Red Thread Disease

Scientific name: Laetisaria fuciformis

Identification

Typically this disease occurs during the middle to late summer and early autumn. Fine red filaments, or outgrowths, are present on the leaf. The size of the infected area can vary from small spots to a large patchiness of infection.

This is generally not considered a serious disease, however, for high profile areas the cosmetic disfigurement and die back of the grass is usually unacceptable and would require treating.

Main grasses affected

Red fescues: Slender and Strong Creeping Red Fescues (Festuca rubra ssp); Chewing's Fescue (Festuca nigrescens) is much less susceptible than the creeping red fescues.

Perennial Ryegrass (Lolium perenne) in intensively maintained winter games pitches on sand profile constructions.

Lesser incidences can occur on 'Highland' Browntop bent (Agrostis castellana) and lesser incidences still on Creeping bents (Agrostis stolonifera) and Browntop bents (Agrostis capillaris). Smooth stalked meadow grass (Poa pratensis) might also be subject to a minor attack.

Conditions favourable to the disease

  • Warm weather;
  • Low nutrient levels, especially Nitrogen;
  • Surface moisture;
  • Very high sand rootzones;
  • Damaged grass tissue;

Control measures

  • Maintain adequate nitrogen inputs. Be careful not to apply excessive amounts of nitrogen as this can encourage fusarium patch disease, especially after late summer;
  • Remove dew early in the morning;
  • Keep the soil well aerated, encouraging a deep rooted healthy turf;
  • Reduce thatch layers - both depth and density of them;
  • Improve air circulation around the area: Consider thinning hedges, trees etc., removing overhanging branches;
  • Use more resistant cultivars where available;
  • Take care with high sand content constructions;
  • Ensure mowers have sharp cutting blades and are correctly set;

Notes

Improved, generally modern, perennial ryegrass cultivars with lower growth habits have an increased susceptibility to red thread disease than the older cultivars.

Reports in 1994 showed occasional attacks of red thread to have been recorded on some 60% of professional football pitches and some 20% of local authority football pitches.

Of the incidences of red thread on the professional football pitches, about three-quarters were in the autumn whilst one-fifth were in the summer.

For football pitches a 50:50 mixture of perennial ryegrass : smooth stalked meadow grass can provide an improved chance of reducing the extent of any red thread attack, (this was also applicable to reducing the incidence of fusarium patch disease). This is in contrast to a sward containing a higher proportion of either one or the other species.

Choosing more disease tolerant cultivars of perennial ryegrass can assist in maintaining improved ground coverage where a pitch is subject to football type wear.

The increasing use of high sand content rootzones has lead to an increase in the incidence of red thread.

References

Baldwin, N.A., 'Turf disease notes', The Journal of the Sports Turf Research Institute, 1987, 157;

Baldwin, N.A., Turfgrass Pests and Diseases, Third Edition, STRI, 1990

Raikes, C., Lepp, N.W., Canaway, P.M., 'Major diseases, pests and weeds of winter sports turf. I. Results of a questionnaire survey of professional football clubs', The Journal of the Sports Turf Research Institute, 1994, 55-82;

Raikes, C., Lepp, N.W., Canaway, P.M., 'Major diseases, pests and weeds of winter sports turf. II. Results of a questionnaire survey of local authorities', The Journal of the Sports Turf Research Institute, 1994, 83-99;

Baker, S.W., 'The effects of shade and changes in microclimate on the quality of turf at professional football clubs. II. Pitch survey', The Journal of the Sports Turf Research Institute, 1995, 75-83;

Raikes, C., Lepp, N.W., Canaway, P.M., 'The effect of dual species mixtures and monocultures on disease severity on winter sports turf', The Journal of the Sports Turf Research Institute, 1996, 67-71;

Raikes, C., Lepp, N.W., Canaway, P.M., 'The effect of red thread (Laetisaria fuciformis) incidence on wear tolerance of monostands of perennial ryegrass (Lolium perenne) cultivars under three nitrogen levels', The Journal of the Sports Turf Research Institute, 1996, 61-66;

Gooding, M.J., Baldwin, N.A. & Smith, M.A., 'Observational note: Red thread on Poa pratensis cultivars', The Journal of the Sports Turf Research Institute, 1990, 174-176;

A.R. Woolhouse, 'The assessment of perennial ryegrass cultivars for susceptibility to red thread disease', The Journal of the Sports Turf Research Institute, 1986, 147-152;