A precision management approach to monitor apple fruit growth and quality
The application of precision management sensing technologies in apple production is challenging as many of the key physiological processes that influence fruit quality occur within the fruit tissue and are masked from the outside by the fruit skin. We report results from a three-year project at the Kompetenzzentrum Obstbau-Bodensee in Southwest Germany to monitor 'Braeburn' apple fruit growth and quality using a precision management approach. Field time-series data were collected regularly with a standard type of hand-held spectrometer and a set of Bluetooth digital calipers from the same marked apples while growing on-tree. Data were collected from three tree sectors (bottom, middle and top, trees were ~3.8 m high) and different field treatments (e.g., calcium spraying and crop load). Fruit were placed in delayed CA storage for a period of ~5 months. After a shelf-life period all fruit were cut and assessed for internal physiological disorders. In 2018, fruit from the bottom tree sectors showed a higher disorder severity for bitter pit than those from the middle or top tree sectors. Total soluble solids content modelled from the spectral time-series data varied notably between measurement acquisitions, whereas chlorophyll (red edge) degradation and fruit diameter growth showed an overall smoother decline or increase, respectively. The results are discussed with some insights into the data management necessary for a precision orchard approach.
Biegert, K., McCormick, R.J., Zoth, M. and Braun, P. (2021). A precision management approach to monitor apple fruit growth and quality. Acta Hortic. 1314, 447-454
'Braeburn', physiological storage disorders, VIS/NIR, Big Data