Check your Lucerne varieties

Looking at the prolific growth of Titan 5 at Toogong: Andrew Greig, Richard Hazelton, Frank McRae. Photo: Frank McRae
Looking at the prolific growth of Titan 5 at Toogong: Andrew Greig, Richard Hazelton, Frank McRae. Photo: Frank McRae

The incorporation of Lucerne into pasture rotations, whether on its own in in combination with other pasture species underpins many mixed farming operations across the state.

It is imperative, therefore, according to Frank McRae, Product Development Manager, Auswest Seeds, Borenore to ensure landholders have the right variety to suit both their soil types and enterprise aspirations.

Mr McRae 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.

Up until the introduction of the Blue Green aphid (BGA) and Spotted Alfalfa aphid (SAA) 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 the 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.

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