Tolerance of Austrodanthonia fulva, Microlaena stipoides and Elymus scaber seedlingsto nine herbicides

I. ColeA, T. KoenA, J. MetcalfeA, W. JohnstonB and M. MitchellC

A NSW Department of Land and Water Conservation, PO Box 445, Cowra, New South Wales 2794, Australia.

B NSW Department of Land and Water Conservation, Queanbeyan, New South Wales 2620, Australia.

C Agriculture Victoria, RMB 1145, Rutherglen, Victoria 3685, Australia.


Summary

Native perennial grasses have the potential to reduce or even reverse environmental degradation in south-eastern Australia. The key to their success as sown cultivars is that high quality seed becomes available in the marketplace at a reasonable price. An important barrier to producing seed of these native species has been the difficulty of establishing commercial seed crops because of competition from annual weeds. This paper reports the results of a glasshouse experiment that evaluated herbicide tolerance of seedlings of Austrodanthonia fulva, Microlaena stipoides and Elymus scaber accessions selected for desirable growth and persistence attributes.Nine herbicides registered in New South Wales for the selective control of annual weeds; atrazine, bromoxynil, chlorsulfuron, cyanazine, diclofop-methyl, metolachlor, metsulfuron-methyl, prometryn and simazine were applied to native grass seedlings at the three-leaf stage at two rates.

Elymus scaber displayed tolerance to metsulfuron-methyl (4.8 g a.i. ha-1), chlorsulfuron (15-30 g a.i. ha-1), metolachlor (432 g a.i. ha-1), diclofop-methyl (563-1125 g a.i. ha-1) and bromoxynil (400-800 g a.i. ha-1). Partial tolerance was shown to metsulfuron-methyl (9.6 g a.i. ha-1) and metolachlor (864 g a.i. ha-1). Sensitivity was shown to atrazine (500-1000 g a.i. ha-1), cyanazine (750-1500 g a.i. ha-1), prometryn (625-1250 g a.i. ha-1) and simazine (750-1500 g a.i. ha-1).

Microlaena stipoides was tolerant to chlorsulfuron (15 g a.i. ha-1) and partially tolerant to bromoxynil (400-800 g a.i. ha-1), metsulfuron-methyl (4.8-9.6 g a.i. ha-1), chlorsulfuron (30 g a.i. ha-1), metolachlor (432 g a.i. ha-1) and to a lesser degree, diclofop-methyl (563-1125 g a.i. ha-1) and metolachlor (864 g a.i. ha-1). Sensitivity was shown to atrazine (500-1000 g a.i. ha-1), cyanazine (750-1500 g a.i. ha-1), prometryn (625-1250 g a.i. ha-1) and simazine (750-1500 g a.i. ha-1).

Austrodanthonia fulva was tolerant of metolachlor (432 g a.i. ha-1) and showed partial tolerance to bromoxynil (400-800 g a.i. ha-1) and metolachlor (864 g a.i. ha-1) but was sensitive to all the other herbicides tested.

Key words: native grass, herbicide tolerance, establishment, Microlaena stipoides, Austrodanthonia fulva, Elymus scaber.

 

Plant Protection Quarterly (2003) 18 (1) 18-22.