In tobacco plants, fruit capsule color indicates the maturity of the contained seeds. With progressing maturity, color changes from green over yellow to brown. When harvesting seeds, it is desired to have same levels of maturity and thus surface color is taken as indicator when selecting the capsules. In an assessment of ripening stages, capsules of different ages were imaged with a Scanalyzer HTS, LemnaTec’s predecessor of the current HyperAIxpert. Images were recorded under visible, near infrared, and infrared light. Using the NIR signal, relative water content was measured and the ripening-related dry-out of the capsules was monitored. Water loss was accompanied by increasing surface temperatures as indicated by the IR signal. The computer-assisted color analysis delivered numerical values for the color changes during the ripening process. In particular this observation opens the way to assist classical visual scoring of capsule colors with digital image processing tools that result in well-documented and operator-independent measures of ripening stages. In addition, morphological factors changed during the ripening so that such factors, together with the color and water content data can serve as indicators of maturity.
The comprehensive assessment of the phenotypic data of the capsules using LemnaTec imaging and image processing technology opens a perspective for digitally assisted fruit assessments in horticultural applications.