Development of Bioassay Method for Detection of Herbicide Residues in Soil

Duration: 1 Sep 2016-31 Aug 2017

Head: Klara Barić (Faculty of Agriculture, Zagreb)

Participants: Sanja Stipičević, Z. Ostojić, A. Pintar, M. Šćepanović (Faculty of Agriculture, Zagreb)

Summary
Modern monitoring methods of pesticides in soil, water and biological samples involve of instrumental analytical techniques. Monitoring of herbicide in soil can be carried out also with bioassay method, i.e. determining the degree of phytotoxicity of herbicides on cultivated plants. Bioassays are useful complement to the analytical methods, which often do not provide an answer for the observed reaction of cultivars due to the very low levels of herbicide residues in the soil. The aim of this project is to determine the synergy of analytical and bioassays methods of mesotrione determinations in soil and to determine the standard curve sensitivity of the test plants at known herbicide concentrations in three the most represented types of soil in Croatia. The total and organic carbon contents and pH were determined in agricultural soil samples (TOC analyses). The most appropriate test plant and its response to different doses of herbicides were investigated by performing a field experiment. Field trial was conducted in Šašinovec, near Sesvete. The field was sown with six test crops (soybean, sugar beet, sunflower, canola, peas and oats). The field was treated with CALLISTO 480 SC suspension of mesotrione at six different doses of herbicides. The sensitivity of test plants was determined periodically by the visual evaluation method and by the mass determination of fresh and dry above-ground mass cultivars. For growing test plants in a controlled conditions the undisturbed treated soil samples will be collected 3, 6 and 12 months after herbicide application. The inhibition of growth of test plants will be determined by the measuring of above-ground mass of plants and of the carotenoid content.