Managing Pests in Home Fruit Plantings

Above: apples and apple leaves severely affected by apple scab

Many homeowners enjoy and actively grow either small fruit or tree fruit in their gardens or landscapes. That popularity does not come without its challenges from a variety of insect and disease pests. If you are a fruit grower, it only takes a season or two to realize these pressures. A Purdue resource can help you become better equipped to meet these challenges next year.

Purdue Extension has a publication under the same title as this article. It is a popular one that helps guide homeowners in their quest to grow fruits at home. I’ll select some excerpts from the publication, written by Purdue experts, for this article.

The Purdue experts state that successful home fruit growers should not have the goal of killing every last insect and eliminating every disease. Rather, growers should aim to produce relatively clean, attractive fruit while accepting a small amount of injury. “That involves choosing cultivars best-suited for the climate and that resist pests at acceptable levels,” they said. “Greater levels of pest control may require more effort and input.”

One feature of the publication is an explanation of fruit development stages. For example, in apples, the stages are dormant, silver tip, green tip, half-inch green, tight cluster, pink, bloom, petal fall, and fruit set. To the average homeowner, many of these terms may sound cryptic. The publication includes photos of each stage for apple, pear, peach, plum, prune, cherry, grape, strawberry, and raspberry. Identifying the fruit development stage is important because recommendations for pesticide applications and cultivation practices are often tied to specific growth stages.

The authors describe several strategies that can be considered in an integrated pest management (IPM) “toolbox.”

Cultural practices help growers prevent many pest problems and reduce the effects of others. They are often the most effective pest control efforts. Cultural practices include choosing resistant cultivars, practicing proper sanitation, properly pruning and training plants, fertilizing appropriately, controlling weeds and rodents, and bagging fruit.

The authors describe in detail various cultural practices specific to each type of fruit. For example, in grapes, they rate various grape varieties and their relative disease resistance to black rot, downy mildew, and powdery mildew.

“Although cultural controls dramatically reduce pest problems, the reality is that most plantings require pesticide applications to ensure a sufficient amount of clean, attractive fruit,” they said. “Pesticides are merely another tool to manage problems.”

However, they emphasized that there are some basic things to know about pesticides before using them, including selecting the right equipment, following safe practices, applying on the proper schedule, and applying at labeled rates. Pesticide applicators should always read and follow label instructions.

The authors describe characteristics of multipurpose fruit sprays (MPFS), insecticides, fungicides, bactericides, and antibiotics used to treat fruit pests.

Finally, if pesticide options are used, the publication includes spray guides for each of the fruits listed above. Each spray guide lists the spray timing based on the fruit development stage, some of the more likely pests encountered at those stages, pesticide options for those pests, and helpful remarks.

This free publication is available at the Purdue Education Store, https://edustore.purdue.edu.