260 PRINCIPLES OF GARDENING. [CH. Till, 



The statements of a practical man in the Gar- 

 deners Magazine, vol. x. 433., entirely support my 

 views of the disease. He remarks that in 1836, 

 through the prevalence of rain, the late crops of 

 potatoes never sufficiently ripened so as to be 

 marketable. They were resei'ved for planting the 

 next season, and the consequence was, that the curl 

 affected the crops that year to a great extent ; but 

 those who planted well ripened tubers had crops 

 free from the disease, and as productive as usual. 

 Now we all know that the ^dtal energy is always the 

 most powerful in a bulb or seed that is perfectly 

 ripened. 



The results of my view of the disease, sustained 

 by numerous experiments, are, that it will never 

 occur if the following points are attended to : — First, 

 that the sets are from tubers that exhibit scarcely 

 any symptoms of incipient vegetation. To effect 

 which, they ought, throughout the winter, to be 

 preserved as cool, and as much excluded from the 

 air as possible. Secondly, that the tubers should 

 be perfectly ripened. Thirdly, that they should be 

 planted immediately after they are cut. Fourthly, 

 that the manure applied should be spread regularly, 

 and mixed with the soil, and not along a trench in 

 immediate contact "VN-ith the sets. Fifthly, that the 

 crop is not raised for several successive years on the 

 same area. 



