Mobility of fomesafen in brazilian soils

To obtain an estimate of a herbicide's potential for leaching and degradation, as well as its weed control efficiency, it is essential to understand its retention processes in the soil. This work evaluated fomesafen leaching in four soils: Inceptisol, Latosol with original and corrected pH, Ultisol and Histosol. Thus, bioassays were carried out using the sorghum hybrid BRS655 as indicator of the presence of fomesafen in soils. The soils were packed in PVC columns of 10 cm diameter and 50 cm in length, marked and sectioned every 5 cm apart. Fomesafen was applied at the top of the columns, at a dose of 500 g ha(-1) Rainfall was simulated 12 hours later, by applying a level of water of 80 mm. Plant poisoning evaluations and aerial part harvest were performed to determine shoot dry matter at 21 days after sowing sorghum in the soil of each column. The decreasing leaching order was: Inceptisol > Latosol, corrected pH > Latosol, original pH > Ultisol > Histosol. The factors that most affected leaching in a decreasing order of importance were: organic matter content, soil texture, and soil pH.