FUNGOUS DISEASES IN SHIPMENTS OF SUGAR CANE. 



11 



of the sheath, which does not have a definite border. Later, the 

 discolored tissue near the center takes on a blackish, sooty tinge. 



The Sclerotium disease enters the stem through the bundles at the 

 point of attachment of the leaf and then advances both above and 

 below the node, frequently forming cankers on the stem. (See 

 fig. 6.) Infection rarely, if ever, takes })lace at the internodes. If 



Fig. 5.— Pineapple disease of sugar cane. The cutting at the right was completely ruined in a few days, 

 although its condition when planted was like that of the sample shown at the left. (After Cobb.) 



the attacked leaf sheath is pulled off there may be seen a network of 

 fine white shiny threads of the fungus at the base of the sheath. 

 Later, the sclerotia, or resting stage of the fungus, consisting of small 

 round bodies, at first white, then light yellow, and finally brown, arc 

 formed. These sclerotia remain in the tissue of the cane or drop oft" 

 on the ground and are capable of carrying the fungus through con- 

 ditions unfavorable for its growth, such as dryness. Under favorable 



[Cir. 126] 



