Fruit tree pest management

Home orchardists often consider fruit tree pest management challenging. Many cannot identify insect pests and diseases nor know how to control them. Applying pesticides can be intimidating or undesirable. Sustainable fruit production aims to reduce inputs of water, fertilizer, pesticides and labor. With some specific knowledge, you can manage fruit tree pests in a sustainable way.

Considerations before you plant fruit trees

Pest management begins even before you plant a fruit tree. The following decisions will help you avoid pest problems later.

Test your soil

Healthy and fertile soil is an important part of pest management. Fertile, well-drained soils with a slightly acidic to neutral pH (6.0-7.0) will increase your tree’s resistance to insect pests and disease. Sending a soil sample to a soil testing lab can tell you about the health of your soil.

Select an appropriate site

In addition to healthy soil, fruit trees require adequate sunlight and warm temperatures to produce and ripen fruit. Select a warm location with at least 6 hours of sun daily.

Choose disease-resistant varieties

Some fruit tree varieties are resistant to common diseases. The apple variety Liberty is resistant to apple scab disease and is suitable for regions with wet weather in the spring and summer.

Learn about insect and disease pests in your area

Sustainable pest management begins with knowing which pests are in your area. Climate often influences which insects and diseases are present.

Fungal disease thrives in the wet and mild climate of western Oregon. Home orchardists can reference Managing diseases and insects in home orchards to learn about the most common pests in Oregon. It is important to learn these common pests because not all insects found on fruit trees are pests.

Observe your tree frequently for insect pests and disease

Some pests can be difficult to find by visually inspecting your tree. Traps are commonly used to monitor insect pests like codling moth, leafrollers or fruit flies. A lure is often used to attract the insects to a sticky trap, which you can observe more easily. Traps can be purchased online or from some garden supply stores.

These traps can also help you monitor the number of pests, which is important for timing pest control. When five codling moths are trapped in one week during May, for example, it is time to start pest control. By monitoring with traps, you can reduce the number of pesticide applications needed to control insect pests.

Home orchardists have many pest control options

Some pests can be effectively controlled without the use of pesticides. For example, mesh bags can be secured around developing fruit to keep unwanted insects from feeding on it. Some pests, like aphids, can be sprayed off the tree with a hose.

Pest control continues even after harvest

Many pests can be controlled with dormant sprays. These sprays are usually done in the fall around Thanksgiving, in mid-January and again when fruit buds begin to swell but are not yet open. Dormant sprays usually mix a fungicide like copper with dormant oil, or sulfur alone. Dormant oil smothers insects or insect eggs on bark or around buds. The fungicide rids the tree of fungal spores.

Homeowners who want sustainable or organic standards should use cultural steps before sprays. For example, when controlling apple scab, plant a resistant variety of apple, such as Liberty. We also recommend cleaning up old leaves and fruit from around the tree in the fall. Mowing and spreading compost around your tree is usually enough to cause the leaves to decompose. This reduces the amount of disease inoculum when the tree starts growing in the spring. Pruning your trees to provide plenty of sunlight and air movement through the canopy helps reduce fungal disease problems.

For every disease and insect pest, cultural steps and orchard sprays make control more effective.

For the safety of homeowners and neighbors, use the least toxic or organic materials for spraying.

• For fungal disease control, use any of the following products: sulfur, copper, wettable sulfur, stylet oil, or potassium bicarbonate as low impact materials.
• For insect control use: Kaolin clay, spinosad product Entrust, Cyd-X (a virus that kills codling moth), horticultural oil, and microbials like Dipel or Javelin.

All these products have been formulated for organic growers. When using pesticides – even organic ones – always read the labels and wear personal protective equipment. At a minimum wear long pants, long sleeve shirts, waterproof shoes, waterproof gloves and a hat. Best practice is to use full rain gear, boots, gloves, eye protection and a simple respirator.