2 MASS. EXPERIMENT STATION BULLETIN 195. 



tural practice was commenced at this time witli a view to outlining 

 experimental field and laboratory work for the ensuing years. 



It has seemed unwise to make a yearly report until the data of at least 

 two years were available, and therefore the present report includes the 

 preliminary observations made during the latter part of 1916, and a 

 discussion of the results obtained from the different lines of experiment 

 suggested by these findings. These will be treated under their proper 

 headings in the body of the report, with a general summary of conclusions 

 and recommendations following. 



Preliminary work was undertaken so late in the season that it was 

 impossible to collect first-hand data on seed-bed conditions. The work 

 was therefore confined to making a survey of the crop and soils in general, 

 with a view to obtaining accurate information regarding the situation. 

 After compiling ^nd correlating these data it was planned to establish in 

 1917 experimental plots in different sections, and by various treatments 

 endeavor to produce a favorable tobacco condition in the so-called "sick" 

 soils. The problem is not primarily one of soil fertility, as it is generally 

 true that crops other than tobacco — such as onions, corn, etc. — make 

 a very luxuriant growth on the "sick" tobacco soils, and this often with- 

 out additional fertihzation. 



Investigations necessary. 



From the results of our study of 1916 conditions, it was apparent that 

 the questions involved required the undertaking of several lines of in- 

 vestigation in order to reach a satisfactory solution. Undoubtedly it 

 may be found necessary to change or modify the various experiments as 

 time passes, but there are certain questions which should be answered 

 as soon as possible. Among the more important are the following: — 



1. Is the average yield of tobacco gradually falling off from year to 

 year, generally, throughout the valley? 



2. Is the quality of the tobacco produced inferior to what has been the 

 average quality? 



3. Has the weather factor been a primary controlling factor in pro- 

 duction, — especially in later years, — and what limits are permissible 

 for profitable production? (This hardly seems necessary of demon- 

 stration.) 



4. Is there a correlation between weather factors and diseases, such as 

 root-rots caused by Thielavia basicola and other organisms? 



5. Aside from the general decrease in crops in 1915-16, and to a lesser 

 extent in 1917, what is the cause of the soil "sickness" on some fields, 

 or parts of fields? Is it due to a parasite, or is it due to improper ferti- 

 lization and cultural methods? 



6. Is there any correlation between the fertilization methods and soil 

 treatment, and the activity of the root-destroying organisms? In other 

 words, have we got some of our fields into a condition which favors the 



