Golf Greens Diseases

The commonest diseases for the majority of greens will typically be Fusarium (Microdochium) patch, Red thread and Anthracnose.

Watch out for Fusarium patch in particular as this can be the most serious and destructive disease of golf greens, which can attack and then spread over a short period of time. Surface moisture control, lower levels of nitrogen and certainly no applied nitrogen when natural growth is slow, reducing plant stress by easing heights of cut, routine aeration and scarification to manage thatch and soil air exchange, and combined with verticutting to reduce decaying surface matter can all help to create agronomic conditions less favourable to this disease. The application of a fungicide to complement good working and agronomic practices may or will be needed, but not too frequently, to ensure the playing surface is maintained to the desirable standard.

Where annual meadow grass has a high percentage presence within a sward then an attack, or two, of fusarium patch disease can be highly likely during the year. An annual meadow grass dominated green needs to be managed carefully, primarily through slightly increasing the height of cut to reduce the stress on the plant (although often the opposite of this takes place, reducing the height of cut which further stresses the plant and produces conditions even less suited to a fescue-bent sward), thinning out (slightly) the sward by verticutting and scarification to improve air circulation amongst the grass leaves, and to ultimately adjust maintenance practices to reduce the encroachment of annual meadow grass by making conditions less desirable and providing conditions which allow the more desirable fescue and bent grasses to be more competitive.

Red thread is a cosmetic disease and if this is noticed during the main growing season then a light application of a nitrogenous fertiliser is all that should be needed to adequately control it. The affected leaves will be rapidly pushed upwards as part of natural plant growth and will be mown off in a relatively short period of time. This disease is a good indicator that a minor adjustment to maintenance practices is needed, often influenced by environmental conditions, to remedy the situation, so if there is a severe attack a review of maintenance practices must be carried out to try and identify any actions which may have contributed to the attack. The main grasses affected will be slender creeping red fescue as well as any dwarf perennial ryegrasses which are occasionally over sown onto some golf greens.

The need to apply a fungicide should be resisted in most cases, except maybe where a major tournament is due and where television cameras are present, and cultural and physical control methods employed to address the cause and not the symptoms.

Anthracnose might also be a significant problem on some greens, especially those which suffer from compaction and where annual meadow grass forms a highly significant percentage of the sward, along with relatively poor soil fertility for the annual meadow grass. The aim should be to encourage maintenance practice which are more suited to a browntop bent and fescue sward, thereby reducing the potential for this disease.

Dollar spot could be an issue on some greens, especially those with high percentages of slender creeping red fescue, although the likelihood of attack is much less common than other diseases. The disease will often occur at the same time as red thread, as well as anthracnose, which can be due to very low levels of nitrogen, but care needs to be taken not to apply too much nitrogen towards the end of August or September as whilst this can help alleviate the effects of dollar spot, it will most likely act as a catalyst for the development of fusarium patch disease. Commonly, the assumed presence of this, often small patchy, disease is more likely either bleached out red thread or yellowing of anthracnose, both of which can superficially look similar to dollar spot from a distance.

Take-all patch disease will be quite rare, often only arising following newly constructed sand profile greens, when soil microbiology is lacking in the antagonistic microorganisms which act as a counter to the take-all pathogen, and will primarily attack Agrostis species. Other conditions when it might occur include where the sand within an established profile is primarily around a pH of 7.0, or where a very acidic profile (for example, one with a pH of about 4.5) has had alkaline materials applied (e.g. lime: calcium carbonate), particularly to the surface layer, to raise the pH to around 6.0 - 6.5.

Fairy rings, types 2 and 3, can provide a visual nuisance, but would typically be tolerated being maintained by picking any fruiting mushrooms and also applying sulphate of iron, or similar, to produce a more uniformly coloured sward at certain times of the year. It is unusual for a destructive type 1 fairy ring to be present on a golf green.

There is often an over emphasis on the range of potential diseases which might potentially attack a golf green but in practice for most courses the actual range is limited.

Reducing fungicide applications can save considerable costs, but will mostly result, especially in the short and medium term, in a reduction in visual and surface quality, especially if annual meadow grass is a significant component of the sward. However, the interpretation of what is meant by detrimental can be quite a subjective judgement. The use of sulphate of iron over the autumn and winter period can help build resilience to fungicide attack and so should be considered where the soil is not excessively acidic.

The use of fungicides can take place at any time of year, although some periods – especially where humid conditions persist for relatively long periods of time – may need more attention than others. A typical number of fungicide applications will vary, with some clubs not applying any to others using these chemicals on four or more occasions per year. Strategies might involve the use of preventative fungicides, supplemented by curative fungicides as and when required, to just the use of curative fungicides; the approach will be influenced by a range of factors, including, available budget, desired quality of surface, the time of year, and especially the extent of annual meadow grass within the sward.