Rules and features of summer treatment of plums from diseases and pests

Plum

Summer treatments for plums against diseases and pests must be carried out strictly according to the instructions. Using unsafe products or improper concentrations can ruin the harvest or even cause chemical burns to the trees. It's essential to prepare the plants in the spring to kill disease spores and pest larvae before fruiting.

What is it processed for?

If no work is done, you could lose most of your fruit or diseases could attack the branches and leaves, resulting in significantly fewer plums the following year. In the most severe cases, trees die or suffer damage that takes several years to recover from. Adhering to proper agricultural practices is important for the following reasons:

Destruction of pest egg clutches and larvae. Larvae often cause the most damage, so they must be destroyed at the earliest stage.
Pest control. If insects or caterpillars are already present on the tree, spray immediately to reduce damage.
Prevention. Creating unfavorable conditions will prevent pests and diseases from affecting trees. For example, spraying them with a strong-smelling compound will make the plants unattractive for a while.
Protecting fruits from caterpillars. Experience has shown that without treatment, at least half of the fruits are worm-infested. Therefore, spraying is necessary to protect the crop.

The benefits of treating plum trees against diseases and pests are enormous, as they are much more susceptible to them than, say, cherries. This work should not be skipped even for a single season; if left untreated, the tree will suffer greatly in just one year.

There are signs that can easily indicate that a crop needs urgent spraying, and every gardener should know them:

The leaves begin to fall prematurely, in early or mid-summer.
The growth of the young tree has slowed down or stopped altogether.
A whitish coating has appeared on the leaves, branches or fruits.
The fruits have become loose, and there are drops of gum on the surface, indicating that there are already worms inside.
Gum appears abundantly on the trunk or skeletal branches.
There are many deformed leaves, this also applies to flower buds.
Poor flower formation or low number of ovaries after normal flowering in spring.

Often, two or more signs are present. It's important to regularly inspect the trees, spot changes early, and prevent them from progressing. Even if there are no problems, plum trees should be treated as a preventative measure.

Which pests are the most dangerous?

To understand what to use and how to spray trees, it's important to distinguish between the main types of pests. Most often, plum trees are attacked by one of several types, each with its own characteristics:

The plum codling moth attacks fruits by gnawing out the flesh from the inside. These light-colored worms grow as they eat the fruit. They are easily detected by the damage to the fruit and small holes in the skin. They are easily eliminated with chemicals. Plum trees should be sprayed at least three times, every two weeks. To maximize effectiveness, pick all affected fruit and discard it.
Weevils. They damage foliage and can appear in both spring and summer. To control them, use either chemicals or trapping belts. These are placed on the trunk; when moved, the beetles stick to them. This simple method significantly reduces their numbers.
Aphids. They affect not only plums but also other garden crops. Ants facilitate their reproduction, so it's best to eliminate them first. Small infestations can be controlled with folk remedies, but if the infestation is extensive, it's best to choose a chemical solution immediately, apply the treatment according to the instructions, and repeat the treatment three times.
Fruit mites, or gall mites, are pests found on almost all trees; if they are present in small numbers, they cause little harm. However, if spraying is not done, the insects multiply rapidly. It's best to combat them using a comprehensive approach, treating plum trees not only in summer but also in spring to eliminate egg-laying mites. Alternate different treatments for increased effectiveness.
Plum sawfly, or plum fruit sawfly. These tiny worms attack plum ovaries and young plums. To control them, try folk remedies first; if they fail, switch to chemicals. Special formulations are used against sawfly larvae in the spring, when they are most vulnerable.
Fruit moth. It attacks not only plum trees but also other trees in the garden. If left untreated, the pests will destroy all the foliage. Pepper infusion is effective for control; it's environmentally safe. Apply the infusion approximately once a month until the moth larvae are completely eliminated.

Almost all of the options discussed pose a risk not only to plum trees but also to other fruit crops. Therefore, if a problem is detected, all plants should be sprayed. Otherwise, it will have to be done later, when the pests have migrated from the treated plant to the untreated one.

Advice!

In the fall or spring, it's essential to thin the crown to ensure adequate ventilation and light. This will reduce the risk of disease and pest infestation.

The most common diseases

Almost all problems encountered on plum trees are fungal in origin. Therefore, using special preventative measures in the spring will significantly reduce the likelihood of their occurrence in the summer. The most common problems gardeners encounter are:

Clasterosporium (shot hole) is easily detected by the holes in the leaf blades. Some people mistake this disease for signs of pest infestation, thinking it's caterpillars, but upon inspection, the tissue is dead. Chemical treatments should be applied strictly according to the instructions. The disease most often occurs in summer, when humidity is high and temperatures are above 25 degrees Celsius.
Various spotting diseases. Besides scab, there are a number of other fungal diseases with varying spot patterns. They always occur in the same way: with high humidity and spores landing on the leaves. The best treatment is with antifungal agents tailored to the specific problem and conditions.
Moniliosis (gray mold) primarily affects fruits with mechanical damage. It can also damage leaves and shoots. It most often affects plants during periods of prolonged rainfall and warm weather, when dampness lingers on the surface for long periods. The most effective treatment is to use specialized antifungal products.
Milky Shine. A dangerous bacterial disease that can destroy a tree in just a year. There are no treatments, but it can be identified by a whitish, shiny coating and a stunted plant. If detected, prune away the affected parts or remove the entire plum tree from the area.
Coccomycosis. It appears as reddish spots that eventually turn yellow or brown, and the affected foliage falls off by mid-summer. Control is easy; use any copper-containing spray. Repeat spraying if the disease is not eliminated.
Rust. Leaves become covered with a rusty coating, and plant growth quickly stops. Spray as quickly as possible to prevent spores from spreading. Use any fungicide. If signs of the disease persist after two weeks, repeat the treatment. For maximum effectiveness, remove affected leaves and shoots; burning is best.

By following basic care rules and conducting preventative measures in the spring, the risk of infection is significantly reduced. Diseases most often affect plum trees during unfavorable seasons with prolonged rainfall. During this period, it's important to pay special attention to the trees to detect the problem early.

Chemicals

There are many options, so listing them all is pointless, as they are effective when used according to instructions and under proper working conditions. It's easier to understand the main types of compounds to select the optimal type depending on the problem, the extent of the damage, and weather conditions. There are only four categories:

Contact chemicals. The principle is simple: they act upon contact with the surface, destroying fungal spores. If pests are being controlled, they die after consuming the leaf containing the toxic component. The advantage is that harmful substances do not accumulate in shoots and fruits. The disadvantage is that the components are washed away by rain.
Systemic formulations penetrate the plant's structure and are long-acting. They destroy disease spores from the inside and provide long-lasting control of insects and caterpillars, even if they appear a week or two later. However, the components can accumulate in the fruit, especially with repeated application. Spraying should generally be done no later than three weeks before harvest.
Insecticides. These attack pests by ingesting them. They work in different ways: some cause paralysis, while others poison the insects or affect other organs, causing death. These are also applied to the surface and act on contact; treatment must be repeated after rain. They are quite toxic and often have a negative impact on beneficial insects, so they are not recommended during flowering.
Biological products. They work through microorganisms that multiply and destroy pests or fungal infections. They are safe for humans and the environment, but they work best at temperatures between 15 and 28 degrees Celsius. In extreme heat and cold, the effect is lost, and beneficial bacteria are destroyed.

The most powerful chemical options are contact and systemic; these are the ones to choose for severe disease or pest infestations. Biological formulations are effective as a preventative measure and as a control measure at the initial stage or for small-scale problems.

Folk remedies

They're great because they're always on hand; you can often gather everything you need from a vacant lot. Most of these options are designed to combat pests, but some are also good for preventing various fungi. The most commonly used solutions are:

Add a liter of milk to a bucket of warm water. Treat the crown and trunk to destroy pests in the bark and their egg nests. Lactic acid bacteria inhibit virtually all insects and also destroy the spores of many fungi.
Pour 3 liters of boiling water over half a liter of tobacco dust and let it steep for 24 hours. Strain and add water until the bucket is full. Spray the leaves and branches to kill aphids and other insects. To improve adhesion, add a little grated laundry soap.
Tomato leaf decoction. Place a kilogram of chopped tomato leaves in a saucepan, add water, and bring to a boil. Let it steep for about 24 hours, strain, and add water to bring the total to 10 liters. Spray the solution every 2-3 weeks for pest control.
Pour 200 g of onion peels into a bucket of hot water and let steep in a dark, warm place for 4-6 days. After straining, generously spray all shoots affected by aphids. For prevention, spray the entire tree, focusing on the undersides of the leaves as much as possible.
Dissolve 50 g of urea in a bucket of warm water. Treat the plum tree to prevent worms, starting at the fruiting stage and then repeating monthly. This not only protects the tree but also nourishes it.

Advice!

Instead of urea, you can use urea, add 100 to 300 g per bucket, spray no more than once every 3 weeks.

Folk remedies are good in the early stages and as a defense against diseases or pests. They only make sense if the infestation is small or there's little time left before the plum harvest and chemicals can't be used.

Processing Features

If you use chemicals, the packaging always includes detailed instructions detailing all the nuances of using the product. These instructions should never be violated. If the instructions call for protective equipment, purchase a respirator, goggles, and long-sleeved clothing in advance. Keep a few simple guidelines in mind to ensure maximum effectiveness:

Consider the region's climate. If it rains frequently, you'll need to find a period of at least two days without precipitation. This is especially important for contact products and homemade solutions that can be easily washed off with water. For systemic solutions, 3-4 hours is sufficient; they'll be absorbed by the plant.
Apply at the appropriate time of day. Avoid spraying in strong winds to prevent the solution from spilling onto the garden or adjacent plots. Choose morning hours, when the dew has dried, or afternoon hours, after the sun has set. Avoid applying solutions in hot weather, as they evaporate quickly and may burn the leaves.
Use a garden sprayer with a long wand; it makes it easy to spray all parts of the tree's crown. If the tree is tall, be sure to have a stepladder handy.
Apply the composition to both the top and bottom of the leaves. Be especially careful when applying contact agents, as they only work where they are applied.
Maintain application frequency. If the packaging states that application should be done every 3 weeks, it's not recommended to do it more frequently. Be sure to check how many days before harvest the last application should be.
Don't apply both a fungal and pest control product on the same day. Allow at least a day between applications, or prepare a tank mix by combining the two chemicals. Information on compatible combinations is always provided in the chart on the packaging; don't mix just anything.

If the instructions specify special working conditions, they must be followed. It's best to prepare the solution immediately before use and not store the liquid for more than 24 hours.

Tips for spring treatment

To reduce the risk of disease and pest infestation in the summer, properly prepare your plum tree in the spring. This work takes little time, but the effect is often much greater than summer spraying. Follow these simple recommendations:

After warm weather arrives, whitewash the trunk and lower parts of skeletal branches. Add a little copper sulfate to the mixture for disinfectant properties. Treat the tree in the same way in the fall before the onset of cold weather to kill pests under the bark.
Prune all damaged and diseased branches before bud break. Inspect the tree, remove all excess shoots, and trim away anything that is crowding the crown or growing in the wrong direction. It's best to remove the branches from the area and burn them.
Spray the plum tree with a solution of copper sulfate or Bordeaux mixture. Apply the solution not only to the branches and trunk, but also to the ground beneath the tree. In the fall, be sure to remove any leaves from the ground.

Advice!

After pruning, treat all cuts with garden pitch or a copper sulfate solution to protect the wood from infections.

In the fall, you can also spray the crown. Do this after the leaves have fallen, using any copper-containing product. Apply it when the temperature is above freezing, at least a week before the onset of frost.

Plum trees must be treated in the summer, as without it, they will become diseased, and most of the fruit will be infested with worms. Use the appropriate solution, prepare and apply it strictly according to the instructions, and wear protective equipment if necessary. Perform treatments in the spring and fall for best results.