Detect Fusarium &

Fusarium is a diverse genus of fungus that causes nail fungus in addition to plant damage. Find out how to spot and fight him early here.

The genus Fusarium includes many different species and is able to produce so-called mycotoxins (fungus toxins). Therefore, Fusarium threatens not only our plants, but also the feeds of animals and us. There are even fusaria that can infest humans and animals. In this article you can find out exactly what is meant by Fusarium, on which plants it occurs particularly frequently, how to recognize it early and how to fight it successfully.

Fusarium: A Wanted Poster

Fusaria are sac fungi (Ascomycota) and belong to the pustule family (Nectriaceae).

Fusaria are characterized by their broad spectrum of hosts, as they can infest cereals, grasses and vegetables. The Fusarium solani group affects not only plants, but also animals and humans. Fusarium can be found in soil or on plants worldwide and is even a problem in food storage.

Fusarium Life Cycle

It is common for mushrooms to have a main fruit form and a secondary fruit form. The main fruit form is characterized by sexual reproduction, the secondary fruit form by asexual reproduction. A part of the Fusarium has both fruit forms, while some only the secondary fruit form is known - therefore these Fusarium belong to the Fungi imperfecti.

The fungus survives in the soil or on plant remains and can remain there for a long time. Fusarium overwinters and settles as mycelium on the remaining plant remains. When the plants start growing due to the spring weather, the fungus also starts to develop.

Warm and humid weather is optimal for the development of the main fruit form, the perithecium. The so-called perithecia are the fruiting bodies of the fungus, in which the ascospores form. These spores are released on the crop residues at temperatures of 11 to 30 °C and at a humidity of 60 to 90%. These spores can grow in soil up tosurvive for two years and are exceedingly sticky. The fruiting bodies can also actively eject these spores - these then spread through air movements.

The asexually formed spores, the so-called conidia, can also cover longer distances. These spores are spread by rain spray, wind, and insects. There are also long-lived chlamydospores that can even infect the roots.

When the spores encounter a suitable host plant, infection begins with spore germination and hyphal growth on the plant surface. The fungus then enters the plant through the stomata or directly through the tissue. When the fungus has settled and developed on the plant, conidiophores form. There the asexual conidia are formed and released by spraying water - which in turn infects other plants. Meanwhile, the fungus also produces various mycotoxins (fungal toxins).

In autumn the spores survive again on crop residues or in the soil and the cycle begins again.

Fusarium Species: Different Species, Different Plants

Below we have compiled various Fusarium species and the plants on which they occur in detail for you.

Fusarium oxysporum

This Fusarium species is one of the most feared fungal diseases and usually causes wilt. In the USA, this fungus was even researched under the name "Agent Green" for use as a biological warfare agent. Fusarium oxysporum causes different symptoms on different crops. Generally, there is wilting, yellowing and deformation of leaves, and also root rot. The vessels also often rot and discolour. Here is an overview of the symptoms:

Cabbage vegetables such as kohlrabi (Brassica olearceae var. gongylodes) or Brussels sprouts (Brassica olearacea var. gemmifera):

• Fusarium wilt caused by Fusarium oxysporum f. sp. conglutinans
• Can only develop above 16 °C
• Optimum development conditions: 24 to 29 °C
• Leaves turn yellow, deform and fall off
• Cabbages wither and die

Spinach (Spinacia):

• Wild and root rot caused by Fusarium oxysporum f. sp. spinaciae
• Given by the seedtransfer

Tuber and root vegetables:

• Vascular disease and wilt caused by Fusarium oxysporum f. sp. raphani
• Reduced growth
• Chlorosis and necrosis on the leaves
• Tubs stay small
• Vessel bundles turn reddish-brown to black

Onion Vegetables like onions (Allium cepa):

• Onion basal rot caused by Fusarium oxysporum f. sp. cepae
• Rot at the bottom of the onion
• Yellowing of the leaves starting from the tip of the leaf
• Shriveling and Rotting of Leaves
• Weak Roots; Onions are easy to pull out of the ground

Bush and Pole Beans:

• Bean wilt by Fusarium oxysporum f. sp. phaseoli
• The lower bean leaves turn yellow, yellowing increases from bottom to top
• Discolouration often only occurs on one side of the plant
• The vessels in the stem turn brown
• Seed transmission

Peas (Pisum sativum):

• Fusarium wilt by Fusarium oxysporum f. sp. pisi occurs in 2 types:
  • American wilt (pathotype 1)
    • From the end of May (before the pea blossom)
    • Curled leaves with dirty green color
    • Withering and Dying
    • Orange, Red, Yellow and Black Discolored Vessels
  • Saint-Johannis disease (pathotype 2)
    • From the end of June (end of pea blossom, beginning of pod formation)
    • Pale green curled leaves and shoots
    • Often only on one side of the plant
    • Vessels turn brick red

Tomatoes (Solanum lycopersicum):

Fusarium Foot disease caused by Fusarium oxysporum f. sp. radicis-lycopersici

• Stem and root rot
• Infestation through the roots
• The bottom 30 cm of the stem turns brown
• A white-pink mold growth forms on the soft rotting spots on the stem

Fusarium graminearum

This Fusarium species causes in cereals such as wheat (Triticum) or barley (Hordeum ) Deafness or also known as ear fusariosis. The grain kernels shrink andstay small. The spikes are pale and there is often an orange or pink spore coating. Cob rot occurs in corn (Zea mays). Fusarium infestation in cereals leads to yield losses and the formation of mycotoxins, which can be harmful to humans and animals.

Fusarium solani

• Potatoes:

In potatoes (Solanum tuberosum), Fusarium solani causes dry rot, also known as white rot. This blight occurs in storage and causes a whitish-bluish lawn of fungus to form on the potato tubers. Under this lawn of fungi, the tuber begins to rot and lose water. The affected areas shrink and the potatoes appear wrinkled. Due to the loss of water, the potato is hard and powdery dry. A second bacterial infection can also occur after the Fusarium infestation. This results in wet rot.

• Peas:

If the upper part of the leaves of peas turns yellow and the base of the stalk is reddish-brown, this could be the cause Fusarium solani f. sp. pisi be. This fungus appears at the beginning of the flower and causes root rot. Damage to the plant occurs, especially in dry and hot weather after an excessively wet period. This root rot can also occur in beans and is also often associated with St. John's disease.

• People:

It is particularly interesting that Fusarium solani can also occur in humans and inflammation of the eyes (Endophthalmitis), inflammation of the cornea ( keratitis) or sinus infections (sinusitis). These diseases are caused by the mycotoxins produced by Fusarium solani.

Fusarium venenatum

In this Fusarium species, only the secondary fruit form Fusarium venenatum is known, especially among vegetarians, since the meat substitute Quorn is made from this mold is won. Fusarium venenatum is grown under controlled conditions, whereby the fungus produces a lot of mycoprotein, which serves as the basis for the meat alternative. Quorn is available in Germany and Switzerland (known as "Cornatur" there) and is used, for example, in vegetarian Bolognese sauces.

Fusarium culmorum

• Onion Vegetables:

In onion vegetables such as leeks (Allium porrum) or garlic (Allium sativum), root rot occurs due to Fusarium culmorum on. This fungus is a wound parasite and causes yellowing and root rot. Therefore, the plants grow only slightly, sometimes a bright red fungal network can be seen on the affected areas.

• Pulses:

On peas or beans, Fusarium culmorum and Fusarium avenaceum often lead to root rot. Because root rot often occurs in a complex, so that several fungi are responsible for the damage to the roots. Often not only combinations of different Fusarium species can be found, Thielaviopsis basicola can also be present and cause blackening of the roots and rot.

Fast identification of Fusarium

Since you usually don't have a microscope or laboratory equipment available in the garden, you can unfortunately Fusarium not identify it by its spore forms or similar. Therefore, we can only orient ourselves to the symptoms on our plants. The following symptoms are often associated with Fusarium infection:

• Lightening or yellowing of the leaves
• Rolling up leaves
• Root rot
• Discolored Vessels
• White-pink mold lawn
• Withering, often only on one side of the plant and in clusters in the stand

Fusarium combat successfully

To prevent your vegetable crop from falling victim to the Fusarium fungus, here are a few tips and tricks for dealing with this dreaded pathogen.

Pesticides against Fusarium

There are a number of pesticides for professional use in agriculture to combat Fusarium, for the garden area only the fungicide “Prestop” is currently approved.

This remedy works with the soil fungus Gliocladium catenulatum and can be used on fruit, cabbage, leafy vegetables and herbs. It can also be used in young plants and seedlings, strawberries and ornamental plants. The application can be done either by spraying or pouring. For more detailed instructions, please refer to the manufacturer's instructions.

Dispel and prevent Fusarium naturally

So that Fusarium does not spread to you, you should consider the following when planting:

• Only plant he althy and undamaged plants, bulbs or tubers
• ResistantUse Varieties
• Make seed dressing with chamomile tea
• Observe crop rotation and cultivation breaks

If you didn't have any problems with Fusarium until harvest, you should also make sure to keep your stores free of it.

To avoid Fusarium solani in potatoes in storage, it is advisable to store only he althy and uninjured potatoes. Injuries allow the fungus to enter the tubers and trigger white rot. Finally, when storing potatoes, make sure not to store too much soil, as this often means that the fungus gets into the potato storage. It is also important that the potatoes can dry off quickly so that no permanent moisture develops.

You should also not harvest other types of vegetables, such as onions, too early and store the vegetables as dry as possible. Again, make sure your camp is well ventilated. Find out how to harvest and store your onions correctly here.

In cucumbers, Fusarium wilt was a major problem in the 1950s. That is why at that time cucumbers began to be grafted onto the fig squash (Cucurbita ficifolia), because this way they are resistant to Fusarium and are generally more robust and less robust Vulnerable.

It is particularly important when dealing with the pathogen that you always remove infested plants as soon as you have discovered them. You should not dispose of these diseased plants in your compost, but in the garbage can.

Once you have discovered Fusarium infection in a bed, you should take a break from cultivation. If Fusarium has appeared on your tomatoes, do not plant any more tomatoes in this place for at least four to five years.

Mycotoxins: What is DON, ZON and NIV all about?

A lot of people are told that eating food that has been infected with fungi is unhe althy. Often there are only tiny little spots on the home-grown vegetables that indicate a mold lawn. In the following we will tell you why you should be particularly careful with mold and why boiling it doesn't make things better.

Myctoxins are the secondary metabolites of moulds, i.e. not the fungus itself, but toxic substances formed by the moulds.

According to the Food and Agriculture Organization (FAO), a quarter of the world's food containsContaminated with mycotoxins, mycotoxins can be found in one fifth of the grain harvested in the EU.

Because these mycotoxins are extremely stable, they are not destroyed by heat, for example in food production. The different types of toxins can have various effects on us and on animals, such as: damage to our organs, nerves, our immune system and even our genes.

Thankfully, nowadays you don't have to worry about groceries from the shops anymore. These are subject to strict maximum values in food production. Pets and farm animals, on the other hand, can suffer major damage from moldy feed.

Here is a small list of myctoxins and their effects:

Fusaria produce fumonisins, zearalenone and trichothecene and can cause the symptoms and diseases mentioned above. The trichothecenes include DON and NIV.

Fusarium can cause root rot on your plants. Find out how to recognize, prevent and combat root rot in this article.