THE BOOK OF THE PEONY 



a new crop of spores find their way to the next 



crop of leaves. 



The Sclerotinia Stem Rot. 



This disease is probably more common than is 

 suspected, but because its symptoms are so like 

 those of the Botrytis disease has probably seldom 

 been recognised. I have had diseased specimens 

 from but one grower some years ago, but recent 

 inoculation experiments which I have made with 

 the pathogens show it capable of rapid destruction 

 of young peony shoots. 



Symptoms, — A sudden wilting of young or 

 even nearly mature stalks, due to a rotting off at 

 the base near the ground, is the first evidence of 

 this disease. At this stage it cannot usually be 

 distinguished from the more common Botrytis 

 disease which affects the plants in the same way. 

 Later the dead stalks on being split open will 

 often show large black bodies, sclerotia, in the 

 pith. These are never present in stalks killed 

 by Botrytis. 



Cause. — The disease is caused by a fungus, 

 Sclerotinia libertiana, which is a most omnipres- 

 ent parasite amongst cultivated plants, especially 

 greenhouse and garden plants. It is not particu- 



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