Farmers are being urged to introduce control measures in the coming weeks to curb this season’s potential increase in Ragwort.
“The trend is attributed to the plant being exposed to the unusual lengthy cold winter followed by improved vernalisation and drought when its deeper roots have been able to access water more easily than grass,” says Nufarm agronomy manager Brent Gibbon,
Mr Gibbon says September is the best month to start Ragwort control as plants are likely to have reached the rosette stage and are still actively growing.
“Treating with a 2,4-D + dicamba (thrust) combination before the end of the month can form part of an eradication programme.
“Introducing a September control programme will also enable farmers to demonstrate they are taking responsibility and adhering to the ragwort control act 2003.
“Following treatment, cattle should not be returned to the field until the plant has fully decayed and become unpalatable, a period likely to take at least six weeks.
“Any surviving ragwort should be dug up and farmers should also be prepared to make a sequential application next spring or autumn since this season’s seeds will continue to germinate.
Treating silage and haylage fields in September also avoids ragwort getting in to cut grass next spring and contaminating the forage, adds Mr Gibbon, which is important as the plant contains a range of related alkaloid toxins which can damage the liver.
“Whilst live ragwort is highly unpalatable, once cut, conserved and eaten by cattle, poisoning tends to occur as a result of eating the plant over a period of weeks or months.
The clinical signs of liver damage can take up to 18 months to develop at which point there is no effective treatment. It is a case of withdrawing the forage and waiting for liver recovery.”