The Botrytis Blight of Tulips 



355 



Fig. 48. intercellular mycelium in leaf tissue. X 600 

 The cells have not yet lost their protoplasm. (Camera-lucida drawing) 



that this toxicity is due to 

 enzymatic action. 



CONTROL 



It has been impossible to 

 carry control experiments far 

 enough to justify making 

 any definite recommenda- 

 tions for the control of 

 Botrytis Tulipae. A con- 

 sideration of the pathogene, 

 however, makes it evident 

 that elimination is probably 

 of first importance. Clean 

 bulbs, free from mycelium 

 and sclerotia, should produce 

 clean tulips, for it is most 

 probable that in these forms 

 the pathogene is carried on 

 the bulbs. Although the dis- 

 ease may possibly be attrib- 

 uted to infested soil, it often 

 occurs on tulips grown in soil Fig. 49. intracellular mycelium in leaf 



, • , , , c , ,. TISSUE. X 600 



in which heretofore no tulips ™ „<•.,,, , 



ine cells ol the leat are devoid of contents, 

 have been grown. (Camera-lucida drawing) 



