Wordnet 3.0
ADJECTIVE (1)
1. 
 (of plants) epidemic among plants of a single kind especially over a wide area; 
- Example: "an epiphytotic blight of potatoes"- Example: "epiphytotic conditions associated with a single-plant agriculture"
WordNet (r) 3.0 (2006):
epiphytotic
    adj 1: (of plants) epidemic among plants of a single kind
           especially over a wide area; "an epiphytotic blight of
           potatoes"; "epiphytotic conditions associated with a
           single-plant agriculture"