Dead Patches On Lawn – Fusarium Patch Disease.
After the slightly more prolonged period of snow this winter in the Uk. Lots of people are finding that there lawns have been effected by Fusarium Patch Disease which shows itself as patches of grass that die back or turn yellow and then die back it Caused by F. nivale can be quite serious in its effects.It is a disease of highly cultivated grass and occurs mainly in autumn during muggy weather,or under a carpet of snow over a lawn when the conditions are right,attacks sometimes occur in spring when warm humid condition are present with low light levels.Small patches of yellowish dying grass appear on the turf and they may join together so that quite large areas are killed.The spores produced lead to further spread of disease. Virulent attacks are difficult to stop, and, of course, the damaged turf,if the attack is in autumn, will remain thin throughout the winter.
Prevention of the disease is better than cure, and this is best achieved by keeping the turf firm, not over fertilized and especially by avoiding forcing dressings of nitrogenous fertilizers in late summer or early autumn. Efforts should be made to keep the grass as dry as possible by switching off the dew, using, say, long bamboo and allowing as much air movement as possible over the turf. Annual meadow grass is most susceptible to this disease but other species may be attacked. Lawns which are closed in by tress, and therefore short of free moving air, are liable to suffer.
In some cases where a lawn is known to be prone to annual attacks, a preventative dressing of fungicide can be used, but this requires renewal at intervals of 7-10 days. Most people adopt curative treatment at the first sign of the disease and there are several reliable proprietary turf fungicides available for this purpose. A well tried and not expensive one consists of a combination of the dye malachite green and Bordeaux mixture.