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The Viroids pp 235-245 | Cite as

Citrus Exocortis

  • Patricia Broadbent
  • S. M. Garnsey
Part of the The Viruses book series (VIRS)

Abstract

When exocortis was first described by Fawcett and Klotz (1948), its cause was unknown, but soon after Benton et al. (1949, 1950) and Bitters (1954) showed that scalybutt (exocortis) was bud-transmissible. Trees on trifoliate orange [Poncirus trifoliata (L.) Raf.] rootstock are severely dwarfed from an early age, show little enlargement of the stock, and exhibit heavy bark scaling of the butt below the bud union (Fig. 1). Trees on citrange [P. trifoliata x Citrus sinensis (L.) Osbeck] stocks are also reduced in size and the rootstock may show scaling due to exocortis in some countries (Garnsey, 1983). Olson (1952) and Moreira (1955, 1959) described a rootstock bark disorder of Rangpur lime (C. limonia Osbeck) stocks that was attributed to exocortis (Brown and Schmitz, 1954; Olson and Shull, 1956; Reitz and Knorr, 1957). Exocortis has also been associated with dwarfing of trifoliate orange stock in the absence of bark scaling (Broadbent et al., 1971; Schwinghamer and Broadbent, 1987a,b). Gummy pitting symptoms in trifoliate orange rootstocks may also be associated with a strain of exocortis (Fraser and Broadbent, 1979).

Keywords

Sweet Orange Citrus Tree Trifoliate Orange Orange Tree Navel Orange 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • Patricia Broadbent
    • 1
  • S. M. Garnsey
    • 2
  1. 1.Biological and Chemical Research InstituteNew South Wales Department of AgricultureRydalmereAustralia
  2. 2.Agricultural Research ServiceU.S. Department of AgricultureOrlandoUSA

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