8 FIELD TREATMENT OF TOBACCO ROOT-EOT. 



greatly reduced the effect of the root-rot. The improvement was 

 doubtless due in part to the leaching away of the lime in watering. 

 The sandy tobacco soils of Connecticut, which leach readily, are not 

 affected with root-rot. It is highly significant that the root-rot in this 

 soil reestablished itself with all its old vigor when the soil was made 

 alkaline through the addition of lime. 



SUMMARY. 



The tobacco root-rot is caused by a soil fungus. 



The fungus attacks the tobacco roots most severety when the soil 

 has become alkaline, due to the use of too large amounts of lime, 

 ashes, or fertilizers containing carbonate of potash. 



Remedy. — Use no lime on diseased fields. Apply potash in the form 

 of sulphate of potash or double manure salts. Apply phosphoric 

 acid in the form of acid phosphate or dissolved bone to correct 

 the alkalinity of the soil. Plaster can be used if desired. 



Where otlier land is available for tobacco, use the diseased fields for 

 some other crop for a year or more. Use no lime or alkaline form of 

 fertilizer until the roots of the tobacco are free from the disease. 

 Lime and alkaline fertilizers can then be used cautiously. 



[Circ. 7.] 



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