BEETROOT AND MANGEL ROT 109 



been surprised by the vigorous and healthy appearance of 

 the new foliage which soon unfolds.' 



Tulasne, Fungorum Carpologia, vol. ii. p. 108, pi. xxxi. 

 Prillieux, Malad. des Plantes Agric., vol. ii. p. 268, figs. 



BEETROOT AND MANGEL ROT 



(Sphaerella tabifica, Prill, and Del. 

 ^= Phoma tabifica, 



Phoma bctae, Frank.) 



During the past few' years the beet crop in France and 

 Germany has suffered severely from a fungous disease. 

 About the month of August the largest leaves droop to 

 the ground, as is frequently the case during very hot, dry 

 weather. This drooping, however, is due to the upper 

 surface of the leaf-stalk having been more or less 

 disorganised by a parasitic fungus ; white patches, bor- 

 dered by an orange-brown zone, are present, often 20-25 

 mm. long, and finally the tissue becomes brown and dead. 

 This disease passes from the large leaf-stalks into the root, 

 penetrating to the heart, and from thence attacking and 

 killing the young heart-leaves. Superficial minute peri- 

 thecia containing numerous minute conidia, produced at 

 the tips of conidiophores, appear on the bleached, dead 

 parts of the leaf-stalk. Sometimes these reproductive 

 bodies are also produced on the lamina of the leaf, on 

 rounded patches of a pale brown colour with darker con- 

 centric lines. This is the Phoma stage. Later in the 

 season the ascigerous, or Sphaerella, condition appears on 

 the dead petioles, in the places previously occupied by the 

 Phoma. The dead heart-leaves are often more or less 



