56 Mildews [CH. 
flowers of sulphur (the leaves should be damp when this 
is done). Spray the trees of Set III with a solution 
containing 1 oz. of liver of sulphur to 3 gallons of water. 
Watch the trees carefully to see if the sulphur or liver 
of sulphur has any bad effect on the leaves or buds, and 
also to see if either of them prevents the mildew from 
spreading. 
CHAPTER V 
ERGOT AND CLOVER SICKNESS 
Ergot (Claviceps purpurea). 
This disease is caused by the fungus Claviceps 
purpurea. Its commonest hosts in this country are 
rye, rye grass, couch, cocksfoot, and timothy, and it is 
found occasionally on wheat and barley. Some of the 
grasses, such as the bromes, are not subject to it. The 
disease first shows itself at the time when the corn is 
ripening or the grasses are dying off. It is often 
abundant on the dried heads of roadside grasses. It 
appears as long blackish bodies sticking out from the 
ears (see Fig. 19). These are called Sclerotia or Ergots. 
They are partly covered by the chaff and take the 
place of the grain in the flower. The flowers of rye 
are much larger than those of the grasses, and the 
sclerotia produced in them are correspondingly larger. 
In the case of rye the sclerotia are often more than 
1 inch in length and about }-} inch in diameter. In 
the case of grasses they may be }-3 inch long, and about 
vz inch in diameter. The longer ones are usually 
curved but the short ones are often straight. They 
are hard and have a groove running along one side. 
