UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 562 



Contribution from the Bureau of Plant Industry 

 WM. A. TAYLOR, Chief 



jaJF^jL 



Washington, D. C. 



PROFESSIONAL PAPER 



September 15, 1917 



THE CONTROL OF TOBACCO WILT IN THE FLUE- 

 CURED DISTRICT. 1 



By W. W. Garner, Physiologist in Charge of Tobacco Investigations, Bureau 

 of Plant Industry; F. A. Wolf, Plant Pathologist and Bacteriologist, North 

 Carolina Agricultural Experiment Station; and B. G. Moss, Assistant in To- 

 bacco Investigations in the Bureau of Plant Industry and Collaborator of the 

 North Carolina Agricultural Experiment Station. 



[In cooperation with the North Carolina Agricultural Experiment Station.] 



CONTENTS. 



Importance of the disease 1 



Symptoms of tobacco wilt 3 



Leaves 3 



Stalk 3 



Rocts 3 



Cause of the disease and its present distribu- 

 tion 4 



Susceptibility of species and varieties of 



tobacco to the wilt 5 



Relation of the physical and chemical prop- 

 erties of the soil to the wilt 7 



Page. 

 Crop rotation as a basis for the control of 



the wilt 10 



Crop-rotation experiments at Creedmoor, 



N.C .' 10 



Length of rotation required to reclaim 



infested soils 15 



Precautions to prevent the spread of the dis- 

 ease 17 



Summary 18 



Literature cited 20 



IMPORTANCE OF THE DISEASE. 



Tobacco wilt is a very serious disease in portions of the flue-cured 

 district of Virginia and the Carolinas, the cigar-leaf district of 



1 This bulletin presents the results of investigations conducted jointly by the North 

 Carolina Agricultural Experiment Station and the Bureau of Plant Industry for the pur- 

 pose of working out practical methods for the control of tobacco wilt. The experiment 

 station began studies to this end in 1903 and the work has been continued from that 

 time. In 1910 cooperation with the Office of Tobacco Investigations, Bureau of Plant In- 

 dustry, was effected, and the scope of the work was considerably extended. On behalf of 

 the experiment station, the work has been directed successively by Dr. F. L. Stevens, Prof. 

 H. R. Fulton, and one of the present writers. Messrs. W. G. Sackett, J. G. Hall, E. H. 

 Cooper, R. O. Cromwell, W. C. Norton, and E. E. Stanford, assistants at the experiment 

 station, have actively participated in the investigations. 



94919°— 17 1 



