Aufnahme von sorbiertem Monolinuron durch Haferpflanzen

Uptake of adsorbed monolinuron by oat plants The uptake of soil adsorbed ¹⁴C-ureido-labelled herbicide monolinuron by oat plants was investigated. After a growing period of 9 weeks 35 to 57 % of the initial ¹⁴C-radioactivity was found in the shoots. An incubation period of 16 weeks of soil and monolinuron reduced the uptake by plants in contrast to either short term adsorption or the addition of monolinuron in solution. Changes in the herbicide soil ratio had no influence on the plant availability of freshly adsorbed monolinuron or monolinuron added in solution. However, after 16 weeks of incubation the availability of monolinuron was reduced by a narrow herbicide soil ratio. Monolinuron was identified in the soil solution by mass-spectrometry. As much as between one half and two third of the total monolinuron was taken up by the plants in the first 3 weeks. ¹⁴C-radioactivity was also found in the roots as well as in shoots of untreated control plants. The amount of ¹⁴C-activity adsorbed on soil after harvest was calculated.