Spraying apple trees for pest and disease
Pest management for fruit trees is a highly nuanced topic, with a wide variety of approaches and options. To keep it simple, we’ll focus on some of the basic approaches to pest and disease management that you can use to quickly protect against the most serious threats to your trees.
In general, a spray program is meant to prevent against two classes of threats to your trees. The first is disease. As mentioned in the “Variety Selection” section, there are a number of diseases that can impact your trees. The most common of these are apple scab, fire blight, and cedar apple rust. Certain varieties have some resistance to these diseases. For those that don’t, spraying is the preferred method of management. The second class of threats is insects. Unfortunately no varieties are resistant to insect pressure and spraying is the preferred method of control.
Classes of sprays for spraying apple trees
As a grower, you have a few classes of sprays to help control insects and disease.
General All-In-One sprays
As the name implies, these sprays are meant to take care of both disease and insect issues through a combination of pesticides and fungicides. They are readily available at most home and garden centers, with Bonide Fruit Spray being the most common offering. These sprays make pest control easy for the first time sprayer, as they offer a single solution for most diseases and pests you will encounter. Take care not to apply during bloom period, as it kills bees as they pollinate the trees.
Dormant spray oils
Dormant oils are a type of pesticides that are applied in early spring, directly to the dormant trees prior to leaf bud opening. While not required every year, they help control scale insects that negatively impact your tree.
Fungicides are the primary disease control agents. They are a component of All-in-one sprays, but can be purchased as stand-alone sprays to target specific diseases. Within fungicides, there are multiple options and subcategories. Captan is the most common fungicide, and assists in controlling apple scab, powdery mildew, and a number of other diseases. Copper fungicides are another option, typically applied for early season disease control of mildews and blights. Take care when applying and read and follow the specific instructions for each spray. Pure fungicides are often applied during the early season and bloom period, when All-in-one sprays should not be sprayed due to pollination concerns. Immunox
Numerous insecticide options are available for pest management. These can be sprayed after petal fall to avoid bee death during pollination. We have had success using Ortho Bug-B-Gon and Triazicide sprays. More advanced sprays are available to those who are approved to use them.
A basic schedule for spraying apple trees
You should adjust your schedule based on your knowledge and specific application. However, the basic spray schedule below can be applied to many growers’ situation
Single application dormant oil for insect control
Bloom through petal fall
Spray fungicide for disease control, approximately every 10 days
After petal through summer and early fall
Beginning approximately a week after petal fall, begin spraying a general purpose spray, or individual applications of both fungicide and pesticide. Spray approximately every 2 weeks.
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