Agricultural welsh onion waste as a source of gibberellic acid

Abstract

The obtention of gibberellic acid from the branches of the Welsh onion, as an option to the conventional gaining from the fungus Gibberella fujikuroi and as an alternative to give some value to this agricultural waste was evaluated. A extract was obtained from the branches and by thin layer chromatography and by comparison with a commercial pattern, the presence of gibberellic acid was evidenced. A ultraviolet spectrophotometry revealed that the concentration of gibberellic acid correspond to a 2.70% of the dry Welsh onion.To evaluate the biological effect of the extract, three groups of peas plants were arranged, including a control, treated with the commercial pattern of the Gibberellic acid. The results showed that the onion branch extract increased the length of plant's stem in a 47%, the foliage in a 67% but had no effect on the main root's elongation compared to the control. In studies with groups of lettuce seeds, arranged in similar ways than the peas plants but with 39 individuals per group, it was found that the extract promotes the seed's germination in 28% more, compared to the control. All the biological tests performed with the onion's extract presented similar behavior to those treated with the gibberellic acid pattern, presenting no differences in the variance analysis ANOVA and Turkey test (p < 0.05). It was concluded that it is possible to obtain a crude extract with the presence of gibberellic acid from this agricultural waste.