Laboratory and greenhouse experiments were made to evaluate the leaching and the inactivation of the metribuzin in clay loam and sand clay loam soils. The clay loam soil was a dark, red latosol with 2,8% organic matter and the sand clay loam soil was a reddish-yellow podzol with 2,17% organic matter. Leaching of metribuzin was studied in the laboratory in colums of 5, 10 and 15 cm high, 7.5 cm diameter, filled with soil. Watermelon cotiledon discs were used to measure the metribuzin leached. The inactivation of metribuzin was estudied in a greenhouse using doses of 0, 50, 80, 110, 140, 170 and 200 g/ha on the two soils, and 0, 4, 6, 8, 10, 12 and 16 g/ha were used for testing in sand. The test plants were cucumber that weighed after 14 days growth. Additional information is needed to explain why the clay loam soil inactivates metribuzin more than the sand clay loam soil and clarify the roles.
metribuzin; leaching; inactivation