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Sondhia S.,Directorate of Weed Science Research | Khare R.R.,Jawaharlal Nehru Agricultural University
Environmental Monitoring and Assessment | Year: 2014

The ability of herbicides to be adsorbed by the soil and sediment and their tendency to be desorbed are some of the most important factors affecting soil and water contamination. Therefore, a sorption study was conducted to evaluate the adsorption of cyhalofop-butyl, butyl (2R)-2-[4-(4-cyano-2-fluorophenoxy) phenoxy] propanoate, in the sandy clay loam and clayey soils using a batch equilibrium method. The adsorption of cyhalofop-butyl was found positively related with the clay and organic carbon content. Freundlich constants (Kf) of cyhalofop-butyl in the clayey and sandy clay loam were found to be 13.39 and 2.21, respectively. Sorption coefficients (Koc) and distribution coefficients (Kd) were found to be 265.38 and 2,092.79, and 1.38 and 11.48, for sandy clay loam and clayey soils, respectively. The adsorption isotherm suggested a relatively higher affinity of cyhalofop-butyl to the adsorption sites at low equilibrium concentrations. The low value of the soil organic carbon partition coefficient (Koc) of cyhalofop-butyl in the sandy loam soil suggested its weaker adsorption in soil and thus increased its risk of mobility into water sources; hence, it should be used judiciously to prevent groundwater contamination © 2014 Springer International Publishing Switzerland.

Yadav U.,Robertson College, Jabalpur | Choudhury P.P.,Directorate of Weed Science Research
Letters in Applied Microbiology | Year: 2014

Sulfosulphuron-degrading fungus was isolated by enrichment technique from the sulfosulphuron-contaminated soil of wheat rhizosphere. To assess the biodegradation potential of isolated Trichoderma sp., minimal potato dextrose agar broth with different levels of sulfosulphuron (up to 2 g l-1) was evaluated in the growth and biotransformation experiments. ESI LC-MS/MS analysis revealed the presence of degradation products 2-amino-4,6-dimethoxypyrimidine (I) and 2-ethylsulfonyl imidazo{1,2-a} pyridine-3-sulfonamide-2-ethylsulfonyl imidazo{1,2-a} pyridine-3-sulfonamide (II) indicating the cleavage of the urea bridge and the presence of the by-product N-(4,6-dimethoxypyrimidin-2-yl)urea (III) indicating the degradation of sulfonylamide linkage. Two other metabolites, N-(4,6-dimethoxypyrimidin-2-yl)-N'-hydroxyurea (IV) and N, N'-bis(4,6-dimethoxypyrimidin-2-yl)urea (V), were also identified. From the previous reports, it was found that the degradation of sulfonyl urea herbicides took place through the chemical degradation of the sulfonylurea bridge followed by microbial degradation. During this investigation, Trichoderma sp. grew well with and degraded sulfosulphuron via both the decarboxylation on the sulphonyl urea bridge and the hydrolytic cleavage of the sulfonylamide linkage as demonstrated by the formation of metabolites. Trichoderma is nonphytopathogenic in nature, and some species of it restrict the growth of soil-dwelling phytopathogens. Therefore, it is a promising candidate for the decontamination of soil from sulfosulphuron residues. Significance and Impact of the Study: The degradation of sulfosulphuron by any individual fungus is being reported for the first time. Trichoderma sp. isolated from wheat-rhizospheric soil could survive in minimal broth rich in sulfosulphuron. Previous reports have described the complete degradation of any sulfonyl urea herbicides by micro-organisms only after the pH-dependent chemical hydrolysis of the sulfonyl urea bridge of the herbicide. This study demonstrates the novel result that the Trichoderma sp. utilized the sulfosulphuron as a sole carbon source and degraded it by cleaving sulfonyl urea bridge and sulfonylamide linkage. Thus, the application of Trichoderma sp., which is nonphytopathogenic, has the potential to decontaminate agricultural soil from sulfosulphuron load. © 2014 The Society for Applied Microbiology.

Sondhia S.,Directorate of Weed Science Research
Toxicological and Environmental Chemistry | Year: 2013

Herbicides applied to vegetables play an important role in higher production of vegetables due to effective and timely control of weeds but at the same time herbicides residue may produce numerous environmental problems. The aim of this study was to determine whether application of herbicide for control of annual weeds in vegetable growing areas at recommended levels resulted in residues at the time of harvest. Thus, terminal residues of pendimethalin in vegetables such as tomato, cauliflower, and radishes were studies under field conditions. Pendimethalin was applied as pre-emergence herbicides at 1 kg a.i. ha-1 to tomato, cauliflower, and radish crops. Soil and vegetables samples were collected from pendimethalin-treated plots at maturity to determine harvest time residues of pendimethalin. At harvest, 0.008, 0.001, and 0.014 μg/g residues of pendimethalin were found in tomato, cauliflower, and radishes, respectively. © 2013 Copyright Taylor and Francis Group, LLC.

Chandra N.,Veterinary Science University of Madhya Pradesh | Jain N.K.,Veterinary Science University of Madhya Pradesh | Sondhia S.,Directorate of Weed Science Research | Srivastava A.B.,Veterinary Science University of Madhya Pradesh
Bulletin of Environmental Contamination and Toxicology | Year: 2013

Deltamethrin (DM) is a broad-spectrum insecticide mainly used to protect crops, fruit and vegetables from pests such as mites, ants, weevils and beetles. Birds, animals and human beings living in same ecosystem are directly or indirectly at the risk of exposure to this insecticide leading to substantial decrease in growth. Thus we studied DM induced toxicity and ameliorative effects of alpha-tocopherol in broiler birds. DM was estimated in liver, breast and leg muscles of chickens feeding with only DM or DM with alpha-tocopherol daily for 42 days. Birds exposed to DM showed a dose dependent decrease in body weight on 5th, 6th and 7th weeks as compared to controls, and alpha-tocopherol partially restored the reduction in body weight. DM residue was found higher in liver as compared to breast and leg muscles. © 2013 Springer Science+Business Media New York.

Naidu V.S.G.R.,Directorate of Weed Science Research
Indian Journal of Agricultural Sciences | Year: 2013

An experiment was conducted in open top chambers (OTCs) to study the growth, water-use efficiency and carbon isotope discrimination (δ13C) in Parthenium hysterophorus in response to elevated CO2. Parthenium plants were grown in OTCs maintained at ambient (370±20 ppm) and elevated (550±30) CO2 levels as well as under open field conditions. Water-use efficiency (WUE) was determined by gravimetric method. The carbon isotope discrimination (δ13C) was determined by Isotope Ratio Mass Spectrometry (IRMS). The CO2 enrichment enhanced both the above and below ground biomass in Parthenium. Water-use efficiency (WUE) and Carbon isotope discrimination (δ13C) were higher in plants grown under elevated CO 2 compared to plants under ambient CO2 conditions. The growth stimulation and increased water-use efficiency in Parthenium indicates that this weed could become more aggressive in future if the atmospheric CO 2 continue to rise coupled with the rise in temperature.

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