Tim Nigussie1, Jason Brand1, Mitchell Fromm1, Laura James1, Larn McMurray2
1 Agriculture Victoria, Department of Jobs, Precincts and Regions, 110 Natimuk Road, Horsham, Vic, 3400, firstname.lastname@example.org,
2 Global Grain Genetics, Clare, SA, 5453
Lentil (Lens Culinaris M.) is a poor competitor with weeds and its sensitivity to herbicides make broad-leaf weed control challenging. Herbicide resistance due to overreliance on group B herbicides in herbicide resistant crop varieties has also become a concern. Group C herbicides control many broad leaf and some grass weeds. However, this group of herbicides have a low safety margin between phytotoxicity to weeds and to the lentil crop. Field experiments evaluated the Group C herbicide sensitivity of three lentil genotypes PBA Hurricane XT, PBA Jumbo and PBA Jumbo 2 in comparison to a new genotype (SP1333) with improved metribuzin tolerance. Diuron, simazine, metribuzin and terbuthylazine were applied post-sowing pre-emergence at various rates. All genotypes did not show sensitivity to 765 gai/ha of diuron and up to 3600 gai/ha of simazine and produced grain yield equivalent to their respective nil treatment. However, application of higher rates of metribuzin and terbuthylazine caused significant injury and a subsequent yield loss of up to 100%. SP1333 had better tolerance to lower rates of metribuzin, terbuthylazine and higher rates of diuron than PBA Hurricane XT, PBA Jumbo and PBA Jumbo 2, providing opportunity for breeding programs to develop varieties with improved tolerance to group C herbicides.