3o8 



Journal of Agricultural Research voi. xviii, No. 6 



There are three other plots in these San Antonio rotations on which 

 cotton has been grown each year and on which the location of the dis- 

 eased plants has been recorded since 1916. On plot A4-19 (fig. 5) 



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Fig. 4. — Diagram oi plot Bs-4, showing the portions of the rows in which the cotton plants were killed each 

 year by rootrot in 1916, 1917, and 1918. 



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Fig. s. — Diagram of plot A4-19, showing the portions of the rows in which the cotton plants were killed 

 each year by rootrot in 1916, 191 7, and 1918. 



cotton has been grown each summer since 1913. The cotton stalks are 

 plowed out in the fall, and the land is then disked and seeded to Canada field 

 peas, which are plowed under the following spring in time to plant cotton 



