Capeweed Control To Boost Grower Productivity

January 14, 2000 The Rural News

Researchers are working with woolgrowers to boost pasture productivity, soil fertility and stocking capacity in southern Australian wool enterprises through the reduction of capeweed content in pastures. A reduction will allow an increase in the legume component and hence boost pasture productivity and profitability.

Trials conducted by the University of Western Australia (UWA) and funded by The Woolmark Company and the CRC for Weed Management Systems have determined the time required to manage capeweed by reducing its seed bank by 90 per cent at low and high rainfall sites.

As capeweed is an annual weed it builds up a large seed bank and through this seed bank capeweed is able to survive from one year to the next, according to Wool-mark program manager, Allan Davey.

"The trial results not only showed the persistence of capeweed's seed bank differing from site to site but found that if the seed is buried it significantly enhanced the longevity, of the capeweed seed;' Dr Davey said.

"At the low rainfall site results showed if the seed was positioned at the soil surface it would Lake three years to reduce the seed bank by 90 per cent and more than four years if the seed was buried.

"While at the high rainfall site, if the seed was positioned at the soil surface only one year was required to reduce capeweed's seed bank by 90 per cent. When the seed was buried, three to four years was required to reduce the seed bank. Capeweed had long been considered a useful feed by woolgrowers but it was of low nutritional value to livestock when compared to legumes and other grass varieties," Dr Davey said.

"Capeweed is one of the most widespread and competitive weeds in southern Australia and the UWA trials had provided the wool industry with extremely useful information to tackle the problem of capeweed.

"In Western Australia alone, the average capeweed content of pastures is between 35 and 50 per cent. The wool industry would now consider undertaking further research that would assist in the development of effective capeweed management strategies which could be implemented by woolgrowers," Dr Davey said.