Anthracnose is a common fungal disease that affects various lawn grasses, primarily caused by the fungus Colletotrichum graminicola. Among the grass species, annual meadow grass is particularly prone to this disease. It is sometimes referred to as the ‘Basal Rot of Annual Meadow Grass’. The disease is not just limited to this type of grass, but its prevalence in annual meadow grass makes it a significant concern for those who have this species in their lawn.
Identifying Anthracnose
The disease manifests itself during the latter parts of summer and the early phases of autumn. One of the initial symptoms to watch out for is the yellowing of individual annual meadow grass plants. If not addressed promptly, this yellow hue intensifies to a shade of orange-red. An evident sign of the disease’s progression is when the leaf can be effortlessly detached from the plant’s crown, which turns a dark shade of black where the rot sets in.
Conditions Promoting Anthracnose
Anthracnose tends to be a significant concern for UK lawns, especially towards the end of the growing season. Several factors increase the risk of this disease:
- Presence of Annual Meadow Grass: As mentioned, this type of grass is highly susceptible. Thus, a lawn dominated by annual meadow grass is at a higher risk.
- Stressed and Compacted Turf: Lawns that experience excessive stress and compaction are more prone to anthracnose.
- Low Fertility: Lawns with low fertility levels are more likely to be attacked by the disease.
- Extended Soil Wetness: If the soil remains wet for prolonged periods, it can create an environment conducive to the disease.
Prevention and Control Measures
Preventing anthracnose largely revolves around addressing the conditions that make the lawn susceptible to the disease. Here are the three best ways to combat anthracnose:
- Switch Grass Species: By changing the predominant grass species from annual meadow grass to a more resilient species and following good lawn care practices, you can bolster disease resistance.
- Balanced Fertilization: It’s essential to maintain adequate nutrient levels in the lawn. Implementing a balanced fertiliser program can help, but caution should be exercised. Excessive nitrogen application in the autumn might promote another disease called fusarium.
- Aerate and Improve Drainage: Regular aeration can alleviate compaction and stress on the turf, making it less susceptible to anthracnose. If poor drainage is an issue, addressing this can prevent prolonged soil wetness, thereby reducing the risk of the disease.
In conclusion, while anthracnose can be a menace, with the right preventive strategies and lawn care practices, it can be kept at bay. Chemical control is seldom necessary, especially for garden lawns. By focusing on the health of the lawn and addressing the factors that increase susceptibility, one can maintain a lush, green, and disease-free lawn.
