Understanding Integrated Disease Management

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A focus on Microdochium patch, by Henry Bechelet, ICL Technical Sales Manager for the UK and Ireland.

Integrated Disease Management (IDM), a term often interchanged with Integrated Pest Management (IPM) or Integrated Turf Management (ITM), signifies a comprehensive approach to disease management that transcends the simple reliance on chemicals to control them. IDM is an all-encompassing strategy that combines good cultural practice with environmental monitoring as well as the judicious use of plant protection products when needed. The aim of IDM is to manage turf diseases effectively and sustainably.

What is IDM?

IDM represents more than just a modern buzzword; it embodies best practice as a deliberate, systematic approach to tackling turf diseases. It requires an understanding of the disease life cycles and the environmental factors that drive their development. The aim is to use this knowledge to create a less conducive environment for the development of the disease and also to understand when the use of control measures might be needed to prevent turf damage. IDM aims to manage diseases in a manner that is extremely effective and well as being economically viable and environmentally sensitive.

Core components of IDM

Effective disease management requires a focus on the following key areas:

1. Species selection: If possible, turf managers should aim to create a dominance of turf species that exhibit a greater natural resistance or reduced susceptibility to problem diseases. For instance, Browntop bent might be preferable to Poa annua when trying to reduce the impact of Microdochium patch disease.

2. Monitoring: It is important to constantly monitor environmental conditions to determine if they are conducive for the development of the disease (temperature, leaf wetness, moisture and so on). Integrated disease management is most effective when treatments are made preventatively in anticipation of an emerging attack. Monitoring can involve the use of advanced tools such as weather forecasting systems and disease prediction models (as found on the Syngenta Turf Advisor app).

Prevention is not always possible and so constant monitoring of the turf is also necessary to identify the signs of early disease development in order to prompt a rapid treatment response. It is common for localised areas of the course to be more susceptible to attack and so these areas can be used as an early indication that a more widespread attack might be in danger of developing.

3. Cultural practices: Considerate mowing, aeration, irrigation and nutrition techniques are needed to maintain turf health and reduce the vulnerability to disease. Other factors such as surface moisture removal and thatch reduction might also be needed to create a less conducive environment for the development of the disease. The cultural management strategy should employ all necessary measures needed to reduce the likelihood of the disease developing.

4. Plant protection products: Fungicidal controls might be needed if there is a high risk of a damaging disease outbreak developing. Preventative strategies should only be used during high risk periods and in conjunction with a fully integrated approach. Plant protection products are highly regulated technologies and should be used in strict accordance with the label specifications.

Applying IDM to Microdochium patch

The way in which we manage Microdochium patch disease, exemplifies the practical application of IDM principles. We take a fully integrated approach because Microdochium patch disease can be extremely damaging, particularly in cool-season turfgrasses. Caused by the fungal pathogen Microdochium nivale, this disease can occur at any time of the year, primarily driven by cool, wet environmental conditions. Because Microdochium nivale is adapted to develop in cool conditions, the autumn and winter would be regarded as the high-risk period in the UK and Ireland.

1. Species selection: In terms of species selection, the majority of golf greens in the UK and Ireland are dominated by the presence of annual meadowgrass (Poa annua), which is highly susceptible to attack from Microdochium nivale given favourable conditions. Many course managers seek to improve the sward species composition of their greens in order to reduce their susceptibility to attack from Microdochium patch. Long-term strategies to increase the proportion of Browntop bent and Creeping bentgrass species are commonly in place for this reason.

2. Monitoring: It is important to be aware of the environmental conditions that trigger Microdochium patch disease activity (cool and damp). The Syngenta Turf Advisor app can help you with the daily monitoring of the temperature (5-15 degrees Celsius being optimal), leaf wetness and growth potential to give an appreciation of the potential for disease activity. The ‘GreenCast Microdochium-model’ will also help in this regard, giving a rating for the level of disease pressure. The longer the period of conducive conditions, the greater the likelihood for attack and so environmental monitoring should be used to trigger preventative action.

3. Cultural practices: Good cultural practice can be extremely effective at slowing down the rate of development of Microdochium patch disease, even during periods of high pressure. Slowing down the rate of disease development is important to give a greater level of flexibility and control, it also limits the level of potential damage, and it might help to enhance the effectiveness of fungicidal applications. We might consider the following cultural management tactics:

• Minimising leaf wetness: Leaf wetness can be minimised with physical removal of surface moisture / dew where appropriate or the use of surfactant-based dew dispersants. Minimising periods of leaf wetness can also be achieved by adjusting irrigation schedules during the summer and early autumn.

• Maintaining optimal nutrient levels: Ensuring adequate growth with the appropriate use of nitrogen and supporting nutrition levels (iron and potassium) to maintain turf resilience and help harden the sward against attack. Avoid using organic or nitrate sources of nitrogen during periods of high disease risk.

• Managing thatch and organic matter: Maintain subsurface organic matter contents with recommended guidelines to maintain a healthy and functioning soil profile and help reduce the saprophytic habitat of the fungus.

• Environmental modification: Enhance light and airflow by managing the surrounding vegetation.

4. Plant protection products: Modern fungicides can be extremely effective management tools against Microdochium patch disease. Generally, they work best when applied preventatively but they can also offer curative control of active outbreaks. Fungicide programmes need to be scheduled properly to be fully effective during extended periods of high disease pressure. The choice of fungicide as well as the sequencing and frequency of applications will be dependent on conditions and may require specialist advice.

Conclusion

IDM is a strategy that blends cultural practice, environmental monitoring and chemical controls to minimise the impact of potentially damaging turf diseases like Microdochium patch. By understanding the nature of the disease, constantly monitoring environmental conditions and implementing thoughtful management strategies, turf managers can maintain healthy, resilient and high performing turf throughout the year.