APPLE PEST MANAGEMENT GUIDE

Prepared by Heather Faubert, Steven R. Alm, David B. Wallace, Richard A. Casagrande and Lisa Tewksbury

     Many home owners derive a great deal of satisfaction from growing their own fruit.  This endeavor, however, is not as simple as one might hope.  There are many insect and disease organisms, and pruning and cultural management functions that must be considered in both planning and maintaining a home to resistance development, so you should use Captan, Sulfur, fixed coppers, or Bordeaux mixture whenever possible.

     Pesticide Application

     Pesticides are poisonous, therefore, applicators should be aware of any hazards associated with pesticides they are applying.  Take appropriate steps to minimize exposure to yourself, neighbors, and the environment.  Although chemicals listed in this guide are relatively low in toxicity to humans and warm blooded animals, safety measures should be followed carefully.  Keep pesticides in a locked cabinet, away from children and pets.  THE LABEL MUST BE READ IN ITS ENTIRETY BEFORE SPRAYING!  Particular attention should be paid to the antidote/treatment in case of an accidental poisoning.  Pesticide applicators should avoid breathing mist or allowing mist to contact skin.  If the label instructs you to do so, wear protective clothing.

     Purchase wettable powder formulations where possible, especially if pesticides will be stored in an unheated garage during the winter.  Do not store pesticides at high temperatures (>86^oF) or allow liquid formulations to freeze.  Optimum storage temperatures are between 65 and 80^oF.

Pest Management

     Before spraying, learn the pests that may be present at various times during the development of the fruit.  It is also helpful to learn insect and disease life cycles so you can time your applications for optimum control.  Identify damage to your fruit at harvest and learn when to control the problem in subsequent years.  You can tolerate more damage to leaves by aphids, leafminers, mites, and leafhoppers, than direct damage to the fruit.  This is a general guide for pest control for apples, pears, peaches, plums, cherries, apricots, blueberries, strawberries, brambles, and grapes.  Your fruit may have additional problems that need attention.  To aid in identification of insect and disease problems, contact the University of Rhode Island's Plant Protection Clinic.  For a small fee, an insect or disease problem will be identified, and a control recommendation given. The address is: Plant Protection Clinic, Greenhouse Conservatory, Cooperative Extension Education Center, Kingston, RI 02881.

APPLES

     The first step in apple pest management is to plant trees that are resistant to apple scab.  This will eliminate the need to apply up to eight fungicide treatments during the growing season.  There are many disease resistant cultivars available, such as, Liberty, Freedom, Macfree, etc. (see end of bulletin for suppliers).  Using disease resistant trees, a dormant oil spray, and sticky red spheres to catch apple maggot flies, you can limit your pesticide sprays to two or three applications per season. To control summer diseases (sooty blotch and fly speck) you need to apply Captan or Captan/Benlate starting in early June and continue every two to three weeks until mid-August.

                                      DISEASE RESISTANT APPLE PROGRAM

    Red sticky spheres can control apple maggot flies without the use of pesticides.  Spheres should be placed within the canopy between 4-6 feet high.  Use 1-8 traps per tree, depending on tree size (1 per dwarf tree, 2-4 per semi-dwarf, or 4-8 per full size standard tree).  Ideally, set out one trap for every 150 apples (see end of bulletin for insect trap suppliers).

     If the use of red sticky spheres for control is impractical because of size or number of trees, the red sticky spheres can still be used to monitor apple maggot fly activity for proper timing of an insecticide application.  One or two spheres per home orchard can be used to determine presence of apple maggot flies.  When 1-2 flies per trap are captured, a half-rate spray of phosmet has been shown to control apple maggot flies. 

DISEASE SUSCEPTIBLE APPLES

     Disease susceptible apple trees require the same insect control as disease resistant trees.  They also require use of a fungicide to protect against apple scab. Captan or Captan/Benlate should be applied as soon as green tissue is showing in April, and should be applied every 7-10 days until the beginning of June.  Continue with Captan or Captan/Benlate every two to three weeks until mid-August or early Sept. (depending upon cultivar harvest date) to protect against summer diseases.

CAUTION - DO NOT MIX OIL AND CAPTAN, AS SERIOUS FOLIAGE INJURY CAN RESULT.  DO NOT USE CAPTAN WITHIN 7 DAYS OF AN OIL SPRAY.

     As with disease resistant trees, an insecticide may be needed at petal fall and again 10-14 days later.  Begin apple maggot fly control at the end of June with red sticky spheres, or with half-rate phosmet applications.  Two or more sprays may be required for apple maggot flies depending upon your cultivars and insect pressure.