Persistence of oxyfluorfen in soil and detection of its residues in rice crop

Abstract

Oxyfluorfen is a post-emergence herbicide used for control of annual and perennial broad-leaf weeds and sedges in rice. There is increasing concern about persistence of pesticide residues in soils, agricultural products and subsequent contamination of ground water through runoff, leaching and drift. Thus, persistence of oxyfluorfen was evaluated under field conditions in a rice cropping system. Oxyfluorfen was sprayed at 240 and 500 g ai ha À1 application rates to the rice crop as post-emergence herbicide. Paddy grains, straw and soil samples were collected at harvest and analyzed for oxyfluorfen residues by HPLC. Straw samples contained 0.01 and 0.03 mg g À1 oxyfluorfen residues at 240 and 500 g ha À1 concentrations, respectively. In the soil, 0.028 and 0.03 mg g À1 of oxyfluorfen residues were detected when applied at 240 and 500 g ai ha À1 , respectively. However, in rice grains, 0.018 and 0.106 mg g À1 of oxyfluorfen residues were found in 240 and 500 g ai ha À1 treated plots. In light of the potential adverse effects of oxyfluorfen, it is important to determine herbicide levels in these crops.

Removal of oxyfluorfen from spiked soils using electrokinetic soil flushing with the surrounding arrangements of electrodes

“…Evaporation and photolysis can help to understand this decrease, according to the literature (Alister et al, 2009;Das et al, 2003;Mantzos et al, 2014;Sondhia, 2010;Sondhia and Dixit, 2010). In this point, it is worth to take in mind that in comparing the vapor pressure of oxyfluorfen (0.026 mPa at 25ºC) with other less volatile pesticide like chlorsulfuron (3×10 -6 mPa at 25ºC) evaporation of oxyfluorfen can be even 10000 times higher.…”

“…Microbial degradation is not a major factor to be accounted for in this herbicide. The half-life in soil approximately ranges from 30 to 56 days, and the organic matter content of the soil seems to influence the oxyfluorfen persistence and activity (Sondhia, 2010;Sondhia and Dixit, 2010). Finally, regarding its transport properties, it has been observed (Mantzos et al, 2014) that oxyfluorfen hardly moves into silty clay soil and exhibits low run-off potential.…”

Effect of Herbicides on Potato and their Persistence in Acid Soil under Semiarid Tropical Condition

“…There are chances for bioaccumulation of residues if oxyfluorfen is used continuously and at higher doses. 13,17 Recent decades, the paraquat has been used in potato as pre plant or early post emergence to control weeds and also as desiccant at the time of harvest of tubers. Similarly the oxyfluorfen has been used as pre emergence herbicide for weed control at potato field in India.…”

Behaviour of pendimethalin and oxyfluorfen in peanut field soil: effects on soil biological and biochemical activities

“…Soil microbial biomass carbon (MBC) is another important parameter of ecological tests since microorganisms form a vital part of the soil food web. [10] The dissipation of pendimethalin and oxyfluorfen has already been studied in the soil of different agroecosystems like rice, [11] cotton, [12] grape, [5] and vegetables [13,14] at varied levels of field doses under different edapho-climatic conditions by adopting unique analytical methods. However, information on the dissipation kinetics of these herbicides in the soils of the peanut ecosystem is yet to be reported.…”