Many homeowners enjoy growing their own fruit, but they have also learned that they require a lot of care. Pruning, pest control, fruit thinning, harvesting and storage are among the tasks an orchardist must undertake each year. The activity of pests is particularly disheartening to the home fruit grower, and it is the subject we’ll concentrate on today.
A basic backyard orchard in northern Indiana typically consists of varieties of apple and/or pear trees. With the exception of late freezes after bud break some years, our climate is suited to these fruits. Some may also grow stone fruits (fruits with a single, hard pit) like peach, apricot, plum or cherry trees, but these fruits are generally more difficult to grow successfully and consistently.
Among the pests that apple growers may deal with are scale insects, aphids, mites, plum curculio, codling moth, apple maggot and Japanese beetle. The “worms” we find in apples are the larvae of codling moths.
Scales, aphids and mites are all quite small. They can typically be controlled with an application of superior oil spray in the delayed dormant season — right before buds swell and break open with new growth. Other pests will generally require insecticide sprays at the right developmental stage for effective control.
The spotted lanternfly is an invasive pest of fruit trees, other trees and grapes. First detected in September 2014 in Pennsylvania, it now threatens growers in northeastern states. Although it has not yet been found in Indiana, we are on the lookout for this pest.
Pests are not only insects, but also diseases. Diseases affecting apple may include: fire blight, apple scab, sooty blotch, fly speck, rust and fruit rots. Most of these are fungal diseases, but fire blight is a bacterial disease. Correct diagnosis of a disease is important so that proper selection of a management product may be made. Once again, timing of application is very important, and it typically happens at regular intervals during appropriate growth stages.
Some years we see severe cases of fire blight – a disease that affects both apple and pear. A common symptom of fire blight is a burnt appearance of the tips of limbs, with the terminal growth curving back in a shape resembling a “shepherd’s crook,” or the curved end of a wooden cane.
Fruit growers dealing with this disease are encouraged to prune affected branches at least 12 inches below the transition on the stem between diseased tissue and normal growth, and also to disinfect pruning tool between every cut in a 10% bleach solution. Prune only on a dry day. Early next year, apply a copper-based pesticide like Bordeaux mixture or another dormant spray mixture before bud break. Streptomycin may also be applied during the bloom period according to label directions.
Pears have many of the same or similar insects and diseases that affect them, although diseases such as pear scab are caused by a different fungal species than the one that causes apple scab.
Many home orchardists raise apples or pears in an organic system where only naturally-derived products and pest control methods are employed. Although extra vigilance and management is typically required, many home-based growers prefer to raise their fruit in this way.
Purdue Extension has a publication authored by experts entitled, “Managing Pests in Home Fruit Plantings,” that many growers find is a helpful resource. The publication describes, with representative pictures, developmental stages of tree fruits. This is helpful when deciding when to properly apply certain pesticides. It also describes cultural practices that help prevent or reduce pest problems. And, it includes a spray guide for each tree fruit, describing typical pest problems at various developmental stages and optimum times to utilize chemical controls.
The publication also includes similar pest management information for small fruits, including grapes, strawberries, raspberries, blackberries, currants and gooseberries.
Find your copy of the above-mentioned publication at edustore.purdue.edu.