170 THE POTATO 



before being given to cattle or pigs, for infection 

 is very readily spread by manure if raw diseased 

 tubers are fed to stock. For the same reason 

 diseased haulms must be burned and never be 

 thrown on the manure heap; this should be done 

 as soon as possible after the crop is lifted, as the 

 'warts' rot very quickly and further contaminate 

 the soil. Dung which has been contaminated in 

 any way should not be used for potato growing. 

 If practicable, it should be applied to land under 

 permanent grass. 



"'Seed' potatoes from a diseased crop or from a 

 field in which disease is known to have occurred 

 within six years should be avoided. If 'seed' 

 potatoes are purchased in a district in which the 

 disease is common, they should be bought as soon 

 after harvest as possible, so that they may be kept 

 under observation; the sets should be freely 

 sprinkled with sulphur (four to five pounds will 

 dress a ton) and should then be stored in boxes or 

 pits until required. 



"Tubers only slightly diseased may be easily 

 overlooked, and may cause widespread infection 

 when planted. Potatoes from an infected crop 

 may appear to be perfectly sound when lifted, but 

 after storing they may develop warts. It is im- 

 portant, therefore, that seed should be carefully 

 examined before planting. As minute warts are 

 difficult to see, a grower would be well advised to 

 reject any seed potatoes among which diseased 

 tubers have been found. 



"In the case of a disease, like wart disease, which 

 infects the land gradually, it is necessary to detect 

 and stamp out the fungus as soon after infection 

 as possible. When discovered the entire plant 

 affected should be carefully removed, the useless 



