250 CHOPS THAT REQUIRE TRANSPLANTING 



Wilt. — Another disease of the tomato is the fusarium wilt. 

 This cannot be controlled by spraying, for it lives over winter in 

 the soil and infects the plants through the roots. The first evi- 

 dence of its presence is the sudden wilting and dying of the entire 

 plant or of one or more of its branches. Cross-sections of the 

 wilted stems show a discolored, brownish appearance of the woody 

 portion, and microscopic examination of the discolored tissue 

 reveals the presence of a fungus. The plants may die before any 

 fruit has matured, or at any time during the normal fruiting 

 season (Fig. 153). 



^k 



Fig. 153. — Tomato plantation completely ruined by fusarium wilt. 



The first season that the wilt appears in a given field, usually 

 only a few plants are infected; but if the same field is used for 

 tomatoes the next year, the attack is likely to be very severe. 

 The best way to avoid serious damage from the disease is to prac- 

 tice rotation of crops so that the soil will not become badly infected. 

 Care should also be taken in securing soil for the hotbeds and cold- 

 frames in which the plants are grown. Fresh soil should be put 

 in the beds each year, and it should be secured from a field which 

 has never grown tomatoes nor received the wash from tomato 



