8 
Journal of Agricultural Research 
Vol. IX, No. i 
♦ SUMMARY 
(1) A new disease of Citrus trees is endemic to the Citrus regions of 
northern and central California. It has been described and given the 
name “Citrus blast” by Dr. J. E. Coit, of the University of California. 
(2) Sections of fresh disease material show a bacterial organism 
present in masses, and on isolation plates bacterial colonies are obtained 
which on inoculation produce the typical lesions of the disease. From 
such positive inoculations the organism has been reisolated and rein¬ 
oculated, giving positive results again, and finally being reisolated. 
The organism is apparently a new species, and the name “Bacterium 
citrarefaciens ” is proposed. 
(3) The organism exists in the parenchyma and destroys cell structure, 
leaving large pockets filled with bacterial masses. The organism does 
not ordinarily invade the vascular bundles and is apparently restricted 
to the parenchyma. 
(4) The disease causes a decrease in leaf surface and a loss of the 
fruit-bearing wood in orchard trees. Young trees in nurseries may also 
be injured. The possibility of the disease becoming distributed through¬ 
out all California and other Citrus-growing regions is to be considered. 
