Tulip Diseases 349 



This would seem to indicate that blindness does not 

 necessarily mean run-down bulbs. It is very likely 

 that the treatment during the curing, storage, or 

 planting to a certain extent predetermines blindness. 



Smut 



Caused by Ustilago tuliptz (H.) Wint. 



Like the tulip rust, the smut is of little or no eco- 

 nomic importance. Very little is known about either 

 the disease or the causal organism. 



Rust 



There are two kinds of rust on tulip leaves. Each 

 of these is caused by two species of Puccinia, namely, 

 P. tulipa Schw. and P. prostii. Very little is known 

 of these rusts; fortunately, also, they are of little 

 economic importance. 



Bulb Rot 



Caused by Sclerotinia parasitica Massee. 



Symptoms. The rot seems to be confined to the 

 scales of the bulb only. The plate as well as the 

 roots remains unaffected. When a tulip bulb is cut 

 open, the scales are found to be more or less soft- 

 ened, grayish, water-soaked, and the inner part to be 

 more or less rotted. As the rot progresses, the outer 

 scales become covered with a mold which forms olive 

 brown, velvety patches (fig. 72, b.). This is made 



