Vegetable and Field Crops 



261 



as the cause of partial or even total losses of the crop. 

 The plants usually reach considerable size, blossom, and 

 set fruit before showing the disease, which first appears 

 in the field on single plants, generally sickly looking, and of 

 unhealthy color, followed by symptoms of wilt. In the 

 worst cases all of the plants die before the end of the growing 

 season, sometimes quite suddenly at the last; or the crop 

 may mature with plants missing more or less extensively. If 

 a l)a(lly affected or dead plant l)e pulled up, the roots are 





I i« .. 1 12. - Tuiuatu licld showjag effect of wilt. 



found to be decayed. If a plant is pulled up as soon as it 

 begins to show wilting, the roots look healthy and sound, 

 but close inspection shows that many of the larger laterals are 

 decayed at the ends. The disease consists of a dry rot of the 

 roots, commencing at the ends and working upward. 



The first symptom is a pale yellowish color of the lower 

 leaves, which soon dry from the tip toward the base without 

 spotting. The veins and woody portion of the stem are 

 darkened, especially upon the side bearing the diseased 

 leaves. 



As to means of dissemination and control, what is said 

 under soil diseases will apply. 



