Assessment of a lenticel breakdown prediction method for the South African pome industry

The objective of this trial was to determine if the number of open lenticels at harvest can be correlated to the incidence of lenticel breakdown disorders in ‘Fuji’ apples after storage.

The number of open lenticels at harvest was determined by exposing a sample of fruit to SO₂ gas which resulted in tissue damage around any open lenticels allowing the quantification of open lenticels. After storage and shelf-life, the level of lenticel breakdown per orchard was evaluated and the correlation with open lenticels at harvest was established.

Fruit maturity at harvest ranged from late-optimum to post-optimum across the two seasons. Open lenticels at harvest correlated with lenticel spot after shelf-life. Other maturity parameters at harvest correlated with bitter pit and lenticel damage after storage.

The lenticel spot risk method has potential, but further data is needed to validate the correlations found. This method together with other maturity indices may be developed into a risk model for lenticel breakdown and bitter pit potential.

There is potential in the method developed by Singh et al. (2016) to determine lenticel breakdown risk. Further research and data collection are needed to develop a model taking into consideration various maturity and orchard factors.