Hyacinth Diseases 267 



Soft White Rot 



Caused by Bacillus hyacinthi septicus Heinz. 



This disease has been studied by Heinz.* Its 

 presence in this country is unknown. Affected bulbs 

 become soft rotted but remain white. 



Yellows 



Caused by Pseudomonas hyacinthi (Wak.) Sm. 



Symptoms. This disease as described by Smith f 

 and others is characterized as follows : Early infec- 

 tion becomes apparent as water soaked stripes, soon 

 followed by a yellowing then browning and dying 

 of the affected tissue. The water soaked stripes soon 

 spread all over the foliage, and the accompanying 

 symptoms are the same as previously mentioned. 

 The stripes usually start at the apex of the leaves. 

 Frequently, the stripe runs down the entire length 

 of the foliage while both margins remain green. On 

 the flower stalks the disease is also manifested as a 

 water soaked spot followed by the characteristic 

 browning and shriveling. Infection on the bulb is at 

 first confined to the vascular bundles the latter of 

 which become yellow and gorged with slime. The 

 disease soon spreads, invading and destroying the 

 scales, the latter becoming yellow and soggy. Nu- 

 merous other invading organisms often enter and 



♦Heinz, Cent. f. Bakt. 5: 535, 1889. 



t Smith, E. F., Bacteria in Relation to Plant Diseases, 2:335-353, 

 1911. 



