I. AGRICULTURE AND RURAL ECONOMY. 393 



against planting their potatoes in a spot where they must, at 

 some time, inevitably be destroyed. 18 A, JVov. 20, 1874,239. 



FAELOW OX THE POTATO EOT. 



A few years ago Dr. "W". G. Farlow, of Cambridge, Massa- 

 chusetts, visited Europe for the purpose of making a special 

 study of the cryptogamic plants, and in this connection spent 

 considerable time in the study of the subject, under the emi- 

 nent Professor De Bary, of Strasburg. A recent number of 

 the Bulletin of the Bussey Institution contains some of the 

 results of this move on Dr. Farlow's part in an elaborate pa- 

 per upon the potato rot. This is an important contribution 

 to the natural history of the subject, embodying as it does 

 the latest knowledge of this most destructive pest. 



It should be remembered that Professor De Bary was com- 

 missioned by the Royal Agricultural Society of Great Britain 

 to carry on investigations in this department, and the labors 

 of Dr. Farlow give the results hitherto ascertained. 



There are still some points in the natural history of the 

 potato rot which are unknown, and which must be deter- 

 mined before any very positive preventive measures can be 

 entered upon. Dr. Farlow sums up the whole matter by 

 stating that there is no such thing as a specific against it ; 

 that is to say, there is nothing that will effectually protect 

 the tubers and also prevent the further development of the 

 fungus, as whatever completely destroys the fungus will be 

 equally fatal to the potato itself; so that the only thing that 

 can be done is to prevent as much as possible any harm to 

 the plants in which the mycelium already exists, and the 

 spread of the disease to healthy, plants. 



If the moisture in the air, about the time when the disease 

 is likely to appear, say from the first of July to the middle 

 of September, can be controlled, the mycelium would not in- 

 crease to any extent so as to produce practically any harm. 

 Unfortunately this can not be done ; but the land can be 

 thoroughly drained, or dry soil used for planting. The wet- 

 ter the soil the more liable is the potato to rot. As the dis- 

 ease does not appear until about the first of August, early 

 potatoes should be less likely to rot than late ones. But ex- 

 actly what variety farmers should plant is not a question for 

 the botanist. Although certain potatoes seem to resist the 



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