RASPBERRY DISEASES IN MINNESOTA. 



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fective. In planting new areas practice rotation where possible ; 

 that is, do not set out new plants on a field that for one or 

 two years previously has grown diseased canes. 



Young plants that are set out in new plantings, of course 

 should be absolutely free from disease. 



Crown Gall. — This is a bacterial disease which usually at- 

 tacks the plants thru the soil on the roots or at the crown. 

 Large, irregular, tumor-like growths are produced, usually on 

 the roots, though sometimes on parts above the surface of the 

 ground. All types of berries are affected, tho there seems to 

 be some varietal difference in certain localities. Under all cir- 



Anthracnose of raspberries. 



cumstances, however, the presence of the disease in any quantity 

 eventually will mean ruin to the productiveness of the plant- 

 ing. 



The disease is very common and is spread largely by means 

 of nursery stock. Infected soil may remain so for years. 

 The bacteria causing the trouble may be spread throughout a 

 patch by cultivation. Badly diseased plants are of little value 

 and serve as a center of infection. They should be removed 

 and burned. The greatest precaution should be taken not to 

 set out plants that show any signs of the disease, nor to set 

 out healthy plants on land that has grown diseased plants 

 previously. 



Yellows, or Curly Leaf. — This disease, so far as is known, 

 is not caused by a parasite. Heavy, flat soils and the presence 

 of crown gall often cause a yellowing of raspberry plants 

 and are no doubt often mistaken for curly leaf. Close observa- 

 tion, however, will enable one usually to distinguish the true 



