Ausi Blog

Organic oil proving vital in broomrape control

May 17th, 2007

Successful trials of an organic pine oil soil drench in the branched broomrape quarantine zone of South Australia are offering hope that a cost-effective tool is around the corner to help contain and eventually eradicate the invader.

Affected farms in South Australia’s Mallee region have been forced to adhere to tough quarantine restrictions in the wake of a broomrape outbreak, but research supported by growers and the Australian government through the Grains Research and Development Corporation (GRDC) has proven broomrape can be tackled by more than just herbicides.

The University of Adelaide’s Dr John Matthews has shown that an organic soil drench based on pine oil is very effective in controlling branched broomrape.

“The pine oil product is now being widely used in the broomrape quarantine zone,” Dr Matthews said. “Primary Industries and Resources South Australia (PIRSA) is applying the product via a boom sprayer at a rate of a couple of hundred hectares per year.”

Dr Matthews said the pine oil product had been very useful because it reduced the reliance on herbicides for broomrape control in the quarantine zone, providing another option in environmentally sensitive areas including scrubland and riparian zones.

“Although herbicides are good for controlling broomrape in legumes and cereal crops, they are not as reliable for in pastures because they don’t have good selectivity,” he said. “We are continuing to search for herbicide options in pastures, and we are studying herbicide rates and timings in broomrape affected areas.”

Dr Matthews said that although the quarantine zone had not increased during the last year, farmers needed to remain diligent and stay aware of the risks of broomrape outbreaks.

“The eradication program is working around the boundary of the quarantine zone, and is progressing with the support of both Federal and State governments,” he said. “However broomrape is an extremely aggressive parasite with a very persistent seed bank, and has long-lived seed which is slow to decay.”

Dr Matthews said broomrape had an extensive soil type range, and had the potential to threaten areas of Victoria and New South Wales if not managed properly.

“Broomrape can survive on many broad leafed grain hosts, including oilseeds, lupins, vetch and field peas, and it can also live on some common weed species such as capeweed and wild brassicas,” he said. “There is a considerable amount of preventative work being done, as broomrape has huge quarantine and export implications, especially if it moves on to horticultural crops.”

Entry Filed under: Australia Blog