Plant Pathology

Pre-and-Post-Harvest Pathology

The pre-and post-harvest pathology research programme addresses a number of important industry issues. The research on incidence and distribution of fungal pathogens in young trees is highly relevant as is the integrated management of apple scab. Apple replant disease and various aspects of post-harvest pathology are also receiving attention.

Phytosanitary and Biosecurity Workgroup
Integrated Pest Management Group

Projects list

  • Determining the risk of mulches in the spread of canker pathogens in apple orchards. (L Mostert)
  • Investigating the relationship of pathogens, particularly Alternaria, in causing fruit spot symptoms/lenticel damage, on apples. (P Louw)
  • Determine the occurrence of fungicide resistance against pyrimethanil and fludioxinol in Monolinia laxa and Botrytis cinerea populations from stone fruit orchards. (P Louw)
  • Evaluation of PVdI transmission through top working infected trees. (H Maree)
  • Development of a hybridisation-based detection assay for PVdI. (H Maree)
  • Alternatives for the management of apple replant disease. (A McLeod and D de Villiers) [Abstract]
  • Evaluation of pruning wound protectants on nursery apple trees. (L Mostert and G Gatsi) [Abstract]
  • Survey of stem canker pathogens on stone fruit propagation material and young stone fruit trees. (L Mostert and V Jacobs) [Abstract]
  • The effect of organic amendments on the severity of apple replant diseases in subsequent apple orchard replantings. (A McLeod and R Janse van Rensburg) [Abstract]
  • The influence of climatically different seasons on the reproductive strategy of Venturia inequalis and the RIMpro disease forecasting model. (A McLeod and E Froneman) [Abstract]
  • Determine fungicide efficacy using qRT-PCR for detection and quantification of Botrytis cinerea inoculum and viability on pear leaves as a substrate, before and after fungicide application. (P Louw) [Abstract]
  • Evaluation of apple rootstocks tolerance against specific apple replant disease (SARD). (I Labuschagne, A McLeod and X Siboza) – see Rootstocks and Nursery Tree Quality
  • Establishing the cause of marbling and corky flesh in plums. (H Maree)
  • Evaluating an ascospore release forecasting model and orchard disease monitoring methods for improving apple scab management. (A McLeod) [Abstract]
  • Identification of inoculum sources of oomycetes, a major contributor to apple replant disease, and the management thereof. (A McLeod, M Nyoni and S Moein) [Abstract]
  • The role of stress factors in predisposing plum trees to invasion by bacterial pathogen Pseudomonas syringae pv. syringae. (T Coutinho, K Bophela and M Modiba) [Abstract]
  • Screening apple rootstocks for tolerance to Phytophthora crown rot. (A Vermeulen) [Abstract]
  • Lipopeptides Fengycin and Iturin as a postharvest fungicide on pome fruit. (C Lennox, J Meitz-Hopkins and S Magwebu) [Abstract]
  • The development of an integrated management strategy for Bull’s Eye rot of apples. (C Lennox, J Meitz-Hopkins and A Russouw) [Abstract]
  • Bioreactor and process development for the production of antimicrobial lipopeptides produced by Bacillus for biological control of postharvest phytopathogens in the perishable fruit industry. (R Pott)
  • Pursuit of sanitiser products for potential use in the apple and pear industry. (P Louw) [Abstract]
  • Purification of antimicrobial lipopeptides produced by Bacillus spp. for biological control of postharvest phytopathogens in the perishable fruit industry. (R Pott, J van Johannides and G Teke) [Abstract]
  • Thermal and non-thermal treatments of stone and pome fruit: Towards efficient phytosanitary measures. (O Caleb, Z Belay and N Nyamende) – also Quality Management  [Abstract]
  • Evaluating the relationship between quantified Botrytis cinerea levels in pear fruit at harvest and the Botrytis rot incidence and severity at the end of storage: Towards the development of a Botrytis rot management model. (S Ferreira and I Wilson) [Abstract]
  • Lipopeptides for the biological control of postharvest phytopathogens (R Pott, G Teke, D Baloyi, J Marais and S Magwebu) [Abstract]
  • Thermal and non-thermal treatments of stone and pome fruit: Towards efficient phytosanitary measures. (O Caleb, Z Belay and N Nyamende) – also Quality Management [Abstract]
  • Develop a storage protocol for plums stored for 6 weeks in bins prior to packing – decay control using alternative gas regimes of CO2 and O2 manipulation, fungicides and GRAS products by drenching and Ozone treatment. (P Louw) – also Storage Techniques  [Abstract]
  • Survey and investigation on the impact of various fungicide application methods and technologies on decay control of plums in the pack-house. (A de Kock and I Wilson) [Abstract]
  • Factors that influence the retention of fungicide residues on plums. (A de Kock) [Abstract]
  • 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) [Abstract]