6. Influence of adjuvants addition on lenacil residues…

6. Influence of adjuvants addition on lenacil residues in plant and soilMariusz Kucharski, Jerzy Sadowski, Barbara Wujek, Justyna Trajdos

Abstract. The aim of this work was to evaluate the infl uence of an adjuvant addition on lenacil residues in soil and roots of sugar beet. Field experiments were conducted during a three-year-period from 2008 until 2010 on arable fi elds located in southwestern Poland. Chemical weed control in sugar beet was carried by commercial formulation of lenacil. Herbicide was applied alone (recommended and reduced doses) and in mixture with adjuvants (oil, surfactant and multicomponent). Lenacil residue was analysed using HPLC/UV. At lifting time the residues of lenacil in soil amounted to 0.0006–0.0042 mg kg-1.
In sugar beet roots samples, the residues of lenacil were lower than in soil and amounted to <0.0005–0.0020 mg kg-1. The addition of adjuvants caused an increase of the active substance residues in soil and roots of sugar beet in comparison with the treatments, where lenacil was used without adjuvant (reduced dose). The increase of the lenacil residues was statistically signifi cant for most of soil and plant samples and amounted average to 45 and 41% respectively. Infl uence of single adjuvant on lenacil residues in soil and plant was different for each year (experimental season). The residues of lenacil determined in roots of sugar beet did not exceed acceptable value (MLR).

key words: adjuvant, herbicide, residue, lenacil, soil, sugar beet