53 



It was considered that soils having calcareous constituents 

 escaped this affection, but Dr. Voelcker wrote, in 1859, that " it 

 must not be supposed that the absence or deficiency of lime is 

 always the cause of the fingers and toes in turnips, and that 

 liming is a, universal preventive of the disease. I have seen 

 fingers and toes in roots grown on calcareous soils, probably 

 containing from 30 to 40 per cent, of lime."* In a field badly 

 attacked by club root Dr. Voelcker found that, upon a small 

 spot, the turnips were free from the disease, and he found that a 

 load of gas lime had been spread there the year before. 

 Dr. Voelcker therefore recommended gas lime as a preventive of 

 this disorder. 



Writing in 1876, Dr. Voelcker says : " My attention has been 

 directed to the investigation of the cause of Anbury, or finder 

 and toe, which did much damage in certain districts in the past 

 season, and I have traced the disease, in a soil sent from 

 Westmoreland, to the deficiency of the available potash and 

 lime in the land upon which the turnip crop was much affected 

 by this disease."t There is no doubt that gas lime, ploughed 

 into the land in the manner described by Mr. Sewell Read, at 

 the rate of two to four tons per acre, would be more efficacious 

 than ordinary lime. It is believed that it is not the absence 

 of lime in the soil constituents that causes Ciub root, since this 

 is found in all soils ; but that lime and gas lime applied hot 

 actually destroy the slime-fungus or their fine particles affect 

 its progress. 



As a means of preventing the slime fungus, Sorauer suggests 

 that plants infected with it should be pulled up and burnt at 

 once, before the plasmodia escape into the soil.J 



It is also very important not to take crops of cruciferous 

 plants, as turnips, cabbage, rape, kohl rabi, and mustard, for some 

 time after an infected crop. Where it is difficult to avoid this, 

 as, for instance, in the case of market gardens, the land should 

 be ploughed deeply, or dug two spits deep, and lime, or gas lime, 

 put on in considerable quantities. Cruciferous weeds should be 

 rooted out from turnip and cabbage land. Charlock is especially 

 subject to the attack of the Plasmodiophora brassica. 



Mr. Jamieson has frequently stated in the reports of the Agri- 

 cultural Research Association that sulphur in the form of manures, 

 acted on by sulphuric acid, increased club root in turnips. 

 He says, " Chief among the predisposing causes seems to be the 

 acidity introduced by manures soaked with sulphuric acid 

 (Superphosphate, dissolved bones, and turnip manure mixtures 

 generally.) This point, which was brought out first by the 

 Aberdeenshire experiments, seems to have been confirmed beyond 

 doubt by Professor Ward in a paper read before the Royal 

 Society. It had also been borne out by the experience of 



* Journal of the Royal Agricultural Society of England, vol. ix., ser. 1, p. 108. 

 f Journal of the Royal Agricultural Society of England, vol. iii., ger. 2, p. 299. 

 j Handbuch der Pflanzenkranhheiten. Von Paul Sorauer. 



