Verticillium wilt is a serious disease that affects a wide variety of cultivated plants around the world. This fungal disease attacks more than 300 plant species, compromising their development and, in the most serious cases, their survival. Let’s find out how to better identify the symptoms and what solutions to apply to combat verticillium wilt.
What is Verticillium Wilt?
Verticillium wilt, also called verticillium wilt, is a fungal disease caused by fungi of the genus Verticillium . These microorganisms belong to the family Plectosphaerellaceae , mainly Verticillium albo-atrum and Verticillium dahliae .
This disease affects a wide range of plants, more than 300 species, including crops of great economic importance, such as potatoes, tomatoes, alfalfa, olives and roses, to name a few. Its impact is particularly feared in agriculture and horticulture because of the losses it can cause.
Verticillium wilt is found in many parts of the world, with temperate zones being particularly favourable to Verticillium albo-atrum . This fungus thrives at around 21 °C (70 °F), but ceases to thrive above 30 °C (86 °F). Verticillium dahliae , on the other hand, thrives in tropical and subtropical climates, with an optimum temperature of between 25 and 27 °C (77 °F and 80 °F).
Development cycle
In the soil, Verticillium dahliae maintains itself thanks to microsclerotia, resistant structures capable of surviving extreme conditions, such as drought or high temperatures. For its part, Verticillium albo-atrum forms a thick mycelium that plays a similar role, ensuring the sustainability of the fungus.
The infection begins with the penetration of the roots , whether they are healthy or damaged by wounds. Once introduced into the plant, the fungus colonizes the conducting vessels. At this stage, it produces spores that move with the sap, thus facilitating a rapid invasion of the internal tissues.
The pathogen is transmitted mainly through contaminated soil , but other vectors, such as water, wind or agricultural tools , also contribute to its dissemination. Contact with infected host plants or the use of contaminated seeds can also spread the disease.
At the end of the cycle, when the host plant dies, the fungus returns to the soil by forming survival structures, such as microsclerotia or dormant mycelium. These persistent forms can remain active in the soil for up to 14 years, making disease management particularly complex.
What are the symptoms of verticillium wilt?
Verticillium wilt causes varying damage depending on the species of plants affected, but certain characteristic symptoms allow it to be identified. These manifestations result from the colonization of the conductive vessels by the fungus, thus disrupting the circulation of water and nutrients. Here are the main symptoms observed:
- Leaf wilting : Leaves lose their turgidity, giving the plant a drooping appearance.
- Progressive discoloration : leaves change from pale green to yellow and may have necrotic areas.
- Leaf edge curling : Leaves curl inward, a distinctive sign of the disease.
- Roots little affected : the root system often remains intact, although the plant appears to suffer from water stress.
- Aggravating conditions : Heat and sunlight exacerbate symptoms, increasing the severity of the damage.
- Vascular discoloration : A cross section of the stems or roots reveals brown streaks in the vascular tissues, indicating the presence of the fungus.
In advanced situations, the entire plant wilts and eventually dies, causing significant crop losses.
Prevention and management of verticillium wilt
The fight against verticillium wilt is initially based on preventive practices and appropriate management methods. These actions aim to limit the spread of the fungus in the soil and to protect sensitive crops.
Here are the most effective measures:
- Choosing healthy material : use seeds, tubers and cuttings certified as pathogen-free to reduce the risk of introducing the fungus into crops.
- Regular monitoring : Frequently inspecting crops helps detect early symptoms, facilitating rapid intervention.
- Crop rotation : alternating with non-susceptible species reduces the presence of the fungus in the soil, depriving it of its usual hosts.
- Resistant varieties : choosing cultivars known for their tolerance to verticillium wilt can limit the impacts of the disease.
- Tool hygiene : disinfecting agricultural equipment after each use, especially after handling infected plants, prevents the spread of the fungus from one plot to another.
- Soil management : careful soil cultivation, accompanied by appropriate cultural practices, can reduce the conditions favorable to the development of the pathogen.
Agrobiotop solutions against verticillium wilt
At Agrobiotop, we develop natural products and biocontrol solutions to protect crops from verticillium wilt and other fungal diseases. If you need an expert, contact us for more information on our products.
For the soil improver allowing aeration and decompaction of soils, avoiding stagnation of water on the ground:
To create a physical barrier against diseases such as verticillium wilt:
- YAKAPROÂ (Biostimulant)
- CHITOPROTECTÂ (basic substance with fungal and bacteriostatic action)
- BENTOBIOÂ (its high absorbency makes this solution an important physical barrier against spores and mycelium of diseases such as verticillium).
Biostimulants that act as a first line of defense against diseases such as verticillium wilt, to be applied to the soil or as foliar sprays:
