The incorporation of lucerne into pasture rotations, whether on its own or in combination with other pasture species, underpins many mixed farming operations across the state.
It is imperative, therefore, says Auswest Seeds product development manager Frank McRae to ensure landholders have the right variety to suit both their soil types and enterprise aspirations.
Mr McRae, based at Borenore, made the point lucerne growth is seasonal; so it must fit not only the environment in which it is being grown but be an important part of the farming system.
"It has also to meet production goals and complement the other forage crops, dual-purpose crops and pastures that are being grown," he said.
Although it was traditionally a summer growing plant, Mr McRae pointed out lucerne varieties are generally selected on late autumn/winter growth, insect resistance and disease resistance.
"Winter active varieties are usually grown where winter feed production is required in cooler months or where seedling vigour is essential for establishment," he said.
"Semi-dormant and winter dormant types persist longer under grazing."
Some varieties are more prone to insect depredation so resistance is important.
Until Blue Green aphid (BGA) and Spotted Alfalfa aphid (SAA) appeared on the scene in the late 1970's, Hunter River was virtually the only lucerne variety grown in Australia.
But its susceptibility to insect attack led to the demise of the pasture mainstay: leading to the introduction of resistant varieties.
Not only was Hunter River susceptible to both the SAA and BGA but was also susceptible to the two major lucerne diseases, Phytophthora root rot and Anthracnose (Colletotrichum trifoli).
"Most varieties today have good resistance to both SAA and BGA," Mr McRae said.
"But once established, the management of the lucerne pastures will override the genetics, so it is vital the plants are not overgrazed."
The plant has a reputation as a high-quality fodder for livestock production, but the influence of growth rates in a lamb-finishing system will depend upon the need to ensure quality.
""Rotational grazing is desirable for all varieties, irrespective of their winter activity," Mr McRae said.
"Having multiple paddocks makes rotational grazing easier to manage, and lucerne should only be set-stocked for short periods. It should be spelled when the plant is directing energy to root reserves for stand persistence and future production.
