58 



FARMERS BULLETIN 856. 



Scab is shown by rough-pitted spots due to a parasite which lives 

 in the soil. It is spread by planting scabby potatoes. (See fig. 65.) 



The seed potatoes there- 

 fore should be disin- 

 fected by soaking, before 

 cutting, 1| hours in a 1 

 to 1,000 solution of cor- 

 rosive sublimate or 2 

 hours in formaldehyde, 

 1 to 240. (See p.^ 8.) 

 Five and one-half gal- 

 lons of the solution will 

 cover a bushel of pota- 

 toes. 



When the garden has 

 become infected, seed 

 treatment will not pre- 

 vent scab. x\void lime, 

 fresh stable manure, 

 and wood ashes. Turn 

 under green crops. Plant potatoes elsewhere if possible. Procure 

 Farmers' Bulletin 544. 



WILT AND DRY-EOT. 



To guard against Avilt and dry-rot. sort seed potatoes critically. 

 Cut a. slice from the stem end one-fourth inch deep, and throw 

 out potatoes that have a deep 

 brown discoloration. (Fig. OO.) 

 Cut out and discard decayed parts 

 of the tuber. 



KARI.Y lU.lCHT. 



Early blight appears about 

 midseason as dark, dead spots 

 on the leaves. (Fig. 67.) 



TIPTU-UX. 



Tipburn is a dying of the edges 

 of potato leaves, from too much 



'^ 1 1 1 i! J. /T-'- /'o \ ^'"'*'- ^^- — I'otiito stoin-oiHl lii-owuing due 



heat and lack ot water, (r ig. Ob.) to the wiit fungus, unfit for planting. 



Fig. (iu. — Potato scab. 



LATE-HLIGHT. 



Late-blight (fig. 69) is the most serious disease of potatoes in the 

 Northern States, since it is followed by rotting of the potatoes. 

 (Fig. TO.) 



