The adoption of quick and reliable laboratory techniques and equipment to choose the best seed lots for marketing will influence the production of soybeans with superior physiological quality, among other areas in the sector. Therefore, the objective of this study was to evaluate the CO2 concentrations produced by water-soaked soybean seeds and to verify the effectiveness of new equipment to help choose lots with different vigor levels. To evaluate the physical and physiological quality of the seeds, eight soybean lots were evaluated with the following tests: water content, weight of thousand seeds, first germination count, germination, electrical conductivity, emergence, and respiration evaluated by the Pettenkoffer apparatus and with equipment designed to measure CO2 in seeds. The results were subjected to analysis of variance with means compared by Tukey’s test at p ≤ 0.05. Conventional methods showed significant differences in vigor and viability in soybean seeds. The equipment designed was efficient in detecting CO2 produced by seeds soaked in water for 8 hours. The CO2 readings with the equipment presented satisfactory results to predict the vigor in soybean seeds through respiration.

The widespread adoption of sensor technology has made it a standard practice for obtaining precise and timely information during the harvest and post-harvest periods. One sensor that has gained popularity for post-harvest seed monitoring is the MQ-3, which identifies ethanol in the air as products undergo fermentation. However, these sensors typically require a stable operation. This study aimed to assess the stabilization time of an MQ-3 sensor when measuring ethanol levels in anaerobic bean seeds. We used six bean seed samples, each with an average moisture content of around 14%. We employed a completely randomized experimental design with nine repetitions for each sample. Every repetition consisted of 25 bean seeds placed in sealed flasks containing 70 mL of distilled water. This setup induced anoxic conditions within the flask, promoting anaerobic respiration in the seeds. After 24 hours, we exposed an air sample to the MQ-3 sensor and took readings at various time intervals (12-14, 19-21, 36-38, 68-70, 130-132, 192-194, 314-316, 616-618 seconds). The average stabilization time for the MQ-3 sensor while quantifying ethanol concentrations in the bean samples were approximately 23 seconds. The sensor demonstrated efficacy, convenience, and rapidity in assessing ethanol levels in anaerobic bean seeds.