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A review of market access and mould wastage problems in the citrus industry. 

Peter Taverner and Nancy Cunningham

Summary

Area freedom from fruit fly

Lightbrown apple moth

Postharvest oil

Mites, Mealybugs and Snails

Postharvest disease control, sanitation and food safety in citrus packingsheds

Future work and information for citrus packers

Area freedom from fruit fly

• Policy to prevent the establishment of fruit fly into South Australia.
• Inland citrus growing regions free of fruit fly.
• Critical to market acceptance
• Modifies the approach to other market access pest problems  

Lightbrown apple moth

• Improving market access for citrus by removing surface pests (Phase 2)
• First intercepted in USA consignments in 1993.
• Epiphyas postvittana (Family: Tortricidae).
• Leaf roller (wide host range).
• USA quarantine risk.
• Difficult to control in field after calyx closure.
• Incidence on citrus varies from season to season.
• Strategy: postharvest oil  

Postharvest oil

• C15 alkane (foodgrade) formulated to emulsify in water.
• Infested fruit are immersed in postharvest dip.
• Compatible with postharvest fungicides.
• Destroys surface dwelling pests.
• Rapidly creeps into crevices to invade the pest’s tracheal system.

Mites

• In 1994, first interception of ‘actionable’ mites.
• Mite Family: Tarsonemidae was perceived as a USA quarantine risk.
• Widespread fumigation.
• Strategy: surveys.
• Survey determined that the ‘risk species’ was a fungivore, Tarsonemus waitei.

Mealybugs

• Two predominant species
• • citrophilous mealybug, Pseudococcus calceolariae.
  • long-tail mealybug, Pseudococcus longispinus.
• These species are not a USA quarantine risk.
• Difficulty in identifying immature stages.
• Delays in marketing.
• Strategy: surveys

 Snails

• In 1996, 3 snail species intercepted on citrus.
• Two species were "actionable" snails;
• The common white snail, cernuella virgata, and
• The small brown snail, Microxeromagna vestita.

Postharvest disease control

• Unable to use Panoctine (Guazatine) for USA.
• Sour rot (Geotrichium citri-aurantii) not controlled by remaining fungicides.
• Strategy: Chlorine-releasing compounds
• Widespread adoption of sanitisers.
• Information gap- no historical use of sanitisers in Australian citrus sheds.

Sanitation

• Range of products used. Na hypo, cal hypo, BCDMH, isocyanurates, chlorine dioxide and QAC’s.
• Range of advice from commercial sales representatives
• lack of knowledge in key areas of rates, pH and influence of organic matter.
• Inappropriate or no monitoring procedures
• Indiscriminate mixing of fungicides and sanitisers.
• Incompatibility issues arising from mixtures.
• Substitution of sanitisers for chemical fungicides.  

Food safety in citrus packingsheds

• Domestic approved supplier programs with emphasis on food safety.
• Increasing international trade - increasing microbiological trade risk. 
• Packer’s role
• • use of sanitisers
  • water quality issues
  • recirculation problems
  • awareness of the specificity of fungicides 

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 Future for citrus packers

• Greater emphasis on packers to control surface pests
• • Systems approaches for pest control - more field to shed processes used.
  • Incorporation of pest control into traditional shed processes -GRAS compounds in washes, insecticidal soaps and cleaning agents (dual purpose).
• Greater emphasis on food safety
• • Review water use in sheds and role of sanitisers
  • Integration of postharvest disease control and food safety measures.
  • Reduction in chemical fungicide use (residues).  

Information for the Packers

• Strategy: Newsletter for packers.
• Based on the Florida Packinghouse Newsletter.
• Simple explanations of the use of sanitisers, etc..
• Compatibility issues.
• Valued by progressive packers.
• Very useful to IDO’s, chemical supplier reps.
• Website address
• • Click here to connect to the 'Packer Newsletter'

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