316 LUTHER BURBANK 



from various quarters are grown that difficulty 

 occurs. 



These pests gather around the lower part of 

 the bulb and if the bulbs are left in the same 

 place several years the insects often destroy them 

 completely. 



Although this is not generally known, it is the 

 common cause for the destruction of lilies. 

 Many have had beautiful lily beds exterminated 

 and have been unable to determine the reason. 

 Often by transferring the bulbs to another loca- 

 tion, if thoroughly disinfected before replanting, 

 they can be saved. 



If gladiolus bulbs, for instance, are planted in 

 the same place year after year, they do not thrive. 



Usually there are fewer and fewer bulbs as 

 the seasons progress, rather than more, and those 

 that are produced are much smaller than the 

 bulbs originally planted. The plants are also 

 sooner or later destroyed. 



The third year the crop is almost a complete 

 failure. It is especially necessary to practice 

 rotation of crops with gladiolus and lilies. 



The same thing is more or less true with most 

 other bulbs, as most of them have a bitter poison 

 or protective principle that repels these insects. 

 Some of them, of course, are not quite so sus- 

 ceptible to the ill effects as others. 



