Permeabilidade de tegumento, condicionamento osmótico e aplicação de fungicida na qualidade fisiológica de sementes de soja

Abstract

The soybean is considered one of the most strategic crops within the Brazilian agriculture scenario, because of its importance to the national economy. This is one of the reasons that lead to the adoption of new technologies to its mass production, including the seed treatment. However, a positive result of this technology depends on the combination of a series of different factors, such as seed coat permeability, and the product and rate used to treat the seed. Besides, a new technique that has been recently studied, known as seed osmopriming, has also showed promising results in soybean seeds quality enhancement. This study aimed to evaluate if there is an interaction of these factors over the seed quality improvement. The experiments were conducted in the Seeds Laboratory of the Mato Grosso Federal University, in a factorial scheme 2 x 2 x 5, with two soybean varieties (P98Y11 and P98Y12), which have contrasting seed coat permeability, with and without osmopriming treatment with polyethylene glycol, and using five rates of the fungicide pyraclostrobin (0, 50, 100, 150 and 200 mL per 100 kg of seeds). The assessments were made by the imbibition, germination and vigor tests. The results obtained indicated that there is no interaction among these three factors. The variety P98Y12 have the most permeable seed coat, with the highest values of germination first counting, but with the lowest vigor indexes because of the damages caused by fast water absorption. The polyethylene glycol hinders germination and seed vigor. The fungicide influences the seeds germination and vigor.