Topic: calomel dust paste

[bedrockdave]

just read this in the topic regarding cauli's. what is it and where do you buy it..We have club root very bad and have to lime heavily but its so wet here in Wales that it washes away ;D
  I was under the impression that all chemicals etc for the control of club root had been banned by the eec. well thats what I've been told ???

[Baccy Man]

Mercurous chloride (calomel) was banned in 1991.
http://www.pesticides.gov.uk/approvals.asp?id=55
http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31991L0188:EN:HTML

[tonybloke]

Hmmm , Mercury, delicious!! (not)
Why would anybody want to put this toxin on their food crop??  ???

[chriscross1966]

Cos it was effective against clubroot.....

[Geoff H]

If you look around you will be able to find some varieties of cabbage and cauliflower that have resistance to clubroot. Also try growing all brassicas in seedtrays at seedling stage so they have a good healthy root system before planting out.
Liming - I would use ground limestone or chalk that is less resistant to being leached out. If there is that much leaching it would become so acidic that it would be toxic to brassicas anyway. You need to get the ph up. What does a soil test say?

[cleo]

Wasn`t mercury once deemed a cure for the `clap`

Images of club root spring to mind-well to a filthy mind like mine.

But to be serious those chemicals belong to the days when I was just learning as a gardener and have no place in my shed now

[Robert_Brenchley]

It was indeed. A century ago they were still doing inlays using a technique which involved using an amalgam of silver and mercury, and evaporating the mercury. People working with the process had a short life expectancy! The proverbial madness of hatters was also due to mercury.

[chriscross1966]

If you look around you will be able to find some varieties of cabbage and cauliflower that have resistance to clubroot. Also try growing all brassicas in seedtrays at seedling stage so they have a good healthy root system before planting out.
Liming - I would use ground limestone or chalk that is less resistant to being leached out. If there is that much leaching it would become so acidic that it would be toxic to brassicas anyway. You need to get the ph up. What does a soil test say?

Seconded... varietal selection, rotation and ph adjustment are prolly the best way.... I try to follow potatos with brassicas so that I can lime the brassicas... it also means that the potatos are well away from the liming lessening the risk of scab..... A dusting of lime every five or six years won't really affect the long-term pH of the soil but it will keep the cabbages happy.....