Fusarium

Fusarium is a dangerous fungal disease that threatens garden and vegetable crops, flowers and wild plants. The infectious agent of the disease is a microscopic fungus of the genus Fusarium. In conditions of high humidity, its spores fall into open cuts and wounds of the rhizome, suck out the juice of leaves, fruits, ears and buds. Due to the high rate of development of the population, the fungus is able to infect a large area in a short time. Fusarium cases can be observed in all climatic regions.

Features of fusarium

Fusarium mushrooms, which have a similar structure and life cycle, belong to the class of imperfect mushrooms, the genus mold. The peculiarity of the pathogen is that asexual reproduction is characteristic of fungi.

Spores are synthesized in roots, stems, leaves, grain and produce toxins that accumulate in plant cells. As a result, such a product is no longer edible and can cause serious poisoning when a person is diagnosed with acute nutritional mycotoxicosis.

Spores are very resistant to external factors and can persist in the ground for a long time. They are not afraid of temperature changes and aggressive environmental factors. Even after several years in a field or ridge where signs of the disease were found, the mycelium can revive again and infect new crops.

If treatment is not started on time, fusarium wilting will occur - a condition in which the vascular system of plants is gradually destroyed. The fungus, absorbing the cytoplasmic fluid, has a negative effect on tissues. As a result, fruits, roots and seeds begin to dry out and rot. A diseased plant, tired of fighting a parasitic fungus, withers. The mycelium clogs blood vessels, releasing toxic substances such as vomitoxin, zearalenone, and other mitotoxins.

The affected bushes bloom worse, the growth and regeneration of tissues is suspended, mineral metabolism and the process of photosynthesis are disrupted, spots with irregular pigmentation of a greenish or yellow color appear. The pathogen first attacks the root system. It no longer develops, and the roots darken and change. Fusarium spores penetrate from the soil into the smallest root processes, and then into the larger roots. After that, they rise through the discharge vessels along the stems to the leaf plates.

Withering begins with the leaves of the lower layer. The plates look watery at the edges. The foliage turns yellow, and in advanced cases flies around. With fluctuations in humidity, toxic mycelium leaves a brown coating on the affected leaf plates. Darkened vessels are visible on the cut stem of a diseased bush. As a result of the loss of turgor pressure, the petioles also weaken.From this moment on, the fading of the ground part is already inevitable.

Fungal diseases, including fusarium, develop more actively with sudden changes in temperature and humidity conditions, especially when the plant is experiencing a lack of nutrients.

Factors contributing to the activation of pathogenic fungi:

• bad weather conditions: dampness, cloudy days, cold weather;
• lack of sufficient distance between plants: when plantings thicken in crowded conditions, diseases begin to develop;
• the risk of getting sick increases in bushes that are weakened due to improper care of bushes and crops that are unsuitable for varietal and winter-hardy qualities;
• dense, deoxidized soil, in which liquid regularly stagnates, which disrupts air exchange in the root zone;
• landing in lowlands;
• oversaturation of the site with a large number of chemicals, chlorine and nitrogen minerals;
• when the planting field is located near an industrial area, highway or metallurgical facility;
• scanty and rare watering of the root system in the heat;
• increased air humidity, lack of light.

Fusarium disease of garden and grain crops

Fusarium wheat

All grain crops: wheat, barley, rye are susceptible to fusarium infection. Fusarium fungi can infect the root system and ears. This disease manifests itself as a pale pink coating on the ear. Sources of infection are plant debris, soil and seeds. Spores are spread by the wind over long distances, so the entire field is threatened. The optimal conditions for the development of a fungus on an ear are cloudy rainy weather, air temperature from 27 to 30 degrees, high air humidity, then there is a massive defeat of grain plantings.

Fusarium infection leads to a loss of weevil weight, which can reduce yields by 30% and, thereby, reduce the income of agricultural producers. Disease also leads to the accumulation of mycotoxins in the grain, which puts the entire batch at risk of being rejected. It is dangerous to eat such grains. Plant residues on the field also contribute to the development of the disease, it is in them that spores like to persist. If during the examination of the grain, infected plants have already been found, it will be too late to carry out the fungicidal treatment.

Fusarium root rot is caused by pathogens that have been in the soil for a long time. They are spread quite quickly by water and wind, or through infected seeds. Symptoms of the disease appear during the formation of sprouts and during their growth.

The pathogenic mycelium through the roots of winter wheat enters all organs and tissues: stems, ear, flag-leaf, tissues of the spikelet and grain, where it actively develops and gradually weakens the culture.

Signs that the plant has started root rot:

• problems with seed germination;
• slow growth and discoloration of bushes;
• blackened diseased rhizome.

Fusarium spike protection strategy:

1. Optimization of cultivated areas.
2. Reducing the number of infections by deep embedding of its sources in the soil or burning plant residues.
3. Carrying out measures to improve the soil, namely: the destruction of post-harvest residues, the improvement of biocenosis, the introduction of biological products.
4. Reducing the rate of reproduction of pathogens by cultivating less susceptible wheat varieties.
5. Shortening of the harvesting period.

Fusarium tomato

Fusarium wilting threatens primarily monoculture tomato varieties planted in greenhouses. In diseased bushes, a change in the structure of tissues is observed. The infection enters the lateral roots through the ground. Particularly vulnerable areas are growth points. The danger of the disease lies in its transience, mycelium spores spread along the petioles and shoots, impregnating the fruits with toxins. The seeds of diseased tomatoes are thrown away, they cannot be used for sowing.The incubation period can vary from 1 to 4 weeks.

Fusarium is often confused with other diseases (late blight) or lack of mineral supplements, however, foliar chlorosis is much more pronounced with Fusarium.

The pathogen is able to live in soil for 10-15 years; it does not require special favorable conditions for spreading. It attacks plants mainly through the root, so the ambient temperature does not seriously affect it. Young growing tomatoes are most affected. The first sign of fusarium wilting is yellowing of the lower leaves. They lose their turgor, the veins become light. In this case, the upper leaves remain green, but curl.

On tomato seedlings, Fusarium develops so quickly that the leaves do not have time to turn yellow. Root and vascular necrosis begins. The plant dries up and withers. Brown vessels can be seen on the cut of the stem. Darkening of blood vessels is noticeable even through integumentary tissues. In diseased tomatoes, the leaves, along with the veins, completely discolor over time, the juice ceases to flow through them. White bloom appears on the roots. The top of the seedling tilts, the whole plant looks sluggish. The stem inside becomes empty, if you do not take action, the tomato bush will die.

Fusarium on eggplant

The risk of Fusarium contamination of eggplants increases during their flowering period. The disease often leads to the fact that the leaves on the plants are covered with yellow spots, and then dry out. Eggplants shed flowers and ovaries. The disease rises from the lower tier to the upper tier of leaves, and later the spores spread to the entire bush. In addition to yellowing, dots and specks can be observed on the leaves, the plates can fall off - in this case, the bushes remain without leaves, their growth, flowering and fruit set stops. The root system is covered with a pink bloom.

Pathogenic ascospores penetrate from the infected soil, where pathogens hide, into the stem or through mechanical damage to the fruit. They cause blockage of blood vessels and release toxins, which is why eggplant develops toxicosis, which manifests itself in the form of necrosis on the leaves. Fusarium is activated at 22-26 degrees against a background of high humidity.

Eggplants are attacked through seeds and root hairs. Sick bushes begin to lag behind in growth, poor fruiting or none at all. In seedlings affected by fusarium wilt, root and root rot develops. The course of the disease accelerates in hot weather and under conditions of increased acidity of the soil.

Fusarium on cucumbers

Cucumbers, like all vegetable crops, are susceptible to various diseases. In order not to lose the harvest and the plants themselves, you need to identify the disease of fusarium in time and start treating it.

Fusarium wilting of a cucumber can be detected at an early stage, when the cucumber is not yet showing signs of disease. In this case, the treatment has a very good effect. Both indoors and outdoors, cucumbers are not immune from disease. However, in greenhouses and hotbeds, the disease progresses faster.

Symptoms of the disease include: wilting of the tops of the stems, lower leaf plates, the appearance of traces of rot on the underground part. In this case, the disease rarely manifests itself earlier than the flowering phase and the formation of ovaries, and in conditions of high humidity, a pinkish fungal bloom settles on the plants. The root collar and roots of diseased bushes acquire a dark brown color, the shell of the shoots is covered with cracks. As in patients with tomato fusarium, the vessels darken.

If the pathogen has already hit the cuts on the root system, it will be difficult to stop its spread. The source of infection is open ground, in which the ascospores of this dangerous disease persist for a long time. The disease begins to develop most actively on those days when the temperature outside does not rise above 10-15 degrees.The plant dies before our eyes in just 3-7 days, if no control measures are taken.

Factors contributing to the development of pathogenic fungi on cucumbers:

• fluctuations in daily temperatures;
• cooling below 13 degrees;
• dense wet soil;
• the site is in the shade;
• poor air permeability of the soil.

The disease is focal in nature, penetrates the soil and small wounds. Weakened plants are most susceptible.

For prevention, it is important to ventilate the greenhouse, water the cucumbers only with warm water, and spray with antifungal drugs.

Fusarium on potatoes

Fusarium disease is extremely harmful: heavily infested potato tubers usually rot, while weakly infested tubers give a low yield. The causative agent is widespread in all areas of potato growing. Tubers can rot both in the field and during storage. The disease manifests itself in stem and tuberous forms. The most characteristic signs of the disease on the bushes appear towards the end of flowering, at first the leaf slices gradually turn yellow and wither, then the stems.

In hot weather, due to active evaporation, fusarium wilting is accelerated. A diseased plant is indicated by discoloration of leaf plates, an anthocyanin color at the edge, in advanced cases - wilting of foliage. The surface of the stems near the ground darkens, and an increase in air humidity contributes to the development of rot and plaque of a pink or orange hue. The cut stem also has a brown color inside.

Infection with dry rot during storage of potatoes occurs mainly through mechanical damage that occurs during autumn or winter processing and sorting of tubers. As a result, the potatoes deteriorate, and depressed brown-gray spots form on the skin. The pulp in this area dries up and becomes loose, and the voids that appear after a while are filled with mycelium. The peel is covered with a pale pink or whitish spore bloom. The affected potato hardens and becomes light. When stored in one place, healthy tubers become infected very quickly.

Fusarium on garlic

By fusarium of garlic, gardeners mean rot of the bottom. The disease poses a serious danger to planting onions and garlic in the area. Bulbous plants that are grown in areas with mild and warm climates are especially vulnerable. After the release of spores, the feathers of healthy garlic wither quickly. A garlic head pulled out of the ground looks soft and decomposes quickly, exuding an unpleasant rotten smell.

The defeat of garlic and onions by fusarium wilting threatens the gardener with the loss of up to 70% of the total harvest. There are about 8 groups of Fusarium pathogens for onion crops, which complicates the treatment process and the search for antidotes. It can take up to two years to fight a pathogen that infects the soil. To avoid this disease on the site, you need proper agricultural technology and healthy seeds.

Rot develops early in the growing season, before harvest and during storage. The source of infection can be water for irrigation, soil, already infected seeds or rotted plant parts left in the garden after last year's harvest. Before planting garlic in the ground, it is important to inspect the cloves from all sides for damage and sort out the defective seed. Rot on the scales of chives and roots progresses in storage with high air humidity and a temperature of 13-30 degrees. Also, the disease actively develops in wet weather at temperatures from 22 to 23 degrees.

The main signs of fusarium on garlic:

• stunting;
• yellowing of the lower leaves;
• weak or decayed root system;
• pink bloom in the axils of the leaves and between the scales of garlic;
• the appearance of brown stripes on the feathers;
• softening of the bottom, traces of mycelium on the surface in the form of a white bloom;
• mummification of the heads.

Crops such as peppers, sunflowers, soybeans, cabbage, corn, peas are also susceptible to disease. In practice, infected spores can infect plants both indoors and outdoors.

Fusarium on fruit and berry crops

Fusarium strawberry

Fusarium wilting of strawberries is one of the most dangerous diseases of berry crops. A plant with root rot withers within six weeks and dries up. Dying off of roots and root collar is observed. It is easy to find traces of necrosis on the leaf blades. At an advanced stage, the leaves of the strawberry turn brown, like the petioles. The rosette disintegrates, and the bushes, due to the loss of turgor in the tissues of the stems and leaves, tilt to the ground.

Often, the disease is activated during the period when ovaries appear or when berries are ripening. It is practically impossible to cure the plant. It is better to remove bushes from the garden and be sure to burn them outside the garden. The causative agent of the disease, living in the soil, affects not only strawberries, but also garden strawberries. The degree of damage depends on the age of the bushes, the climatic conditions of the region where the crop is grown, and adherence to agricultural practices. To stop the spread of the pathogen, the following drugs are used: trichodermin, trichoplant, glyocladin. The soil and roots of seedlings are treated with a solution of these drugs. The variety Zenga belongs to strawberry varieties that are resistant to fusarium wilt. To protect the planting from infection, process the seedlings before planting.

Fusarium melon

Fusarium of melons and gourds is widespread in the countries of Central Asia, where favorable conditions for the development of the pathogen are recognized. Depending on the variety and growing conditions, this fungal disease can destroy up to 70% of melon plantations.

The development of the disease begins with roots and shoots. They turn brown. On the root layers, hairs disappear, and the base of the root becomes covered with reddish spots or stripes. Affected bushes quickly die. If the pathogen touched the bushes during the period of fruit laying, then the melon will not fully ripen, it will lose its taste and will no longer be edible. The fruits will become watery and tasteless and will fit only for livestock feed. On days when the temperature outside fluctuates between 23-25 ​​degrees, and the humidity is about 80%, the fungus on the melon develops faster.

Fusarium on flowers

Asters

Almost all annual asters have insufficient resistance to fusarium diseases. Flowers are attacked by a fungus at the bud formation stage or at the beginning of the calyx opening. In sick asters, foliage curls, buds droop, brown oblong specks or black veins appear on the stems. Brown stripes are formed on the surface of the root collar. Shoots are deformed due to tissue destruction. The basal areas are overgrown with a whitish bloom from the mycelium or pinkish tubercles. Such a plant may not live to bloom, and if the aster begins to bloom, then it is extremely not decorative. The culture lags behind in growth, the buds fade quickly. The causative agent of gray rot penetrates through the roots and moves higher along the vascular system, which by that time is already functioning intermittently.

Lilies

The plant is afraid of moisture and loves dry, sunny places. Mechanical damage to the roots and waterlogged soil are the main causes of gray rot. When the spores spread throughout the bush, the buds begin to crumble and the bulb may die. Carriers include rodents, insects, water and wind.

Infected lilies have brownish trunks, rot is noticeable on the rhizome and bottom. The bottom gradually dies off, voids form inside the bulb, and on the surface there are ulcers and specks of a yellow-brown hue. Rot affects both the inside and outside of the bulb and the base of the stem. Heat and high humidity are the main factors contributing to the development of the disease.A diseased plant lags behind in growth, the higher healthy bushes rise, the brighter the contrast becomes.

Orchids

Gray rot on orchids can develop for months, but its last stage is really fleeting, when, within a couple of days, due to illness, the leaves rapidly turn yellow and their leaves begin to fall. A distinctive feature of Fusarium will be the presence of a raspberry ring on the cut and the appearance of red-brown areas on the aerial roots. A sick flower must be isolated, since the spores of this rot can easily be transferred to a neighboring flowerpot. A feature of the treatment is dry resuscitation and treatment. Moisture on the leaves, soaking in this case are contraindicated. Fundazol is diluted with water and applied in the form of a gruel to the affected area.

How to deal with fusarium

In any case, before diagnosing a plant for fusarium, it is necessary to exclude damage by other pests, viral mosaic, spotting, scab, etc.

Today this disease is considered incurable. The defeat by the pathogen begins from the roots, therefore, the disease can be detected only at the last stage, when the vital functions of the plant are already impaired. When vegetables, cereals and flowers with obvious traces of fusarium spores are found, the bushes are dug up and must be destroyed by fire. The area where the diseased plant was located is treated with a solution of copper sulfate. A good prophylaxis would be to spray outwardly healthy plantings with a solution of a fungicidal preparation.

An indoor flower with signs of fungal wilting is burned. In vases of healthy plants, the soil is changed, which is spilled with a biofungicide solution, before being poured into the pot.

If the disease could be identified at an early stage, then the stalk is cut off from the affected bush and the cut site is carefully examined. Cuttings with clean vessels in the cut can be rooted, but it will not work to save the parent bush. They dug it out, treatment in this case will no longer help.

The stalk is disinfected in a container with a dissolved biofungicide, and then rooted in moist calcined sand. The cut area is moistened in special preparations, like Heteroauxin, Kornevin or Zircon - root growth stimulants.

Fusarium prevention measures

The best prevention of fusarium disease is considered to be proper care and adherence to agricultural technology and hygiene in the garden, which helps to exclude the possibility of a disease.

It is important to disinfect the cutting tool in a timely manner when working with sick and healthy plants, disinfect the soil after plants that have had viral or fungal diseases, and destroy pests. Competent protection of crops from the initial stages and right up to the harvest itself is the key to an effective fight against fusarium and the consequences of its life, and preventing the development of the disease means preventing crop loss.

Autumn bioprocessing of the soil from pathogenic bacteria and fungi that overwinter on plant debris, including the fusarium fungus, which is the source of the disease, also reduces the risk of disease.

It is important to disinfect seeds and seedlings with fungicidal preparations before sowing. During the active growing season, the culture is fed with potassium-phosphorus compositions. Fresh organic fertilizers are applied to the soil with care.

To kill pathogenic microflora, the beds are covered with black or transparent film. Before storing tubers, seeds, corms and bulbs, they are carefully examined, and injured specimens with foci of mycelium are removed. Before planting in the ground, healthy planting material is treated with Fundazol.

Sour soil in the area is diluted with chalk or dolomite flour, which helps to reduce the likelihood of gray mold infection. It has been proven that the causative agent of this disease does not live in a neutral substrate with a high calcium content.To protect berry crops and flower beds from fusarium, a weak solution of potassium permanganate is poured under the roots, you can also add a little boric acid. For preventive purposes, it is enough to carry out the procedure at least once a season.

Problems with fungal and bacterial diseases can be avoided if you regularly maintain cleanliness in the garden, remove weeds and loosen the soil, treat the soil from pests, observe the dosage and frequency of both mineral and organic fertilizing. Avoid the accumulation of plant residues, fallen fruits and berries, it is better to bury them or burn them outside the garden. Before planting seedlings or seeds under the open sky, the substrate is disinfected with potassium permanganate or antifungal drugs to kill pathogenic bacteria, spores and insect larvae, but no later than a month before sowing.

Diseased plants are promptly disposed of, they are burned together with an earthen clod, and not covered with compost. In such microflora, pathogens multiply faster.

At the end of the work, the surface of garden tools that came into contact with a diseased bush is disinfected with technical alcohol. In order not to spread fungal spores to healthy beds, the soles of the shoes in which they walked around the site are also wiped and disinfected. Not only the soil, but flower pots and other containers where cultivated plants were grown, can serve as a source of infection.

Fusarium treatment: a list of effective fungicides

For the treatment of seeds, seedlings and substrate from fusarium, the following fungicidal agents are used:

• Agat-25K - a biological product that has a balanced composition of macro- and microelements, contains pine extract and chlorophyll-carotene paste. It increases the yield, destructively affects the pathogens of fungi of the Fusarium genus and improves the quality of the soil.
• Fitosporin-M - a preparation of natural origin, which serves to protect soil, compost, planting material from fungal and bacterial diseases.
• Baktofit - a broad-spectrum fungicide for the prevention and treatment of fusarium disease, is responsible for the development of healthy microflora, prevents the manifestation and suppresses pathogens of a wide range of plant diseases.
• Trichodermin - widely used in agricultural technology, increases soil fertility, protects seeds from fungal infections before planting in the ground, inhibits the growth of fungi and completely destroys them.
• Vitaros - used for disinfection of planting material and processing of bulbs and root crops before sending them for storage.
• Potassium humate - fertilizer based on humic acid, peat and brown coal, has effective fungicidal properties, stimulates the growth of vegetative mass.

Folk remedies for fusarium

It is practically impossible to cure a plant with signs of fusarium with folk remedies, especially in the midst of the disease, but for timely prevention and maintenance of the health of the bushes, they will be no less effective than chemicals. Below we will consider several methods of treating fusarium with alternative methods:

1. 35 drops of iodine, 25 g of laundry soap (preferably shavings) are added to 1 liter of milk. The components are mixed until complete dissolution and the resulting mixture is treated with healthy bushes.
2. In two liters of water dissolve 1 glass of wood ash and 1 tbsp. l. laundry soap. Insist for about two days, after which they spray the bushes and soil with a mixture in the area with plantings. Re-spraying can be done after a week.
3. A glass of onion peel is poured with boiling water (the norm for a bucket of water). After 30 minutes, when the liquid is infused, it is filtered and diluted with water in a 1: 1 ratio. Onion infusion is watered over the ground parts of the plant
4. Garlic is cleaned and crushed, 1 liter of water is added and infused for 24 hours, filtered and brought to a safe concentration by adding another 9 liters of water. Processing is carried out in the evening.