LUTHER BURBANK 



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. Some- 

 times by transferring the bulbs to another location, 

 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 less 

 vigorous. 



The third year the crop is almost a complete 

 failure. It is necessary to practice rotation of 

 crops with gladiolus. 



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 suscep- 

 tible to the ill effects as others. 



Various bacterial and fungous diseases also 

 attack plants that are grown in one place year after 

 year. These organisms, although they may not 

 be entirely destructive the first year or two, grad- 

 ually multiply and become a greater pest from 

 year to year. 



[294] 



