REPORT OF PLANT PATHOLOGIST 



G. L, Peltier 



Auburn, Ala., October 25, 1917. 

 Prof. J. F. Duggar, Director, 



Agricultural Experiment Station, 

 Auburn, Alabama. 

 Sir: 



I am herewith submitting a brief statement relative to the 

 projects now in progress in the Department of Plant Patholo- 

 gy for the past year. 



1. Under the Adams Fund only one project, Citrus Canker, 

 is being carried on. The citrus canker organism has been iso- 

 lated directly from the soil and a method is being developed by 

 which this can be done with ease and consistency. One of the 

 most important factors to be determined is to find out how long 

 the organism causing the Citrus Canker can persist in the 

 soil, after the infected trees are destroyed, so that the develop- 

 ment of a successful method for the isolation of the organism 

 from the soil is of the utmost importance. 



Through an agreement with Dr. W. T. Swingle, of the Bu- 

 reau of Plant Industry, a series of plants representing the 

 more important wild relatives and species of Citrus, together 

 with the more common species and hybrids, have been ob- 

 tained and placed in the field at Loxley and in the greenhouse 

 at Auburn, for use in determining the relative susceptibility 

 and resistance. These plants have been inoculated with viru- 

 lent strains of canker and already some of them give promise 

 of immunity. If resistant, they can replace the more suscep- 

 tible Citrus plants in the orchards now destroyed and also 

 replace the plants now in use as stock in South Alabama. A 

 number of other important phases in the life history of Citrus 

 canker organism are also under way. 



During the summer a well equipped field laboratory was 

 maintained for the study of Citrus Canker at Loxley, in charge 

 of Mr. D. C. Neal, formerly^ a fellow at the Missouri Botanical 

 Garden. Through an agreement with Dr. K. F. Kellerman, 

 Mr. Neal will continue the work at Loxley during the com- 

 ing year. 



