22 a EXPERBIEXT STATION. [Jan. 



Plant Disease: Control. 



Depdiimnit of Boiany. 



Project 2. " Tobacco investigations and a study of so-called 

 tobacco sick soils." 



Professor Chapal^n and Professor Anderson. 



Active work on this project was started through a field 

 survey in the summer of 1916. The year following, fertilizer 

 plots were located on three tobacco farms in the Connecticut 

 valley. With some necessary changes these plots were con- 

 tinued over four years, when the experience gained made it 

 apparent that further progress could be made only on land 

 under the complete control of the station. Experimental work 

 on privately owned land was therefore discontinued, being 

 replaced by experimental work carried on at the Tillson farm. 

 The reorganized project embraces a study of soil reaction as a 

 means of controlling root rots of tobacco; also a study of the 

 effects of soil reaction on the growth and development of the 

 crop. 



Project 8. "Investigations of the methods of controlling 

 lettuce drop." 



Professor Osmun and Assistant Professor Krout. 



Although this project was not formally organized until 

 January, 1918, the department had previously conducted many 

 investigations along this line. During the year just past, a 

 paper dealing with the more technical phases of this work 

 was submitted for publication in the Journal of Agricultural 

 Research. The most striking result of the investigation to date 

 is the determination of the fact that lettuce drop may be 

 easily and inexpensively controlled by treating infected soils 

 with a formaldehyde solution. A complete report of the 

 Avork in bulletin form is in course of preparation. 



Project 5. "Experimental spraying for the control of cu- 

 cumber mildew under glass." 



Assistant Professor Krout. 



Because but two serious epidemics of this disease have 

 occurred since the project was started, actual spraying tests 

 have been conducted two seasons onlv. During the summer 



