Leaching of Seven s-Triazines

Abstract

Leaching of seven s-triazines in Lakeland fine sandy soil under greenhouse and field conditions was demonstrated by use of oats (Avena sativa L., var Seminole) and cucumber (Cucumis sativis L., var. Palomar) for bioassay. Depth of leaching was determined by abnormalities of these species grown in soil samples from the surface of treated soil to a depth of 22 in in the field and to 36 in in columns. Symptoms of injury by the different materials were similar and included primarily leaf chlorosis of both species and bending and breaking of cucumber stems within 7 to 10 days after planting; plants that failed to survive usually died 12 to 14 days after planting. Leaching of 2-methoxy-4-ethylamino-6-isopropylamino-s-triazine (atratone) was greatest, followed in decreasing order by 2-chloro-4,6-bis(isopropylamino)-s-triazine (propazine), 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine), 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine), 2-chloro-4-diethylamino-6-isopropylamino-s-triazine (ipazine), 2-ethylamino-4-isopropylamino-6-methylmercapto-s-triazine (ametryne), and 2,4-bis(isopropylamino)-6-methylmercapto-s-triazine (prometryne). Oats did not significantly reduce the soil concentration of ametryne and prometryne during a growing period of 56 days.