THE BROWN EOOT ROT OF TOBACCO AND OTHER PLANTS 



19 



The duplication of plats was begun in the opposite corners of the 

 experimental area, so as to compensate as much as possible for 

 the natural variation in the land. 



The general plan of the plats is best understood by referring to 

 Table 1. 



Table 1. — Succession of crops and fertilizer applications on the orown root-rot 

 plats at Whately, Mass. 





Crop grown 



Plat 



1922: A and 



1923 



1924 





B series 



A series 



B series 



A series 



B series 



No. 1 



Corn Corn 



Timothy.... Timothy.. .. 



Beans Beans 



Potatoes Potatoes 



Tomatoes. .. Tomatoes...' 



Fallow Fallow 



Onions Onions 



Tobacco Tobacco 



do do 



Clover Clover 



Tobacco Tobacco 



Corn Corn 



Timothy Timothy 



Beans Beans 



Potatoes Potatoes 



Tomatoes... Tomatoes. — 



Fallow Fallow 



Onions Onions 



Tobacco Tobacco 



do do 



Clover Clover 



Tobacco. ._ 



.-.do 



--.do 



...do 



_-_do 



Tobacco... 



...do 



...do 



...do 



do 





No. 2._ 



Do. 



No. 3— 



Do. 



No. 4 



Do. 



No. 5 



Do. 



No. 6 



— .do j_-.do 



Do. 



No. 7_-_ 



Do. 



No. 8.— 



...do 



...do 



_-.do 



...do 



—do 



...do 



...do 



...do 



do 



Do. 



No. 9 (double fertilizer application) 



No. 10 



Do. 

 Do. 



No. 11 Qimed) 



No. 12. 



Do. 



Do. 



No. 13- . 



_-.do !— .do 



-..do ...do 



_-.do —_.do 



..-do L.-do 



_--do L— do 



...do !— .do 



-__do ...do 



-_.do ...do 



...do ...do 



Do. 



No. 14 



Do. 



No. 15 



Do. 



No. 16 



No. 17 



Do. 

 Do. 



No. 18 



Do. 



No. 19 



Do. 



No. 20(double fertilizer application) 



No. 21 



No. 22 (limed) 



Do. 

 Do. 

 Do. 















TESTS AT WHATELY, MASS. 



The Whately plats were located on a level medium-sandy loam 

 soil. The field had been in timothy following failures with tobacco 

 in 1917 and 1918. This field was used by the senior writer in 1918 

 in connection with studies on varietal resistance tests, and the stunt- 

 ing of all varieties on this land indicated that it was not only a 

 typical brown root-rot soil but also that Thielavia root rot was not 

 present to any extent. 



The timothy sod was plowed on April 25, and following a thor- 

 ough preparation of the land twentieth-acre plats were laid out. 

 An application of 175 pounds of approximately a 6-5-6 commercial 

 fertilizer was made to each plat, plats 9 and 20, however, receiving a 

 double application and plats 11 and 22 being treated with 100 pounds 

 of lime in addition. The crops were planted in their respective 

 seasons, except that the onions were planted somewhat too late for 

 the best results. 



Good crops of corn, timothy, and clover developed, reaching 

 average heights of more than 12 feet, 18 inches, and 12 inches, respec- 

 tively. The beans, potatoes, tomatoes, onions, and tobacco, however, 

 made only slow progress, apparently for different reasons. In the 

 case of tobacco and tomatoes the main injurious agent was apparently 

 brown root rot, but other diseases probably influenced the results 

 with beans and potatoes. Data on the weight of beans were not ob- 



