Pecan scab

Pecan scab is the most economically significant disease of pecan trees (Carya illinoinensis) in the southeastern United States.[1] Venturia effusa is a fungal plant pathogen that causes pecan scab. The fungus causes lesions and tissue death on pecan twigs, petioles, leaves, nuts and shucks beginning in early spring, with multiple cycles of infection repeating until late summer. Wind and rain spread the fungus to a susceptible host. Control of the disease is achieved by fungicide, sanitation and, in some cases, quarantine.[2]

Pecan scab lesions caused by Venturia effusa on pecan husks

Since its first description in 1882, the pecan scab fungus has been reclassified ten times,[3] with other names such as Fusicladium caryigenum, Cladosporium effusum and Cladosporium caryigenum commonly associated with the fungus.[4]

Pecan scab lesions caused by Venturia effusa on pecan leaves
  1. ^ Sanderlin, R. S. (n.d.). Pecan scab disease. Retrieved from http://www.lsuagcenter.com/NR/rdonlyres/A30CB512-CDB1-4DFB-8D41-9E6086DEF9EE/70679/ScabDisease_CorrectedName.pdf
  2. ^ Smith, S., & Vann, S. (2013). Arkansas plant disease control products guide. Informally published manuscript, Division of Agriculture, University of Arkansas, Little Rock, AR, Retrieved from http://www.uaex.edu/Other_Areas/publications/PDF/MP154/pecan-diseases-commercial.pdf
  3. ^ Seryan, M; et al. (2010). "Phylogeny of the pecan scab fungus Fusicladium effusum G. Winter based on the cytochrome b gene sequence". Mycol Progress. 9 (2): 305–308. doi:10.1007/s11557-009-0638-9. S2CID 6396142.
  4. ^ Gottwald, T. R. (1982). "Taxonomy of the pecan scab fungus Cladosporium caryigenum". Mycologia. 74 (3): 382–390. doi:10.2307/3792959. JSTOR 3792959.