Fusarium Patch

Disease Background

Microdochium nivale

Fusarium patch is a fungal disease which affects most cool season grasses, annual meadowgrass (Poa annua) being particularly susceptible. Fusarium patch is most prevalent during cool, wet conditions, especially on swards which are weakened by unbalanced nutrition or suffer environmental pressures such as waterlogging, thatch or high pH. The severity of the infection will depend upon environmental influences and the susceptibility of the grass plant (stress factors or improved tolerance).


The significance of disease tolerance in grass breeding

There are significant differences in tolerance to Fusarium between individual cultivars within a species. Cultivar selections from the breeding programme are deliberately infected with Fusarium, both in the laboratory climate rooms and in field trials. In addition, Fusarium is also allowed to occur naturally in field trials in order to have a comprehensive picture of a particular cultivar’s tolerance. Graph 1 shows the tolerance of cultivars of fescue (Festuca rubra spp.). Graph 2 shows the tolerance of cultivars of browntop and creeping bent (Agrostis spp.) and crested hairgrass (Koeleria macrantha) and Graph 3 shows the tolerance of perennial ryegrass (Lolium perenne).