Most high throughput systems for automated plant phenotyping involve a fixed recording cabinet to which plants are transported. However, important greenhouse plants like pepper are too tall to be transported. In this research we developed a system to automatically measure plant characteristics of tall pepper plants in the greenhouse.

With a device equipped with multiple cameras, images of plants are recorded at a 5 cm interval over a height of 3 meters. Two types of features are extracted: (i) features from a 3D reconstruction of the plant canopy and (ii) statistical features derived directly from RGB images. The experiment comprised 151 genotypes of a recombinant inbred population of pepper, to examine the heritability and QTLs of the features.

Features extracted from the 3D reconstruction of the canopy were leaf size and leaf angle, with a heritability of 0.70 and 0.56 respectively. Three QTLs were found for leaf size, and one for leaf angle. From the statistical features, plant height showed a good correlation (0.93) with manual measurements, and QTLs were in accordance with QTLs of manual measurements. For total leaf area, the heritability was 0.55, and two of the three QTLs found by manual measurement were found by image analysis.