VII.] 



" F1NGER-AND-T0E " 



245 



soils of an acid reaction, in which calcium carbonate is 

 wanting, or present in very small proportions. The 

 fungus, as is generally the case with fungi, refuses to 

 grow in a neutral or slightly alkaline medium, and the 

 only way to get rid of the infection in the land is to 

 restore its neutrality by repeated dressings of lime. At 

 the same time, the land should be rested as long as 

 possible from cruciferous crops ; uneaten fragments of 

 diseased turnips, etc., should not be allowed to go into 

 the dung, or if they do, the dung should be used on 

 the grass land. Manures, again, which remove calcium 

 carbonate from the soil, like sulphate ot ammonia or 

 acid manures like superphosphate, should not be em- 

 ployed ; neutral or basic phosphates, with sulphate of 

 potash on sandy soils, should be employed instead. 



The following figures show the amount of lime dis- 

 solved by hydrochloric acid from soils affected with 

 " finger-and-toe," as compared with spots in the same 

 field where the disease was not in evidence : 



It must be remembered that in these cases the total 

 lime soluble in acids is given, not merely the lime 

 present in carbonate. 



Whenever a turnip crop is seen to be infected with 

 "finger-and-toe" the land should be well dressed with 

 3 or 4 tons per acre of quicklime immediately the 

 crop has been removed ; as long an interval as possible 

 should be given before again taking a cruciferous crop, 



