104 DISEASES OF FIELD & GARDEN CROPS. [CH.XVII. 



farmers not to use manures containing sulphur and chlo- 

 rine elements ; the one given usually as sulphuric acid and 

 sulphate in dissolved or soluble manures, the others given 

 in chloride, or muriate of potash, and in common salt. 

 Sulphuric acid is a characteristic ingredient in nearly all 

 vitriolated or phosphatic manures. Prof. Jamieson states 

 that the only crops which are uninjured by these manures 

 are the cereals, and that they should never be used for 

 other crops unless the soil is unusually black ; he con- 

 siders that club-root and sickness in turnips is aided by 

 sulphur, and that chlorine is injurious both to Swedes 

 and peas. Prof. Jamieson is of opinion that the sulphur 

 in the manure (in whatever form) accelerates the elabor- 

 ation of the delectable sulphurous material, in which the 

 dormant spore finds abundant sustenance. At the same 

 time, by the readily available form of the mineral food, a 

 flush of premature growth pervades the cultivated plant, 

 and consequent weakness. Simultaneously the fungoid 

 enemy, at the expense of the higher plant, increases in 

 myriads, war is waged, in which the assailing foe the 

 fungus is never subdued, but may have either a com- 

 plete victory in the death of the higher plant, or only 

 partial victory, resulting in a more or less clubbed root, 

 and a more or less normal bulb above. 



In August 1883 experiments at Hassocks, in Sussex, a 

 conspicuously unhealthy appearance is said to have been 

 observable in all the turnips of the superphosphated plot ; 

 although it had been stated that the club-root disease had 

 previously been unknown in Sussex. 



In October the plants were taken up from all the plots, 

 with the following result : 



M QTI , loAd Total diseased and 



Manures used. knied Plants> 



Ground coprolite . . 11. 



Ground bone-ash 



Superphosphate 



No phosphate . 



Steamed bone-flour . 



Coprolite and steamed bone-flour 



16. 

 51. 

 45. 

 16. 

 3. 



