Residual thenylchlor concentration in soil water and its phytotoxic activity in soil

Abstract

The phytotoxic activity of soil‐applied thenylchlor (2‐chloro‐N‐[3‐methoxy‐2‐thenyl]‐2′,6′‐dimethylacetanilide) on the growth of rice seedlings and its behavior in two different types of soil, Ryugasaki soil and Tsukuba soil, after application was investigated with emphasis on the concentration in the soil water. The greatest inhibition of thenylchlor on the growth of rice seedlings was found immediately after application to both the Ryugasaki and Tsukuba soils. The phytotoxic activity decreased with time in both soils. However, the rate of decrease in phytotoxic activity was slower in the Ryugasaki soil than in the Tsukuba soil. The concentration of thenylchlor in soil water, the amount adsorbed on the soil solid, and the amount in the total soil reduced with time after application to both soils. The amount of thenylchlor adsorbed on the soil solid phase was more persistent than that in the soil water in both soils and the concentration in the soil water was higher in the Ryugasaki soil than in the Tsukuba soil at any given time. The residual phytotoxic activity of thenylchlor on the growth of the rice seedlings in the soil was highly correlated with its concentration in the soil water but not with the amount in the total soil. These results suggested that the residual phytotoxic activity of thenylchlor in the soil is determined by its concentration in the soil water after application.

Residual activity of clomeprop and its downward movement under laboratory conditions

“…The soil texture of the Ryugasaki soil and Tsukuba soil was sandy loam and clay loam, respectively. The physical and chemical properties of these soils were different (Murano et al . 2007).…”

“…The soil texture of the Ryugasaki soil and Tsukuba soil was sandy loam and clay loam, respectively. The physical and chemical properties of these soils were different (Murano et al 2007). Clomeprop (99% purity) and DMPA (99% purity) were obtained from Bayer CropScience (Tokyo, Japan).…”

Effects of the application of carbonaceous adsorbents on pumpkin (Cucurbita maxima) uptake of heptachlor epoxide in soil

“…In addition, it has been reported that the concentration of a relatively hydrophilic herbicide in soil solution collected by centrifugation is related to its activity in plants (Lee et al . 2004; Murano et al . 2007).…”

Herbicide‐resistant weeds in the Philippines: Status and resistance mechanisms

“…Examples of the herbicides that were introduced after the 1990s for grass control include thenylchlor, cafenstrole, flufenacet, fluthiamide, fentrazamide, indanofan, dithiopyr, thiazopyr, pyributicarb, oxadiargyl, pentoxazone, clethodim, butroxydim, pyriminobac, pyribenzoxim, etobenzamid and cumyluron. New herbicides that were introduced for grass control in the 2000s include pyriftalid, clefoxydim, metamifop, oxaziclomefone, flucetosulfuron and propyrisulfuron (Takahashi et al 2000;Tomlin 2000;Kanzaki et al 2001;Morita 2003;Kobayashi et al 2004;Murano et al 2007;Kobayashi & Tsunekawa 2010;Ikeda et al 2011;Krämer et al 2012;Lainsbury 2013). New herbicides with new modes of action are inhibitors of the enzymes that are involved in pigment synthesis and include protoporphyrinogen oxidase, deoxy-D-xylulose-5-phosphate synthase, hydroxyphenylpyruvate dioxygenase, phytoene desaturase and the inhibitors of cellulose biosynthesis (Krämer et al 2012).…”