Break-down of the molluscicide N-tritylmorpholine in soil and in rice.

The molluscicide N-tritylmorpholine (Frescon, WL 8008) is likely to be applied to flowing water systems in bilharziasis control programmes. The treated water in irrigation systems will sometimes be applied to growing crops, such as rice, and the nature of the terminal residues of N-tritylmorpholine in rice has therefore been investigated. Crops were grown under greenhouse conditions in soil treated with water containing 14C-and3H-N-tritylmorpholine, using dosage levels very much greater than those that will generally be used in the field. The major radiocomponent in the rice plants was triphenylcarbinol (triphenylmethanol), together with smaller amounts of unchanged N-tritylmorpholine and o-, m-, and p-hydroxytriphenylcarbinol. The hydroxytriphenylcarbinols were present as the free hydroxy compounds and as plant conjugates. Residues of the parent molluscicide and its break-down products are not considered likely to present a toxic hazard to animals or men that eat the crops.