HOW TO FIGHT POTATO ENEMIES. 59 



FUNGUS DISEASES.* 



While there are several fungus diseases which attack the 

 potato,, the scab and the early and late blight are the most prev- 

 alent and the ones most to be feared in Maine. 



POTATO SCAB. 



Potato scab, which is too weli known to need description, can 

 be held in check by planting previously treated seed in clean land. 

 As it is next to impossible to get this fungus out of the soil, 

 great care should be taken not to get it in. Soak the uncut seed 

 potatoes for two hours in either formula i or ia and then spread 

 out to dry. After drying the potatoes may be cut and planted 

 in the usual way, care being taken not to allow them to touch 

 any box. bag or bin where scabby potatoes have been kept. All 

 treated tubers should be planted to avoid danger from the poison 

 on them. 



EARLY BLIGHT. 



This disease is wide spread and destructive. It is confined to 

 the leaves and green stems, and appears about the time the tubers 

 begin to form, but may come earlier if the growth of the plants 

 has been checked in any way. The first indication of its pres- 

 ence is the appearance on the leaves of grayish brown spots, 

 which soon become hard and brittle. The disease progresses 

 rather slowly, the spots gradually becoming larger, especially 

 along the edges of the leaflets. At the end of ten days to two 

 weeks half of the leaf surface may be brown, withered, and 

 brittle, while the rest is of yellowish green color. The tubers 

 stop growing almost as soon as the leaves are attacked, and as a 

 result the crop is practically worthless.- This can be prevented 

 by the use of Bordeaux mixture, formula 2. 



LATE BLIGHT, OR ROT. 



This disease attacks the leaves, stems and tubers. Generally 

 the first noticeable effect upon the leaves is the sudden appear- 

 ance of brownish or blackish areas, which soon become soft and 

 foul smelling> So sudden is the appearance of the disease in 

 some cases, that fields which one day look green and healthy may 

 within the next day or two become blackened as though swept 



* For illustrated description of the fungus diseases of the potato send to your 

 congressman, or the Secretary of Agriculture, Washington, 1). C, or to this Station 

 for Farmers' Bulletin No. 91 of the U. S. Department of Agriculture. 



