Apple and Pear

Apple and pear trees are subject to serious damage from pests. As a result, a preventive spray program is needed. The following practices will improve the effectiveness of the pesticides and may lessen the need for sprays.

• Plant disease-resistant varieties. This method of disease control is especially important for fire blight, where chemical control options are limited. Varieties resistant to cedar-apple rust, scab, and powdery mildew also are available and will potentially reduce the need for sprays.
• Rake and discard or burn leaves in the fall if apple scab or pear leaf spot are problems. The fungi that cause these diseases can survive through the winter in infected leaves.
• Remove diseased galls from cedar trees. Spores from these cedars can infect apples, causing cedar- apple rust. Elimination of the source of spores (cedar trees) is effective but not always possible. Where cedars are part of an established landscape, remove and destroy all galls caused by the rust fungus on cedars in the late fall. Inspect the cedars again in the early spring during or just after a rain when the orange, gelatinous fungus growth from any remaining galls is highly visible. Remove these galls.
• Prune trees according to recommendations to improve control of all aboveground diseases. In well- pruned trees, air circulation and sunlight penetration are improved. This helps to control diseases by promoting rapid drying after rains and dew. Penetration of sprays into the canopy also is better if the trees are well pruned.
• Prune out and destroy all dead or diseased shoots and limbs during the dormant season. This helps to reduce fire blight, fruit rots, and certain leaf spots, as the organisms that cause these diseases can survive through the winter in the wood. Removing mummified (dark, shriveled, dry) fruit helps to prevent the overwintering of the fruit rot organisms.
• Prune out fire blight–affected shoots and blossom clusters during the growing season only as symptoms appear. Prune during dry weather and sterilize tools between cuts. Make pruning cuts at least 8 to 12 inches below infection.
• Control weeds that may harbor insect pests.
• Use only copper, mancozeb, sulfur, and streptomycin sulfate disease control products on pear trees. Streptomycin sulfate can be used for fire blight as found in table 1. Mancozeb, copper and sulfur can be used for leaf spot, scab, quince rust, and other diseases as directed on the label. Both copper and sulfur can injure pears, so read the label carefully.
• Once fruits have formed, bagging is an alternative to pesticide sprays. For more information, see the Clemson University Cooperative Extension, College of Agriculture, Forestry, and Life Sciences website.
• If you have only a few fruit trees, one option is to use a multipurpose fruit tree spray. These multipurpose products contain both a fungicide and insecticide and are a convenient and effective method to control many but not all common pests and diseases. Bonide Fruit Tree & Plant Guard is a multipurpose product that contains a mixture of two fungicides and an insecticide and can be used on peaches, plums, and nectarines. This product may be applied up to five times during the growing season. Because it contains an insecticide, don’t apply this product during bloom so you will protect pollinators. See the product label for more information.

Peach, Plum, and Nectarine

Peach, plum, and other stone fruits are commonly affected each year by several insect and disease problems. A spray program is therefore needed for successful fruit production. The following sanitation and cultural practices will improve the chances of success and may lessen the need for sprays.

• Prune trees according to recommendations to allow better air circulation and sunlight penetration. Pruning helps to control diseases by promoting rapid drying after rains and dew. Penetration of sprays into the canopy is also better if the trees are well pruned.
• Remove and discard old mummified fruit left hanging in the tree or laying on the ground. Mummified fruit is an important overwintering site of the brown rot fungus.
• Avoid planting peach varieties that are highly susceptible to bacterial spot, as there are few options for control of this disease. Examples of highly susceptible cultivars are Elberta, Halehaven, Rio- Oso-Gem, O-Henry, Cresthaven, and Sunhigh.
• Control broadleaf weeds with regular mowing to control insect pests.
• Remove fruit damaged by insect or bird feeding.
• If you have only a few fruit trees, one option is to use a multipurpose fruit tree spray. These multipurpose products contain both a fungicide and insecticide and are a convenient and effective method to control many but not all of the common pests and diseases. Bonide Fruit Tree & Plant Guard is a multipurpose product that contains a mixture of two fungicides and an insecticide and can be used on peaches, plums, and nectarines. This product may be applied up to five times during the growing season. Because it contains an insecticide, don’t apply it during bloom so you will protect pollinators. See the product label for more information.
• Control black knot of plum trees by removing knots before they begin to produce spores. In late winter, prune out and destroy these rough, black swellings or galls that develop on twigs and branches.

Blueberry

If diseases have been a problem in past years, captan can be used at intervals of 7 to 10 days from bud break to harvest. If mummy berry disease has been a problem, rake the area beneath and around plants to collect or bury any mummified fruits from the previous year’s crop in the location where the diseased fruit was found. Relocating disease fruit for burying elsewhere risks spreading the disease. This will help to reduce the incidence of mummy berry. To reduce dieback diseases, prune out and destroy dead twigs and branches.

• Monitor for insects and spray as needed.
• Monitor for spotted wing drosophila (SWD), which is a new pest that infests developing fruit. Make sprays once or twice a week to control or prevent SWD. If maggots are found, pick all blue and ripe fruit from the plants. Also remove fruit from the ground. Burn the fruit or seal it in a bag and take it off-site for disposal.
• Apply insecticidal sprays regularly if the orchard was previously infested with SWD.

Blackberry

An intensive spray program is generally not needed for blackberry plants. Fungicide and insecticide sprays can be applied as needed. The following sanitation practices will reduce the need for pesticide sprays.

• Remove and destroy nearby wild blackberries to reduce the source of pests.
• Remove and destroy fruiting canes immediately after harvest.
• Promote rapid drying and good air circulation within the canopy by controlling weeds and keeping the plants properly thinned.
• Pick berries often during the harvest period to minimize the amount of overripe fruit. This will reduce problems with berry rots, sap beetles, wasps, and fruit flies.
• Promptly dig up and remove or destroy plants infected with orange rust as soon as symptoms appear in spring. Symptoms of orange rust
  include willowy growth of new shoots and the presence of orange spore pustules on the undersides of the leaves.
• Remove and destroy infected canes before blooms begin to open to control the spread of rosette. You can recognize rosette by the presence of clusters of stems on fruiting canes that produce a bunchy appearance. Flower sepals are extended and pinkish in color on plants with rosette.
• Make sprays once or twice weekly to control or prevent spotted wing drosophila (SWD), which is a new pest that infests developing fruit.
• Apply insecticidal spray regularly if the orchard was previously infected with SWD.

Bunch Grape

Most grape plantings, except muscadine, require a preventive schedule of fungicide and insecticide sprays for successful production. Pests such as black rot can completely destroy a crop of fruit. However, the following sanitation and cultural practices will reduce the need for pesticides.

• Keep vines well pruned according to recommended standards. This prevents overgrowth of vines and a dense canopy. It also removes insect-infested wood. Pruning improves air circulation and sunlight penetration, thus promoting rapid drying after rains and dew. Penetration of sprays into a foliar canopy also is better when vines are pruned.
• Remove and destroy mummified fruit (shriveled, dry, raisin-like) on vines as well as fruit on the ground. Fruit rot organisms of grapes can survive through the winter on old vines and dried fruit on the vines and ground.
• Prune and destroy vines with stem cankers as they are also a site for fungi to survive through the winter.

Fig

Figs can grow as tall as 60 feet in some regions of the country. In the southeast, tree height is reduced to 15 to 20 feet because of freezes that cause significant dieback and regeneration of the plant tissue during some years. In places like California, the fig is trained to have a single trunk, but in the southeast and other places that can have damaging freezes, figs are grown more like shrubs with multiple canes rather than a single trunk.
The common fig is highly adapted to the southeast, but the following practices will help to ensure that quality fruit is harvested throughout the season.

• Plant the most adapted varieties. Planting varieties that are tolerant to the cold will result in reduced incidence of damage to plant tissue. Damage to the trunk or stems can provide entry points for disease and insects. Additionally, varieties that produce fruit with a closed eye (ostiole, which is the opening at the end of the fruit) provides less opportunity for fruit flies and other insects to gain entry.
• Train figs to have multiple trunks or canes. In the southeast, damaging cold weather is a common occurrence. The trunks/stems of figs are often damaged by cold weather; weather-induced delays can significantly reduce harvestable fruit. Maintain no more than nine canes (trunks) per tree. This will allow sunlight penetration and air flow for good fruit development along with rapid drying of leaves for reduced disease spread. This type of plant training will reduce chances of the plant being toppled by wind. Newer canes can be used to replace aging canes for continued harvest of quality fruit.
• Prune out dead and diseased wood. This will remove disease inoculum as well as entry points for insects.
• Avoid planting in soils with nematodes. A nematode infestation can be diagnosed by digging up a few fig roots and looking for small nodules or bumps. To prevent planting on an infested site, have the soil tested for nematodes.
• Harvest fruit often. Figs are highly perishable. Frequent harvests (once daily or 3 to 4 times per week) will discourage disease and insect pests.
• Control fig rust. Fig rust and other leaf and twig blight can be controlled through removal of infected leaves or application of Bordeaux mixture.

For more detailed information, see “Fig Production Guide” at on the Alabama Extension website at www.aces.edu .

Strawberry

Strawberry plants often can be grown almost disease- free without spraying. Weather conditions, however, can cause diseases to develop and spread, and spraying will be necessary. The following practices will improve the effectiveness of the pesticides and may lessen the need for sprays.

• Practice dormant season sanitation. This can reduce disease pressure most years. Strawberry leaf spots and botrytis blight pathogens can survive through the winter on old leaves and debris on the bed. Clipping old leaves, raking, and composting or destroying will help with disease control.
• Control weeds during the growing season. Weeds increase disease by reducing light penetration and air circulation, and they intercept pesticide sprays. Weeds also can harbor insects and mite problems.
• Spotted wing drosophila (SWD) is a serious, invasive pest that infests developing fruit. To reduce the population of SWD, remove fruit that has fallen to the ground as well as fruit on plants that is diseased or damaged.
• Alternate insecticides so that SWD does not build resistance to insecticides.

Sources

R.E. Durham, R.E., J.G. Strang, N. Ward, R. Bessin. 2013. Disease and Insect Control Programs for Homegrown Fruit in Kentucky Including Organic Alternatives. University of Kentucky Bulletin ID-21. 19 pages.

Hansen, Zachariah, Karen Vail, Frank Hale, and Natalie Bumgarner. 2021 Disease and Insect Control in Home Fruit Plantings. The University of Tennessee Agricultural Extension Service, PB1622

Bost, Steve; Karen Vail, Patricia Barnwell, and Frank Hale. 2015. Disease and Insect Control in Home Fruit Plantings, The University of Tennessee Agricultural Extension Service, PB1622

James Jacobi, Extension Specialist, Commercial Horticulture, and Edgar Vinson, Extension Fruit Specialist, Assistant Extension Professor, Commercial Horticulture, both with Auburn University

Revised April 2022, Home Orchards: Disease and Insect Control Recommendations, IPM-1308