Illustrated guidelines on citrus post-harvest diseases

CONTACT DETAILS: +27 13 759 8033 / +27 82 335 7543 /
DURATION: Two years
LEAD INSTITUTION: Citrus Research International
BENEFICIARY: The citrus industry

Several post-harvest fungal diseases affect the quality and shelf life of citrus fruit.

They vary in occurrence and severity, with green mould and blue mould responsible for probably the most significant economic losses to the South African citrus industry. Pathogen virulence, fruit susceptibility and environmental conditions influence the frequency and intensity of disease occurrence. Since decay and spoilage can occur at any point in the supply chain, quality is managed via a system of critical control points – from the orchard to final market destinations.

Creating an understanding of citrus post-harvest diseases

Although some citrus post-harvest diseases originate pre-harvest, they typically manifest after harvesting and often after packing for export. The orchard is a vital control point. To prevent wastage, the correct cultivation practices should be managed efficiently to ensure that healthy fruit in good condition is delivered to pack houses. Other measures that assist in the control of post-harvest pathogens and subsequent diseases are general good agricultural practices (GAPs), the use of certified nursery trees, approved pre-harvest fungicide spray programmes, orchard sanitation and proper fruit handling during picking and packing.

It is very important to create an understanding of where citrus post-harvest diseases originate and how they infect fruit. It is equally important that producers, exporters, pack houses and other role-players know what the different types of diseases look like.

Illustrated guidelines on citrus post-harvest decay

In a project financed by the Post-Harvest Innovation (Phi) Programme, Citrus Research International (CRI) established a set of comprehensive guidelines for citrus post-harvest handling in accordance with the best practices. All the major post-harvest citrus diseases are illustrated in colour, with descriptions that include an explanation of the symptoms, modes of infection and the various control measures.

Benefits to industry

  • It is designed to help all relevant role-players, but the main purpose of the illustrated guidelines is to assist fruit inspectors in pack houses, at inspection depots in local harbours and overseas ports of arrival, to correctly identify citrus post-harvest decay.
  • It also ensures accurate feedback of information to local marketing agents to take timely corrective action. In turn, it can prevent unnecessary losses and reduce claims.
  • The updating of post-harvest handling guidelines, in an illustrative form, is ongoing.
  • It is linked with a new Phi-funded project (PHI-2), coordinated by the Citrus Cold Chain Forum, in which different manuals and guidelines will be updated and published in the CRI Production Guidelines (Volume IV).