CEREAL PESTS PARASITIC FUNGI 537 



in Australia for a long time, where it is universally 

 known as " take-all." In England it is said to cause a 

 loss ranging from ^V to half of the crop. In France and 

 Germany it is serious, and known as " foot disease." 

 For some time the fungus could not be identified, as the 

 fruiting stage usually is produced during the winter 

 months on stubble, and, therefore, escaped observation. 

 There are two distinct aspects of the disease, known as 

 " take-all " and " white heads." The condition called 

 " take-all " occurs at an early stage of growth of the host, 

 causing the latter to become yellow and often die before 

 a culm is formed. Infection occurs at the base of the plant, 

 which appears blackened. The condition of " white 

 heads " occurs when the host has attained full growth. 

 The spikes are of normal size, but the grain either remains 

 undeveloped or is very much shriveled. The spikes and 

 straw appear to be bleached or prematurely ripened, the 

 entire plant is found to be dry and dead, and for 2 or 

 3 inches at the base of the culm, is blackened as if 

 charred. 



The earlier varieties of wheat are said to be most 

 susceptible, and red wheat least so, but none is im- 

 mune. Land that has grown a diseased crop is certain 

 to be infected, as the fungus is confined to the base of 

 the culms, and is therefore left in the stubble. Crop 

 rotation is important, where this fungus is bad. 



579. Soil sickness. There is no doubt that many of 

 the imperfect fungi, long considered as injurious pests in 

 the Old World, are recently becoming more prevalent in 

 this country, and will be serious pests here. Naturally 

 they are more common where there is continuous grain 

 cropping. Bolley (1913) has considered a number of these 

 fungi together as being largely responsible for diminished 



