Fruit rot (moniliosis)

Moniliosis, or fruit rot, is a fungal disease caused by pathogenic fungi of the Monilinia genus (family Sclerotiniaceae). This disease is especially dangerous for fruits, leading to its spread in horticulture, where it can cause significant damage to fruit and berry crops, including apples, peaches, apricots, cherries, plums, and strawberries. Moniliosis causes fruit rot and also affects flowers and shoots of plants, which can lead to reduced yield and deteriorated product quality. The infection often occurs under conditions of high humidity and warmth, especially during rain periods or sharp temperature fluctuations.

It is important for houseplant owners to be aware of the signs of moniliosis and methods of prevention to avoid damage to decorative plants and fruits. Knowing the symptoms and ways to fight this disease helps effectively maintain plant health.

Article goals:

The goal of this article is to provide comprehensive information about moniliosis: from the signs and causes of the disease to methods of fighting it. The reader will learn how to prevent plant infection, what steps to take when signs of moniliosis are found, and how to care for plants during the disease.

Signs and symptoms of the disease

The symptoms of moniliosis can manifest in different parts of the plant — from flowers and ovaries to mature fruits and shoots. These symptoms depend on the stage of the disease, the type of plant, and environmental conditions. The most characteristic symptoms include:

1. Flower and Ovaries Infection:
   • One of the first signs of moniliosis is the infection of flowers and ovaries. Brown spots appear on the flowers, which gradually turn black and decay. The flowers lose their vitality and start to fall off.
   • The ovaries turn brown, leading to premature death. This can lead to reduced yields, especially in stone fruits.
2. Fruit Infection:
   • On infected fruits, watery spots appear that gradually increase in size and darken. The fruits become soft and lose their firmness.
   • The appearance of decay may range from gray, brown, to black spots that gradually cover the entire fruit. The rot spreads quickly, and the fruit starts to decompose, emitting an unpleasant odor.
   • Infected fruits become inedible and lose their marketable appearance. This is especially dangerous for crops used for processing, such as apples or peaches.
3. Shoot and Branch Infection:
   • In some cases, moniliosis can affect the shoots and branches of plants. Ulcers and brown spots appear on the affected areas, gradually leading to wilting and death of the shoots.
   • The fungus can penetrate the wood, causing rot, which in turn can lead to the death of entire branches.
4. Sap and Resin Infection:
   • In some cases, infected fruits begin to secrete resin, which is a clear sign of the fungus's activity. Resinous exudates are a result of the plant’s reaction to the infection.

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Etiology of moniliosis

The causative agents of moniliosis are fungi from the Monilinia genus, with the most well-known being:

• Monilinia fructicola — the main pathogen causing moniliosis on stone fruits (cherries, plums, apricots).
• Monilinia laxa — a pathogen causing disease on apples, pears, and some other stone fruits.
• Monilinia fructigena — a species that affects apples, pears, as well as some berries and other fruits.

The fungi of the Monilinia genus are widely distributed in nature and can survive in soil, on plant residues, and infected fruits as slime or oospores. They can develop and spread quickly under conditions of high humidity and temperatures, making them especially active during the summer and fall periods.

Moniliosis is not only a dangerous disease for fruits but also for other parts of the plant, including flowers, shoots, and branches. As a result of infection, rapid tissue decomposition occurs, reducing yield and affecting product quality. Plants growing in conditions of high humidity and poor ventilation are particularly susceptible to the disease.

Life cycle of moniliosis

The life cycle of Monilinia fungi includes several key stages, each of which actively develops its pathogenic activity:

1. Spore Germination: The infection begins when conidia (vegetative spores) land on the plant surface. Spores can be carried by wind, rain, insects, or via human tools and equipment.
2. Penetration into Plant Tissue: After germination, the spores begin to penetrate the plant tissue through stomata, cracks in the fruit surface, or damaged areas. The fungus uses enzymes to break down cell walls and penetrate the plant’s tissues.
3. Mycelium Development: The fungus forms mycelium, which spreads inside the plant, destroying cellular structures. This leads to wilting and rotting of infected tissues.
4. New Spore Formation: In the later stages of the fungus's development, new spores are formed that can re-infect plants. Conidia (new spores) are spread by raindrops, wind, and other mechanical means.
5. Survival Under Unfavorable Conditions: The fungus can survive in the form of overwintering structures (scions, sclerotia), which can survive the winter period, leading to re-infection in the following season.

Conditions for moniliosis development

Moniliosis develops under the combination of several factors, including:

1. High Humidity: Infection develops under high humidity because fungal spores germinate on the plant surface in the presence of water. Rain, fog, and night dew are especially dangerous.
2. Temperature: The optimal temperature for Monilinia development is between 18°C and 24°C, though the fungus can also develop at higher temperatures.
3. Poor Ventilation: Too dense planting, lack of good air circulation, and high humidity create favorable conditions for moniliosis. This is particularly typical for gardens with dense shrub or tree planting.
4. Plant Damage: Moniliosis often develops in areas where plants are mechanically damaged, affected by pests, or already diseased. In such conditions, the fungus can penetrate plant tissues faster.
5. Plant Vulnerability: Plants in stressful conditions (such as insufficient water or nutrients) are more susceptible to infections like moniliosis.

Improper Care:

• Excessive or Insufficient Watering: Excessive watering contributes to the development of the fungus, creating a wet environment ideal for moniliosis. Insufficient watering weakens the plant, reducing its immunity.

Environmental Conditions:

• High Humidity or Dryness: High humidity promotes the development of moniliosis, while dry conditions weaken plants, making them vulnerable.
• Temperature Fluctuations: Sharp temperature changes, especially at night, can worsen the plant's condition, creating stress.

Poor Sanitation:

• Contaminated Tools and Pots: Using non-sterile tools can lead to the spread of the fungus from one plant to another.
• Frequent Movement of Plants: Moving plants frequently from one location to another increases the risk of spreading fungal diseases.

Plant Import:

• Introduction of New Plants, Which May Carry Pests or Pathogens: New plants, especially those purchased from stores, may introduce pathogens, including moniliosis.

Stressful Conditions for Plants:

• Overwatering, Drying, Intense Lighting, or Lack of Nutrients: All these conditions create stress for the plant, weakening its immune system and increasing susceptibility to diseases.

Diagnosis of moniliosis in plants

Moniliosis is a fungal disease caused by pathogenic fungi of the Monilia genus (family Moniliaceae), which affects both fruit and ornamental plants. To accurately diagnose moniliosis and prescribe effective treatment, several stages of diagnosis are required.

1. Visual Inspection:
   The primary method of diagnosing moniliosis is inspecting plants. Symptoms can vary depending on the type of plant and stage of the disease.
   • On Fruits: One of the most prominent signs of moniliosis is the appearance of brown, gray, or white spots on fruits, which can spread quickly and lead to rotting. The fruits become soft, watery, and develop a white coating (fungal spores).
   • On Flowers and Shoots: Moniliosis can cause blackening of flowers, premature wilting, and dropping. Dark or brown spots may appear on shoots, also indicating infection.
   • On Leaves: Sometimes, leaves show spots with brown or gray edges, which can become ulcers and lead to leaf drop.
2. Microscopic Diagnosis:
   Microscopy is an additional diagnostic method. Under the microscope, characteristic structures of the Monilia fungus can be observed:
   • Mycelium: In affected tissues, the fungus’s mycelium can be observed, spreading into plant cells and destroying them.
   • Spores: Monilia produces conidia, which can be found on infected plant areas. These spores have a characteristic shape and size, distinguishing them from other fungi.
3. Laboratory Diagnosis:
   To confirm the diagnosis more accurately, laboratory methods can be used:
   • Cultivation of the Fungus: The fungus can be isolated from infected tissues (fruits, flowers, shoots) and cultured on nutrient media, allowing accurate identification of the pathogen.
   • Polymerase Chain Reaction (PCR): This method allows accurate identification of Monilia DNA in infected plant tissues. PCR is effective for detecting the disease in its early stages.
4. Differential Diagnosis:
   It is important to differentiate moniliosis from other diseases that may exhibit similar symptoms:
   • Root Rot: Moniliosis differs from root rot in that the affected plant parts show a characteristic white or gray coating, as well as fungal spots that spread rapidly.
   • Bacterial Infections: In bacterial infections, leaves and fruits may develop wet spots, but these will have a looser structure and spread rapidly. Moniliosis, on the other hand, shows a characteristic coating.

Thus, the diagnosis of moniliosis involves visual inspection, microscopic studies, and laboratory methods. The earlier the diagnosis is made, the easier it will be to prevent the spread of the disease and treat the plant.

Treatment of moniliosis in plants

Moniliasis treatment requires a comprehensive approach, which includes the use of chemical agents, improving growing conditions, and removing infected parts of the plant. Moniliasis is a serious disease that can spread quickly and lead to the death of the plant if timely measures are not taken. Here are some effective methods for combating moniliasis:

1. Use of Fungicides

Fungicides are the main method of combating moniliasis. These preparations help control the development of the fungus and prevent its spread to healthy parts of the plant.

• Contact fungicides: Preparations such as copper sulfate, Bordeaux mixture, sulfur-based products are effective in the early stages of the disease when the fungus has not yet penetrated deeply into the plant tissues.
• Systemic fungicides: These penetrate the plant tissues and protect it from within. For example, preparations based on triazoles (such as Topsin-M) or strobilurins (such as Fundazol) are effective in fighting moniliasis. They act for a long time and prevent the spread of infection through vascular tissues.

Application of fungicides:

• Treatment should begin as soon as possible, at the first signs of the disease.
• The treatment should be repeated every 7-14 days, depending on the degree of infection and the chosen product.
• It is important to follow the dosage and instructions on the packaging to avoid overdose and plant damage.

2. Removal of Infected Parts of the Plant

If moniliasis has spread to the fruits, leaves, or shoots, all infected parts of the plant must be removed. This will help stop the further spread of the fungus.

Steps for removal:

• Inspect the plant and carefully prune sick and wilted parts, including leaves, fruits, and stems.
• Use sterile tools (e.g., pruning shears or scissors) to minimize mechanical damage to healthy parts of the plant.
• Properly dispose of infected plant parts: burn them or dispose of them in sealed bags to prevent the spread of fungal spores in the soil and to other plants.

3. Correction of Growing Conditions

Moniliasis develops in conditions of high humidity and poor ventilation. Improving growing conditions will help prevent the spread of the disease and support the plant’s health.

• Ventilation: Ensure good air circulation around the plants, especially in greenhouses, to prevent moisture stagnation.
• Watering: Water the plants at the root, avoiding water on the leaves and stems. Drip irrigation helps maintain optimal soil moisture without creating conditions for fungi.
• Cleaning of plant debris: Remove affected plant parts and plant residues, as they can serve as a source of infection for future plants.

4. Use of Biological Preparations

Biological fungicides can be used to fight moniliasis, providing a safe alternative to chemical agents and helping to reduce the spread of the disease.

Examples of biological preparations:

• Trichoderma – a fungus that suppresses the growth of moniliasis and other pathogens. Used for prevention and treatment.
• Bacteria Bacillus subtilis and Bacillus amyloliquefaciens – these microorganisms have antiseptic properties and help protect plants from moniliasis and other fungal infections.

5. Fertilizing Plants

After moniliasis infection, plants become weakened, so it is necessary to provide them with additional nutrition to accelerate recovery.

• Nitrogen fertilizers will help speed up growth recovery, but avoid overdosing to prevent excessive green mass growth, which can weaken the plant.
• Phosphorus-potassium fertilizers strengthen the root system and increase plant resistance to diseases.

6. Using Resistant Varieties

Using moniliasis-resistant plant varieties will minimize the damage caused by the infection in the future. Varieties resistant to this disease significantly reduce the likelihood of infection.

7. Tool Processing

It is necessary to regularly clean and disinfect garden tools and equipment, such as pruning shears, scissors, shovels, and others, to prevent the spread of infection from one plant to another.

Moniliasis treatment requires a comprehensive approach, including both chemical and biological methods, improving growing conditions, and removing infected parts of the plant. It is important to identify the disease in time and take measures to prevent and treat it to minimize damage and preserve plant health.

Prevention of moniliosis in plants

Preventing moniliosis is crucial to avoid plant infection and minimize the risk of disease spread. The main goal of preventive measures is to create conditions that hinder the development and spread of the fungus. Here are several effective preventive methods:

Choosing Resistant Varieties

One of the most effective methods of preventing moniliosis is using plant varieties resistant to this disease. Modern varieties often have increased resistance to fungal diseases, including moniliosis. When purchasing planting material, it is important to pay attention to varieties that have higher resistance to moniliosis, which significantly reduces the likelihood of infection.

Crop Rotation

Crop rotation is an important practice for preventing the accumulation of pathogens in the soil. Moniliosis can persist in plant residues and soil for a long time, and if susceptible plants are grown in the same area year after year, the risk of infection increases. Regular crop rotation helps reduce the concentration of the fungus in the soil and minimizes the risk of re-infection.

Managing Plant Residues

It is important to remove all plant residues, especially those affected by moniliosis, to prevent the overwintering and spread of the pathogen. Leaves, stems, and fruits left on the site can serve as a source of infection, providing the pathogen with a survival environment. All plant residues should be collected and destroyed, for example, by burning or sealing them in bags for disposal.

Optimizing Growing Conditions

Moniliosis develops in conditions of high humidity and poor ventilation, so creating optimal conditions for plants plays a key role in disease prevention.

• Ventilation: Ensure good air circulation around the plants to prevent moisture buildup. This is especially important for greenhouses and enclosed spaces.
• Watering: Water plants at the root, avoiding water on leaves and stems to prevent creating favorable conditions for the fungus. Using drip irrigation helps maintain the required soil moisture level.
• Mulching: Mulching helps maintain stable soil moisture, preventing overheating or rapid drying, which promotes healthy root development and reduces the risk of fungal infections.

Regular Plant Inspection

Constant monitoring of plant health helps identify early signs of moniliosis. This is important for timely intervention to prevent the disease from spreading. When the first symptoms of infection (such as brown spots on leaves or wilting) appear, immediately remove the affected parts of the plant.

Using Fungicides for Prevention

Preventive fungicide treatments help prevent moniliosis before the disease manifests. Applying fungicides at early stages of growth, especially under conditions of high humidity and rain, significantly reduces the risk of disease.

1. Contact Fungicides: Copper-based products (such as copper sulfate or Bordeaux mixture) effectively protect plants from fungal diseases and are used for moniliosis prevention.
2. Systemic Fungicides: Products like Ridomil Gold or Topsin-M penetrate plant tissues and provide long-term protection against moniliosis.
3. Trichoderma — a fungus that suppresses moniliosis growth and other pathogens.
4. Bacillus subtilis and Bacillus amyloliquefaciens bacteria — help protect plants from moniliosis and other fungal infections.

Using Biological Protection Means

To improve plant resistance and minimize the use of chemicals, biological fungicides can be used. These products are environmentally safe and suitable for organic farming.

Examples of Biological Products:

1. Tool and Equipment Cleaning
   To prevent the spread of pathogens between plants, it is important to regularly clean and disinfect garden tools and equipment, such as pruning shears, scissors, shovels, etc. This helps prevent mechanical spread of infection and minimizes the likelihood of contamination.
2. Soil Sterilization
   Before planting new plants, it is important to sterilize the soil, especially if it was previously used for plants infected with moniliosis. This helps prevent the spread of pathogens in the soil and reduces the risk of disease.

Prevention of moniliosis in plants involves a comprehensive approach that includes proper plant care, the use of resistant varieties, crop rotation, creating optimal growing conditions, and using chemical and biological products. Regular inspections and preventive treatments will help protect plants from moniliosis and other diseases.

Care for infected plants

Isolation of Infected Plants:

• Separate infected plants from healthy ones to prevent the spread of the fungus. This helps minimize the risk of infecting other plants in your home or garden.

Pruning and Removal of Affected Parts:

• Remove all affected leaves, stems, and fruits. This will help the plant focus its resources on healthy parts and increase the chances of recovery.

Specific recommendations for different types of plants

Flowering Plants (Orchids, Geraniums, Philodendrons):
The care for these plants includes maintaining optimal humidity and temperature levels, preventing water stagnation, and regularly checking for fungal diseases.

Green Foliage Plants (Pachira, Sansevieria, Zamioculcas):
These plants are more resistant to moniliosis but still require careful care, especially under high humidity conditions.

Succulents and Cacti:
Succulents are less susceptible to moniliosis but may get sick if they are exposed to excessive watering or high moisture levels.

Professional help and consultation

When to Seek Specialists:
If the symptoms of the disease progress and home remedies do not help, it is important to seek professional help. This is especially crucial if the plant is valuable or has special significance.

Conclusion

Moniliosis is a serious fungal disease that can cause significant damage to plants if timely measures are not taken. It is important to monitor plant health, promptly detect disease symptoms, and effectively fight the pathogens using both chemical and natural remedies.

Frequently Asked Questions (FAQ) about moniliosis

1. What is moniliasis in plants?

Moniliasis is a fungal disease caused by pathogens of the Monilinia genus, the most common of which is Monilinia fructicola. This disease affects various fruit trees, such as apples, pears, peaches, cherries, and plums, causing wilting and rotting of flowers, fruits, and green tissues of the plant.

2. Which plants are most susceptible to moniliasis?

Moniliasis most commonly affects fruit trees, including:

• Apple trees
• Pear trees
• Peach trees
• Cherry trees
• Plum trees
• Apricot trees

However, the disease can also affect other plants, especially those with fleshy fruits and flowers.

3. What are the main symptoms of moniliasis in plants?

Symptoms of moniliasis include:

• Wilting and rotting of flowers: Flowers become soft, change color to brown, and rot.
• Fruit mold: Fruits begin to soften, developing dark or brown spots, which then spread.
• Decay of green tissues: Young shoots and leaves may also be affected, showing dark spots and softening.
• Formation of gray mold: Gray spore-producing mold may appear on affected areas, especially in high humidity conditions.

4. How does moniliasis spread in plants?

Moniliasis mainly spreads through fungal spores, which can be carried by wind, rain, insects, or human activity. Infection can occur during flowering or fruit ripening. The fungus can survive on fallen fruits and leaves, serving as a source of infection for new generations of plants.

5. What factors contribute to the development of moniliasis?

The development of moniliasis depends on several factors:

• Humidity and precipitation: High humidity and prolonged rainfall create favorable conditions for fungal growth.
• Temperature: The optimal temperature for Monilinia growth is between 15°C and 25°C.
• Damaged tissues: Plant damage, such as mechanical injuries or wounds, increases the risk of infection.
• Susceptibility to overwatering: Excessive watering and poor drainage contribute to disease development.

6. How to diagnose moniliasis in plants?

The diagnosis of moniliasis is based on visual inspection of symptoms:

• Presence of wilted and rotting flowers.
• Appearance of dark spots and softening of fruits.
• Presence of gray mold on affected areas.

To confirm the diagnosis, laboratory tests such as microscopic examination of tissue samples or culture-based methods can be used to identify the fungus.

7. What are the prevention methods for moniliasis in plants?

Main preventive measures include:

• Crop rotation and removal of fallen fruits: Removing infected fruits and organic material reduces the source of infection.
• Proper plant care: Regular pruning to improve air circulation and reduce humidity.
• Timely fertilization: Healthy plants are less susceptible to diseases.
• Using resistant varieties: Choosing varieties resistant to moniliasis can significantly reduce the risk of infection.

8. How to treat moniliasis in plants?

Treatment of moniliasis includes a comprehensive approach:

• Fungicides: The use of chemical or biological fungicides during flowering and before harvest.
• Removal of infected parts: Removal and destruction of infected flowers, fruits, and branches.
• Improving agronomic conditions: Ensuring good drainage, reducing overwatering, and improving ventilation.
• Natural remedies: Using solutions based on copper or biological agents such as Bacillus subtilis bacteria.

9. Can organic methods be used to combat moniliasis?

Yes, organic methods of control include:

• Biological fungicides: Products based on microorganisms that inhibit the growth of Monilinia.
• Soap solutions and plant infusions: Some natural substances have fungicidal properties.
• Using oak bark and other natural materials: Help reduce humidity and inhibit fungal growth.

Organic methods require regular application and may be less effective in severe infections, so they are often used in combination with other methods.

10. How does moniliasis affect yield and fruit quality?

Moniliasis significantly reduces yield because it affects and causes the falling of flowers, preventing fruit formation, and also causes the rotting of already formed fruits. Additionally, the quality of the fruits deteriorates due to dark spots, softness, and decay, making them unsuitable for consumption and commercial sale. In severe cases, the disease can lead to the death of trees.