TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Overbeck, Verena A1 - Schmitz, Michaela A1 - Blanke, Michael T1 - Non-Destructive Sensor-Based Prediction of Maturity and Optimum Harvest Date of Sweet Cherry Fruit JF - Sensors N2 - (1) Background: The aim of the study was to use innovative sensor technology for non-destructive determination and prediction of optimum harvest date (OHD), using sweet cherry as a model fruit, based on different ripening parameters. (2) Methods: Two cherry varieties in two growing systems viz. field and polytunnel in two years were employed. The fruit quality parameters such as fruit weight and size proved unsuitable to detect OHD alone due to their dependence on crop load, climatic conditions, cultural practices, and season. Coloration during cherry ripening was characterized by a complete decline of green chlorophyll and saturation of the red anthocyanins, and was measured with a portable sensor viz. spectrometer 3-4 weeks before expected harvest until 2 weeks after harvest. (3) Results: Expressed as green NDVI (normalized differential vegetation index) and red NAI (normalized anthocyanin index) values, NAI increased from -0.5 (unripe) to +0.7 to +0.8 in mature fruit and remained at this saturation level with overripe fruits, irrespective of variety, treatment, and year. A model was developed to predict the OHD, which coincided with when NDVI reached and exceeded zero and the first derivative of NAI asymptotically approached zero. (4) Conclusion: The use of this sensor technology appears suitable for several cherry varieties and growing systems to predict the optimum harvest date. KW - Sweet cherry (Prunus avium L.) KW - bio-innovation KW - harvest prediction KW - maturity index KW - modeling KW - NAI KW - NDVI KW - nondestructive examination UN - https://nbn-resolving.org/urn:nbn:de:hbz:1044-opus-29140 SN - 1424-8220 SS - 1424-8220 U6 - https://doi.org/10.3390/s17020277 DO - https://doi.org/10.3390/s17020277 PM - 28146114 VL - 17 IS - 2 PB - MDPI CY - Basel ER -