Spray Guide and Schedules
Suggested Spray Schedule For Home Garden Apples
By: Kerry Retzel, Urban Horticulturist, Chelan County Cooperative Extension; Marlane Gumard, Field Representative, Chelan- Douglas Horticultural Pest and Disease Boards; Timothy J. Smith, Chelan-Douglas-Okanogan WSU Area Agent
In late winter, just as the buds begin to show the first green tissue. Dormant oils: IPM practices recommend treating only a seriously infested tree with oil. Avoid destruction of beneficial insects. Manage pests as they hatch in early spring (see "PINK"). Spray on a relatively warm day (45°- 55° F.) with no frost forecast overnight. Be sure to finish spraying by noon to insure good drying during daytime. SPRAY: Example products like Volck Oil Spray, Superior Type Spray Oil, etc. at the rate on the label. This spray is for overwintering scales, aphids, and mites. Oils are not effective against woolly apple aphids.
Just as the flower clusters open, but before the flowers open. Apply this spray only if powdery mildew is a problem on your apple variety. SPRAY: Lime-sulfur (such as Polysul Summer & Dormant Spray or Dormant Disease Control Lime-Sulfur Spray, etc.) at the rate on the label. Do not apply this spray to Delicious varieties at this time as severe fruit drop can occur later. Insecticidal soaps (Safer's, Concern, etc.) are useful against hatching insect pests (mealybug, Iygus bug, stinkbug, aphid, etc.) and appear to suppress mildew as well. Follow label directions. For feeding caterpillars , use Bacilhts thuringiensis .
Just after the petals fall from the blossoms. Apply this spray only if powdery mildew is a problem on your apple variety. However, this is a critical time for management of insect pests listed in "PINK. " SPRAY: Use the same spray materials suggested above in the "PINK" section.
Late Spring and Summer
For Codling Moth (the worm in the apple): Start preventive spraying of the fruit 21 days after full bloom. Keep the trees protected through August. A third generation can occur from late August to mid-September, so additional protection may be needed through this time . Use malathion-methoxychlor* liquid (Ortho Home Orchard Spray, Green Thumb Liquid Fruit Tree Spray, etc.) at the rate listed on the label. SPRAY TIMING IS CRITICAL. Follow the spray schedule given on the label. Reapply the spray after a brief, heavy rainfall or showers of longer duration and then resume your regular schedule. If the apple is not protected, the egg laid by the codling moth will hatch and the small worm will enter the apple and be protected from the sprays. If your apples become infested with worms, remove the apples from the tree and seal them in large, black garbage bags. Leave these bags in the sun for two weeks to kill the worms.
* Available stock now but less likely after this year.
"Stings" are shallow entries made on the surface of the fruit where the worm only chews through the apple skin or bores into the flesh a short distance before giving up and trying another place, or dying from various causes. Treat "stung" apples as a source of codling moth reinfestation, remove them immediately and dispose of them in the manner stated previously.
Aphids: Seldom build up to damaging levels in home garden trees. If you learn to tolerate them or wash them off with the hose, you rarely have to spray. If you must spray, use insecticidal soaps (Safer's, Concern, etc.) at the rate directed on the label. Spray prior to 9 AM. For mites , insecticidal soaps are useful at earliest detection, usually late spring. Make sure the spray covers undersides of leaves as well.
The Codling Moth The most important pest of apples in Washington. 2-3 generations occur per season. Female codling moths lay their eggs singly on foliage or fruit, with 50 to 100 eggs produced per female. The worm stage damages the fruit, eating its way to the core and seeds of the apple. The mature worm is about 3/4 inch long, pinkish-white with a brown head. The adult moth is about 1/2 inch long, has brownish-gray wings with dark bands and a large, dark brown spot at the wing tips. The mature worm stage of the codling moth overwinters in waterproof cocoons under loose bark or in other sheltered areas on the tree. The worms that overwinter emerged in late July and August from infested fruit.
NOTE: Vary products during the season and in following seasons to minimize pest resistance.
- Check with the store location for current product availability.
CAUTION: Read this guide carefully. Read the product label directions carefully. Read and follow a1l label directions for responsible, safe use of any pesticide
If fruit poundage is unmanageable and a nuisance to handle, cut the tree down and purchase quality fruit that you can realistically use. Help your commercial orchard neighbors provide quality fruit by maintaining good car e and good pest management practices for your desired fruit trees!!
For other home garden fruit tree questions, contact WSU Cooperative Extension at 509/667-6540 , or check out our website, www.tfrec.wsu.edu/tfrec.php.
In some cases, trade names of products have been provided as examples of suggested materials. No discrimination is intended and no endorsement by WSU Cooperative Extension is implied.