Effect of season on the efficacy of artificial inoculation of Nigrospora oryzae in Sporobolus fertilis

A study has been conducted to determine the effect of season and inoculation method on the expression of the bio-control agent Nigrospora oryzae on Sporobolus fertilis (giant parramatta grass; GPG). Trial sites were established in five locations across NSW with two treatment methods: spore inoculation and planting symptomatic diseased S. fertilis. Results from the first six months after the spring treatment are presented. The results show planting was better than spore inoculation at 26 WAT in Tweed and Manning sites and the opposite in Richmond. At the Clarence site both methods produced similar levels of disease. The study also suggests that a rise in soil temperature could limit the expression of disease. Both methods resulted in crown rot in S. fertilis. Further research is currently under progress to study the effect of disease in other seasons.