THE RESULTS presented in this report were obtained 
in 1915 under an informal cooperative agreement 
between the Office of Acclimatization and Adaptation of 
Crop Plants, of the Bureau of Plant Industry, and the 
Office of Extension Work in the South, of the States Rela- 
tions Service. 
The writer wishes to acknowledge the cordial cooperation 
of the various State, district, and county agents of the 
last-named office and the assistance rendered by the many 
farmers who were interested in the experiments. 
