The persistence of phorate and carbofuran in soil and rice plants.

The insecticides phorate and carbofuran applied at a range of 1 kg a.i./ha in a field trial against the important rice pest Hydronomidius molitor Faust, the rice root weevil, had largely degraded after 4 and 3 months, respectively, in flooded soil. In rice plants a strong decrease in the content of these insecticides was found three weeks after application. At the time of harvest, the rice plants did not contain any insecticide.