Herbicidal Effects of Pyroligneous Acid for Control in Weed Seed Bank

Aims: Pyroligneous liquor, a by-product extracted from wood pyrolysis during charcoal production, is mainly discarded. Pyroligneous liquor has a phytotoxic effect and can be used environmentally as an herbicide of natural and sustainable origin for plant control. The objective of this research was to evaluate the effectiveness of pyroligneous liquor to control the plant seed bank.

Study Design: Different concentrations of pyroligneous liquor (0, 1, 2, 3, 4, 5, 10, 15, 20, 25, 50, 75, 100% (v/v)) were tested in soil samples with 10 replications each. Statistical analysis of the data found was carried out using the OriginPro 2018 software, employing a nonlinear regression model.

Place and Duration of Study: The experiment was carried out in the Federal University of Tocantins, Gurupi – To, Brazil. Soil collection and formal analyzes carried out between January 2023 and August 2023.

Methodology: The soil was collected with the aid of a digger, with five subsamples within the useful area of ​​the plot and constituted a composite sample. After collection, samples from the Seed Banks were separated to quantify the seeds present in the soil seed bank, the other half of the sample, the soil was divided into 10 gerbox boxes for each treatment and benches were placed with natural light and kept under irrigation to stimulate germination. Throughout the experiment, temperature and relative humidity were monitored, remaining on average at 26.4°C and 73.5%, respectively. From the pyroligneous liquor obtained, dilutions were made with distilled water at liquor concentrations 0, 1, 2, 3, 4, 5, 10, 15, 20, 25, 50, 75, 100%(v/v) that were used in the treatments.

Results: Higher pyroligneous liquor concentrations inhibited seed germination, while lower concentrations had less impact.

Conclusion: These findings suggest that pyroligneous liquor can be used to control of weed seed bank.