The summer period presents a unique set of disease management challenges for sports turf. Elevated temperatures, increased humidity, intense wear, and irrigation stress create ideal conditions for a range of fungal and physiological turf diseases. For golf greens and football stadia alike, the consequences of poor disease control during summer can be severe loss of turf quality, reduced playability, and costly renovation work.
Even with the most diligent adherence to best cultural and mechanical practices, high disease pressure can still lead to visible symptoms and the need to intervene directly with remedial action, although this may require the use of fungicide, the presence of disease may not always need chemical intervention.
Fortunately, the sports turf industry in the UK does indeed continue to benefit from a wide range of amenity fungicides and although -with the loss of products with eradicant potential- it may be fair to point out the options are not quite as wide ranging as they once were, nevertheless, with a more considered approach, such as the utilisation of tank mix fungicide combinations, combined with the ready availability of nutrients and biostimulants, prevention and outcomes after a disease outbreak, can be much improved when compared to using proprietary fungicide products alone.
During the summer, turfgrass plants are often under significant stress due to high soil and air temperatures, reduced root depth and oxygen availability, increased wear from play and maintenance operations, drought stress or excessive irrigation, nutrient imbalances, particularly low nitrogen. Stressed turf is far more susceptible to opportunistic pathogens, many of which thrive under warm, humid conditions.
Anthracnose is one of the most destructive summer diseases on golf greens, particularly on annual meadow grass (Poa annua). It typically develops during periods of heat stress and low nitrogen availability. Symptoms include yellowing and thinning of turf, basal rot leading to plant death and under magnification the presence of black fungal structures. Control strategies include maintaining adequate nitrogen levels through light, frequent application. Avoidance of excessive drought stress and this would typically involve the use of wetting agent. The reduction of mechanical stress where possible and improvement to surface compaction by aeration. Should fungicide be required, Instrata Elite, for example, with its combination of two active ingredients, mixed with phosphite was proven to be highly effective at controlling the foliar blight stage and initiating recovery of anthracnose disease under independent trial conditions.
Dollar spot certainly once considered a more common summer disease on closely mown turf in the south of the country is now seen to be more widespread. It thrives in warm days, cool nights and prolonged leaf wetness. Typical symptoms include small, circular straw-coloured patches with white mycelium visible in early morning dew. Control strategies include maintaining balanced fertility, especially nitrogen, reduced leaf wetness by improving airflow and irrigation timing, the removal of dew and once more, if necessary, the use of a preventative fungicide programme. Again though, independent trials demonstrated a mix of two fungicides, Maxtima and Insignia but this time combined with the plant growth regulation Attraxor and Greenlawnger TR, a green pigment, demonstrated significantly improved efficacy and longevity compared to using the two fungicides in isolation.
Microdochium patch, although traditionally associated with cool, wet conditions can persist into the summer, particularly on golf greens under stress. Contributing factors include compacted, poorly drained surfaces, excessive shade and humidity and turf weakened by heat stress. Control strategies typically involve improving air movement and surface drainage, minimising prolonged leaf wetness, maintaining a steady growth through balanced nutrition and fungicide protection, especially where historical pressure is high.
Indeed, as Microdochium patch is usually the most common disease likely to occur throughout the year, extensive independent trials have been undertaken and consistently proven the benefits of tank mixing active ingredients, nutrients, biostimulants and adjuvants or a combination of all three. In this regard, attention is drawn to the independent trial mixing Heritage (azoxystrobin) with Go Green Plus a unique complexed iron with the mix improving Heritage performance by over 50%. Arguably, similar performance could be achieved with other iron-based products, but it nevertheless focusses attention on how to achieve the best outcome from fungicide use, especially when disease is already prevalent. In this regards the trial began when the presence of disease was already over 15% coverage placing even greater pressure on the performance of the mix.
Rapid blight has become increasingly problematic on football pitches, particularly in stadia environments. Symptoms include rapid decline and dieback, patches of turf failing despite adequate moisture and is most severe during hot weather. The key risk factors are high salinity in irrigation water or soils, elevated summer temperatures and stress. Control strategies include regular monitoring of soil and water salinity, the reduction of salts from the rootzone and the use of preventative fungicide applications during periods of high risk. Rapid blight management relies heavily on cultural practices alongside chemical control.
Gray leaf spot is an aggressive summer disease primarily affecting perennial ryegrass and is increasingly being reported on football pitches and training grounds. Once established, gray leaf spot can cause significant turf loss in a short timeframe. Symptoms include small gray or brown lesions with dark borders, rapid turf collapse under warm, humid conditions, fast spread during periods of intense rainfall or irrigation. Control involves avoidance of excessive nitrogen during high-risk periods, improvement to airflow and reduction of canopy humidity, a reduction in the duration of leaf wetness and the application of fungicides.
Brown leaf spot is an extremely common occurrence on sports turf and is associated with many fungi genera. Typically, affected tissue appears to be discoloured yellow from the tip downwards with a reddish to brown border separating the affected and healthy tissue. An outbreak of leaf spot disease is favoured under warm humid conditions, but it can be found throughout the year and under a range of temperatures, especially when the grass is wet and under stress. In most turf situations it will not lead to serious damage and maybe tolerated rather than treated, although in a stadia environment where presentation is highly scrutinised, treatment and prevention is usually required. In this regard, the only UK labelled fungicide for the treatment of brown leaf spot is Medallion (Fludioxinil), although looking further afield, such as the USA, many of the same UK approved fungicides and active ingredients have label approval for brown leaf spot control.
Across both golf, football surfaces and the many other natural sports surfaces, successful summer disease control depends on an integrated management strategy combining a balanced nutrition programme tailored to plant demand, stress reduction through sound irrigation and cultivation practices. Environmental modification (airflow, drainage, shade) and preventative fungicide programmes with tank mix combinations to ensure optimal fungicide efficacy.
Early identification and proactive management are critical. Waiting for visual symptoms often means irreversible damage has already occurred.
Summer disease management in sports turf requires careful planning, close monitoring, and a willingness to adapt practices to prevailing conditions. For golf greens, diseases such as anthracnose, dollar spot, and Microdochium patch demand a preventative, stress-reduction approach. In football stadia, rapid blight and grey leaf spot highlight the importance of water quality, airflow, and timely intervention.
By integrating cultural, nutritional, and chemical controls, turf managers can maintain high-quality, resilient playing surfaces throughout the most challenging period of the growing season.