Have you noticed brown or grey spots on your lawn, followed by rapid dieback in certain areas? This may be Helminthosporiosis, a fungal disease feared by lawn managers, sports fields and garden professionals. This disease, which mainly targets grasses, spreads quickly in certain conditions that are favorable to it. What are its symptoms? How to combat it with suitable solutions?
Helminthosporiosis: a fungal disease
Helminthosporium leaf spot is a fungal disease caused by fungi of the genus Dreschlera and Bipolaris . Several species, including Helminthosporium dictyoides , Helminthosporium siccans and Bipolaris sorokiniana , are responsible for this disease. These fungi mainly attack grasses used in lawns, such as Kentucky bluegrass, perennial ryegrass and fescues, causing significant weakening of lawns.
The disease is particularly active between spring and autumn, periods when climatic conditions favour its development:
- High and persistent humidity , often caused by heavy dew, frequent rain or excessive irrigation.
- Mild temperatures , ideal for the germination and proliferation of mushrooms.
Lawns already weakened by inappropriate practices, such as excess nitrogen, poor aeration or mowing too short, are more exposed. In addition, the presence of thatch on the ground or excessive shade creates an environment conducive to infection. This context underlines the importance of balanced management to limit the risks and contain the impact of this disease.
Do you need a solution against lawn leaf spot?
What are the symptoms of turf rot?
The first signs of leaf spot appear as brown or gray spots on lawn leaves. As the infection progresses, these discolored areas expand, causing visible dieback of the grass. If left untreated, the damaged patches can multiply rapidly, creating bare patches in the lawn.
Affected lawns often have uneven texture and color, and their general appearance becomes dull . These symptoms, although attributable to various causes, are accentuated when climatic conditions remain favorable to the disease.
Biological cycle and dissemination
Helminthosporium fungi persist as conidia or dormant mycelium on plant debris left on the ground, such as uncollected grass clippings.
Spread occurs mainly by wind or by direct contact between infected and healthy leaves.
In addition, the presence of thatch on the lawn creates an environment where fungi can easily move from one plant to another. This mode of spread, combined with inadequate maintenance practices, accelerates infestation and complicates disease management.
How to prevent helminthosporiosis?
Prevention of helminthosporiosis is based above all on rigorous and thoughtful management of the lawn. Balanced fertilization , favoring slow-acting fertilizers, helps avoid excess nitrogen that weakens the grasses.
Mowing should be carried out regularly, with a cutting height of around 50 mm , and waste should be carefully collected to limit the spread of fungi.
Watering, a key factor in moisture management , requires special attention. It is advisable to avoid nighttime watering to reduce the duration of moisture on the foliage.
At the same time, aeration of the soil helps to improve air circulation and limit the conditions conducive to fungal development.
Agrobiotop solutions against turf helminthosporiosis
At Agrobiotop, we develop natural treatments and solutions to combat various lawn diseases such as helminthosporiosis. Do not hesitate to contact us for any treatment protocol. Here are our recommended products:
For soil improver, soil aeration and decompaction :
Biostimulants :
- YAKADOP (First line of defense against lawn diseases)
For protection against Helminthosporiosis:
- CHITOPROTECT CHITOSANE
- Chitosane (Aspergillus niger)
- YAKAPRO
