Biological Answer To Blackberries Sought

March 3, 2000 The Rural News

State Forests is taking part in a research project to quantify the impact of a biological control agent, blackberry rust, on blackberry around Tumut and Tumbarumba.
State Forests' Flume regional manager, Don Hobson, said the aim of the project was to determine the rust in strain most effective for biological control.

"Since rust epidemics are determined on climate, an extensive study is being conducted to determine the climatic limitations of rust in Australia:' he said.

"This three-year project, co-ordinated by the Keith Turnbull Research Institute of the Department of Natural Resources in Victoria, will help in the selection of new rust strains from Europe, to further improve the biological control of blackberries in Australia"

The blackberry leaf rust is a defoliating disease that attacks blackberry leaves, making the plant unhealthy and reducing growth and seed production.
The main species of blackberry being targeted is Rubus discolor, the most common species found in Australia.

Mr Hobson said as part of the project, State Forests is required to record daily weather details such as rainfall and temperature at a variety of locations in the forests, as well as establishing a number of blackberry monitoring sites close to each weather site.
"We measure blackberry development throughout the growing season from September to May to September and monitor rust infection on leaves:' he said.
Blackberry is one of the most significant weeds in southern Australia. It can cover large areas in short periods, effectively competing with and dominating other vegetation because its dense impenetrable canopy excludes light from the soil surface. Birds and mammals that feed on the ripe fruit readily disperse seed.

In addition to the monitoring program, State Forests' commenced its annual blackberry-spraying program in early January. Two contractors had been engaged to undertake the spraying work and the spraying program is likely to continue through to April.