Vol 117 (2004): Proceedings of the Florida State Horticultural Society
Ornamental, Garden & Landscape

Thielaviopsis diseases of palms

Joseph F. Garofalo
University of Florida
Published December 1, 2004
  • thielaviopsis paradoxa,
  • trunk-rot,
  • budrot,
  • stem-bleeding,
  • black scorch,
  • dry basal-rot,
  • bitten leaf,
  • heart-rot
  • ...More


Palm trunk-rot, caused by the vascular pathogen Thielaviopsis paradoxa has the potential to devastate global palm resources. Palm rot is found in three states in the continental USA. This range encompasses the subtropical and arid regions where palmsare important landscape plants. At least 23 species are susceptible to T. paradoxa. Factors relating to stand composition and structure directly influence the incidence and severity of palm trunk-rot. Host susceptibility, the potential for inoculum production, and spatial distributions of different palm spp are all important in determining disease progress. Localized outbreaks have been associated with environmental stress and mechanical damage. The pathogen adapts to all the palm ecotypes, as illustrated by its occurrence in the dry deserts of Arizona and California, and in humid, wet Florida. There are many aspects of palm trunk-rot that are poorly understood, hampering the ability to predict the course of this pathogen. The pathogen can be controlled in the early stages of the disease by applying the systemic fungicide thiophanate methyl.