Germinação de sementes e crescimento de plântulas de soja submetidas à diferentes concentrações de cobre

Abstract

With the passing of the years the soybean crop has been gaining space in planted area and a increase in productivity, some factors are responsible for this culture to have gained space, as the demand of the internal and external market mainly for agroindustries related to the meat sectors. A well-nourished soil is an essential factor to meet the growing demands, this is also responsible for the good development of the plants, but some care must be taken in relation to the source to supply our soils with nutrients. As the region west of Santa Catarina is a reference in the production of pigs, their waste ends up being used as fertilizer by the farmers. It's excessive use has negative implications, since they contain heavy metals, among them copper sulphate (CuSO4), which in situations of successive applications cause an accumulation of this metal in the soils. Thus, the objective of this work was to analyze experimentally the effect of different doses of copper under the germination and initial development of soybean. The experiment was carried out in the Seeds and Grains laboratory of the Federal University Fronteira Sul in a scheme of plots subdivided into blocks at random, with cross-classification and evaluations at the fifth, sixth, seventh and eighth days. The seeds were divided into 4 batches of 16 replicates with 50 seeds, where the replicates were seeded on germitest paper previously moistened with a volume of water corresponding to 2.5 times the weight of the paper. In the water used to soak the 4 batches was diluted different concentrations of copper sulphate (CuSO4), so that the final concentrations of copper were 0, 100, 200 and 300 mg L-1, generating four different treatments. The paper rolls were kept in germinators at a constant temperature of 20ºC, and the evaluations were performed in 4 replicates of each treatment on the fifth, sixth, seventh and eighth days after sowing. The germination rate decreased as the copper dose increased, but it was possible to verify that up to the 100 mg L-1 dose increased germination and root size, the above concentrations had deleterious effects on the crop, and it was possible to perceive that the copper had no effect on the aerial part of the soybean.