Modelling Soluble Solids Content Accumulation in 'Braeburn' Apples.

Abstract

Optical sensor data can be used to determine changes in anthocyanins, chlorophyll and soluble solids content (SSC) in apple production. In this study, visible and near-infrared spectra (729 to 975 nm) were transformed to SSC values by advanced multivariate calibration models i.e., partial least square regression (PLSR) in order to test the substitution of destructive chemical analyses through non-destructive optical measurements. Spectral field scans were carried out from 2016 to 2018 on marked 'Braeburn' apples in Southwest Germany. The study combines an in-depth statistical analyses of longitudinal SSC values with horticultural knowledge to set guidelines for further applied use of SSC predictions in the orchard to gain insights into apple carbohydrate physiology. The PLSR models were investigated with respect to sample size, seasonal variation, laboratory errors and the explanatory power of PLSR models when applied to independent samples. As a result of Monte Carlo simulations, PLSR modelled SSC only depended to a minor extent on the absolute number and accuracy of the wet chemistry laboratory calibration measurements. The comparison between non-destructive SSC determinations in the orchard with standard destructive lab testing at harvest on an independent sample showed mean differences of 0.5% SSC over all study years. SSC modelling with longitudinal linear mixed-effect models linked high crop loads to lower SSC values at harvest and higher SSC values for fruit from the top part of a tree.

Plant phenotyping relevance

リンゴ果実のSSCを非破壊光学測定とPLSRで推定する方法を開発・検証しており、独立サンプルおよび実験室分析との比較も行っているため、植物形質取得法が中心である。

Code and data availability

The article describes Vis/NIR spectral scans, PLSR models, and LME analyses of 'Braeburn' apple SSC, but contains no data availability statement, no public dataset deposit, and no author code/workflow URL. The Felix model builder software and R package pls are generic tools, not paper-specific assets. No supplement is附

No evidence-backed public reproduction asset is currently recorded.