Avaliação da qualidade fisiológica de sementes de soja por meio do biospeckle laser

Abstract

The analysis of seed quality involves several tests, with methodologies used in all stages of production, and mainly aim to evaluate vigor and viability from harvest to sowing. The search for new test alternatives that allow faster and less subjective analyzes is a current trend, the use of new techniques such as biospeckle laser can help to obtain efficient and fast methodologies. The objective of this work was to evaluate the ability of the biospeckle laser to differentiate soybean seed samples according to physiological quality and to determine suitable methodologies for this purpose. Twelve samples of seeds with different levels of quality, determined by means of traditional tests, were evaluated. For the analysis using the biospeckle laser, 512 images of each seed were captured and submitted to two processing methods: the Graphic Absolute Value of the Differences (GAVD), which generated maps of biological activity of the cotyledons of the seeds, and the Numerical Analysis of the Average Difference (NUMAD), which provided numerical values that quantified biological activity. The traditional tests used to validate the quality of the samples were: germination; first germination count; emergency; first emergency count; Electric conductivity; accelerated aging test on paper and substrate. The experimental design adopted was completely randomized (DIC). The data obtained were submitted to analysis of variance and Scott-Knott mean test. To validate the results obtained with the biospeckle laser, Pearson's correlation was performed with the results of traditional tests commonly used in seed analysis. In the Scott-Knott mean test, the separation of soybean seed samples by image processing, proved to be like the traditional tests. By Pearson's coefficient, NUMAD obtained the highest correlation with the tests of accelerated aging on substrate, emergence, and accelerated aging on paper, respectively. The biospeckle laser proved to be capable of evaluating the physiological quality of soybean seeds, and the results indicated a greater correlation with vigor tests.