Germinação e crescimento de plantulas de Glycine max submetidas a concetrações tóxicas e subtóxicas de cádmio e o efeito protetor do bioestimulante acadian

Abstract

The use of pigs manure application in the field as a fertilizer to the soil without any planning, repeated applications may exceed the support capacity of the soil, causing changes in the concentrations of heavy metals, such as cadmium, that in high levels in the soil can be characterized as extremely toxic. However one proposals is the use of biostimulants, reducing the effects of this heavy metal in soybean plants. As this culture is of great importance for the economy, it is of big relevance the study that demonstrates the effects of this metal in toxic and subtoxic contents. The propose of the present work is to verify the effects of toxic and subtoxic concentrations of cadmium on the germination and growth of soybean seedlings using Acadian® Biostimulant. The seeds were conditioned in a plastic bag of 2 kg capacity, where the dosage of 24 mL / kg seeds of the Acadian® biostimulant was inserted. The seeds were then divided into four batches of sixteen replicates of fifty seeds and each replicate seeded on Germitest paper substrate, previously moistened with a volume of water corresponding to 2.5 times the paper weight. The water used to soak the 4 batches was increased by different concentrations of cadmium chloride (CdCl²), so that the final concentrations of cadmium were 0.0, 25.0, 50.0 and 100.0 mg / L, generating four different treatments. The paper rolls were kept in germinators at a constant temperature of 25ºC, and the evaluations were performed in 4 replicates of each treatment on the fourth, fifth, sixth and seventh days after sowing. The parameters vigor, viability, germination speed and growth evaluations were analyzed. Cadmium affected all the parameters in which they were evaluated, it was observed that the use of biostimulant had ineffective results when the seed is in an environment that occurs the presence of this heavy metal.