Residual phytotoxicity effects of different integrated herbicides management in soils from field-treated plots and post-harvest field

Soil residual phytotoxicity of commonly used herbicides in cotton crop in India were investigated through bioassay. Pendimethalin at 900 g a.i. ha-1, oxyfluorfen at 180 g a.i. ha-1, oxadiargyl at 90 g a.i. ha-1, quizalofop-ethyl at 40 g a.i. ha-1, imazethapyr at 75 g a.i. ha-1, propaquizafop at 50 g a.i. ha-1 and glyphosate at 960 g a.i. ha-1 were applied to field plots of 6.0 x 6.0 m2. Sorghum and cucumber were used in the bioassay and succeeding crops groundnut, green gram & pearl millet to test the residual effect of herbicides in the soil of the treated plots and post-harvest field. Soil, sampled at 30 day after treatment (DAT) for pre emergence herbicide and until 2 weeks (WAT) for post emergence herbicide later, show significant affect the seed germination and seedling development stage of sorghum and cucumber. There was no residual toxicity of pre and post-emergence herbicides as observed through field bioassay after harvesting cotton crop and it was found safe to grow groundnut, green gram and pearl millet as succeeding crop.