July IS, 19J0 



Relative Susceptibility to Citrus-Canker 



345 



somewhat the loose, corky spots on Poncirus trifoUata. During the 19 19 season 

 M. australis was severely infected in the field, leaves, twigs, and branches 

 being attacked. This species has shown almost as much susceptibility as P. trifoUata. 

 Some leaf and stem cankers have also developed on M. australasica. However, it is 

 much more resistant than M. australis. 



In Table I the data on the susceptibility of the wild relatives of Citrus 

 obtained by Lee {4) are listed for comparison with those reported on by 

 the senior author. Lee worked in the open under field conditions at the 

 Lamao Experiment Station, P. I., while the senior author, using the 

 same type of plants, carried on his inoculation experiments in the green- 

 houses at Auburn, Ala. None of the field results are included in the 

 table, since with few exceptions they were of a negative nature. 



Table I. 



-Findings of Lee and Peltier on the susceptibility of the Citrus relatives to 

 citrus-canker 



