POTENTIAL management solutions for the problematic weed, blue lupin, have been prioritised for further investigation following a Grains Research and Development Corporation (GRDC) review and industry consultation.
The review and consultation have also facilitated discussions with commercial third-party organisations, some of which have indicated they will pursue research options.
This was the message to growers and industry stakeholders attending the GRDC Grains Research Update in Geraldton last week where an update was provided on possible options for managing blue lupin in lupin crops.
Also known as sandplain lupin, blue lupin (Lupinus cosentinii) has hard seeds which persist in the soil and germinate to compete with narrow-leaf and albus lupin crops, particularly in the Geraldton port zone.
Although still used for soil improvement and sheep feed in some areas where there are infertile deep sands, most growers now consider it a weed and no registered herbicides will selectively control it in grain lupin crops.
GRDC senior manager biosecurity and regulation Ken Young said a 2020 review commissioned by the GRDC had provided broad recommendations which had since been prioritised in consultation with growers, agronomists and commercial organisations.
"The report, conducted by Independent Consultants Australia Network, confirmed that there are no viable short-term chemical options available for controlling blue lupin in lupin crops," Dr Young said.
"However, other possibilities for investment in research and development (R&D) identified by the report were discussed with growers and industry representatives at a stakeholder meeting in Geraldton in February.
"At this meeting, the feasibility of the review recommendations was explored and the potential research activities were prioritised.
"The review and industry discussions have also served the valuable purpose of facilitating informed communication with commercial third-party industry players, some of which have indicated they intend to pursue possible research solutions."
Dr Young said it was pleasing to see the broad R&D cross-industry effort on blue lupin that has occurred as a result of this review and consultation.
"In order to get the best outcome on complex issues like blue lupin, it's vital that the GRDC works collaboratively with the commercial industry," he said.
Dr Young said the stakeholder meeting in Geraldton had placed the highest priority on pursuing novel herbicide tolerant lupin varieties.
"During the meeting, lupin breeder Australian Grain Technologies indicated it is prepared to investigate the development of lupin crops that are tolerant to the imidazolinone (imi) herbicides, that could control blue lupins in-crop," he said.
"Lupin varieties tolerant to imi herbicides would serve the additional purpose of controlling other weeds present in grain lupin crops.
"Most people at the stakeholder meeting did not consider it worthwhile to pursue the development of lupin crops tolerant to glyphosate and glufosinate, due to the requirement for genetically modified technology and, in the case of glufosinate, also the cost of the herbicide.
"Pyridine tolerance was also discussed but was ranked a lower priority than pursuing imi tolerance."
Dr Young said another R&D activity identified as a potential option at the stakeholder meeting was to explore the use of pre-emergent herbicides incorporated by sowing - to keep herbicide away from the emerging lupin crop while selectively controlling blue lupin in the inter-row.
"GRDC has initiated a fruitful discussion with the Australian Herbicide Resistance Initiative (AHRI) regarding research to be undertaken in this area by a Masters student this season," he said.
Dr Young said blue lupin biology and ecology was also identified as a research 'gap', particularly in the areas of seedbank persistence, depth of germination and conditions for germination.
"GRDC will pursue blue lupin biology and ecology as an area of interest in its next round of its grains PhD scholarships," he said.
Dr Young said investigating the in-crop use of triclopyr was also discussed and there were varying attitudes expressed at the stakeholder meeting, with some people present being very concerned about the level of crop damage that can occur.
He said another priority identified was the use of 'green on green' optical spraying technology for managing small populations of blue lupins.
"The GRDC has had discussions with the commercial sector, with Bilberry indicating they will prioritise developing an algorithm to distinguish blue lupin present in narrow leaf lupin crops," Dr Young said.
He stressed that any new chemical use patterns for control of blue lupin would require support from chemical registrants and said the GRDC continued to actively work with them.
