weeds as older, established orchards. Young trees do not have well-developed
limbs to shade the soil surface in late summer, which minimizes the competitiveness of
late summer weeds. In general, preemergence herbicides registered for use after
transplanting provide effective preemergence control of annual grasses and small-seeded
broadleaf weeds. Painting the lower 18 inches of the tree trunk with a white latex paint
is highly recommended. The paint provides a barrier to herbicides, protecting tender,
green bark from serous injury.
Apple Pollination, Honey Bees, and Pesticides
Most apple varieties are self-incompatible and require cross-pollination with a suitable
pollinizer variety to obtain good fruit set. Honey bees and other native bees are the primary
pollinators for apples. All bees are susceptible to insecticides and need to be protected
during bloom and at other times.
Most insecticide labels include a warning: “This product is highly toxic to bees exposed to
direct treatment or residues on blooming crops or weeds. Do not apply this product or allow
it to drift to blooming crops if bees are visiting the treatment area.” Any apiary within 2 ½
miles of the orchard is at risk from insecticide applications. Bees are highly attracted to
flowers in the ground cover. Before applying insecticides, reduce dandelion, clover, and
other ground cover flowers by mowing or herbicide.
The following recommendations will help to minimize bee kills:
! Read and obey warning statements on pesticide labels regarding honey bees.
! Select the safest available formulation. Emulsifiable concentrate (EC) formulations
usually have shorter residual toxicity than wettable powder (WP) formulations.
! Insecticides applied during unusually low temperatures will remain toxic to bees for a
much longer time compared to normally warm weather.
! Avoid applying insecticides to blooming cover crops, and avoid insecticide drift to
nearby plants in bloom.
! If an insecticide hazardous to bees must be used, apply it in the early evening to
minimize hazard to bees. Always check to make sure bees are not foraging when
pesticides are applied.
! Never apply a pesticide directly over a beehive. Notify neighboring beekeepers when
applying pesticides toxic to bees.
! Dispose of all unused pesticides safely so that pesticides do not end up in watering
sources used by bees.
39
Soil and Plant Analysis Guidelines for
Southeastern Apple Production
Routine nutrient analysis of soil and plant leaf tissue should be an integral part of any
orchard management plan. Soils used for apple production in the Southeast vary greatly,
especially in the mountains. Other factors, such as weather and crop history, can affect
the trees’ nutrient status. The only way to be sure your trees are being fertilized
efficiently and properly is by using soil and plant analysis. Proper use of these tools will
help ensure sustained yields while preventing unneeded fertilizer application. Ideally,
both soil and plant sampling should be done every other year. On sites that have a
history of nutritional problems, such as bitter pit, sampling every year may be needed.
A soil analysis estimates the ability of the soil to supply a particular nutrient. Plant
tissue analysis measures the current nutrient status of the tree. Potential nutritional
problems can often be detected before visual deficiency symptoms appear. By using
both soil and plant analysis together, a fertility program can be custom designed for your
orchard. The general idea is to give each block of trees what is needed for growth and
apple production, but not to apply nutrients that can be supplied by the soil in adequate
amounts.
Sampling for Soil Analysis
A soil analysis report is only as good as the sample it represents. For soil analysis to be
meaningful, the sample must be representative of the soils in the orchard. Due to soil
variability, each sample should represent no more than a 5-acre block of similar terrain
and soil type. Trees in the block should be of the same age, rootstock, and variety. A
good sample consists of up to 20 sub-samples (cores). These should be throughly mixed
in a clean bucket before filling the soil sample box. Samples should be divided into two
depths: 0 to 6 inches and 6 to 12 inches. This is easiest when using a soil sampling tube.
Sampling for Plant Analysis
Plant sampling needs to be carried out in a manner similar to soil sampling. For best
results, plant sampling areas should be the same as selected for soil sampling. All trees
should be the same age, variety, and rootstock. To make full use of published critical
nutrient levels, and thus obtain the best information, routine plant samples should be
taken mid June to mid July, with earlier sampling at lower elevations. Sample mid-shoot
of this season’s growth from the upper third of the tree. Collect a total of 40 leaves taken
from at least ten trees selected randomly from the sample area.
Using Soil and Plant Analysis as an Aid in Troubleshooting
Soil and plant analysis can be invaluable in properly identifying and correcting nutrient
deficiencies. In this case, samples are collected over a smaller area that represents the
problem. If possible, it is advisable to collect samples from “good” areas adjacent to the
problem areas. Both soil and plant samples need to be collected.
Interpretation of Soil and Tissue Analysis
Soil and plant analysis laboratories differ in analytical procedures and report format.
Southeastern laboratories, both private and public, use at least two different soil-extracting
solutions. A single soil sample processed by these two methods could yield very different
results, especially for phosphorus. Also, different laboratories report the results in different
units – some use an index system while others report parts per million or pounds per acre. A
given laboratory takes these factors into account when giving fertility recommendations. In
other words, their recommendations are calibrated to their methods. Thus recommendations
from different labs’ soil analyses should be similar. However, the differences in reporting
units make it difficult to compare results from different laboratories. To track the progress
of a fertility program over the life of the trees, it is best to use either one laboratory or pick
laboratories with the same methods and reporting units. Even though tissue analysis
methods are more uniform, reporting units still differ between laboratories, making it
difficult to track trends over time.
Special Considerations for Calcium and Boron
Calcium and boron deficiency can result in fruit being culled due to bitter pit (calcium
deficiency) or cork spot (boron deficiency). In some years, the percentage of cull fruit
exhibiting bitter pit or cork spot can be quite high. These nutrients can be difficult to supply
in needed quantities, especially in older trees and large-f