Ryegrass: 'Bio genocide' target. A humble fungus is the latest weapon in the graingrowers' arsenal against ryegrass

RICHARD Medd, of the Orange Agricultural Institute, NSW, is winding up research exploring the feasibility of using Pyrenophora semeniperda (fungus) to disturb seed germination and reduce seedling vigour in ryegrass. The project has made encouraging progress in developing P. semeniperda's ryegrass infection rate. The research team has shown that infection can climb to 68 per cent in favourable conditions - or potentially bringing seven out of 10 ryegrass plants under some sort of control.

Continuing resistance to infection has turned the researchers towards methods of weakening ryegrass's defences prior to infection. Trials are now testing >- Current Australian Research application of a range of herbicides at low rates to see if they can be used in partnership with the fungus to lower ryegrass resilience and allow infection to affect its seed germination and seedling vigour.

The project, which has placed significant emphasis on ensuring the fungus has no unwanted environmental side effects, is awaiting laboratory results to gauge P. semeniperda's effect, if any, on neighbouring wheats' grain quality.

Program 3.3.2 Contact: Dr Richard Medd 0263913827