Physiological Defects

Physiological Defects

The main internal quality defects receiving research attention are lenticel breakdown, mealiness, superficial scald and internal browning. Research is aimed at understanding the underlying causative factors (both pre- and post-harvest) and biochemistry of these defects so as to allow the development of technology to limit or prevent their occurrence. Other aims are to generate best practice guidelines for handling of fruit both pre- and post-harvest and to develop indicators to predict the risk of the various defects in a given season.

Expertise:
Physiological Defects Workgroup

Projects list

  • Soft scald development and management in apples. (A Botes)
  • Compilation of a database of high quality images of pome fruit disorders from South African growing and storage conditions to contribute to the further development of software based determination (APP) for the detection and reduction of bearing damage in fruit (Frudistor) in an international context. (I Crouch) [Abstract]
  • Detection of internal heat damage and identification of techniques to prevent the expression of the disorder in plums. (A de Kock) – also Storage Techniques  [Abstract]
  • Fuji browning types explored via x-ray CT in collaboration with existing trial. (E Crouch and K Chigwaya) [Abstract]
  • Quantifying the role of vapour pressure deficit in the development of lenticel breakdown in Braeburn apples. (E Lötze, D Viljoen and N Mzizi) [Abstract]
  • Superficial scald on Granny Smith – understanding the mechanisms and limitations of the storage protocols used by industry and assess risk indicators in storage for scald development. (E Crouch, A Botes, P Mathabe, D Viljoen, T Pandian, M Gerber and A Hlungwani) [Abstract]
  • Determining ‘Forelle’ pre-harvest mealiness / cavity development stage, due to environmental factors and exploring prevention of mealiness developing after storage and ripening. (E Crouch, L Schoeman and L-M Dippenaar) – see Growing Season Climate, Crop Production Programme [Abstract]
  • Identification of factors involved in the expression of internal browning in Fuji apples and the development of a strategy to reduce risk of incidence. (D Viljoen) [Abstract]
  • To assess Internal Browning development potential from high watercore incidence FEMA Forelle. (D Viljoen) [Abstract]
  • Summary of Fuji Browning Study and Literature Review (I Crouch)
  • Quantification of lenticels in Japanese plum cultivars and their effect on total fruit peel permeance (I Kritzinger)*
  • Stone hardening and broken stones in Japanese plums (Prunus salicina Lindl.) evaluated by means of computed tomography scans (E Lötze)*