Estimativa da germinação e vigor de sementes de milho envelhecidas usando sensoriamento remoto proximal

Abstract

The quality of maize seeds is a determining factor in the success of the crop. It is directly influenced by sowing density, as well as the physiological and sanitary conditions of the seeds. Traditional evaluation methods, such as germination and vigor tests, are widely used to assess seed viability, particularly under stressful conditions. However, given the growing demand for more sustainable agricultural practices, new technologies are gaining prominence, such as remote sensing (RS). In this context, the general objective of this study was to evaluate the effectiveness of proximal remote sensing (PRS) in estimating the germination and vigor of corn seeds subjected to accelerated aging. The study was conducted at the Laboratory of the Federal Technological University of Paraná (UTFPR) on the Santa Helena campus, located in the municipality of Santa Helena, Paraná, Brazil. The experimental design was entirely randomized (DIC) in a double factorial arrangement (5x4), with 20 treatments, four replications, and two experimental factors: accelerated aging time (0, 24, 48, 72, and 96 hours) and proximal sensor positioning height (30, 40, 50 and 60 cm). The variables analyzed included the NDRE (Normalized Difference Red Edge Index) vegetation index, obtained using an active optical sensor, and the biophysical characteristics of the seeds, such as aerial part height, root length, dry mass, water content, germination percentage, germination speed index (GVI), number of seedlings and seedlings. The statistical analysis included descriptive statistics, a normality test, an analysis of variance (ANOVA), and, where appropriate, Tukey's test for comparing means. Polynomial regression models were fitted based on the NDRE in order to estimate the biophysical characteristics of the seeds. The data was processed using AgroEstat, Python, and Microsoft Excel software. We used the QGIS software to create a map that shows the location of the experimental area. The results obtained showed that the NDRE index is sensitive to detecting physiological changes in maize seeds subjected to accelerated aging, allowing for accurate estimates of attributes such as shoot height, dry mass, root length, water content, germination percentage, and the germination speed index (GVI). The polynomial regression models fitted showed coefficients of determination (R²) that were considered satisfactory, especially for the aerial part height variable (R² = 54.66%) and for the germination values obtained on different evaluation dates (R² ranging from 66.62% to 76.00%).