Autumn Diseases 

As Autumn settles in, it is essential to focus on common turf diseases that thrive in the season’s cooler, moist conditions. Proper identification and management of these diseases are crucial for maintaining healthy turfgrass and ensuring optimal playing surfaces. We like to ensure Autumn diseases are controlled so turf is at its healthiest going into Winter. Hence preventative treatment is critical because the turf has limited ability to recover. Below, we explore six key turf diseases and effective management strategies to mitigate their impact.

Microdochium Patch (Fusarium Patch)

Microdochium nivale 

This disease can affect all turf species. Symptoms appear as small, water-soaked patches that enlarge and turn brown. In humid conditions, pink or white mycelium may be visible around the edges of the patches. The disease spreads easily through machinery, foot traffic, and water movement. 

This disease is very common during and after cold, wet, and overcast weather (0-16°C). Note high nitrogen (N) and potassium (K) inputs in autumn and winter can increase disease severity. 

Large Patch 

Rhizoctonia solani AG 2-2 LP

Large Patch is a disease affecting warm-season grasses historically seen in SA and WA but spreading to other states.  Large Patch, as the name suggests, presents as large, irregular patches, displaying colours from brown and tan to yellow. A key indicator of Large Patch is the “orange firing” effect, where the outer edge of the affected area develops a bright orange hue due to the presence of dark brown mycelium.

The disease is commonly observed in the fall when soil temperatures range between 10-30°C with the optimal infection range being 21-27°C. High humidity, persistent rainfall, and poor air circulation accelerate disease development. Again, a preventive treatment plan is essential. The disease spreads easily through machinery, foot traffic, and water movement. 

Ectotrophic Root-Infecting Fungi (ERI) 

ERI are soil–borne pathogenic fungi that cause several root-related diseases, including Spring Dead Spot, Take-All Patch, and Take-All Root Rot (Couch Decline).  This group of disease species is fast becoming the greatest disease threat of turf.  They damage all turf species in all turf situations.  Latest news is our identification of unique ERI species that cause the winter patch disease symptoms in kikuyu in eastern Australia.

(i) Spring Dead Spot  

Ophiosphaerella narmari & O. korrae 

Symptoms appear as brown or dead patches. As the infection spreads, roots, stolons and crown become necrotic. Cold weather mostly contributes to disease spread. Soil temperatures of 15-24°C, with most infections occurring below 21°C. 

(ii) Take-all Patch   

Gaeumannomyces avenae  

Most infections are initiated in autumn when soil temperatures are favourable for mycelial growth. Mycelium can survive in previously infected root, rhizomes or stolons. Symptoms appear as reddish-brown, yellow, or tan patches. As the disease spreads, these patches may merge, leading to large areas of turf discoloration and eventual turf death. 

Soil temperatures between 12-18°C, high soil pH (>7), and nitrate-based fertilizers, increase the severity of the disease.

(ii) Take-all Root Rot (Couch Decline)   

Gaeumannomyces graminis  

Symptoms may appear in autumn. Mycelium surviving in previously infected roots, rhizomes and stolons can spread the infection. Affected areas initially turn tan or yellow, leading to reduced turf growth. Few roots, rhizomes, and stolons remain in affected areas, and they appear rotten. 

Optimal soil temperatures range between 25-30°C, with infections initiating at >20°C, and high soil pH (>7) increases disease severity. 

Of all diseases the ERI group are the most critical to manage preventively.  It is highly recommended to develop a bespoke program that addresses your individual turf type, climate and soil.  Living Turf has harvested research results worldwide to develop a programming tool so you can customise a management program. 

Dollar Spot 

Clarireedia spp.

(C. monteithiana in warm season grasses; C. jacksonii in cool season grasses) 

This disease affects all turf species. Symptoms appear as small, round, tan spots that merge into larger patches as the infection spreads. The disease thrives in soil temperatures between 15-30°C, with high humidity and cool nights encouraging dew formation. Low nitrogen levels and dry soils exacerbate disease severity. 

Pythium Root Rot

Pythium spp.

Pythium root rot is a disease caused by water moulds (oomycetes) that affects both the crown and roots. While we think of Pythium Root Rot as a Summer disease it can cause damage to turf that has been renovated and top-dressed.  The turf is damaged by coring/scarification then exposed to high moisture making it very susceptible to infection.  Preventative sprays before renovation are highly recommended.  Pythium symptoms may first appear as small, diffused yellow patches which expand as the disease progresses. Severely infected turf exhibits discoloured, reduced roots. This disease can occur in saturated soils at temperatures above 15°C, particularly in areas with excessive thatch and poor drainage. 

Helminthosporium (Leaf Spot & Melting Out) 

Bipolaris, Drechslera, Exserohilum spp.

The fungi responsible for leaf spot and melting-out diseases penetrate and infect leaf tissues, initially producing small brown spots. As the disease progresses, these spots expand across the entire leaf blade, leading to complete leaf blight. Bipolaris & Exserohilum cause leaf spots and streaks. 

During the melting-out phase, the fungi infect crowns and roots, causing brown or black tissue rot and severe turf thinning. Drechslera spp. primarily attack the crown and roots, leading to melting-out symptoms. 

Favourable conditions for disease spread includes temperature ranges between 20-35°C for Bipolaris spp. and Exserohilum spp. Symptom expression is turfgrass species dependent, warm season turfgrass is infected in cooler wet periods of autumn, winter and spring. Cool season turfgrass infection occurs during warm, wet weather in summer. Drechslera spp. are active between 3-27°C, with optimum growth at 15-18°C.

Preventative Measures for Disease Management 

Please contact your Living Turf Technical Sales Rep to discuss a plan that fits your specific needs. The following are points that really should be considered. 

 Fungicide Applications:

•  Enhances water penetration and uniform distribution 

•  Reduces water loss due to runoff

•  Increases root mass and length

Recommended Fungicides:

Tribeca provides both preventative and curative control for ERI (Spring Dead Spot), Dollar spot, Fusarium Patch and Helminthosporium. 

Banol and Subdue Maxx offer preventative control against Pythium. 

Heritage Maxx and Azoxy provides control and prevention for a broad spectrum of turf diseases, including Pythium, Helminthosporium, Fusarium patch and Spring Dead Spot. 

Lexicon Intrinsic is a broad-spectrum fungicide that protects against many diseases, including Large patch, Dollar Spot, Fusarium patch, Pythium, and ERI. Intrinsic fungicides also provide the dual benefit of disease control and improved plant health. 

Fertilisation Management:

•  Maintain optimal nutrient (Nitrogen and Potassium) levels and avoid excessive applications.

Irrigation & Moisture Control:

•  Water early in the morning to minimise prolonged leaf wetness

•  Avoid overwatering and ensure proper irrigation scheduling

•  Improve soil drainage through core aeration and thatch reduction

Mowing & Turf Stress Management:

•  Follow proper mowing techniques to reduce stress on turfgrass.

For more help and further information about our Autumn Disease management strategies and/or any of the products mentioned above, please contact your friendly Living Turf Technical Sales Agronomist.