Peach Tree Diseases and How to Manage Them Successfully

Widespread peach tree diseases are something you should be aware of when growing this deciduous shrub in your garden.

Many people grow this tree for its delicious fruits, but others cultivate the peach plant for its ornamental appearances.

Peach trees look very stunning when flowering as well, adding another reason for people to grow them in their backyard or garden.

An Introduction to Peach Trees (Prunus persica)

The peach is a deciduous tree first domesticated and cultivated in Zhejiang province of Eastern China.
Peach Tree Fruits

This deciduous tree is a member of the Rosaceae family that can grow up to 19 ft (18 m) tall. Peach trees can generate fruits for 10 to 20 years depending on their living conditions.

The peach tree has supple, slim branches and is not as tall as many other deciduous trees. It provides stunning pink flowers with five petals that you can enjoy between January and February.

While the fruits are soft and come with yellow to orange colors, peach leaves are sharp, slender, and alternately arranged.

The diameter of the produces is around 3 to 8 cm.

Some people may refer to peach fruits as nectarine since both belong to a similar species. However, nectarines acquire smooth skin while peaches are more velvety.

Common Peach Tree Diseases and Treatment

Unfortunately, peach trees are prone to many diseases and pests. Here are some of the most common ones for your reference.

  1. Crown Gall

Crown gall is a bacterial disease caused by the bacterium Agrobacterium tumefaciens. Typically, the bacteria enter the tree through wounds in the bark, which can be caused by insects, pruning, improper handling, or other environmental factors.
Peach Tree Crown Gall

Due to damage caused by nematodes and poorly-drained, alkaline soils encourage the development of crown galls on peach trees.

This disease starts at the site of plant wounds and is not noticeable to the naked eyes until it reaches 4 inches (10 cm) in diameter.

You will see white, fleshy swellings at first and they gradually turn to a darker color of tan to brown.

To manage crown gall, do not bother to try chemical control since this is ineffective. Instead, you should try disease management that involves bacterial for commercial production.

Cultural management techniques also make a great option when dealing with these peach tree diseases.

In this view, you should perform good sanitation practices, plant only disease-free materials, and rotate affected fields with a non-host.

  1. Bacterial Spot

Bacterial spot is an important disease of peaches, nectarines, apricots, and plums caused by Xanthomonas campestris pv. pruni.
Bacterial Spot Peach

Peach trees are prone to bacterial spot infection when they grow in areas with frequent rainfall, especially during late bloom.

The symptoms of these peach tree diseases include lesions on fruits and beneath the foliages. If these wounds are severe, they may turn into chlorotic and drop from the plant.

A serious infection that occurs in years can make the whole fruit crop die. To avoid this, you should apply protective copper in the fall before the peach tree drops its leaves.

You should not plant your peach tree in areas where this disease is familiar as well since it can be hard to manage when already visible.

  1. Brown Rot

Brown rot is a common and destructive disease of peach and other stone fruits (plum, nectarine, apricot, and cherry). The brown rot fungus may attack blossoms, fruit, spurs (flower and fruit bearing twigs), and small branches.
Brown Rot of Peach

The fungus that stays alive in mummified fruit on peach trees, infected twigs, and destroyed flowers can result in brown rot diseases.

Long periods of wet climates increase the risk of this problem.

Once infected, the fruit skin and inner tissue of your peach tree will turn brown. You may also notice tan blights with dark frames on twigs.

Other symptoms of these peach tree diseases include wrinkled fruit skin and the presence of gray-brown spores on cankers.

To control brown rot, you can apply suitable protective fungicides to your peach trees.

For good results, you should perform the application after a wet period or when the vulnerable flower parts are noticeable.

It is necessary to provide your peach trees with sufficient levels of fertilizer and water as well. This will decrease plant stress and prevent brown rot diseases consequently.

You should avoid using sprinkler irrigation to protect the blossoms and leaves of the peach trees from wetness too.

Pruning infected twigs and getting rid of mummified fruits from peach trees can help to prevent this disease as well.

  1. Peach Tree Diseases Caused by Virus

Peach rosette is a disease of peach caused by a virus commonly known as peach rosette virus. The disease was noted in Georgia in 1890 and distinguished from peach yellows by Smith (4), who also ascertained that the causal entity was not a bacterium or fungus.
Peach Diseases Caused by Virus

Bacteria and fungus are not the only causes of diseases in peach trees. Plum pox virus, for example, is a common issue that infects this plant through aphids.

The symptoms of plum pox on peach trees include visible dark rings or spots on fruits and distorted lamina.

To avoid the plum pox virus, you should always plant certified healthy material and keep aphids under control by using chemical sprays.

You must get rid of infected trees from the orchard too so that they will not prolong the spread of the virus.

  1. Peach Leaf Curl

Peach leaf curl, also known as leaf curl, is a disease caused by the fungus Taphrina deformans. Peach leaf curl affects the blossoms, fruit, leaves, and shoots of peaches, ornamental flowering peaches, and nectarines, and is one of the most common disease problems for backyard gardeners growing these trees.
Peach Leaf Curl

This common fungal disease infects flowers, fruits, leaves, and even shoots of peach trees. Since this infection is pretty serious, it can make your tree die within 2 to 3 years if left untreated.

Your peach tree may get infected by this fungal disease if there are reddish or yellow raised areas on the leaves that develop a white powder of the fungus’ silky spores.

The blooms of the infected peach trees may drop without forming fruits. Meanwhile, affected shoots acquire tiny yellowish foliage and are distorted.

To avoid these peach tree diseases, you can consider growing resistant varieties such as Redhaven Peaches, Frost, Muir, Kreibich, and Indian Free Cultivars.

As a heavy feeder, your peach tree will require a lot of energy to produce fruits. Thus, you should provide it with organic fertilizers with high nitrogen.

You may also treat peach leaf curl with copper or sulfur-based fungicides after leaf fall in the autumn. Make sure to follow your product’s label before using this to dust or spray your tree.

  1. Bacterial Canker

Bacterial canker of stone fruits is caused by Pseudomonas syringae pv. syringae, a widespread organism that generally causes disease on trees that are stressed.
Peach Bacterial Canker

Low temperatures and high moisture encourage the development of this disease in the spring. Peach trees grown in poorly-drained sandy soils and young ones are particularly vulnerable as well.

The cankers appear in pruning wounds, on twigs at bases of leaf buds and bloom, or the bottom of spurs. These then spread upwards, creating sunken spots during winter.

Similar to the previous peach tree diseases, applying protective copper spray allows you to control the spread of the problem successfully.

Besides, you can prevent stress to peach trees by growing a variety that is suitable to your geographic location and environmental conditions.

Pruning peach trees at the beginning of summer can also limit the spread of canker disease infection.

  1. Peach Scab

Peach scab is caused by Cladosporium carpophilum, a fungus that occurs worldwide and affects peach trees in regions with a warm, humid climate conducive to the disease.
Peach Scab Disease

The infection of the fungus Taphrina deformans can make your peach fruits spotted in green. High wetness levels promote the emergence of this disease in the tree.

Since this fungal disease enters your peach tree’s system via branches’ cracks and splits, you should get rid of a broken or dead branch when needed.

You can also spray your peach tree with a fungicide once the flower petals start to drop.

Then, do not forget to perform proper pruning practices as well to decrease the buildup of humidity around the branches and promote sufficient air circulation.

How to Identify Peach Tree Disease Caused by Pests

Disease symptoms occur on the fruit as small (less than ¼ inch in diameter) velvety dark spots and cracks. In cases of severe infection, spots may join together to form large dark lesions.
Identify Peach Disease by Pests

Peach tree problems caused by pests come with different signs depending on the insects that invade the plant.

For instance, Fruit-tree leafroller makes the leaves tied and rolled together with silk webbing. Besides, symptoms like plant defoliation and extensive scarring on fruits may present too.

Meanwhile, the identification of scale insect infestations may include damaged twigs, fruits, and branches of the peach trees.

Scale insects have no noticeable legs and generate a white waxy coating that becomes black gradually. If the infestation of these pests is severe, gumming may happen on the twigs and bark of your peach tree.

When it comes to the infestation of oriental fruit moths, the symptoms include wilting shoot tips and mushy, squashy, and discolored fruits.

You may notice insect frass around the fruits’ entry holes burrows. Its larvae are white with a black head at first, but they turn pink with a brown head as adults.

How to Treat Peach Tree Diseases and Prevent Them

Use fungicides with propiconazole or captan (make sure they're safe for peach trees). Start spraying at full bloom and repeat twice at 10- to 14-day intervals.
Treat Peach Tree Disease

For problems caused by pests, introducing their natural enemy is pretty effective to keep the population under control.

For example, you can encourage the presence of predacious beetles and some wasps to keep the populations of scale insects in check.

You can manage scale insects by using horticultural oil sprays as well. Apply them when your peach tree is dormant without worrying about killing beneficial insects.

To deal with oriental fruit moths, you may need to involve the use of insecticides.

However, remember that you should not apply chemical sprays to your peach tree within two weeks of harvesting.

When it comes to peach tree diseases caused by fruit-tree leafroller, you can control it by removing weeds from the bases of the plant.

After that, apply Entrust SC or Bacillus thuringiensis on organically grown varieties.

Meanwhile, the general practices to prevent diseases and pests from coming back to your peach trees include:

  • Use good sanitation practices to avoid your peach tree getting infected by various diseases.
  • Maintain the location of your peach tree free of plant debris (including twigs and foliages) and weeds.
  • Eliminate all mummified fruits as well as dead branches from the peach trees and the ground.
  • Practice a recommended spray program for peach trees that starts in the dormant season and continues through the growing period.

Finally, you should not forget to include regular watering and application of the needed fertilizers as another good method to prevent a variety of peach tree diseases.

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