266 



The Spraying of Plants. 



BLACKBERRY. 



The insect and fungous troubles of the blackberry are treated 

 under RASPBERRY, which see. 



CABBAGE. 



FUNGOUS DISEASES. 



Club-root ; Club-foot ; Finger-and-Toe (Plasmodiophora Brnssi- 

 cce, Woroniu). Description. As its name indicates, this disease 

 causes distinct and marked swellings 

 or " clubs " at certain portions of the 

 root system of the cabbage and re- 

 lated plants; when the attack is 

 severe, the roots are apparently all 

 united into one large swelling wholly 

 distinct from the normal growth of 

 the plant (Fig. 48). The fungus caus- 

 ing the disease may remain active in 

 the soil for several years, and the 

 young plants are frequently very 

 seriously attacked even before they 

 are set in their permanent quarters. 

 Affected plants appear weak and 

 sickly, they grow slowly or not at all, 

 and are disinclined to form heads. 



Treatment. Although club-root is 

 one of the most serious of the dis- 

 eases attacking cabbages, its treat-, 

 ment is not well understood. The 

 successful use of fungicides appears 

 to be hopeless, and until some means 

 of destroying the fungus in the soil 

 has been discovered, the best plan of overcoming the parasite is 

 to starve it out by growing other crops upon the land. It has 

 been recommended that cabbages and allied plants should not 

 be grown upon infested land oftener than once in three years. 

 All material which is capable of encouraging the growth of the 

 fungus should be destroyed, and the spread of the disease should 



FIG. 48. Cabbage club-root. 



