PERSISTENCE AND MOVEMENT OF CYANAZINE AND PROCYAZINE IN SOIL UNDER FIELD CONDITIONS

Abstract

The herbicides cyanazine (2-chloro-4-(1-cyano-1-methyl ethylamino) -6-ethylamino-s-triazine) and procyazine (2-chloro-4-cyclopropylamino-6-(1-cyano-1-methyl ethylamino)-s-triazine) were applied (post-emergence) to two corn fields that were drained by separate tile drains. Soil (0- to 20-, 20- to 40-, and 40- to 60-cm depths) and tile-drain water samples were collected before application and at frequent intervals for 6 mo following application. Cyanazine and procyazine showed similar, relatively short persistence in soil with half-lives of 6 and 13 days, respectively. The major portion (greater than 95%) of the residues of both herbicides was detected in the 0- to 20-cm depth. The herbicides were detected in tile-drain water at concentrations ranging from 2 to 111 ng/L. Overall losses of cyanazine and procyazine residues via tile-drain water represented less than 0.01% of the quantity applied.