158 DISEASES OF CROPS. 



stems of lettuce plants which have been destroyed by the 

 fungus." 



Prevention. — (1) Burn infested lettuce stumps, etc. (2) 

 Destroy groundsel, nipplewort, corn sowthistle, and other 

 weeds. 



Cure. — Water infested plants with a solution of iron 

 sulphate (2 per cent, solution). 



(7) The Parasites of the Tomato {Lycopersicum 

 esculentmn). 



The Tomato Eelworm {Tylenchus sp.?), like the 

 various " eelworms " already described, belongs to the 

 Anguillulidoe. It attacks the roots and rootlets of L. 

 esculentum. 



The Dodder (Cuscuta trifolii), already described as 

 a parasite of clover, attacks tomato plants. 



Prevention and Cure. — See chapter ii. 



Peronospora infestans also attacks L. esculentum, 

 especially when grown out of doors. 



Prevention and Cure. — See the treatment of the potato 

 disease in chapter iii. 



Chlorosis of Tomato Stems and Leaves. Tomato- 

 growers are well aware that the leaves and stems become 

 spotted or blotched. This is not due to the attacks of 

 fungi or insects, but indicates imperfect nutrition. 



Prevention and Cure. — Use dressings containing kainit, 

 nitrate of soda, superphosphate of lime, and iron sulphate. 



