THE POTATO DISEASE 251 



thoroughly rotted, for rank manure induces a gross and 

 late growth highly favourable to attack by the fungus. 

 7. Plant on a sandy loam, or a well-drained soil, as the 

 moisture of a heavy or badly drained soil favours the 

 disease. 8. Use whole sets about two ounces in weight 

 or if cut seed is used the surface should be allowed to dry 

 or preferably be dusted with quick lime. 9. Select 

 varieties least subject to the attack of the disease. 10. 

 Choose a time for planting when the ground is in good 

 working order, allow due space for the development of 

 the plants, as sturdiness of habit induced by due exposure 

 to light and air implies corresponding disease-resisting 

 power ; also supplement the stable or farmyard manure 

 application by a dressing of artificial manure tending 

 to promote sturdy growth and early maturity of crop, 

 always avoiding rank manure and chemicals that induce 

 gross and late growth. 1 1. Cover the seed four inches 

 deep and never exceed six inches. Keep the ground 

 clean and in due course earth up the plants well, not 

 only to prevent the greening of the tubers, but also to 

 safeguard them from infection by conidia of the fungus 

 washed into the soil by rain. 12. Spray the plants 

 with Bordeaux mixture or Bouille Bordelaise, early 

 kinds during the last fortnight of June and other 

 varieties during the first fortnight of July. 



Repeat the spraying a fortnight or three weeks 

 after the first application. As a rule the first dressing 

 of Bordeaux mixture may be made after the plants are 

 earthed up and about one-third grown or before the 

 plants meet in the rows, and the second in about a fort- 



