Sir, – Prof Eugene O'Brien's call (March 8th) for the prevention of the spread of rhododendron is welcome but is certainly less pressing than the prevention of the spread of more pernicious and dangerous plants. There was a time when if farmers, particularly, became aware of the presence of ragwort they had to report it to the authorities or face prosecution under the Noxious Weeds Act 1936. It would be interesting to discover how many prosecutions there have been under this Act in recent years, bearing in mind how abundant ragwort is during the summer, as is visible to any casual observer driving around the country. Even worse is Japanese knotweed, which isn't even on the list of noxious weeds, and it seems to be proliferating throughout the country where it can do real damage, particularly in urban areas. Perhaps it is time for the Minister responsible to revisit this whole area. – Yours, etc,
BRENDAN McMAHON,
Naas, Co Kildare.