DISEASES OF RICE 101 



sheath, usually for about an inch, and for perhaps a 

 half-inch below. A section cut through the stalk shows 

 the presence of the dark mycelium of the above-named 

 fungus. In consequence of this slow cutting-off of the 

 stalk at the joint the parts above slowly die, and the 

 stalk may break off entirely, especially when it is the 





FIG. 47. Germinating rice grain affected with the blast disease. 



first (leafless) joint below the head that is affected. 

 Any or all joints may become diseased at any stage in 

 the development of the plant, from the period before the 

 head is shot out until the grains are mature. The 

 grains may thus be completely filled out, partially filled 

 out, or not filled at all, according to the time when the 

 attack of the disease occurs. Obviously, a late attack 



