Fungal Disease in Lawns

Fungal diseases can cause the most serious diseases in turf lawns. Disease problems can be made worse by poor turf grass maintenance but they can also be improved by the introduction of a sound lawn care maintenance regime.

How fungi grow

Some types of fungi have the ability to attack living plants (pathogens) but others live only on dead organic matter (saprophytes) . When high humidity and moisture at the plant base become favourable, they attack the living tissue of the grass, causing severe damage or death. Unfortunately, when the conditions are right, the odd fungal issue will rear its head. Some turf varieties are more susceptible than others and some areas are prone to suffer more than others too.

Thatch

A thatch layer of 6-8 mm is beneficial, any more than 20 mm and problems become more likely. Over time your lawn can develop a thick layer of thatch, dead organic matter, excessive roots and stems within the profile of your grass.  Diseases known to be favoured by high thatch levels include: dollar spot, fusarium blights, pythium blight and helminthosporium leaf spot. Dethatch using a metal rake or dethatching machine can assist in controlling these diseases.

Humidity

Adequate soil moisture levels are essential for the health of your grass and must be provided to keep grass growing actively. But if good drainage is not maintained from over-watering and excessive periods of waterlogging this can encourage fungal disease development. Humid air and heavy dews can also be major factors leading to disease development by keeping the foliage wet.

Soil

An essential requirement for good turf growth is an open, well-drained soil. Compacted areas of soil need to be broken up and treated with gypsum and organic matter to improve soil structure. Core aeration followed by loam topdressing can be helpful over wider areas.

Fertilising

Fertilising can affect the frequency and severity of disease attack. Turf that has been weakened by starvation or is soft and succulent because of excessive nitrogen fertiliser, is often more susceptible to disease attack.
Make sure that you stick to a fertilising program that provides your grass with the nutrients it needs in regular intervals throughout the year.

Injury

It is essential that mower blades are kept sharp to reduce the amount of damage to grass blades. Broken or injured grass blades and stems are more susceptible to wilting and disease attack.

Shade Management

Regular pruning of nearby thick shrubs can improve turf grass growth by increasing light levels and improving air circulation. Water early in the morning not at night, to allow the area to dry during the day. Water deeply, but less frequently, to encourage stronger roots and to allow the water to absorb properly.

If all of the above fail to work, you will need to apply a fungicide. Fungicides kill fungi and the spores within the soil or plant and usually come in a liquid form.

Mancozeb™ is a trusted protectant fungicide that controls a wide range of diseases like powdery mildew, dollar spot and rust. For best results, a complete spray of the entire lawn is recommended.

For more information on specific fungal diseases and how to treat them contact Daleys Turf to learn more.