How to treat plum tree fungus
Plum Tree Diseases - What to Watch for and How to Protect Your Plum Tree
Our trees form such important parts of our yards and home gardens. They give us privacy from neighbors, shade to make our yards tolerable on hot summer days, and sometimes even tasty fresh fruit. In this article, we will identify plum tree diseases, treatment options, and, of course, prevention of the diseases .
Plum Tree Diseases: Bacterial
Bacterial canker (Pseudomonas syringae)
Bacterial canker is easiest to spot in the spring when buds do not open and the nearby twigs die back. Cankers also occur and trunks and main branches and manifest as oozing spots, or sores, that produce a sour smell. The cankers additionally create spots on leaves that begins as small purple spots that transitions to black before finally turning into a shot hole as the leaf tissue dies and falls out.
Ultimately, the canker causes necrosis of the leaves and woody tissues until the branch, and perhaps the whole tree, dies.photo shows gummosis, a bacterial canker causes decline of fruit trees
Source and Treatment of Bacterial Canker
Bacterial canker affects all stone fruit trees and colonizes on the surface of healthy trees. It only becomes a problem for stressed trees or trees with an entry point of leaf scars or pruning wounds.
Unfortunately, treatment for bacterial canker is disappointingly inconsistent and ineffective. Some options are to apply a copper fungicide or a broad-system fungicide. In addition to trying a fungicide, containment will be your most important course of action as it can be spread from tree-to-tree.
Bacterial Spot (Xanthomonas campestris)
Bacterial spot also produces oozing cankers on the tree trunk, sometimes so significantly that the tree is left pitted and ridged from the ever-increasing cankers. Long before you notice the cankers, the bacterial spot will damage the leaves.
You will see angular, as opposed to round, spots on the underside of the leaves. Shot holes will appear. And then finally, the leaves will turn yellow and fall off the tree, which will then lead to sunburned fruit. Fruit may also have black sunken spot.Sunken canker on trunk of tree, a common symptom of bacterial
Source and Treatment of Bacterial Spot
Bacteria colonizes on healthy tree tissue then spreads with rain to the leaves, fruit, and twigs. Warm rain and temperatures above 65 degrees Fahrenheit permit the bacterial growth, so warm, wet springs year after year promote severe infections.
The oozing cankers can also spread the disease to uninfected trees.
Chemical applications can prevent additional or new infections but cannot cure an existing infection. Prevention will again be key.
Crown Gall (Agrobacterium tumefaciens)
Crown Gall creates burly gnarls on the root or trunk of trees, and it impacts many, many types of fruit and nut trees. On plum trees, the gnarls will be soft and sometimes hollow. The galls stunt the growth on young trees and can cause wood rot on older trees.Tree Burr Knot (Burl) or Crown Gall close-up, plant disease that cause abnormal growths of galls
Source and Treatment of Crown Gall
Crown Gall is a bacterial, and it is particularly problematic because it can live independently in soil and in roots. This means that even if you get rid of a diseased tree, the crown gall can remain.
There are no effective treatments for Crown Gall, but botanists suggest just tolerating it for the life of the tree. Trees can continue to bear fruit.
Plum Tree Diseases: Oomecyte
Phytophthora Root and Crown Rot (Phytophthora spp.)
Root and crown rot is caused by Oomecytes, which are water molds. Plum tree leaves will have noticeable maladies – wilting, followed by discoloration and then premature drop. As the disease progresses, you will see branch and twig dieback. Brown lesions encircle feeder roots, and the feeder roots eventually disappear. Ones left behind will be woody and brittle. The tree may ooze black sap.
Root and crown disease can stunt growth, and eventually cause the death of the tree. Young trees are most susceptible.
Source and Treatment of Root and Crown Rot
Root and crown rot can survive in the soil for years, but it requires a high level of moisture to infect a tree. Gardeners are most likely to have the disease introduced to their property by the planting of an infected tree purchased elsewhere. It can then spread through the soil.
Phosphonates can help control the rot. Ensure your soil has proper drainage.
Plum Tree Diseases: Fungal
Armillaria Root Rot (Armillaria mellea)
Armillaria root rot is commonly known as oak root fungus and is ultimately fatal to infected frees. The soil-borne fungus infects the root and crown of the plum tree, and by the time you can see above-ground symptoms, it is likely too late to save the tree.
During wet seasons, mushrooms may appear at the base of the tree, but the small stand of mushrooms is a deceptive sign of the massive infection below the ground.
Source and Treatment of Root and Crown Rot
Containment of infected soil, wood, and root tissue is critical for preventing the spread of the fungus. The fungus continues to live in the dead root tissue long after the tree is cut down or dies back. Planting a new susceptible tree in the same soil is not recommended unless there is complete removal of the tree and and fumigation of the soil.
Black Knot (Apiosporina morbosa)Closeup of a fungus growth on a tree branch
Black knot is a blissfully accurate and descriptive name for fungal diseases. On plum trees, you will see black, swollen masses on the twigs and branches. The masses will start as subtle green or light brown soft spots that grow over multiple seasons to black tumor-like growths. They can be up to a foot long and encircle an entire branch.
When the branch is encircled by the knot, the branch will die. The tree may suffer from decreased fruit production, structural damage, and ultimately death if the infection is severe. Mature trees are more resilient and may survive without any noticeable ill effects.
Source and Treatment of Black Knot
The knots house the fungus, and the fungus spreads throughout the tree and even to other trees by spores that settle on new green growth. Without moisture, the spores will not develop into a larger colony that creates the knot.
Unfortunately, fungicides alone will not remedy black knot, and removal is much more laborious. Botanists recommend pruning the tree in the winter to remove any visible knots. Remember, the spores will be released from those knots in spring. Applying a copper fungicide can help prevent the creation and spread of the stores.
Dip your shears in a 10% bleach mixture between cuts, and burn the infected branches. As it takes a few seasons for the knot to materialize, it may take a few years of heavy winter pruning to fully control the infection.
Brown Rot (Monolinia spp.)Plum Fruit Infected by Fungal Disease Monilia cinerea in Orchard.
Brown rot impacts stone fruit like plum trees the world over, but it will actually be most noticeable as fruit rot rather than abnormal tree growth. Like black rot, brown rot is a fungus spread by springtime spores. The fungus overwinters in infected fruit and twigs and then settles on the blossoms in spring after being transported by wind and rain.
The fruits develop brow spots that expand into larger spots or rings of spores. The fruit rots and shrivels, known as a mummy.
Cankers will also appear on the twigs and branches, creating cankers that can disrupt the vascular system in the tree and cause damage or death.Rotten mummified plums on the fruit tree, Monilia laxa (Monilinia laxa) infestation, plant disease
Source and Treatment of Brown Rot
Because the spores overwinter in the infected fruit and twigs, you must be sure to clear infected fruit as it appears and at the end of the growing season. Prune the infected twigs and branches to remove the source of the infection, and treat with a fungicide.
Apply a fungicide during bloom and prior to harvest for maximum effectPowdery Mildew (Sphaerotheca pannosa and Podosphaera tridactyla)Powdery mildew on leaf of apple tree
These two fungi manifest as a white, powdery substance that rapidly spreads throughout the tree. Sphaerotheca pannosa effects the fruit while Podosphaera tridactyla attacks the leaves. Depending on which type, it may look stringy or like a powder.
Source and Treatment of Powdery Mildew
The spores overwinter on fallen leaves, bark, and on shoots of the tree. The powdery mildew easily spreads from roses and other stone fruit trees, so any treatment must treat the collective impacted plants. Apply fungicide starting at full bloom at 10-14 day intervals until fruit pits harden. Rotate fungicides to prevent resistance.
Rust (Tranzschelia discolor)Plum rust (Tranzschelia pruni-spinosae) on green leaf of Plum or Prunus domestica
Plum rust creates tiny, rust-colored spores on plum tree (and other fruit tree)leaves. It can cause leaf drop and a reduced plum yield, but it is unlikely to kill the tree. Plum trees are usually impacted at the end of the growing season, making it more resistant to the mal effects of the fungus.
Source and Treatment of Plum Rust
The spores spread easily on the wind, but the fugus can be treated with fungicides. Rotate your chemicals to manage any resistant fungi.
Plum Tree Diseases: Viral
Plum Pox VirusVirus-triggered symptoms of chlorotic mottling and mosaic on green leaves of bird cherry.
The USDA identifies plum pox virus (PPV) as a serious viral disease impacting plum and other fruit trees. Fortunately, it does not kill the tree, but it does reduce the fruit yields of impacted trees and it mottles and severely deforms the fruit, rendering it unmarketable. PPV does not cause harm to humans, but it can devastate commercial orchards.
Source and Treatment of Plum Pox Virus
PPV is highly contagious and is spread by the infected plant or fruit.
Once an infection is identified, the source tree and all trees within a 50-meter radius should be removed and destroyed.
Plum Tree Disease Prevention
Because many of the above diseases are easily or effectively healed, prevention will be the best bet to maintain the beauty, fruit production, and ultimate survival of your plum trees. Here are some key tips to avoid infection of your plum treesBeautiful ripe purple plum on a branch in autumn
- Correct pruning is the number one thing you can do to keep your trees safe. Prune flowering trees when they are blooming because wounds heal the fastest. By eliminating weak, damaged, or brittle branches, you are removing possible entry points into the tree. The increased air circulation promotes a dryer environment to impede fungal growth
- Apply sealant to any wounds to prevent diseases from entering the tree, and not jus pruning cuts. Did you nick the tree with the weed whacker? Did your teenager tie a hammock and cause a break in the bark? Seal it.
- Select disease-resistant varieties. Many species of plums are resistant to some diseases but not others. Consider the most pressing risks in your climate, and be sure to choose a strain that is resistant to that issue.
- Apply NEEM oil to fungus-infected trees. NEEM oil is a natural infection control medium that smothers insects and spores alike. For trees struggling with a fungicide-resistant fungus, the NEEM oil can inhibit the spread of spores and give you a leg-up in controlling the fungus through pruning and condition control.
Excited for more plum content? Then check out our plum trees page for the latest growing tips, care guides, recipes, and more!
Black Knot Disease: Symptoms, Treatment and ControlBest product
for Black Knot
Black knot is a widespread fungal disease that attacks plum and cherry trees, both fruiting and ornamental. The fungus, Apiosporina morbosa, (also identified as Dibotryon morbosum and Plowrightia morbsum), singles out trees of the genus prunus, which includes peach, apricot, and chokecherry. Once established, black knot is easily identified with its hard, uneven, black galls that seem to enwrap twigs and branches. Black knot is a slow developer, taking a season before it’s visually apparent and producing spores. The trick to controlling the fungus is identifying the infection well-before the disease becomes firmly established. If left to grow, it effectively strangles new growth, girdling branches and dooming the tree to deterioration and poor fruit production. Insects and plant diseases use the galls as an entry to the tree.
The disease cycle starts when spores are released from established knots where the fungus overwinters. This occurs during damp spring conditions when temperatures reach 60 degrees or higher. The spores travel to other parts of the tree and, depending on the breezes, to nearby host trees. The spores germinate on stems beneath a thin film of moisture, often at the juncture of a new leaf start. They form small, olive-colored swellings over the first season, darkening in color as the season progresses, hidden by the leaves they’ll eventually kill,. By the second year, the galls are expanding quickly, especially where the weather remains humid. The growing infection begins releasing its own spores as it swells into the dark, easy-to-spot (especially after leaves have fallen) warty black fungus that coils along stems and branches. At this point, astute pruning and chemical treatments may not be enough to save the tree, no matter how careful the pruner is not to spread spores or leave them behind when removing the galls.
Paying close attention to your fruit trees and catching the infections as soon as they’re apparent, followed by quick pruning and careful disposal of the gall-infected branches, can save trees. Organic treatments can also help protect trees while keeping harmful chemicals off your fruit.
When choosing new plantings, consider that some varieties of tree and shrubs are more susceptible to the disease than others. They should be avoided in areas where the fungus is prolific. Tart cherry varieties are said to be less susceptible to the disease than sweet. Japanese plums are said to be less susceptible than American varieties. A number of plums, including President, Early Italian, Santa Rosa and Shiro carry varying degrees of resistance to the fungus. Susceptibility varies depending on the climate zones. Varieties that are susceptible in humid southern climates may be less so in dryer or cooler ones. Talk to your local nursery staff to see which varieties of plums, cherries, and ornamentals do best in your area. The Ohio State University Extension site has a chart on their black knot page that list the various levels for susceptibility to a number of plum and cherry tree varieties. (Not surprisingly, plum trees with resistance to black knot don’t do well in cold, northern climates.)
How to Control
- Inspect your trees carefully for first signs of the disease. This is best done in winter, when leaves are absent, but should be continued as well throughout the growing season. Look for cracks, discoloration, swelling, or other first signs of infection. Check carefully around twig and leaf axils.
- Remove any knots that are found. This is best done during winter when spore production is down. Cut well-past the galls, four to eight inches, to ensure all the infection and its spores are removed. Larger branches with established knots should be removed entirely. Use a pruning knife or chisel to remove galls on trunks and large branches, cutting down to the wood and out to at least an inch beyond the infection.
- Continue to inspect for and remove galls as the season progresses.
- Take care not to spread spores when pruning trees with black knot. Don’t allow twigs or other cuttings to fall to the ground where the spores could survive.
- Dispose of infected stems and branches by burying or, where allowed, burning. Small cuttings can be stuffed in trash bags and hauled away. Do not compost any infected cuttings unless your heap has an internal temperature of 160 degrees (not many do).
- Clean pruning tools as you use them with a solution of 1/2 cup bleach to a gallon of water. Wipe tools between cuts and leave your pruning blades in the solution for three to six minutes when finished. Or use a safe, commercial fungicide cleaner such as Physan 20.
- The Alberta Ministry of Agriculture and Forestry has a detailed guide to pruning and disposing of infected trimmings at their website.
- Fungicides can offer significant protection against black knot, but are unlikely to be effective if pruning and sanitation are ignored. Organic gardeners will want to avoid all but OMRI listed fungicides.
- Spraying trees with NEEM oil, a natural fungicide that controls leaf spot, rust, scab, and other tree fungus, can help inhibit the spread of black knot (it will not kill fungus that is already present). Spray trees per instructions just ahead of leaf and blossom emergence and, if possible, ahead of rain. Continue on a 7-10-day cycle until weather dries. Use of other fungicides can also discourage spores from germination. But few are specifically indicated for use on already infected trees.
- Spraying lime sulfur on trees during the dormant period is said to prevent the production of spores. Copper sprays applied during dormancy may also inhibit spore production.
- Take out wild cherry and plum trees around your property. They harbor the disease and release spores that are easily carried to your susceptible nursery trees.
- When planting new trees, place them away and upwind from established or wild prune and cherry trees.
Pest Problem Solver
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Diseases of plums – we treat the fungus and recognize the virus + video
Wounds on the leaves and gum on the fruits – what is happening?
It happens that oval spots of gray-brown color with a crimson edge 4-5 mm in size appear on the leaf plates, which dry up and fall out after a couple of weeks, and through holes form in their place. These signs indicate the development of a fungal disease called clasterosporiasis or perforated spotting. With a large scale of damage, the leaves dry out ahead of time and fall off.
Gum on fruits
Fruits are often affected. On them you can see small depressed spots, where growths form over time, from which gum protrudes. With the further development of the disease, the plum is affected to the very bone, is significantly deformed, stops growing and dries up.
In advanced cases, entire branches are affected. Elongated spots form on the bark, they burst, and gum oozes from the cracks. Neglect of treatment leads to the death of entire groups of shoots and bacterial cancer. The spores of this fungus overwinter in the leaves, so clean up fallen leaves regularly and don't leave them to decompose until next year. Remove affected shoots promptly in early spring and autumn after harvest, do not overcrowd plantings, clean wounds in case of gum formation and treat them with garden pitch.
Use 1% solution of Bordeaux liquid or copper oxychloride to control perforated spotting. We carry out the first spraying in early spring before bud break and after the appearance of the first buds. Then we repeat the procedure immediately after flowering and again after 2-2 weeks. The last spraying should be no later than three weeks before harvest. If klesterosporiosis has affected the stone fruit culture too much, additionally spray the tree with a more concentrated 3% solution of Bordeaux mixture after the final collection of all fruits.
Gum disease – how to avoid the “bitter tears” of a tree?
Gum disease is a common problem in stone fruits, including plums. It appears as a thick mass, the color of which varies from light yellow to brown. In appearance, the gum resembles a hardened resin. It is formed in the most vulnerable parts of the cortex. Mechanical damage, inaccurate pruning of branches, lack of sealing with garden pitch, sunburn and adverse weather conditions - all this leads to cracking of the bark and the formation of wounds that gum fills over time.
Excessive watering and oversaturation of the crop with mineral fertilizers, especially nitrogen, can provoke the development of gum. Damp and cold weather, numerous damage to the bark by pests are another faithful companions of gum treatment. Gum is a good platform for the development of bacteria, stem cancer and the death of the tree as a whole.
To prevent gum bleeding, regularly monitor the condition of the bark, do not allow the formation of cracks and wounds on it. In case of gum formation, remove it with a sterile garden knife, clean the place to living tissue, disinfect with a 1% solution of copper sulfate and carefully seal it with petrolatum or garden pitch. Remove severely affected branches.
Rust, coccomycosis and black fungus - a triple attack on the leaves
Brown spots that are localized near the veins of the leaf blades indicate infection of the plum with a fungal disease - rust. The main peak of the disease occurs in July. If the tree is left untreated, then small brown swellings will appear on the outside of the leaf, which over time can occupy the entire area of \u200b\u200bthe leaves. Trees affected by rust are weakened due to premature fall of leaves and a decrease in immunity. Rust is caused by a fungus. Therefore, in order to avoid infection, remove fallen leaves in time, and also treat trees with fungicides. Before flowering, spray the horticultural crop with copper chloride and 1% solution of Bordeaux liquid after harvest. Attention, three weeks before harvesting the fruits, we stop all spraying.
Dangerous and very common plum disease - coccomycosis. The main focus of its defeat is the deciduous part of the tree, although the fungus can also affect young shoots and fruits. The activity of coccomycosis occurs in the first half of July. The first signs of damage - the formation of multi-colored spots on the leaves, from purple-violet to red-brown. With a prolonged course of the disease, small spots grow and cover almost the entire surface of the leaf plates, and a pink-whitish bloom appears from the inside of the leaf. These are fungal spores. These leaves dry up and fall off.
If the fungus infects the fruits, they become covered with watery spots, stop growing and dry out. Favorable conditions for coccomycosis are warm, humid weather. However, the spores of the fungus perfectly tolerate cold and frost, settling in fallen leaves, so it must be removed and burned for the winter. We fight coccomycosis using standard familiar methods: we spray the trees before flowering and after harvesting with a 1% solution of Bordeaux mixture or copper oxychloride, using 30–40 g of the substance per 10 liters of water to prepare a solution.
Is there an unpleasant black coating on the leaves and shoots? This is a clear sign of soot fungus. It prevents the penetration of oxygen and sunlight into the tissues of the plant, thereby slowing down growth and disrupting the normal vital activity of the culture. Whatever the cause of the soot fungus, reduce watering and reduce planting density. As the main control measure, use spraying with a copper-soap solution, at the rate of 5 g of copper sulfate and 150 g of laundry or green soap per 10 liters of water.
Monilial burn - how to deal with a dangerous fungus?
If the branches of plum trees dry, become covered with brown spots, this is a sign of a fungal disease - moniliosis. This disease appears in cold and wet weather in the spring, when the flowering of trees begins. The flowers are the first to fall into the lesion, then the leaves and branches dry. Over time, spores form on them, from which the bark becomes covered with gray growths. Affects monoliosis and fruits. Wet weather is ideal conditions for the development of the fungus in fruits.
Plums with mechanical damage and cracks are the first to be affected. Penetrating into them, the fungus forms brown spots, they increase in size and merge. At the final stages of the lesion, the spores of the fungus form small gray-brown growths on the drain. This is one of the most dangerous fungal diseases. If measures are not taken to treat it, infected trees can completely die.
The fight against moniliosis begins with the collection of affected fruits located on the tree and under it. We must burn all collected specimens; they are not suitable for compost. After harvesting, we spray the trees with a 1% solution of copper, iron sulfate or Bordeaux mixture.
Plum pockets - causes and manifestations of the disease
Deformed plums are not uncommon in the garden. However, if the fruits on your trees form elongated and do not have a distinct shape, these are clear signs of plum pockets or marsupial disease. In such infected specimens, there are no seeds, the taste of the fruit is lost. Another characteristic sign of a fungal infection is the formation of a sticky powdery coating with spores. You can track the infection of stone fruit crops with marsupial disease immediately after the start of flowering. As with many fungal diseases, the ideal conditions for the development of plum pockets are high temperature and high humidity. The fungus overwinters in the scales of the buds and forms mycelium on the shoots.
If you do not start the fight against marsupial disease, you can lose up to 60% of the crop. To prevent this from happening, remove the branches that are dry and damaged by the fungus, and burn the affected fruits. In early spring, before bud break, treat the trees with a 3% solution of Bordeaux liquid, and immediately after flowering begins with a 1% solution of the same preparation. In order for the chemical preparation to linger in the tissues of the plant, and not to be washed off during the first precipitation, use systemic fungicides, such as Horus, before and after flowering.
Viral infections - a global threat to the plum crop
If fungal diseases are easy enough to treat, then the same cannot be said about viruses. One of the dangerous viruses is plum dwarfism. Its initial signs can be seen in small leaves, they have an elongated shape and uneven edges. Over time, the compaction of the sheet plate and its fragility are added to the non-standard form. A large number of such leaves are located at the top of the shoots. The flowers of stone fruit crops are tied poorly, have a painful and pale appearance. As a result, the dwarfism virus leads to slow growth and death.
Fighting the virus is useless. Dig up the infected tree and burn it. As a preventive measure against dwarfism, we recommend using only sterile garden tools, using all pest control methods on the site, and choosing virus-resistant seedlings.
Smallpox occurs not only in humans, but also in stone fruit crops. Smallpox, also known as Sharkey's virus, primarily infects leaves, forming chlorotic ring spots on them, which can be clearly seen in sunlight. The fruits are also susceptible to infection. They become dense, significantly deformed. Inside, the pulp acquires a brown-red hue, and ring depressed spots form on the skin, gum is visible in the cracks. Such fruits lose their taste, they fall off and are absolutely not suitable for human consumption.
Plum virus infections
To prevent the development of Sharkey virus, choose resistant varieties such as Renklod, avoid planting Mirabell Wangangheim, Nancy and Zimmer. The disease can manifest itself on stone fruits throughout Russia, it is especially common in the southern regions, where all favorable conditions are created for its development. Aphids are frequent carriers of Sharka, so be especially attentive to this pest and take appropriate measures to destroy it in time. Ornamental plants should not be planted near plums, as well as those crops that can be potential carriers of the virus - clover, sweet clover, nightshade, etc. Infected specimens are not subject to treatment, they are uprooted and burned.
Chlorotic ringspot is another dangerous plum virus. It is characterized by the formation of a blurry pattern on the leaf plates. Over time, the annular spots fall out, and in their place there is a thin mosaic border and through holes. The virus also affects the leaves. They become smaller, become narrow and rigid, have a wrinkled texture. Infection can occur through non-sterile equipment, poor-quality planting material, and also be carried by pests. Affected trees must be dug up and burned.
Witch's broom - what does it have to do with mystical inventory?
Witch's broom is a fungal disease that affects stone fruits, especially plums. Affected branches become thin, close to each other, there are no flowers on them, and leaves are rarely found, which are significantly deformed and small. Outwardly, the overall picture really resembles a panicle, from which the disease probably got its name. Over time, a whitish coating (spores) can be seen on the underside of the leaf plates, from which they become even more fragile and wrinkled. The pale shade of the leaves often changes to red.
The proven method of spraying trees with a 3% solution of Bordeaux mixture in early spring, as well as a less concentrated 1% solution of the drug after flowering, helps to prevent the development of the disease. Among other fungicides, Ridomil Gold has a good effect against the fungus, which should be applied a few days before flowering, as well as Thiovit Jet after flowering.
- Author: Ole Lukovoe
- 3 How to deal with plum pests: preventive treatment
- 4 Conclusion
Plum is a fairly common plant that can be found in every garden. You can get a good harvest of tasty and healthy fruits only from a healthy tree. However, often gardeners are faced with growing problems such as plum diseases and pests that can lead to the death of the entire garden.
Tree diseases are associated with insufficient care and improper planting. Most often, plum is affected by viral and fungal diseases that appear on weakened trees. In order to start treatment on time, it is important to know the main signs of the manifestation of the disease.
Plum bushiness or overgrowth
This fungal disease is popularly called "witch's broom". On the affected tree, many thin, short shoots are formed, which are collected in bunches. Such shoots will not bear fruit. In the fight against the disease, only the destruction of infected plants will help.
As a prophylaxis, not only mineral and organic fertilizers are used, but also Bordeaux liquid. In addition, in order to secure the site, only healthy seedlings are planted in the garden. They must be purchased only from trusted nurseries.Bushiness on a plum tree
The disease is widespread on stone fruits that were previously affected by fungi. Most often, the disease begins to develop if the irrigation regime is disturbed or too much fertilizer is applied to the soil. Resin on a tree can stand out after frost or improper pruning. Signs of gum disease are as follows:
- wounds and cracks are visible on trunks and shoots;
- in places where the gum flowed out, transparent frozen drops appeared.
If you do not pay attention to the signs that appear in time, the tree may die. Affected bark is a great place for the development of bacteria that lead to tree cancer.
Affected areas on trunks must be treated with 1% solution of copper sulphate or garden pitch. Strongly affected shoots are best cut. In order to further increase the immunity of the plant and avoid re-infection, you need to properly care for the plum.Plum gum disease
An insidious viral disease that occurs more often in a latent form. It is difficult to identify the affected tree. Dwarfism can manifest itself only at the last stage, when the fight against the disease is meaningless. Therefore, all actions of the gardener should be directed more towards preventive measures.
Signs of the disease:
- inhibited tree growth;
- unnatural leaf shape. They become elongated, clumsy and more like willow leaves;
- premature leaf drop. This is because the sheet plate becomes brittle;
- reduced yield;
- lack of peduncles or a small number of them. The flowers are ugly and underdeveloped.
At the last stage of the development of the virus, there are practically no leaves on the tree branches, they are bare. Single needle-shaped leaves can be seen only on the tops of the shoots.
Dwarfism affects not only plums, but also other stone fruits. The virus spreads along with infected planting material, parasites (mites, aphids), with a working tool for pruning.
Infected trees cannot be cured and must be uprooted.
As a preventive measure, resistant varieties of plums are planted in the garden, and plants are regularly treated against pests.
A fungal disease caused by the golomarshy fungus. Infection occurs in the conditions of a cold long spring, when the humidity of the air is increased. The spores of the fungus penetrate the flowers of the tree, so ugly ovaries are formed.
The fruits of the affected plant are not suitable for food, they grow deformed. The development of the fungus occurs inside the fetus, in a kind of pocket, so there is no stone in the plums. The flesh becomes grainy and wrinkled. Since the fungus affects only the fruits, the disease appears once per season.
- Destroy affected shoots in the first half of summer.
- Collection and disposal of infected fruits is carried out until the spores of the fungus disperse.
- Preventive spraying of plums with 3% solution of Bordeaux mixture. The first time the treatment is carried out before bud break, then before flowering and after.
Mycelium overwinters in tree branches, so the fight against the disease must begin in the fall. To do this, carry out sanitary cleaning and pruning of shoots, preventive spraying with copper oxychloride, copper sulphate.Plum pockets
Clusterosporia or perforated spot
Fungal disease develops during a long warm but rainy summer, when the air humidity exceeds 70%. The fungus overwinters under the bark. Mycelium begins to develop already at a temperature of +4 degrees. It can be found on the shoots or buds of a plant in the form of a dark, weak coating.
Young leaves are carried by wind and most pests. The disease spreads very quickly. During the season, many colonies of the fungus are formed, which adversely affects the condition of the tree.Plum hole blotch
Symptoms can be seen on all tissues of the plant, but most often they appear on young leaves.
- Small round spots of various colors that increase in size in a short time.
- Tissue dies in the center of the spot, which leads to the formation of holes in the leaves.
- The edges of the holes have a reddish border. This is the main sign of clasterosporiasis, which distinguishes it from other types of spotting.
- When the disease is advanced, the bark of the tree is covered with orange-red spots with a dark border. Subsequently, they are pressed into the trunk, crack and lead to the flow of gum.
- Affected buds and shoots also leak gum , causing them to die off and reduce yields.
- Fruits are affected by ulcers, become one-sided, dry out, harden and fall off. They can also leak gum.
To prevent the disease, the garden is cleaned in the autumn, tree trunks are dug up, shoots are destroyed, affected fruits and fallen leaves are collected and disposed of. In addition, it is important to treat wounds and cracks in the tree in time, preventing gum bleeding. For processing, a solution of copper sulfate, manganese or garden pitch is used.
In the fight against the fungus, spraying the tree during the growing season will help. Treatments begin in early spring, repeat in late autumn. Use drugs Kuproksad, Skor, Horus, Topaz or Vectra. The last treatment is carried out 20 days before harvest.
The causative agent of the disease is the monilia fungus. Infection of the tree occurs during the flowering period, if there are drops or a decrease in temperature. Cold spring weather only speeds up the process. Spores penetrate the plant tissue through the pistil, gradually affecting the entire tree.
Signs of damage:
- sudden drop of flowers;
- desiccation of peduncles and adjacent leaves;
- old shoots and branches crack, gum flows from formed wounds;
- all wood looks "burnt".
The disease spreads not only to fruits, but also to shoots, plum leaves. The pathogen overwinters in the affected tissues of the tree. Prevention of moniliosis begins in the fall. All affected shoots are cut out and the garden is treated with Hom, Bordeaux liquid or copper oxychloride. To spray one tree, you will need up to 4 liters of solution.Plum moniliosis
Sharka, commonly called plum pox, is a viral disease. It appears on young leaves of a tree in the form of chlorosis, spots or stripes. Over time, the leaves acquire a characteristic marbling, light areas appear on them. If you do not take any measures, then the disease passes to the fruits. They become spotty, the flesh coarsens and loses its taste. In addition, the spots begin to deepen into the fetus. Diseased plums ripen prematurely, fall off or dry out right on the tree.
Unfortunately, it is impossible to fight the disease. All affected trees must be burned. Control measures are only preventive in nature, aimed at timely treatment of the garden from pests that can spread the virus.
In July, young plum leaves show rust spots that gradually increase in size. Affected trees shed their leaves earlier. Leave the plum in this state can not be. The winter hardiness of the plant and the future harvest are sharply reduced.
For prevention, trees are treated with copper oxychloride before and after flowering. In autumn, after harvesting, spraying is carried out with a 1% solution of Bordeaux mixture.Plum leaves affected by rust
A dangerous fungal disease that affects the leaves of the tree, less often the fruits and young shoots. The first signs of the disease are noticeable in early summer.
- The leaves are covered with small, red-brown spots.
- A whitish coating can be found on the reverse side of the sheet. These are fungal spores.
- Leaves rapidly turn yellow and fall off.
- Fruits do not develop, become watery and fall off.
Most often, the disease develops in warm and humid weather, reduces the winter hardiness of the tree. The fungus overwinters in fallen leaves, so in the fall it must be collected and burned. In addition, the trunk circle of the tree is sprayed with copper preparations or Bordeaux liquid.Plum coccomycosis
Recently, the disease has been frequent. The reason for its appearance are pathogenic bacteria in the soil, which penetrate into the tissues of the plant through cracks in the roots. Specific growths form on infected plum roots, which leads to the death of the tree. Severe drought and a weakly alkaline environment contribute to the development of the disease.
As a preventive measure, the garden is located in a place where no outbreaks of the disease have been observed before. Severely affected seedlings are destroyed. The landing site is disinfected with a solution of copper sulfate.Root cancer on a plum tree
Plum tinder fungus
Dangerous fungal growths on the bark of a tree. Penetrating through small cracks in the bark, spores destroy the wood. Hollows form in the affected areas. A few years later, a solid fungal body grows in their place. Sometimes she looks quite harmless.
To prevent infection of the tree, carefully treat wounds and cracks in the plum bark. The fruit bodies of the fungus are destroyed before the spores disperse, usually in early June. The remaining wounds are cleaned of rot, washed with a solution of copper sulfate, and then filled with a mixture of cement and sand (1: 4).Plum tinder fungus
This is a bizarre insect that lives near the fruit buds of plums in galls. One gall can contain up to 400 insects. At the end of May, overwintered individuals come to the surface of the bark and feed on the cell sap of the plant. In places of bites, reddish growths form again on the bark, where the females lay their eggs. More than one generation of pests grows in one season. It is possible to determine the defeat of a plum by a gall mite by characteristic ugly growths.
Insects should be dealt with immediately after plum blossoms. Carry out several treatments with colloidal sulfur preparations. In case of mass damage, it is recommended to cut and burn the shoots.Gall mite
This is a white butterfly with yellowish hairs on its abdomen. Pest caterpillars hibernate in fallen leaves. The golden tail begins to harm after the plum buds open, actively eating them. Butterflies are nocturnal, laying their eggs on the surface of leaves. The caterpillars that have appeared are very voracious, in a short time they cause great damage to young leaves. They eat holes in them, slowing down the normal growth of the plant.
As an insect control, trees are sprayed with a solution of karbofos. In the fall, the fight against the golden tail does not stop. They collect fallen leaves, loosen the soil under the trees, thereby destroying the nests of the pest.
The first spraying is carried out before plum blossoms.
Plum codling moth
This grey-brown moth is harmful to plum fruits. Its reddish caterpillars hibernate under tree bark or in the topsoil. In early spring, butterflies lay their eggs in the still green fruits. When the caterpillars appear, they feed on the pulp of the fruit, after which they leave for the winter. Affected plums turn purple and fall off, often with drops of gum.
Preventive spraying with karbofos is carried out against the plum codling moth, trapping belts are put on the trees, and the soil is regularly loosened.
At the beginning of autumn, additional tillage and loosening are carried out to destroy the nests of the pest. In addition, all wounds and cracks are washed with manganese, covered with a garden thief.Plum beetle
Small, pale green insect that sucks cell sap. Aphids can be seen with the naked eye:
- tops of shoots curl;
- tree stunted;
- pour dry and fall off;
- small insects visible on the reverse side of the sheet.
At the beginning of the growing season, plums are treated with preparations against leaf-eating and sucking insects. Spraying is repeated after 10-14 days. The first treatment is carried out "along the green cone".Aphids on plum leaves
Diurnal white butterfly. Its caterpillars feed on buds, leaves, buds and plum blossoms. The methods of struggle are the same as with the golden tail, plum codling moth.
Why worms appear in plum fruits
Gardeners often complain that almost the entire crop of plums is wormy. Why does this happen, which leads to spoilage of the fruit?
The reason for this is the presence of pests on trees. Sometimes there may be more than one insect.
Plum sawfly and worm fruits
The larvae of this insect destroy plums while still green. They eat away not only the bone, but also the pulp of the fruit. As a result, the cream falls unripe, but already wormy. To get rid of parasites, you will have to try and remove the painful fruits.Fruit affected by plum sawfly
Plum weevil on leaves
Females of this insect eat plum buds and flowers by biting into ovaries. There they lay larvae that eat the fruits from the inside. The harvest is ruined. For wintering, larvae and beetles go into the soil. Trees should be treated in the spring.Plum weevil
How to get rid of fruit worms in plum trees
Trees in the garden should be treated as early as possible, before the pests set to work and the fruits begin to rot. The first treatment should be carried out in early spring. You need to re-spray the plum before flowering and after it. If the number of pests is very large, then the treatments are repeated at intervals of 10 days. But the latter must be carried out no later than 25 days before harvest.
To prepare the working solution, Phosfamide, Dursban, Metaphos, Bordeaux liquid or iron sulfate are used. With a small number of insects, spraying is done with infusions of tobacco, wormwood, dandelion or ash. Infusions are prepared in different ways.
A universal recipe for herbal infusion is prepared at the rate of 200 g of dry plant parts per 1 liter of boiling water. Boil the mixture for 15 minutes, then strain and cool. Dilute with water up to 10 liters.
How to deal with plum pests: preventive treatment
Every gardener knows that preventing a disease is easier than curing a garden. Therefore, prevention should always be.
- Every tree needs proper care , regular watering and fertilizing.
- Regularly sanitize the garden, cut out thickened branches, remove fallen leaves and dig up the soil.
- In spring and autumn, spraying is carried out not only on the tree, but also on the soil under it.
It is very important that all activities are ongoing. If a neighbor's garden is affected by worms, scab, coccomycosis or curliness, then this means that it's time to get to work and process your own trees. You should not hope for "maybe it will blow over.