MODELLING THE EFFECT OF ORCHARD TEMPERATURE AND FRUIT MATURITY ON SUPERFICIAL SCALD DEVELOPMENT DURING CA STORAGE OF POME FRUIT

J. Lopresti, R. Holmes, S. Kriedl, G. Hale
Superficial scald is a physiological disorder of apples that occurs during cold storage, resulting in unmarketable fruit due to brown skin discolouration. Scald susceptibility varies greatly with cultivar, orchard environment, fruit maturity, storage duration, and season. The aim of this study was to model the effect on superficial scald incidence of orchard air temperature, fruit maturity, and storage duration, under controlled atmosphere, for ‘Granny Smith’ and ‘Pink Lady’ apple cultivars grown in three climatic regions of Australia. Superficial scald incidence, as a measure of susceptibility, was successfully modelled, and significant explanatory factors were determined for specific cultivar and orchard combinations. The importance of particular factors, in explaining variation in scald incidence, was highly dependent on both cultivar and climatic region. The accumulation of preharvest hours <10°C was the most important factor affecting scald incidence in both ‘Granny Smith’ and ‘Pink Lady’ apples from cooler climatic regions, where many hours below 10°C accumulated prior to harvest. In contrast, fruit maturity, measured by starch index score, had the most explanatory power in warmer regions, where it increased rapidly in the period prior to harvest. The relationship between scald susceptibility, and either accumulated preharvest hours or fruit maturity for specific storage duration was usually sigmoidal or exponential, with low scald susceptibility in fruit with higher maturity or greater accumulated preharvest hours. Further model development, for ‘Granny Smith’ and ‘Pink Lady’ apples, over several more seasons, could potentially enable producers to predict scald susceptibility at harvest, prior to storage. Scald prediction could, thus, become an important component of an alternative approach to control superficial scald in apples.
Lopresti, J., Holmes, R., Kriedl, S. and Hale, G. (2015). MODELLING THE EFFECT OF ORCHARD TEMPERATURE AND FRUIT MATURITY ON SUPERFICIAL SCALD DEVELOPMENT DURING CA STORAGE OF POME FRUIT. Acta Hortic. 1068, 273-280
DOI: 10.17660/ActaHortic.2015.1068.34
https://doi.org/10.17660/ActaHortic.2015.1068.34
Malus domestica (Borkh.) L., superficial scald, CA storage, orchard temperature, starch index
English

Acta Horticulturae