THE POTATO DISEASE 253 



About 100 to 1 20 gallons of the mixture are neces- 

 sary for a first dressing, and from 120 to 160 gallons 

 for a second dressing per acre. With the knapsack 

 sprayers, Eclair or Antipest, a man can dress about half 

 an acre per day. The cost of dressing is from eight 

 shillings to ten shillings per acre, depending upon the 

 price of labour and the quantity of Bouille used for 

 each application. 



Affected crops not dressed with Bordeaux mix- 

 ture should be dug up as soon as the skins are suf- 

 ficiently set, as the disease spreads rapidly to the tubers, 

 especially if the weather be wet. 



Thoroughly dry the Potatoes before storing them. 

 Those for seed may be " greened " by exposure to light ; 

 but those for use as food must be kept dark. If stored 

 when wet the spores lodging in them will germinate and 

 develop the disease, whilst the affected tubers speedily 

 decay. 



Store in a cool dry place and sort the tubers oc- 

 casionally, removing infected ones, and dusting in case of 

 infection with dry air-slaked lime at the rate of one 

 bushel of lime to twenty-five bushels of Potatoes. 



THE ILLUSTRATIONS REPRESENT THE POTATO DISEASE (PHYTOPHTHORA 

 INFESTANS). 



A, diseased leaf : a, small brownish blotches ; b, curled leaflets ; 

 c, blackened and decayed portions ; d y whitish mould. B, 

 set : e, apparently healthy sprouts ; f, sprouts retarded in 

 growth and slight depressed blotches on skin. C, section of 

 set : g, browned tissue. D, portion of mycelial hyphae (myce- 

 lium) from browned tissue. E, cluster of conidiophores : 



