Qualidade sanitária e fisiológica de sementes salvas e comerciais de soja

Abstract

Soybean is the main oilseed cultivated worldwide, and Brazil is its largest producer. Since seeds are the basis of crops, obtaining high quality seeds is desired by both companies and producers, since the use of saved seeds provides a significant reduction in production costs. However, illegal commercialization of these seeds has become common practice, and the quality control of lots is often non-existent, directly affecting the establishment and productivity of crops. Thus, the aim was to evaluate the physiological and sanitary quality of different lots of soybean seeds from saved and certified sources, available in the city of Santo Augusto - RS. The experiment was developed in the Phytopathology Laboratory of the Universidade Federal da Fronteira Sul, campus Cerro Largo - RS. Seeds of the cultivars BMX RAIO IPRO, BMX ZEUS IPRO, NA 5909 RG, NEO 610 IPRO and SYN 1561 IPRO, of commercial and saved origins, were used. The following variables were evaluated to assess the physiological quality of the seeds of the cultivars in relation to their origin: first count, germination, germination speed index, radicle and aerial part length, radicle and aerial part dry mass, and accelerated aging test. To evaluate the sanitary quality of the seeds, the sanitary test was performed by the incubation method on paper substrate, and the evaluation was performed individually on the seeds with the help of a stereomicroscope, observing the presence of typical fruiting of fungus development, and the results were expressed in percentage at the end of the evaluation. In general, there was no significant difference for the cultivar factor; however, the origin of the seeds significantly influenced the results of the first count, germination and GVI, where seeds of commercial origin of the cultivars BMX ZEUS IPRO and NEO 610 IPRO provided the best results. As for radicle and aerial part length, there was no interaction between cultivars and origins, with the best results observed for the BMX RAIO IPRO and BMX ZEUS IPRO cultivars, respectively. Regarding radicle and aboveground dry mass, the best results were observed for commercial and sage origin, respectively. In general, seeds from sage origin showed superior results during accelerated aging, but only seeds from cultivar SYN 1561 IPRO showed viability for use. The presence of fungus was low, with Fusarium sp. and Aspergillus sp. being the most expressive. In general, regarding the physiological quality and seedling performance, seeds of commercial origin presented superior results when compared to those obtained for saved seeds. The cultivars BMX ZEUS IPRO, BMX RAIO IPRO and NEO 610 IPRO gave the best results. The salted seeds showed superior results, according to the accelerated aging test, however, only the seeds of cultivar SYN 1561 IPRO resulted in acceptable values for use. The sanitary quality of the seeds was high, since the incidence of pathogens was low, with the most significant being Fusarium sp. and Aspergillus sp. in the sage and commercial origins, respectively.