Bioactivity, adsorption and persistence of pretilachlor in paddy field soils

Abstract

The effects of environmental factors on bioactivity, adsorption and persistence of pretilachlor were studied in the laboratory and greenhouse using cucumber (Cucumis sativus L.) as the bioassay species. The three soils studied viz. Bernam, Selangor and Sabrang series were chosen for their different characteristics. The half-life of pretilachlor decreased from 10.24 to 4.90 days as temperature increased from 25°C to 35°C in the Selangor Series soil and from 10.86 to 7.63 days in the Bernam Series soil at 60% field capacity. At the same moisture level, an increase of temperature from 25°C to 35°C also reduced the half-life of pretilachlor in Sabrang soil from 8.87 to 2.59 days. The half-life of pretilachlor also decreased with increasing moisture levels in Selangor and Sabrang series but not in Bernam series soils. The greatest adsorption of pretilachlor was observed in Bernam series, followed by Selangor and Sabrang series. No phytotoxic residue of pretilachlor was detected in the supernatant after 10 h incubation. Since the residue was strongly adsorbed in Bernam series, its biological activity was less than in the other soils studied.

Persistence behaviour of pretilachlor in puddled paddy fields under subtropical humid climate

“…Most of the available literature has been confined to laboratory dissipation studies (Ismail and Handah 1999;Fajardo et al 2000a;Murata et al 2004;Adachi et al 2007), and a few have reported the dissipation of pretilachlor under field conditions of Japan (Fajardo et al 2000b) and Italy (Vidotto et al 2004). In India, limited research has been conducted under coastal ecosystem (Dharumarajan et al 2011) and alpine climate (Sharma et al 2013) whereas there are literature gaps about pretilachlor behaviour in subtropical humid agroclimatic conditions.…”

Pretilachlor Releasable Polyurea Microcapsules Suspension Optimization and Its Paddy Field Weeding Investigation

“…However, pretilachlor is usually toxic to mammals and fish and even has high phytotoxicity in crops such as rice (Kaushik et al, 2006;Takahashi et al, 2007;Diyanat et al, 2019). The overuse of pretilachlor may cause harm to the environment by damaging non-target plants, water, sediment, and food (Ismail and Handah, 1999;Vencill et al, 2012;Palma et al, 2014;Papadakis et al, 2015). For these reasons, numerous efforts have been devoted to minimizing the adverse effects and environmental toxicity of herbicides, such as using them along with safeners, packing them with carrier materials, or loading them into microcapsules (Hedaoo et al, 2013;de Oliveira et al, 2015;Cao et al, 2016;Liu et al, 2016;Wu et al, 2020).…”

Ultimate fate, transformation, and toxicological consequences of herbicide pretilachlor to biotic components and associated environment: An overview

“…Pretilachlor was found to be highly effective herbicide in saturated soil conditions (Chauhan et al, 2014); however, rapid degradation in soil was observed under the flooded conditions (anaerobic conditions) as compared to the wetted conditions (aerobic conditions) (Moon et al, 1988). A study on three soil series, namely, Selangor, Sabrang, and Bernam series, showed that degradation of the herbicide in soils with higher moisture levels was high (Ismail & Handah, 1999). At higher moisture levels, the half-life of pretilachlor gets reduced as water molecules compete with the herbicide for adsorption sites on soil colloids, and as a result, herbicide concentration in the soil solution increases, which would make herbicide molecules more accessible to soil microbes (Mukherjee et al, 2018).…”