Can near infrared spectroscopy be used to select superior popcorn lines under drought conditions?

Abstract

This study sought to answer the following questions: i) Is it possible to use the near-infrared (NIR) spectrum for the indirect selection of superior popcorn genotypes
based on grain yield (GY), popping expansion (PE), and volume of expanded popcorn per hectare (VP)? ii) Is it possible to detect differences between different water
conditions (WC) applied to the soil using NIR? iii) Is it possible to identify the phenological stages (days from male anthesis) of the crop in a given WC using NIR, considering
the morphophysiological transformations during plant development? To this end, thirteen popcorn lines, under well-watered and soil water stress imposed at male
anthesis, were evaluated for GY, PE, and VP traits and correlated with NIR indices in the 908 to 1680 nm spectrum. Measurements were made at different times in relation to
male anthesis. It was impossible to associate the NIR spectra with the GY, PE, and VP traits due to the lack of correlation based on the R2 values resulting from the analysis of
standard normal variate (SNV), first derivative, and SNV + first derivative. In turn, via NIR, it was possible to differentiate the WCs and associate them with the phenological
stage the plants were in.