A bioassay technique to study clomazone residues in sandy loam soil

Abstract

A bioassay test was conducted to evaluate the sensitivity of maize, sunflower and barley to clomazone residues in sandy loam soil. Clomazone was applied at different rates from 0.12 to 12 mg a.i./kg of soil. The parameters measured 14 days after treatment were: shoot height, fresh and dry weight, and content of pigments (carotenoids, chlorophyll a and chlorophyll b). The results showed that the lowest clomazone concentration caused a significant reduction in all measured parameters for barley and sunflower shoots. Fresh weight of maize shoots was not sensitive to clomazone residual activity in soil while the other parameters were highly inhibited. Nomenclature: clomazone (2-(2-chlorbenzyl)-4,4-dimethyl-1,2-oxazolidin-3-one), maize (Zea mays L.), sunflower (Helianthus annuus L.), barley (Hordeum vulgare L.).

U radu je ispitivana osetljivost kukuruza, suncokreta i ječma na rezidualno delovanje klomazona u zemljištu tipa peskuša, metodom biotesta. Klomazon je primenjen u seriji koncentracija 0.12-12 mg a.s./kg zemljišta. Nakon 14 dana rasta biljaka mereni su vegetativni (visina, sveža i suva masa izdanka) i fiziološki parametri (sadržaj karotenoida hlorofila a i hlorofila b). Dobijeni rezultati pokazuju da su i najmanje koncentracije klomazona izazvale značajno smanjenje merenih vegetativnih i fizioloških parametara kod ječma i suncokreta. Izdanci kukuruza nisu pokazali istu osetljivost prema ostacima klomazona u zemljištu tipa peskuša pa je sveža masa izdanka ostala nepromenjena u varijantama sa različitim koncentracijama herbicida, a ostali mereni parametri su bili značajno inhibirani.