596 Heart Rot of Beet, Mangold and Swede. [Jan., 



of the piles of bricks will depend on the other conditions, but if 

 there is any danger of considerable fermentative activity the 

 bricks should be so disposed as to permit perfect ventilation 

 between two or more adjacent rows. 



When the bricks are thoroughly " run " they should be dried 

 under cover, since in a moist brick the spawn would continue 

 to grow and would soon produce small mushrooms or else 

 become mouldy. 



In conclusion, Professor Duggar observes that it is not to be 

 supposed that the method will enable all mushroom-growers to 

 manufacture their own spawn with comparative ease, but there 

 is no reason why the manufacture of mushroom spawn in the 

 manner indicated should not become a specialised industry. 



This disease {Sphaerella tabifica) is not uncommon in France, 

 where it often causes considerable damage to sugar beet. In 

 this country it has of late years been fre- 



Iteet r ^ Mangold ^ uent ^ reported on mangold and swedes, 

 and Swede.* An instance occurred recently where nearly 

 every root grown on a fcur-acre plot of 

 " Yellow Globe " mangold was badly diseased. At the time of 

 its discovery workmen were busily engaged in cutting off the 

 sound portions for cattle food, and chopping up the diseased 

 parts and scattering them over the land to be ploughed in. 

 The disease rarely appears before the middle of August, and 

 first attacks the stalks of the largest leaves. Its presence is 

 indicated by the wilting of the leaves, such as follows a hot, dry 

 day ; diseased leaves, however, do not recover their erect posi- 

 tion during the night, but remain lying on the ground, turn 

 yellow, and decay. This is due to the fungus growing in the 

 leaf-stalk having choked the vessels and thus prevented the 

 passage of water into the leaf. When the leaf is dying, whitish 

 patches of variable form and size, bounded by a dark line, and 

 studded with minute black spots, the fruit of the fungus, appear 

 on the leaf-stalk. Similar patches are also sometimes present on 

 the leaves. Later in the season, when the leaf-stalks are dead 



* Journal, November, 1904, p. 488. 



