I 'iSAHY OF THE 

 .Massachusetts Agricultural Collegt, 



AMHERST, MASS, 



massachusetts 

 Agricultural Experiment Station 



BULLETIN No. 219 



JANUARY, 1924 



COMBATING APPLE SCAB 



Spraying and Dusting Experiments in 1923 with Summary of Three 



Years' Results 



By WILLIAM L. DORAN and A. VINCENT OSMUN 



Recentlv' completed studies on apple scab and its control show that 

 development of this disease ma\' be prevented through the use of a num- 

 ber of different materials — lime-sulfur, dry lime-sulfur, or copper sprays 

 followed by lime-sulfur, may be effectivel}' used, as also dusts of various 

 kinds. Scab development is governed largely by weather conditions; 

 possibilit\- of successful control, b\' the proper timing of protective 

 treatment and efficienc\' in the actual spra\ing and dusting work. These 

 facts are brought out in this bulletin, which is the fmal report of a three- 

 \ear investigation. Tabulated results of the work carried on in 1923 are 

 presented, likewise a summarization of all data collected during the course 

 of the stud\-. 



PUBHC.\TIOX OF THIS DOCUMENT APPUOVED BY THE COMMISSION ON .\DMINISTRATI0N AND FiNANCE 



Requests for Bulletins should be addressed to the 



AGRICULTURAL EXPERIMENT STATION 



AMHERST, MASS. 



