Definition of rhizomania in English:

rhizomania

noun

Botany
  • (Originally) an abnormal proliferation of roots, especially as a sign of disease; (now usually) specifically a viral disease of sugar beet whose main symptom is the excessive production of small fibrous roots at the expense of the main storage root.

Origin

Mid 19th century; earliest use found in John Lindley (1799–1865), botanist and horticulturist. After German Rhizomanie.