206 GARDEN FOES. 



growths, which penetrate the cells, destroy the chloro- 

 I)h3'll, and cause the decay of the leaf and fruit. 



Kemedies. — Once the disease has made itself manifest 

 tlie only remedy is to burn the infected haulm and tubers. 

 On no account should either be allowed to lie on the 

 ground or be given to pigs, as the disease will retain its 

 "vitality and reappear the next year. Nor should tubers 

 from infected crops be used as " seed." Of late years pre- 

 ventive measures have been adopted with great success. 

 Spraying in good time — early in July, again about the 

 middle of the month, and lastly at the end of the month — 

 before the disease appears with the Woburn Bordeaux 

 Emulsion (Formula 21), or the Mixture (Formula 20) is 

 a sure and safe preventive. 



Potato Rot— Dry and Wet Rot of potato tubers is 

 said to be caused by two fungi, Periola tomentosa and 

 Fiisarium solani. The tubers in one case become rotten, 

 although dry, and in the other wet and rotten. These 

 diseases attack the tubers in the soil, as well as in the 

 store. 



Remedies. — Dressing the infected land with ground-lime 

 at the rate of Icwt. per twelve square yards in winter will 

 kill the mycehum present in the soil. All infected tubers 

 should be burnt, not given to the pigs. 



Potato Scab (Sorosporium scabies). — A fungoid dis- 

 ease which causes olive-coloured, scab-like eruptions of a 

 superficial nature to foi*m on the surface of the tubers, 

 which render them unsightly. It has been found by ex- 

 periment that tubers grow^n in sour soils, or where arti- 

 ficial manures containing acids, as superphosphates and 

 dissolved bones, have been lavishly used, are most sus- 

 ceptible to infection. 



Remedies. — As a preventive of Scab, place the seed 

 tubers in a coarse sack, and steep this for two hours prior 

 to planting in a solution of formalin and water — half a pint 

 of commercial formalin to fifteen gallons of w^ater. After 



