dry rot vs mildew

dry rot

noun
  • A fungal infection which affects plants, in particular potatoes. 

  • The crumbly, friable decayed portions of wooden members of buildings, especially at or below grade, usually caused by a fungal infection. 

  • Any progression of decay, corruption, or obsolescence. 

mildew

noun
  • A growth of minute powdery or webby fungi, whitish or of different colors, found on various diseased or decaying substances. 

verb
  • To taint with mildew. 

  • To become tainted with mildew. 

How often have the words dry rot and mildew occurred in a corpus of books? (source: Google Ngram Viewer )