THREAD BLIGHT OF TEA PLANT 327 



The amount of evidence forthcoming seems to suggest 

 that the mycelium travels underground, and first attacks 

 the root, afterwards passing up the stem, either externally 

 or internally, always finally coming to the surface. 



PREVENTIVE MEANS. It seems to be generally admitted 

 that thread blight is common in the jungle on various 

 plants; and to prevent its spread to the tea plants, narrow 

 trenches should be kept open. These need not be very 

 deep, as underground mycelium runs near the surface. 

 By similar means, diseased patches in the plats should be 

 isolated. Prunings should be burned and not buried, as 

 each buried mass may prove a centre of infection. If 

 quicklime is available, and not in other respects injurious 

 to the tea plant, a shallow trench should be made round 

 the stem, filled with lime, or lime mixed with sulphur, and 

 covered over with soil. 



Spraying with Bordeaux mixture or with potassium 

 sulphide would check the external spread of the mycelium 

 on the plant. 



Watt, Pests and Blights of the Tea Plant, p. 433. 

 Cunningham, Scientific Mem. Med. Officers of Army of 

 India, pt. x. p. 20. 



Massee, Kew Bulletin, 1898, p. in, figs. 



COFFEE TWIG DISEASE 



(Necator decretus, Massee. ) 



Bursting through the epidermis of young shoots as 

 minute white spots, which soon become orange-red and 

 gelatinous. Said to be a destructive parasite on coffee 

 trees at Singapore. Commencing at the tips of young 



