POTATO. 189 



in pots. New sprouts will start from the eyes again, and the 

 process may be repeated until the tuber is exhausted. By an- 

 other way, the tubers are cut up and planted in good rich 

 loam. As soon as the shoots are six inches or more high, 

 about three inches is cut off the top of each. These pieces are 

 ]3ut in moist sand, watered frequently and allowed all the sun- 

 light they will stand without wilting and treated the same as 

 it is common to treat cuttings of house plants. In three or 

 four weeks, they will be rooted and maybe potted in rich soil. 

 These shoots may again be cut when nicely started,. and so on. 

 The plants thus grown are planted out when the weather is 

 settled in the spring. For best success with these methods of 

 propagation, the work should begin in the late winter or very 

 early spring. 



Insects. There are but few insects that do serious injury 

 to the potato in this section, and the most important of these 

 is the Colorado potato beetle, or ''potato-bug, " but it may 

 also be injured by blister beetles, wire worms and white grubs. 

 (For remedies for these pests, see chapter on insects.) 



Diseases. There are several diseases that sometimes injure 

 the potato. The most common of these are known as the scab 

 and the blight. Scab is a term used to refer to the rough 

 patches with which potatoes are frequently covered. Potatoes 

 so infected are lessened in yield, and on account of being un- 

 sightly and rough do not sell readily. The term blight refers 

 to a disease that kills the tops. 



Scab of Potatoes is caused by a fungous plant working in 

 the surface of the potato. The germs of it are very abundant 

 and live for many years in the soil and also over winter on 

 the potatoes. If these germs are fed to stock, they undoubted- 

 ly grow in the manure, and the use of such manure may often 

 be the cause of infection. Also, they may be spread in the 

 soil by natural drainage, and land receiving the drainage 

 from infested fields may become infested with the disease with- 

 out ever having potatoes on them. Scabby seed potatoes 

 when planted on new or old potato land will generally pro- 

 duce a scabby crop, but the amount of the disease will gener- 

 ally be much more on the old land than on the new. 



Perfectly clean seed potatoes planted on land which is free 

 from the scab fungus will always and in any season produce 



