Post Harvest Decay

Postharvest Decay

With reference to pome fruit, the original project on Bull’s Eye rot of apples has not reached its full conclusion in terms of an integrated management strategy. Co-funding has been provided by the SA Pink Lady Association to complete the process. A one-year project to confirm the causal agents for core rot, using the latest research techniques, was completed. Core rot remains an intractable problem. Botrytis was detected and quantified in pears using a Real-Time PCR technique.

A survey of stone fruit packhouse atomising systems revealed shortcomings which were addressed by a Fresh Notes prior to the season. The ecology of botrytis on plums and weeds in plum orchards was studied. Strangely, a relationship between botrytis levels and monilinia decay was found. Following on several PHI projects, an investigation into the purification and in vitro testing of a biological fungicide (antimicrobial lipopeptide) is proceeding, with possible THRIP co-funding.

Expertise

Postharvest Pathology Group

Projects list

To read more about these projects click on the title where you’ll be directed to the relevant Annual Report.

Pome Fruit Projects

New Projects
  • The development of an integrated management strategy for Bull’s Eye rot of apples. (C Lennox, J Meitz-Hopkins and A Russouw)
  • Pre and post-harvest monitoring of Alternaria spp. in orchards with historically high incidence of dry core rot. (S Ferreira and I Wilson)
Current Projects
  • Development of a fungicide resistance monitoring service for SA pome fruit pathogens. (C Lennox and B Cloete)
Completed Projects
  • Detection and quantification of Botrytis cinerea incidence and severity in harvested pears for the development of a monitoring system to support commercial exports. (S Ferreira, I Wilson, M Wells and N Mangwana)

Stone Fruit Projects

New Projects
  • Survey and investigation on the impact of various fungicide application methods and technologies on decay control of plums in the pack-house. (I Wilson and A de Kock)
  • Quantification of the presence of Botrytis cinerea, Monilinia laxa and Penicillium expansum in blossoms and plums at harvest, and correlation of relative pathogen presence to decay after shelf-life: Potential application of diagnostic information early in the season to use as a management tool of plum decay post storage and shelf life. (S Ferreira and I Wilson)
Completed Projects
  • Production of antimicrobial lipopeptides by Bacillus spp for biological control of postharvest phytopathogens in the perishable fruit industry. (K Clarke, V Rangarajan, W Herbst and S Mazibuko)
  • The prevalence of Botrytis cinerea in and on plums, and alternative host plant tissue: A preliminary investigation on the occurrence of the fungus pre-and-post harvest in order to elucidate pathogen ecology, for new decay control strategies. (I Wilson and S Ferreira)