| Bud Stage | Recommendation (rate per acre) | Target Pest(s) |
 |
GREEN TIP |
fire blight, scab |
 |
HALF-INCH GREEN Microthiol Disperss (10 lb) |
scab |
 |
TIGHT CLUSTER Microthiol Disperss (15 lb) Note: beginning at this bud stage, the frequency of sulfur/lime-sulfur application may need to be increased. Sulfur is a protectant fungicide only and must be applied before leaf wetting. |
scab |
 |
PINK |
scab, foliar nutrition |
 |
Microthiol Disperss (15 lb) NO INSECTICIDE DURING BLOOM Foliar nutrient spray |
scab, foliar nutrition |
 |
PETAL FALL |
scab, pum curculio (PC) foliar nutrition |
| 1st Cover (~ 20May) |
Microthiol Disperss (15 lb) |
scab, PC, codling moth (CM), Oriental fruit moth (OFM), leafrollers (LR) foliar nutrition |
| 2nd Cover (~ 05Jun) |
Lime Sulfur Solution (see label) |
scab, PC, CM, OFM, LR foliar nutrition |
| 3rd Cover (~ 20-Jun) |
Lime Sulfur Solution (see label) |
scab, CM, OFM, LR foliar nutrition |
| 4th Cover (~ 10-Jul) |
Lime Sulfur Solution (see label) |
summer diseases (SD), CM, OFM, LR |
| 5th Cover (~ 25-Jul) |
Lime Sulfur Solution (see label) Surround® (25 to 50 lb), or apple maggot trap-out with red spheres Entrust (2 oz) Foliar nutrient spray (calcium) |
SD, CM, LR, apple maggot (AM) |
| 6th Cover (~ 10-Aug) |
Lime Sulfur Solution (see label) Entrust (2 oz) Surround® (25 to 50 lb), or apple maggot trap-out with red spheres Foliar nutrient spray (calcium) |
SD, CM, LR, AM |
Notes:
NOTE that is is up to the user to check to make sure any product or formulation is deemed organic by their particular certifying agency. Where a specific product is listed above, it was OMRI certified as of the date of this fact sheet (early 2010).
SCHEDULE is approximate. Spray interval/timing may have to be adjusted based on pest pressure and location.
TANK MIXES are tricky. Avoid mixing chemicals unless you are sure they are compatible as a tank mix. Most sprays are best applied by themself.
SANITATION is a key to management of organic apples. Use every opportunity to chop leaves and debris, remove (or destroy) fruit drops, mow grass, etc. This will help immensely in control of insects and diseases. Eliminating wild hosts outside the orchard is also highly recommended where possible.
FERTILIZATION is relatively easy. In addition to the foliar sprays recommended above, composted manure applied to the base of trees is recommended. Use app. one-three bushels per tree on small-medium-large trees respectively.
SCAB-RESISTANT apples will reduce the need for lime sulfur sprays, however, they are not completely free from disease. They can still get fireblight, rust, black-rot, and various summer diseases.
WEED CONTROL is a bugger. Young and dwarf trees need a relatively weed- and grass-free strip down the row. Careful cultivation, flame weeding, and/or organic-approved weed killers are options.
INSECTICIDE options are limited. In addition to Surround® and B.t. used above, they include:
- neem products (Azadirachtin), mostly effective on aphids, tarnished plant bug, leafhoppers, and leafminer.
- pyrethrum/pyrethrin for apple maggot, plum curculio, sawfly, leafhoppers, codling moth.insecticidal soaps for aphids
- spinosad (Entrust, GF-120) for caterpillars, apple maggot
Any of these can be substituted or used in the above spray schedule against the appropriate pest(s) with varying results.
FUNGICIDE options are even more limited! Lime sulfur or just sulfur in its several forms are protectant fungicides that MUST be applied before an apple scab infection period. Sanitation and contol of primary scab are essential so lime sulfur use can be curtailed in the summer. (It's phytotoxic if it is hot.) Lime sulfur should not be used within a couple weeks of oil application either.
MATING DISRUPTION (MD) for adult moths (codling moth, oriental fruit moth, leafrollers) should be deployed whenever possible. MD typically needs to be supplemented with insecticides and used in a minimum 5 acre block size.
OIL spray at green tip (2-3% v/v) may be necessary if European red mites were a problem the previous season. Oil, however, is not compatible with lime sufur application, so you will have to wait until tight-cluster to begin lime sulfur sprays. (Which may be too late.)
Other organic RESOURCES include:
A Growers’s Guide to Organic Apples
Organic Apple Spray Program
OSU Organic Apple Disease Spray Guide
Organic and Low-Spray Apple Production
The Apple Grower (A Guide for the Organic Orchardist
OrganicA - A resource for Organic Apple Production