162 THE POTATO. 



CHAPTEE XVIII. 



DISEASES OF THE POTATO. 



THE potato, like many other vegetables, has its enemies. 

 Fortunately, in this country it is comparatively immune 

 from insect pests, but not so in regard to diseases. One, 

 at least, has proved a formidable enemy to the potato ever 

 since its appearance was first noticed in Europe about 

 1845. From then onwards to the present time the disease 

 known as the Potato Blight has been a source of great 

 anxiety to potato growers. Science and skill, however, 

 have clearly demonstrated its life history, made growers 

 better acquainted with its manner of development, and 

 taught them the wisdom of adopting preventive measures 

 as a safeguard against attack. The up-to-date grower, 

 therefore, does not run the risk of injury to his crops by 

 disease, but uses his utmost endeavours first of all to 

 plant disease-resisting varieties ; and secondly, to spray the 

 foliage with fungicides before the disease appears. The 

 grower who plants diseased tubers, or varieties prone to 

 disease, or waits till the disease is manifest in the foliage, 

 is on all-fours with the hero of the fable who " locked the 

 stable door after the horse was stolen." So much by the 

 way. 



Potato Blight (Phytophthora Infestans). 



This is the dreaded disease which commits so much havoc 

 among the potato crop in wet seasons. It first manifests 

 itself in the form of brown patches on the leaves, followed 

 by curling of the latter, and finally by their becoming black 

 and decayed. The disease is caused by a fungus, the 



