200 The Sugar-Beet in America 



comes black and crisp. The outer, or older, leaves are 

 the ones first affected. 



Townsend, 1 in summarizing methods of control, says: 



" (1) Leaf-spot may be controlled on a commercial scale 

 and in an expensive manner by a carefully planned and 

 thoroughly executed system of crop rotations or by deep 

 fall plowing. The best results are obtained by combin- 

 ing these two methods. 



"(2) A proper and uniform supply of soil moisture, 

 spraying, and proper disposition of beet tops and stable 

 manure are important aids in the control of the leaf -spot. 



"(3) The principal agencies in the distribution of the 

 leaf -spot fungus are wind, water, insects, and man and 

 other animals. 



"(4) Leaf-spot tends to reduce either the tonnage or 

 the sugar content of the beet, or both, depending on the 

 time, duration, and severity of the attack. 



"(5) Leaf -spot seriously injures the feeding value of 

 beet tops." 



Bordeaux mixture is used as a spray. The fungi are 

 killed when the beet tops are siloed. 



Heart-rot (Phoma betae Frank). 



This disease, which is one of the most serious of the 

 sugar-beet in sections of Germany, Austria, and France, 

 has recently been introduced into the United States where 

 it will probably become rather serious in the next few 

 years. It has already gained a strong foothold in several 

 beet-growing sections. 



1 Townsend, C. O., U. S. Dept. of Agr., Farmers 1 Bui. No. 618 

 (1914). 



