Fusarium wilt of cultivated plants - how to prevent and overcome. Infectious plant disease - fusarium: how to fight Fusarium causes

), hazardous to the health of people and animals.

Protective measures: alternation of grain crops and corn with a break of at least one year in crop rotation; growing varieties tolerant to the disease (there are no varieties highly resistant to the disease); treating seeds with fungicides to reduce the development of seedling rot (the measure does not affect the development of fusarium head blight); treating plants with fungicides, which to some extent reduces the severity of the disease; incorporating plant residues to help reduce disease; storing seeds at a moisture content of less than 14%, preventing the growth of pathogens and the production of mycotoxins.

Fusarium head blight on rye

Fusarium head blight of barley

Fusarium alfalfa

Caused by a complex of species Fusarium, among which dominates Fusarium oxysporum. The fungus causes root rot and plant wilting. The leaves turn whitish-yellow initially on one stem, later the other stems of the bush turn yellow, and then the whole plant. The top of the stem dries out or the entire plant dries out. In a diseased plant, the main root and root collar begin to rot. Sometimes the roots look outwardly healthy, but on the cut there is a browning of the vascular-fibrous bundles. Fusarium wilt is more common on 2-3 year old and older alfalfa. The aerial mycelium on potato-sucrose agar is filmy-cobwebby or felt-like, low, pale lilac or white. Macroconidia are few. Microconidia are abundant, in false heads, cylindrical, oval, ellipsoidal, unicellular. Chlamydospores are intermediate and apical, smooth, single and in pairs, round, uncolored.

The development of the disease is promoted by increased acidity and unstable water regime in the soil, as well as high temperature. In the territory of the former Soviet Union, alfalfa fusarium has been registered in the Voronezh region, Rostov region, Stavropol region, Krasnodar region, the Baltic states, Ukraine (Poltava region, Kharkov region) and Uzbekistan (Tashkent). The disease can cause the death of alfalfa and lead to thinning of crops. Protective measures: destruction of plant residues, compliance with crop rotation recommended for each zone, use of resistant varieties.

Fusarium blight on corn seedlings

Pathogens: fungi of the genus Fusarium. The disease is widespread.
Low temperatures during seed germination, high humidity and acidity of the soil enhance the development of the disease. On the surface of the germinating grain there is a faint coating of pink or white fungus. Soon after the corn plant reaches the surface, the sprout turns brown and dies. If the sprout survives, then it has a poorly developed root system, diseased plants are stunted in growth, leaves dry out, and some plants lie down.
Protective measures: it is recommended to sow treated seeds in well-warmed areas and at optimal times; implement a set of agrotechnical measures that promote faster seed germination and better plant development. Much attention is paid to the creation and use of disease-resistant hybrids.

Fusarium corn cob

Pathogens: hemibiotrophs Fusarium verticillioides(Sacc.) Nirenberg (syn.: Fusarium moniliforme J. Sheld., Gibberella moniliformis Wineland).
A pale pink coating of fungus appears on the surface of corn cobs at the end of milky - beginning of waxy ripeness. With a thick coating, the grains are destroyed. There may be 15-30 dilapidated grains on the cob. The coating consists of mycelium and microconidia of the fungus. The source of infection is contaminated seeds and post-harvest corn residues. In spring, germination of microconidia and infection of plants is observed. The marsupial stage of the fungus can form on post-harvest corn residues - Gibberella fujikuroi. In this case, ascospores can also be a source of infection. Caryopsis damaged by insects is especially susceptible to infection by the fungus.
Fusarium cob blight is the most widespread disease of corn, especially in areas with high humidity. In these areas, up to 50-60% of corn crops are affected. Fusarium cob disease leads to a decrease in yield and deterioration in its quality. The disease continues to develop when cobs are stored in conditions of high humidity and insufficient aeration. Mushroom F. moniliforme may produce mycotoxins known as fumonisins. These toxins are carcinogenic to humans and animals.
Protective measures: removal of diseased cobs; autumn plowing of the field with removal of corn plant residues; seed dressing; carrying out measures to combat insects that damage cobs; correct storage conditions for cobs and monitoring mycotoxin content before storing grain.

Fusarium pea (root rot and tracheomycosis wilt)

Fusarium blight of rice

Pathogens: some species of the genus Fusarium, in particular Fusarium graminearum Schwabe (syn.: Gibberella zeae(Schwein.) Petch).
The spots on the surface of the glumes are initially whitish, then yellow, pink or carmine. Affected grains are light, puny, crumbling, and may have a reddish color or brown spots. The nodes of the stems rot, turn black and collapse. The stems wither, break and the plants die. Sporodochia, clusters of conidia, and blue-black perithecia may be visible on the scales. Perithecia also form on the nodes of affected stems. The source of the primary inoculum is the affected plant residues, on which bags with ascospores, overwintered conidia and infected seeds are preserved. The fungus persists in the seeds for more than 13 months. The germination capacity of affected rice seeds is reduced by 2-3 times. The fungus produces mycotoxins that contaminate grain.
Protective measures: optimal agricultural technology, compliance with crop rotation, cultivation of relatively resistant varieties, destruction of affected plant residues, cleaning seed material from puny seeds, treating seeds before sowing, spraying with fungicides during the growing season.
In the territory of the former USSR, the disease is observed in the Rostov region, the Caspian region, the Krasnodar region, Dagestan, the Far East, Kazakhstan, Uzbekistan and Tajikistan.

Fusarium root rot of wheat

Fusarium soybean (root rot, tracheomycosis wilt)

Sunflower fusarium, sunflower root rot

Fusarium or tracheomycosis wilt of coniferous trees

Fusarium wilt of tomatoes

Fusarium wilt of cucumber

Cucumber root rot

Tracheomycosis wilt of rhododendron

Pathogen: mushroom Fusarium oxyspopum. Symptoms: the roots turn brown and rot, the fungus penetrates the plant’s vascular system and fills it, blocking the movement of nutrients. The leaves, starting from the upper parts of the shoots, gradually lose turgor, turn brown and dry out. The leaves fall along with the petioles, and a grayish-white mycelium begins to spread from the vessels of the stem along the bark. The infection persists in plant debris and infected plants.
Control measures: timely burning of dead plants along with the roots. For industrial cultivation, preventive spraying of plants and watering of the root zone with a 0.2% solution of foundationazole.

Notes

1. Sokolov M.S. Research by SKNIIF on the epiphytotiology of fusarium head blight and fusariotoxygenesis // Abstracts of reports: fusarium head blight of cereal crops. - Krasnodar, 1992. - pp. 4-7.
2. Shipilova N.P., Gagkaeva T.Yu. Fusarium head and grain blight in the North-Western region of Russia // Plant protection: Journal. - 1992. - No. 11. - P. 7-8.
3. Levitin M., Ivashenko V., Shipilova N., Gagkaeva T. Fusarium head blight of the cereal crops in Russia // Plant Protection. - 2000. - T. 51, No. 231-232. - pp. 111-122.
4. Voilokov A.V., Gagkaeva T.Yu., Dmitriev A.P., Baranova O.A. Resistance of autofertile lines of winter rye to leaf rust and fusarium head blight // Bull. VIZR. - 1998. - No. 78-79. - pp. 59-63.
5. Levitin M.M., Ivashchenko V.G., Shipilova N.P., Nesterov A.N., Gagkaeva T.Yu., Potorochina I.G., Afanasyeva O.B. Pathogens of fusarium head blight of grain crops and forms of manifestation of the disease in the north-west of Russia // Mykolgia and phytopathology. - 1994. - T. 28, No. 3. - pp. 58-64.
6. Shipilova N. P. Species composition and bioecological characteristics of fusarium pathogens in grain seeds // Author's abstract. diss. Ph.D. - 1994.

Fusarium is an insidious fungus that affects both ornamental and productive crops - a real disaster for a personal plot. The disease caused by it can instantly destroy even a healthy adult plant, not to mention fragile seedlings. Nevertheless, this dangerous disease can and should be fought – first of all, using preventive methods.

Fusarium is an infectious disease caused by a fungus of the Fusarium genus. The pathogen lives in the soil and infects plants through the root system or damage to the stem. The disease is characterized by a focal form of spread. The fungus is resistant to adverse environmental conditions and can survive in the soil for years.

First of all, young and weakened plantings fall victim to fusarium. Infection can also occur from seeds or seedlings already infected with the fungus. The development of the disease is influenced by factors such as sudden temperature fluctuations, lack of nutrients and damage by insect pests. Increased humidity of the substrate and air can also trigger the development of the disease.

Symptoms of fusarium are wilting and deterioration of flowering, yellowing of foliage and its subsequent falling. If you dig up an infected plant, the darkened and weakened root system will immediately become visible. Another reliable sign of fungal activity is a dark ring on the cut of the stem, indicating that the disease has already irrevocably destroyed the plant.

Development of the disease

Fusarium begins with rotting of the underground part. Tender roots become the first target of the fungus, which supports its own vital activity due to the nutrients produced by the plant, while simultaneously poisoning it with mycotoxins. Young shoots and seedlings usually die quite quickly from such destructive activity - an apparently healthy plant falls to the ground, and the characteristic thinning of the dark shade in the lower part of the stem eloquently indicates the cause of the incident.

Stronger plants are destroyed almost entirely by fusarium - as the fungus grows, it moves higher and higher through the vessels of the stem, gradually clogging them with its threads. Because of this, the leaves at the base of the stem begin to wither, those that are higher become watery at the edges and acquire a pale green or yellowish tint; at high humidity, a whitish coating appears on them. The toxins released by the fungus destroy the plant and eventually it dies. On average, it can resist the disease from several days to 2 months. At temperatures below +16°C, infected specimens die relatively quickly.

Crops susceptible to the disease

The fungus that causes fusarium is practically “omnivorous”, so hardly any garden or garden species is 100% protected from its destructive effects. Thus, certain varieties of this phytopathogen specialize exclusively in productive crops:

• Fusarium cereal - destroying the plant and feeding on its tissues, the fungus simultaneously releases highly toxic substances into it, which accumulate in the ears, making their contents poisonous to people and animals.
• Fusarium potato affects not only the well-known root crop, but also representatives of other crops, including legumes and pumpkins. It appears both on green plants and on already harvested potatoes. A more popular name among people is dry rot.

Fusarium is also destructive for such popular crops as tomatoes, carrots and strawberries. The symptoms are similar in all cases - first the roots are affected, and then the above-ground part gradually withers. The chance of developing the disease may increase slightly when grown in greenhouses and in conditions of consistently high temperature and humidity. Reduces the likelihood of Fusarium infection by following crop and crop rotation regimes.

This is what dry (fusarium) rot on potatoes looks like

The fungus has not spared flowering plants either. Thus, in representatives of the Asteraceae family, infection with fusarium occurs during budding and at the initial stage of flowering, which is almost guaranteed to lead to the death of diseased specimens. Other decorative flowers may also be affected: roses, petunias, carnations and dahlias.

Disease prevention

Curing plants affected by Fusarium is usually not possible, so the most effective measure to combat the fungus remains a preventative approach. First of all, it is necessary to carefully approach the choice of planting material - healthy, strong plants get sick much less often. It will also be useful to soak seeds or tubers in a fungicide solution before planting.

The fungus makes its first “blow” from the soil, so regular loosening and removal of excess moisture will be useful. By the way, you will also have to disinfect the soil, as well as the tools used in caring for your garden. The risk of developing the disease increases if the soil is highly acidic. To neutralize such a substrate, ash or dolomite flour is suitable. It is recommended to leave natural water used for irrigation for some time with the addition of the drug Fitosporin-M.

Potted flowers can also fall victim to an insidious fungus. To avoid this, it is advisable not to expose them to stress: do not move them unnecessarily, do not subject them to mechanical stress and always orient the container in one direction. It would be a good idea to disinfect the pots in advance: wash with soap and treat with bleach. Before planting, it is recommended to add Trichodermin or a similar fungicide to the soil: the already mentioned Fitosporin-M, Fitolavin, etc.

Treatment of fusarium

If preventive measures have not had the desired effect and pronounced symptoms of fungal infection are noticed among the plantings, it is necessary to immediately isolate the diseased specimen and disinfect the area it occupies, as well as spray neighboring plantings with an antifungal drug. Under no circumstances should the removed green mass be thrown into the compost heap - this way the disease will not go away. Without exception, all infected crops and weeds must be burned.

In some cases, the development of the disease can be stopped. To do this, cuttings are cut from a diseased plant until traces of fungal activity are no longer visible on the cut. After this, the cutting is immersed in a solution of one of the fungicides mentioned above or similar, and then rooted in calcined sand. The use of biostimulants like Kornevin or Zircon will help the plant “come to its senses” faster.

The following folk method is effective in suppressing the development of fusarium: about 2.5 kg of freshly picked stinging nettle and the same amount of celandine are soaked in 50 liters of water for at least 24 hours. The solution is diluted in a ratio of 1:5 and used for irrigation.

Conclusion

Fusarium is a dangerous and unpredictable disease that can negate the hard work of an amateur gardener to decorate his favorite plot or grow edible crops. However, if you follow simple prevention rules, an unwanted guest is unlikely to ever visit your garden.

Fusarium head blight is an extremely harmful disease of cereal crops, including wheat. Owners of private farms who grow grain must be able to cope with this disease. In this article we will talk about fusarium blight on wheat, talk about symptoms and modern control methods.

The causative agent and symptoms of fusarium blight in wheat

Fusarium blight is an infectious disease caused by fungi belonging to the Fusarium genus. The specific type of fungus depends on the region and climatic conditions. For example, in the south of Russia, wheat is more often affected by Fusarium graminearum, in more northern regions - Fusarium avenaceum.

The characteristic manifestations of fusarium are as follows:

• the scales on the formed spikelets become dark and oily;
• signs of conidial sporulation appear on the scales: in Fusarium graminearum - loose pink and reddish pads, in Fusarium avenaceum - bright red waxy pads;
• the ear is covered with a spore-bearing coating completely or at the top;
• pads are observed in leaf sheaths and on stem nodes;
• White mycelium is visible on the grains.

The listed symptoms are found on ears closer to grain ripening. Infection occurs much earlier - during wheat flowering.

Fusarium mycelium can infect grain to varying degrees. With a small lesion, it penetrates only into the membrane. If it is strong, it goes into the deep layers, where protein decomposition begins.

Distribution and harmfulness of fusarium blight in wheat

The fusarium pathogen can overwinter both in the form of spores and in the form of mycelium.

The harmfulness of fusarium lies in the fact that infected grain becomes unsuitable for food and even dangerous to health. As a result of the vital activity of the mycelium, mycotoxins accumulate inside the grain, causing severe poisoning.

• They are not destroyed by heat treatment, so if bread is baked from diseased grains, after eating it, vomiting, diarrhea and symptoms reminiscent of severe alcohol intoxication are observed. Hence the popular name for fusarium blight in cereals – “drunken bread”.
• Grain affected by fusarium differs from healthy grain in the following ways:
• colorless or slightly pinkish dull surface;
• frailty and wrinkling;
• a coating of mycelium is noticeable in the groove;

decrease or loss of glassiness, crumbling of the endosperm;

A dark, dead embryo is visible on the cut.

The germination rate of diseased grain is zero or very low. In addition, it is poorly stored, cakes, and at a certain temperature and humidity mycelium grows.

For the spread and development of fusarium blight in wheat, appropriate weather conditions are required. The most severe damage to crops is observed in years with warm and damp summers. The most favorable conditions for morbidity are air temperature during flowering from +20 to +30 0 C and air humidity from 75%. In addition, the following agrotechnical errors can create a serious risk:

Mistake #1. Fine tillage.

According to data published by the All-Russian Institute of Plant Protection, in fields where the soil was plowed with rotation of the layer, the prevalence of fusarium blight on wheat was about 15%. In experimental fields that were treated superficially, this figure reached almost 49%.

Mistake #2. Poor field cleaning.

Since the pathogen overwinters on plant debris, after harvesting the wheat it is necessary to clear the field of it. All crop residues must be chopped and plowed deep into the soil. Their mineralization is accelerated, and the amount of preserved infectious material is significantly reduced.

Mistake #3. Improper storage of seed.

Increased humidity, self-heating of grain or its damage by insects contribute to infection of the seed, and then outbreaks of fusarium on the field.

An additional risk factor is non-compliance with the rules of sowing shifts. The more saturated the crop rotation is with grains, the more pathogens accumulate in the soil. Beetroot is also an unfavorable predecessor for wheat.

Tip #2. If a Fusarium infestation is detected in a field, it is important to choose the right wheat harvesting tactics. It is recommended to carry it out as quickly as possible and subject the grain to immediate drying.

Agrochemical methods for combating fusarium blight in wheat

Unfortunately, in the fight against fusarium head blight it is impossible to do without agrochemicals. Chemical fungicides should be used even before sowing - to treat the seeds. There are different methods of pre-sowing treatment of wheat seeds:

In addition to dressing, spraying is also necessary during the growing season. Long-term studies of wheat crop protection products show that drugs from the group of triazoles and benzimidazoles demonstrate the greatest effectiveness against head fusarium blight.

Spraying in the phases of flag leaf, ear extension or beginning of flowering. The consumption rate of the working solution is 200-300 l/ha.

Biological method of combating fusarium blight in wheat Agrochemical preparations can be supplemented and their effectiveness can be increased with the help of biological products. The developers base them on any strain of microorganisms that exhibit antagonistic activity against a particular pathogen. The fungi Trihoderma lignorum and bacteria Pseudomonas fluorescens exhibit the greatest antagonistic behavior towards Fusarium.

But since the simultaneous use of beneficial fungi and fungicides is impossible, only preparations based on pseudomonads remain in the farmer’s arsenal: There are also eco-technologies that allow you to grow healthy wheat using only biological products - without chemical fungicides. For example, for pre-sowing seed treatment, it is recommended to use a mixture of Trichodermin and Planriz. Then spray wheat crops with this mixture twice - in the phases of emergence and tillering.

In the phase of exit into the tube, perform another treatment by adding Becimid (Lepidocid) to the initial mixture.

The main agrotechnical methods for preventing fusarium in wheat fields are deep autumn plowing, careful harvesting of plant residues and sowing in compliance with the density of wheat standing.

Wheat varieties resistant to fusarium

There are no wheat varieties that are completely immune to fusarium blight. They are differentiated by the degree of resistance or susceptibility. It has been noted that soft wheat varieties, on average, resist Fusarium damage better than durum varieties.

Among the varieties that exhibit satisfactory resistance are winter wheat Esaul, Delta, Batko, Veda, Kingfisher, Tanya, Soratnitsa, Moskvich. Spring wheat is generally more susceptible to fusarium blight. The soft variety Svecha, which is characterized by a high degree of adaptability to agroclimatic conditions, shows good resistance.

The summary list of preventive measures to prevent fusarium blight in wheat is as follows:

• mandatory pre-sowing treatment of seeds with fungicides:
• deep plowing of the soil;
• compliance with wheat seeding standards and stem density;
• timely preventive spraying of seedlings with fungicides;
• timely harvesting;
• good drying of the collected grain;
• compliance with the humidity and temperature conditions in the granary;
• preliminary disinfestation of granaries before filling grain for storage;
• thorough cleaning of fields after harvesting;
• compliance with crop rotation rules;
• sowing resistant varieties of wheat will also reduce the risk of Fusarium infection of crops.

Current questions about fusarium blight in wheat

Question No. 1. Is it possible to use fusarium-infected wheat to feed livestock and poultry?

It is forbidden. Fusarium mycotoxins cause severe liver and kidney damage in animals, ulcerative stomatitis, skin necrosis, and reduce their reproductive function.

Question No. 2. Is it possible to get rid of fusarium in wheat using folk remedies?

It is forbidden. Fusarium is a serious problem, the solution of which must be approached responsibly and only modern methods must be used. No folk remedy guarantees that the mycelium will not be preserved under the shell of the grains.

Question No. 3. What crop plants can Fusarium wheat spread to?

Any cereal can be affected - rye, oats, barley, corn, rice. Some species of Fusarium wheat cause Fusarium root rot of legumes.

Question No. 4. How to properly dispose of fusarium-infected grain?

In practice, grain affected by fusarium can be used to produce acetone or technical alcohol. If it is not possible to hand it over to an acetone-butyl plant, it is better to burn the crop. You cannot put it in compost pits.

Fusarium called a dangerous and fairly common fungal disease. It can affect a plant of any age. The fungus found in the soil penetrates the plant through wounds and through the soil itself. In young plants Fusarium manifests itself in the form of rotting of the root collar and roots. The tissue in this place becomes brown, the stem becomes much thinner, and the leaves acquire a yellow tint. The fungus spreads very quickly throughout the plant and soon it dies. Weak plants are most susceptible to this disease, and its spread is facilitated by increased air and soil humidity.

Description of fusarium

Fusarium is widespread. This disease affects plant tissue and the vascular system. The pathogen can survive for a long time in the soil, as well as on plant debris. The source of this infection may be contaminated seeds or seedlings. Fusarium develops especially quickly if there are sudden changes in temperature and humidity of the soil and/or air. Factors such as the weakened state of the plant and damage by insects can also contribute to the wilting of plants.

The disease always begins with root rot. Initially, the pathogen penetrates into small roots. Then, when the mycelium begins to grow, it becomes larger. Through the conducting vessels, the source of the disease spreads to the stem and then reaches the leaves. Typically, the lower leaves wither, and the edges of the remaining leaves become watery, with some areas turning a light yellow or pale green hue.

If the air temperature drops below 16 degrees, then diseased plant dies very quickly. In such cases, the pathogen releases toxins that cause cell decomposition, drying of leaves and branches, and root rot. In case of high humidity, a faint white coating forms on the leaves.

Signs of damage by fusarium

With fusarium wilt, damage (death) of the plant occurs due to severe disruption of vital functions due to vascular blockage by the fungal mycelium, as well as the release of toxic substances by it. Affected plants bloom poorly, leaves turn yellow and fall off, roots darken and weaken. There is a general wilting of the plant.

In bulbous plants Red-brown spots appear near the bottom, slightly pressed inward. When humidity is high, a pink-white coating appears on the spots. Because of this, Fusarium bulbous is often also called red rot. When storing bulbs, the disease quickly begins to progress, rot appears, which is also a serious source of infection.

Fusarium wilt is the most dangerous for bulbous plants; roses, chrysanthemums, neoregelias, echmeas, gerberas, anthuriums, impatiens, cyclamen, zygocacti and other articulated cacti also suffer greatly from it.

Methods to combat fusarium

Often the disease is detected too late, when most of the plant is already captured by the disease and death is inevitable. In this case, the diseased plant and bulb are isolated, healthy ones are sprayed with the drug Fundazol.

If the plant is not severely damaged by the disease, you can root its cuttings. To do this, the top is cut off and kept in a solution of Fundazol with the addition of a drop of the drug Epin for 8 hours. If the cutting takes root in the near future, it means the plant has coped with the disease.

Prevention against fusarium

Prevention of fusarium involves freezing or calcining the soil. In addition, it is necessary to treat the seeds before sowing. When preparing the soil, it is allowed to apply Trichodermin; a few grains of the drug are enough for a pot with a diameter of 25 centimeters. You should also follow the rules for keeping plants. The disease progresses only in weakened species.

High humidity in the air and soil contributes to the spread of the disease, so it is necessary to ventilate the premises more often, loosen the soil, and disinfect fresh soil before use. Before work, you need to sterilize tools - scissors, knife, garter materials using alcohol. If plants are watered with rainwater or from natural reservoirs, then it should first be soaked with the drug Fitosporin-M.

Fusarium grain blight is a plant disease that causes significant losses in both yield and the quality of harvested grain. Infection of grain with Fusarium fungi leads to a decrease in germination energy and seed germination. Some fungal species produce mycotoxins such as deoxynivalenol (DON), T-2 and NT-2 toxins, zearalenone, nivalenol, etc. Mycotoxins present in grain make it unsuitable for food and feed purposes.

Fusarium grain blight is caused by various species of fungi of the genus Fusarium.

The most dangerous and widespread species in the Russian Federation are:

• Fusarium graminearum
• Fusarium culmorum
• Fusarium sporotrichioides
• Fusarium langsethiae
• Fusarium avenaceum
• Fusarium poae
  Species of fungi of the genus Fusarium

  F. graminearum

  
  F. culmorum

  
  F. avenaceum

  
  F. sporotrichioides

  
  F. langsethiae

  
  F. poae

  Symptoms of fusarium head blight

  Symptoms include:

  Pink-orange coating of mycelium and fungal sporulation on the glumes of the ear

  

  

  

  Fusarium graminearum, F. culmorum, F. avenaceum

  Pale pink sporulation of the fungus on the glumes

  

  

  Fusarium sporotrichioides, F. poae and others

  Eye spot on glumes

  

  

  

  Fusarium tricinctum, F. sporotrichioides and others

  Formation of puny, wrinkled, lightweight grains

  

  

  The main signs of grain affected by fusarium

  • the affected grains are puny, wrinkled with a depressed deep groove and pointed barrels;
  • the surface of the grain is discolored or pinkish, without shine;
  • endosperm is loose, crumbling; low glassiness of the grain or its complete loss;
  • in the groove and especially in the embryonic part of the grain there is a cobweb-like coating of fungal mycelium, white or pink, and pads of conidia accumulation;
  • The grain embryo is nonviable, dark in color on the cut.

  

  However, apparently healthy grain can also be affected by fungi and contain mycotoxins!

  Life cycle of fungi of the genus Fusarium

  

  Distribution of fungi of the genus Fusarium

  Fusarium fungi overwinter in the form of mycelium and spores on dying plant debris, such as straw and stubble.

  Ascospores, which develop in fruiting bodies (perithecia), spread by the wind long distances. Conidiospores They infect the ear, then form again on the affected glumes and are spread by wind and raindrops to other ears during the growing season before harvesting.

  
  Chlamydospores

  
  Conidia

  
  Ascospores

  
  Perithecia

  The process of plant infection by fungi

  Infection of secondary spikelets

  During flowering, ascospores or conidia penetrate into the inner part of the grain shell

  After flowering, the hypha of the fungus penetrates the ear tissue and can infect the resulting grain at all stages of its development.

  

  Microscopic development

  
  Conidia develop on the surface of the plant...

  
  form mycelium...

  
  penetrate the plant...

  
  and develop in tissue...

  
  After the incubation period, symptoms appear and new conidia are formed

  Reasons for increased damage to grain by fusarium

  • Saturation of crop rotation with grain crops
  • Direct seeding and minimum tillage
  • Susceptible varieties
  • Warm weather and high humidity during flowering - ripening and harvesting of plants
  • Lack of protection methods!!!

  Direct yield losses up to 15-20%
  Loss of grain quality up to 100%

  Factors influencing infection

  Fusarium infection is affected by three main risk factors:

  
  1. Weather during flowering

  
  2. Tillage

  
  3. Previous culture

  Influence of weather conditions

  Grain damage is possible at all stages of its formation.

  Plants are especially susceptible to fusarium in the flowering phase under conditions of high humidity and temperatures around 20-25°C (especially F. graminearum).

  

  However, for the development of Fusarium sporotrichioides, F. poae, such indicators as high humidity and temperature are not key!

  Effect of tillage

  Tillage methods have a great influence on the development of fusarium.

  

  • The presence of fungal-infected plant residues on the surface or in the surface layers of the soil after minimal processing greatly increase the likelihood of infection of growing plants.
  • This means that the risk of infection can be reduced by plowing in the leftovers plants into the soil, where they decompose faster.

  No-Till or minimum tillage increases the risk of developing Fusarium

  * DON - deoxynivalenol

  Impact of crop rotations

  

  • The rotation of crops in a crop rotation has a particular impact on the potential development of infection.
  • Saturation of crop rotation with grain crops contributes to the accumulation of inoculum.
  • Short crop rotation, especially including corn, increases the damage to plants by fusarium.
  • Beetroot is also an unfavorable predecessor.

  Influence of previous culture

  Corn and other grain precursors significantly increase the risk of fusarium

  

  Influence of variety resistance

  

  • Cultivation of resistant varieties has a greater impact on reducing disease incidence and improving grain quality.
  • Most cultivated varieties of grain crops are susceptible to fusarium.
  • Bread wheat varieties vary in level of susceptibility from relatively resistant to highly susceptible.
  • Durum wheat and oats are highly susceptible to fusarium grain blight.

  

  What is the effect of fusarium on grain?

  • Productivity
  • Seed quality of seeds (reduced germination energy and germination)
  • Nutritional value of grain-based food and feed products due to the presence of mycotoxins
  • Baking qualities of flour
  • Beer quality (hashing effect)

  

  Fusarium and food quality

  During heat treatment, the level of mycotoxins does not decrease!

  Bread quality

  Fusarium-infected grains are of low quality and produce dense bread with large pores

  

  Quality of pasta

  Fusarium affects the quality standard in terms of viscoelasticity and color of pasta products made from durum wheat.

  

  Beer quality

  Spontaneous and intense foam formation can lead to rapid, uncontrolled emptying of the bottle, similar to the gushing effect.

  

  The influence of fusarium on bread quality

  
  Uninfected grain

  
  Grain affected by fusarium

  • Mycotoxins produced by various types of fungi. Fusarium have various toxicological properties.
  • Mycotoxins have different effects on different species, such as pigs, poultry, humans, etc.
  • The most common mycotoxins in cereals are deoxynivalenol (DON) and T-2 toxin

  
  DON

  
  T-2 toxin

  
  Zearalenone

  Type of mushroom	Trichothecenes		Zearalenone	Fumonisins	Moniliformin
  	Type A 1	Type B 2
  		DON, NIV	+
  	T-2/HT-2
  		NIV, DAS
  					+
  				+

  1 - trichothecenes type A: T-2 and HT-2 toxins, diacetoxyscirpenol (DAS)
  2 - trichothecenes type B: deoxynivalenol (DON), nivalenol (NIV)

  Fusarium - a threat to people in the past and present

  Mitotoxin toxicity

  All mycotoxins cause decreased immunity

  	Toxicity
  Trichothecenes type A (T-2, HT-2, DAS)	The most toxic metabolites. More toxic than type B trichothecenes Responsible for nutritional toxic aleukia (ATA) Causes epidermal necrosis and ulcerative stomatitis, serious gastrointestinal disorders that can lead to death
  Trichothecenes type B (DON, NIV)	Acute toxicity characterized by vomiting (more sensitive in pigs), food refusal, weight loss, diarrhea, tissue necrosis No indication of carcinogenic, mutagenic or teratogenic effects
  Zearalenone	Reduce animal productivity Estrogenic effects causing infertility, miscarriage (pigs are especially sensitive) Possible effect on cervical cancer in women
  Fumonisins	Equine leukoencephalomalacia (a disease of horses), characterized by neurotoxic effects, pulmonary and cerebral edema, and liver damage Possible link to esophageal cancer in humans
  Moniliformin	Changes in cardiac muscle tissue Intestinal bleeding (limited studies)

  Distribution of deoxynivaleonol in fusarium wheat milling products

  Fraction	Deoxynivalenol content
  	mg/kg	% to original grain
  Source grain	5,4	100
  Flour 70% yield	2,16	40
  Flour with Sh etc. and 3rd size. systems	3,6	67
  Torn bran	9	167
  Grinding bran	7,71	142

  It has been proven that in bread made from fusarium grain the content of mycotoxins does not decrease, and sometimes even increases, especially when producing yeast dough and bread!

  Effect of mycotoxins on animals

  Wheat represents 50% of pig growth feed. If mycotoxins are present, feed consumption by pigs is significantly reduced. Serious symptoms include refusal to eat, weight loss and vomiting. Moreover, reproductive function may be affected

  The influence of mycotoxins on feed consumption by pigs

  

  Impact of fusariotoxins contained in feed on the health of animals and poultry

  

  

  

  

  • Refusal to feed
  • Decrease in productivity
  • Immunosuppression
  • Damage to internal organs (liver, kidneys, reproductive system organs, etc.)
  • Ulcerative stomatitis
  • Epidermal necrosis

  LD 50 for some mycotoxins through the gastrointestinal tract

  Mycotoxin	LD 50 for mice		LD 50 for poultry
  	mg/kg FA	Relates. toxicity	mg/kg FA	Relates. toxicity
  T-2 toxin	5,2	1,0	5,0	1,0
  HT-2 toxin	9,2	1,8	7,2	1,4
  DON	70,0	13,5	140,0	28,0
  Nivalenol (NIV)	4,1	0,8	—	—
  Diacetoxyscirpenol (DAS)	23,0	4,4	3,8	0,7
  Moniliformin	20,0	3,8	5,4	1,1

  Occurrence of species of the genus Fusarium in grain samples from various regions of Russia

  Type of mushroom	Region of the Russian Federation
  	North Caucasus	CCR + Center	Vol. Vyatsky	North West	Ural	Siberia	Far East
  F. graminearum	+++	++		+			+++
  F. culmorum		++	++	+		+	+
  F. sporotrichioides	+++	++	+++	+++	+++	+++	+++
  F. langsethiae	++	+		++
  F. poae	++	+++	+++	+++	+++	+	+++
  F. cerealis	++	+					++
  F. avenaceum	++	++	+++	+++	++	++	++
  F. tricinctum	+	++	++	++			+
  F. verticillioides	++		+				++

  The ability of fungi of the genus Fusarium to cause typical symptoms of fusarium and produce a mycotoxin characteristic of the species

  Type of mushroom	Presence of typical symptoms of fusarium		Mycotoxin produced
  	generative organ	corn
  F. graminearum	++	++	DON, ZEN
  F. culmorum	++	++	DON, ZEN
  F. sporotrichioides	+	-	T-2
  F. langsethiae	-	-	T-2
  F. poae	-	-	NIV
  F. tricinctum	+	-	MON
  F. avenaceum	++	+	MON
  F. verticillioides (on corn)	++	+	FUM

  Mass phenomenon; + possible phenomenon; - absence

  The share of species of fungi of the genus Fusarium (%) in winter wheat grain from the Krasnodar Territory in 2010-2011

  2010

  

  

  2011

  

  

  The share of species of fungi of the genus Fusarium (%) in winter wheat grain from the Stavropol Territory in 2010-2011

  2010

  

  

  2011

  

  

  Proportion of samples (%) of wheat grain with different levels of Fusarium infection in the Krasnodar and Stavropol territories

  2010

  On average, federal law - 3,1% - 6,9%

  

  2011

  On average, federal law - 2,6% - 4,3%

  

  How to identify fusarium?

  Visual assessment

  In areas where the species F.graminearum, F.culmorum, and F.avenaceum are distributed, visible symptoms of fusarium blight on ears can be detected in the field. However, this method is not reliable enough.

  

  How to identify Fusarium?

  Mycological analysis

  In the laboratory, infected plant parts can be placed in a growing medium that encourages fungal growth.

  After a few days of incubation, fungi of the genus Fusarium can be identified under a microscope based on their characteristic taxonomic features.

  

  

  Molecular biological methods: the principle of polymerase chain reaction (PCR) diagnostics

  • PCR is based on enzymatic amplification of a DNA fragment
    using an enzyme (Taq polymerase).
  • The chain reaction is a process that occurs in three stages (denaturation, annealing and expansion), repeated in several cycles.
  • At each stage of the process, the number of copies doubles from two to four, then to eight, and so on. After 20 cycles there are approximately 1 million copies, which is enough material to determine the desired DNA using the traditional method

  Diagnosis of Fusarium using PCR technologies

  • PCR is a relatively fast and reliable method for identifying fungi.
  • Allows you to detect the presence of a certain type or several types of fungi in plant tissue.
  • Detection of the number of fungi is possible using quantitative PCR (real-time PCR). The amount of fungal DNA detected is related to the presence of mycotoxins produced by them.

  

  

  Planar Waveguide Technology

  A reliable and fast method using innovative planar waveguide technology to determine four to five toxins per measurement!!!

  • Simultaneous determination of several mycotoxins.
  • Ease of sample preparation.
  • Quick result (25 min).
  • No special laboratory training required

  

  

  How to fight fusarium?

  For many years, scientists around the world have been working on the problem fusarium- a disease widespread throughout the world that affects various grain crops.

  Intensive research work has led to a better understanding of disease aspects and the development of optimal solutions to suppress pathogenic fungi and reduce their negative impact on product quality.

  Application of fungicides

  Azoles are the best weapon against fusarium!

  Treating crops with a fungicide during flowering is an important method of combating fusarium.