August 10, 2013
Farmers could soon have access to more lentil varieties bred with improved tolerance to group B herbicides.
Researchers from Department of Environment and Primary Industries (DEPI) in Horsham last year tested levels of tolerance to a range of group B herbicides in several breeding lines of lentils.
DEPI scientist Dr Jason Brand said the work highlighted potential in several emerging lines but also showed different level of tolerance to different chemicals.
“We grew four tolerant varieties from the Pulse Breeding Australia breeding program – PBA HeraldXT, released in 2011 and emerging varieties CIPAL1101, CIPAL1208 and CIPAL1209 – as well as one intolerant variety,” Dr Brand said.
Varieties received 19 different Group B herbicide treatments including the range of imidazolinones, and selected sulfonylurea and triazolopyrimides applied at various rates to the crop at the five node growth stage.
Dr Brand said crops were planted on May 8 last year at Curyo into a no-till system with 30cm row spacings and standing stubble. Growing season rainfall was 30 per cent below the average.
“Visual herbicide damage symptoms were noticed for all treatments applied to the intolerant variety and varying levels of damage observed among the four tolerant lines,” he said.
“PBA HeraldXT and CIPAL1101, which have similar genetic background, showed good tolerance to all but one of the imidazolinone herbicides. The lines CIPAL1208 and CIPAL1209 had greater tolerance to this herbicide.
“Combining the tolerance from lines like CIPAL1101 and CIPAL1209 could lead to new varieties with tolerance to the full range imidazolinone herbicides, with excellent yield potential.
“Early results have also highlighted the importance of testing across a range on chemicals within a herbicide group and not assuming that tolerance will be consistent within a herbicide group.”
The trial was replicated in three other Victorian and South Australian sites with similar results.
Dr Brand said herbicide tolerance could provide considerable benefits to the industry if managed well and the research findings would help define future breeding directions for Pulse Breeding Australia.
“These benefits include improved weed control, increased control options in lentil crops and in the previous rotation phase, and decreased pressure on herbicides currently employed for broadleaf weed control in lentil,” he said.
“We do need to continuously monitor weed resistance levels and discuss and define the best methods for maximising the benefits of this herbicide tolerance technology for the whole farming system.”