Citrus black spot is absent in the Western Cape, Northern Cape and Free State Provinces

  • Elma Carstens Department of Plant Pathology, Stellenbosch University, Stellenbosch Citrus Research International, Nelspruit
  • Hendrik F. le Roux Citrus Research International, Nelspruit
  • Michael A. Holtzhausen Department of Agriculture, Forestry and Fisheries, Pretoria
  • Liezl van Rooyen Department of Agriculture, Forestry and Fisheries, Pretoria
  • Joey Coetzee Department of Agriculture, Forestry and Fisheries, Pretoria
  • Ria Wentzel Department of Agriculture, Forestry and Fisheries, Pretoria
  • Wilhelm Laubscher Department of Agriculture, Forestry and Fisheries, Pretoria
  • Zorina Dawood Department of Agriculture, Forestry and Fisheries, Pretoria
  • Elrita Venter Alternafruit, Paarl
  • Gerhardus C. Schutte Department of Plant Pathology, Stellenbosch University, Stellenbosch Citrus Research International, Nelspruit
  • Paul H. Fourie Department of Plant Pathology, Stellenbosch University, Stellenbosch Citrus Research International, Nelspruit
  • Vaughan Hattingh Citrus Research International, Nelspruit Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch
Keywords: citrus fruit, pest free areas, quarantine, phytosanitary, trade regulation

Abstract

The South African citrus industry is strongly focused on exports and South Africa is a signatory member of both the World Trade Organisation Agreement on the application of Sanitary and Phytosanitary Measures and the International Plant Protection Convention. Citrus black spot, caused by Guignardia citricarpa, does not occur in all the South African citrus production areas and, therefore, South Africa has a responsibility to provide those trading partners that have identified G. citricarpa as a regulated pest with reliable information about the distribution of citrus black spot within South Africa. Detection surveys were conducted in citrus production areas in the Western Cape, Northern Cape and Free State Provinces and appropriate diagnostic protocols were used to ensure reliable detection of G. citricarpa. Trees in commercial orchards and home gardens on farms and in towns of 17, 9 and 5 magisterial districts in the Western Cape, Northern Cape and Free State Provinces, respectively, were sampled between 1995 and 2010. Fruit samples were taken during June and July, and leaf samples from November to January. None of the 3060 fruit and leaf samples collected during these surveys tested positive for G. citricarpa. Phyllosticta capitalensis, a non-pathogenic, ubiquitous, endophytic species was, however, detected during these surveys. In compliance with relevant International Standards for Phytosanitary Measures and based on the outcome of these official surveys, these three provinces in South Africa can be recognised as citrus black spot pest free areas.

Author Biography

Elma Carstens, Department of Plant Pathology, Stellenbosch University, Stellenbosch Citrus Research International, Nelspruit
Researcher (Plant Pathology) - Citrus Research International and PhD student - Univrsity of Stellenbosch
Published
2012-06-07