Diseases that affect your lawn can be roughly divided into two categories:
Turf Foliar Disease: Foliar diseases come in a range of spots and marks on the leaves of the grass. For example, you may have seen tiny orange coloured blobs on grass leaves from time to time. These are indicative of the presence of the rust fungus. Most of these foliar diseases are often 'cured' in the home situation when the grass is next mown and the spots disappear.
Turf Root Disease: The root diseases are caused by a wide range of fungi and can be difficult to diagnose. Sometimes there are few symptoms that anything is wrong except that perhaps the grass is not growing as vigorously as it should or used to. Because the root system is damaged the plant can't uptake nutrients and water and shoot growth is slowed or stopped.
In the home situation, the severity of diseases is rarely enough to warrant fungicide applications unless wanting to maintain a high turf standard. Prevention is a better course and includes encouraging steady growth of your turf through the use of slow release fertilisers and ensuring irrigation occurs at times when water won't sit on the leaf surface for long periods. Many fungi require the presence of high moisture and humidity to attack, so irrigating very late in the day or at night when the water can't evaporate can increase the chances of infection, while watering when the leaf surface can dry relatively quickly will decrease chances of infection.
Below we have provided a range of turfgrass diseases that are found and can result in causing damage to warm- and or cool-season turfgrasses. Included within each disease thumbnail are technical descriptors and control options for both the home owner and professional sports turf ground manager or superintendent.
Nostoc, Oscillatoria, Chlamydomonas and Anabaena spp.
Colletotrichum graminicola and Microdochium bolleyi
Drechslera spp., Curvulari spp., Bipolaris spp. and Exserohilum spp.
Grey slime mould
Drechslera, Curvularia and Pyricularia spp.
Leptosphaerulina Leaf Blight
Puccina & Uromyces spp.
Spring Dead Spot